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Controls of soil pipe frequency in upland blanket peat
Soil pipes were surveyed in 160 British blanket peat catchments using consistent application of ground-penetrating radar. Soil pipes were found in all catchments. The mean frequency of piping was 69 per kilometer of surveyed transect. Land management (moorland gripping) appears to exert the most important control on hillslope pipe frequency in blanket peats. Management practice in peatlands may therefore induce
Joseph Holden
Land management as a factor controlling dissolved organic carbon release from upland peat soils 1: spatial variation in DOC productivity.
The importance of soil storage in global carbon cycling is well recognised and factors leading to increased losses from this pool may act as a positive feedback mechanism in global warming. Upland peat soils are usually assumed to serve as carbon sinks, there is however increasing evidence of carbon loss from upland peat soils, and DOC concentrations in UK rivers have increased markedly over the past three decades. A number of drivers for increasing DOC release from peat soils have been proposed although many of these would not explain fine-scale variations in DOC release observed in many catchments. We examined the effect of land use and management on DOC production in upland peat catchments at two spatial scales within the UK. DOC concentration was measured in streams draining 50 small-scale catchments (b3 km2) in three discrete regions of the south Pennines and one area in the North Yorkshire Moors. Annual mean DOC concentration was also derived from water colour data recorded at water treatment works for seven larger scale catchments (1.5-20 km2) in the south Pennines. Soil type and land use/management in all catchments were characterised from NSRI digital soil data and ortho-corrected colour aerial imagery. Of the factors assessed, representing all combinations of soil type and land use together with catchment slope and area, the proportion of exposed peat surface resulting from new heather burning was consistently identified as the most significant predictor of variation in DOC concentration. This relationship held across all blanket peat catchments and scales. We propose that management activities are driving changes in edaphic conditions in upland peat to those more favourable for aerobic microbial activity and thus enhance peat decomposition leading to increased losses of carbon from these environments. PMID:19345986
Yallop, A R; Clutterbuck, B
One-dimensional compression of peat is characterized using a simple rheological model in which the structural viscosity is assumed to be linear. This model utilizes three empirical parameters pertaining to the primary compression, secondary compression, and the rate of secondary compression. Based on the analysis of 43 laboratory and 10 field compression-time data, it is found that the primary and secondary compressibility parameters depend on the stress level and therefore can be determined in the laboratory. However, the values obtained in the laboratory tend to overestimate the field rate of compression and underestimate the magnitude of secondary compression. These parameters must be corrected for the effects of the non-linearity of peat behavior for accurate field prediction. Successful field predictions also require consideration of other important factors such as deviations from one-dimensional compression conditions, decomposition, vertical and lateral variability, and temperature effects. The compression behavior of precompressed peat under the final stress (reduced load) is affected by the amount of preloading ratio (ratio of the surcharge stress to the final stress). The magnitudes of primary, secondary, and tertiary compressibility parameters increase as the magnitude of the final stress increases relative to the surcharge stress while the viscosity of peat structure during secondary and tertiary compressions becomes smaller. The available criteria for selecting the surcharge stress application period developed for clay soils are not directly applicable to peat soils. A method to determine the compression parameters of peat using a constant rate of strain triaxial compression test is developed.
Mochtar, N.E.
Link between DOC in near surface peat and stream water in an upland catchment.
Hydrologic transport of dissolved organic carbon (DOC) from peat soils may differ to organo-mineral soils in how they responded to changes in flow, because of differences in soil profile and hydrology. In well-drained organo-mineral soils, low flow is through the lower mineral layer where DOC is absorbed and high flow is through the upper organic layer where DOC is produced. DOC concentrations in streams draining organo-mineral soils typically increase with flow. In saturated peat soils, both high and low flows are through an organic layer where DOC is produced. Therefore, DOC in stream water draining peat may not increase in response to changes in flow as there is no switch in flow path between a mineral and organic layer. To verify this, we conducted a high-resolution monitoring study of soil and stream water at an upland peat catchment in northern England. Our data showed a strong positive correlation between DOC concentrations at -1 and -5 cm depth and stream water, and weaker correlations between concentrations at -20 to -50 cm depth and stream water. Although near surface organic material appears to be the key source of stream water DOC in both peat and organo-mineral soils, we observed a negative correlation between stream flow and DOC concentrations instead of a positive correlation as DOC released from organic layers during low and high flow was diluted by rainfall. The differences in DOC transport processes between peat and organo-mineral soils have different implications for our understanding of long-term changes in DOC exports. While increased rainfall may cause an increase in DOC flux from peat due to an increase in water volume, it may cause a decrease in concentrations. This response is contrary to expected changes in DOC exports from organo-mineral soils, where increase rainfall is likely to result in an increase in flux and concentration. PMID:18076974
Clark, Joanna M; Lane, Stuart N; Chapman, Pippa J; Adamson, John K
Soil zonality of the Chukotka Upland
NASA Astrophysics Data System (ADS)
The vertical soil-geographic zonality of the Chukotka Upland in the area of the Amguema River valley can be considered a model vertical zonality in the Low Arctic regions at the interface between the continental and oceanic climates. The plain bottom of the valley has a continental climate. The surrounding mountains are under the influence of an oceanic climate, which is more pronounced in the low mountains and less pronounced in the medium-high mountains. Three altitudinal soil zones are distinguished: (1) the plain Subarctic zone with the absolute heights below 200-400 m a.s.l., where cryoturbated humus-impregnated peat-mucky gleyzems are developed from loamy substrates, and gleyed soddy podburs are developed from loamy sandy substrates; (2) the low-mountain zone of a creeping alder forest (the forest-tundra zone?) of the Low Arctic at the heights of 400-700 m a.s.l., where mucky-gray-humus humus-impregnated podzolized gleyzems are developed under tundra patches, cryoturbated peat-mucky high-humus-impregnated podzolized gleyzems are developed under creeping alder thickets, and pedoliths are exposed in the zones of landslides; and (3) the mountain Middle Arctic zone at elevations above 700 m a.s.l., where very thin soil films predominate; gray-humus cryometamorphic lithozems are developed from the eluvium of magmatic rocks, and humus-impregnated cryometamorphic soils with quicksand suprapermafrost horizons are developed from the eluvium of hard sedimentary rocks.
Karavaeva, N. A.
The role of common upland vegetation on gaseous carbon cycling on UK blanket peat bogs
NASA Astrophysics Data System (ADS)
The most important control upon the carbon dynamics of any peatland is vegetation. However there is a gap in the literature with respect to comparative, in-situ studies of common upland vegetation types on peat bogs from a carbon cycling perspective. Where studies exist they tend to be narrowly focused (i.e. on one or two species or a small geographical area) or are laboratory manipulation studies. This study set out to compare gaseous CO2 exchange, in situ, across a broad (geographic) range of sites dominated by differing, common, upland vegetation types. The vegetation types studied were; Calluna vulgaris, Sphagnum spp., Eriophorum (E. angustifolium + E. vaginatum), Molinia caerulea and areas revegetated with a lawn grass mixture that was used for restoration (Festuca spp, Deschampsia spp. and Agrostis spp.).The primary aim of the study was to assess the carbon cycling potential of the common upland vegetation types, in order to produce clearer evidence as to which upland species produce the most efficient carbon sinks. The study was carried out in the South Pennines and Peak District of England. All readings were taken from upland-blanket peat bogs, as this type of bog accounts for 87% of the UK's peatlands, and therefore the results of this study can have the widest possible applicability to the rest of the UK's peat reserves. NEE and NER measurements were taken with a PP Systems EMG-4 infra-red gas analyzer. PAR and air temperature readings were taken along side water table and soil pore water samples from every site. Each site was visited monthly for at least 12 months and between 3-9 replicates were recorded per site. The results of this study will deal with the effects vegetation has on NER, GPP and NEE, focusing on which vegetation types make the most efficient gaseous carbon sinks. Moreover the effect of vegetation on water table levels and water quality will be discussed. Finally a consideration of how the age of Calluna vulgaris affects the parameters above will be given.
Dixon, Simon; Rowson, James; Worrall, Fred
The article looks at the U.S. peat market as of July 2013. Peat is produced from deposits of plant organic materials in wetlands and includes varieties such as reed-sedge, sphagnum moss, and humus. Use for peat include horticultural soil additives, filtration, and adsorbents. Other topics include effects of environmental protection regulations on peat extraction, competition from products such as coir, composted organic waste, and wood products, and peatland carbon sinks.
Apodaca, Lori E.
Impacts of peat restoration on peak flow characteristics of upland headwater catchments
NASA Astrophysics Data System (ADS)
As part of the current focus on ecosystem services provided by peatlands, there is renewed interest in the hydrology of upland blanket peats and more specifically in the hydrological changes associated with peat erosion and restoration. Peat restoration has often been cited as having potential benefits for downstream flood risk through the reduction of peak flows and increases in storm hydrograph lag times. However, evidence of the impacts of peatland restoration practices on storm hydrology and downstream discharge peaks has been limited by lack of measurement of flow response following restoration programmes. This paper reports a hydrological monitoring programme associated with the restoration of a blanket peatland in the Peak District, UK through the practices of erosion gully blocking and the re-vegetation of bare peat. The main component of the project is a before-after-control-impact (BACI) study on three hectare-scale eroded, bare peat catchments, two of which have been restored and one of which is acting as an unmodified control. Monitoring commenced in early summer 2010, and restoration of the experimental sites by reseeding and gully blocking took place between July 2011 and March 2012. To complement the main study, a broader spatial comparison of the hydrological behaviour of catchments with different degradation and restoration conditions has been made, including (i) an intact reference peatland, (ii) the eroded/bare peat sites, and (iii) a 'late stage' restored area of peatland which was re-vegetated in 2003. Results reveal significant differences between the storm hydrograph characteristics of intact, eroded and restored catchments consistent with the hypotheses that (a) peat erosion significantly decreases storm flow lag times and increases storm flow peaks in these peatland systems and (b) peat restoration reverses these effects. Associated overland flow data suggest that gully blocking and re-vegetation within gully systems are crucial controls on the storm hydrograph and peak flow responses. The study shows that peat restoration in upland blanket peat systems can contribute to the reduction of downstream flood risk.
Allott, Tim; Evans, Martin; Agnew, Clive; Milledge, Dave; Pilkington, Mike; Maskill, Rachael
Lead contamination of fluvial sediments in an eroding blanket peat catchment
Over the last few years there has been growing concern over the mobilisation of anthropogenically derived, atmospherically deposited Pb from upland blanket peat soils to receiving surface waters. The near-surface layer of blanket peat soils of the Peak District, southern Pennines, UK, is severely contaminated with high concentrations of Pb. Erosion of peat soils in this upland area may be
J. J. Rothwell; M. G. Evans; T. E. H. Allott
Seasonal phosphatase activity in three characteristic soils of the English uplands polluted by long-term atmospheric nitrogen deposition
Phosphomonoesterase activities were determined monthly during a seasonal cycle in three characteristic soil types of the English uplands that have been subject to long-term atmospheric nitrogen deposition. Activities (?mol para-nitrophenol g?1 soil dry wt. h?1) ranged between 83.9 and 307 in a blanket peat (total carbon 318 mg g?1, pH 3.9), 45.2�86.4 in an acid organic grassland soil (total carbon
Benjamin L. Turner; Robert Baxter; Brian A. Whitton
Adoption of soil conservation: the case of the Philippine uplands
Soil degradation in the sloping uplands of Asia is a serious problem that threatens the sustainability of agriculture. Although several soil conservation technologies have been developed and promoted, their adoption has not been widespread. A micro-economic analysis of adoption of contour hedgerows by upland farmers in the Philippines is conducted to identify the factors that determine adoption. The empirical results
Ma. Lucila A. Lapar; Sushil Pandey
Phosphorus management for perennial crops in central Amazonian upland soils
The present contribution discusses the soil P status of central Amazonian upland soils, the effects of tree crops on soil P availability and the factors controlling soil P cycling in land use systems with tree crops. Soil fertility management has to target the prevalent P deficiency by adequate P fertilization, especially in southern and northern municipalities of central Amaz�nia where
Johannes Lehmann; Manoel da Silva Cravo; Jeferson Luiz; Vasconselos de Mac�do
Controlled drainage on a cultivated peat soil
NASA Astrophysics Data System (ADS)
Controlled drainage can delay the decomposition of organic material in peat soils, as high water table means a thin oxidized layer in the soil surface. Therefore, greenhouse gas emissions, and mineralization of nutrients will be decreased. There will also be less outflow from the field. These mean less nutrient leaching. However, controlled drainage systems may not always manage to keep the water table on the desired level in practical field conditions. In this study, the water tables in two controlled drainage systems were monitored on a cultivated peat soil in southern Finland around a year. Results show how the water table reacts to the changes of the water height in the control wells, and to the surrounding weather conditions. The data collection is still going on.
Myllys, Merja; Regina, Kristiina
Phenol oxidase activity in secondary transformed peat-moorsh soils
The chemical composition of peat depends on the geobotanical conditions of its formation and on the depth of sampling. The evolution of hydrogenic peat soils is closely related to the genesis of peat and to the changes in water conditions. Due to a number of factors including oscillation of ground water level, different redox potential, changes of aerobic conditions, different
K. Styla; L. Szajdak
Climate mitigation scenarios of drained peat soils
NASA Astrophysics Data System (ADS)
The national inventory reports (NIR) submitted to the UNFCCC show Sweden - which as many other countries has wetlands where parts have been drained for agriculture and forestry purposes, - to annually emit 12 million tonnes carbon dioxide equivalents, which is more GHG'es than industrial energy use release in Sweden. Similar conditions can be found in other northern countries, having cool and wet conditions, naturally promoting peat accumulation, and where land use management over the last centuries have promoted draining activities. These drained peatland, though covering only 2% of the land area, have emissions corresponding to 20% of the total reported NIR emissions. This substantial emission contribution, however, is hidden within the Land Use Land Use Change and Forestry sector (LULUCF) where the forest Carbon uptake is even larger, which causes the peat soil emissions become invisible. The only drained soil emission accounted in the Swedish Kyoto reporting is the N2O emission from agricultural drained organic soils of the size 0.5 million tonnes CO2e yr-1. This lack of visibility has made incentives for land use change and management neither implemented nor suggested, however with large potential. Rewetting has the potential to decrease soil mineralization, why CO2 and N2O emissions are mitigated. However if the soil becomes very wet CH4 emission will increase together with hampered plant growth. By ecological modeling, using the CoupModel the climate change mitigation potential have been estimated for four different land use scenarios; 1, Drained peat soil with Spruce (business as usual scenario), 2, raised ground water level to 20 cm depth and Willow plantation, 3, raised ground water level to 10 cm depth and Reed Canary Grass, and 4, rewetting to an average water level in the soil surface with recolonizing wetland plants and mosses. We calculate the volume of biomass production per year, peat decomposition, N2O emission together with nitrate and DOC/POC leakage. Based on the modelling results a cost benefit analysis is performed (economics), guiding to the design of environmental policies needed for land use change to come true.
Kasimir Klemedtsson, �sa; Coria, Jessica; He, Hongxing; Liu, Xiangping; Nord�n, Anna
Peat soil properties and erodibility: what factors affect erosion and suspended sediment yields in peat extraction areas?
NASA Astrophysics Data System (ADS)
Peatland drainage and peat extraction operations change soil properties and expose bare peat to erosion forces, resulting in increased suspended sediment (SS) loads to downstream water bodies. SS yields from peat extraction areas are known to vary significantly between sites, but the contribution of peat properties and catchment characteristics to this variation is not well understood. In this study, we investigated peat erosion at 20 Finnish peat extraction sites by conducting in situ and laboratory measurements on peat erodibility and associated peat properties (degree of humification, peat type, bulk density, loss on ignition, porosity, moisture content, and shear strength), and by comparing the results with monitored long-term SS concentrations and loads at each catchment outlet. Here, we used a cohesive strength meter (CSM) to measure direct erosion thresholds for undisturbed soil cores collected from each study site. The results suggested that the degree of peat decomposition clearly affects peat erodibility and explains much of the variation in SS concentration between the study sites. According to CSM tests, critical shear stresses for particle entrainment were lowest (on average) in well-decomposed peat samples, while undecomposed, dry and fiber rich peat generally resisted erosion very well. Furthermore, the results indicated that two separate critical shear stresses often exist in moderately decomposed peat. In these cases, the well-decomposed parts of peat samples eroded first at relatively low shear stresses and remaining peat fibers prevented further erosion until a much higher shear stress was reached. In addition to peat soil properties, the study showed that the erosion of mineral subsoil may play a key role in runoff water SS concentration at peat extraction areas with drainage ditches extending into the mineral soil. The interactions between peat properties and peat erodibility found in this study as well as critical shear stress values obtained can be used for several purposes in e.g. water conservation and sediment management planning for peat extraction areas and other bare peat-covered catchments.
Tuukkanen, Tapio; Marttila, Hannu; Kl�ve, Bj�rn
Diversity and Activity of Methanotrophic Bacteria in Different Upland Soils
Samples from diverse upland soils that oxidize atmospheric methane were characterized with regard to methane oxidation activity and the community composition of methanotrophic bacteria (MB). MB were identified on the basis of the detection and comparative sequence analysis of the pmoA gene, which encodes a subunit of particulate methane monooxygenase. MB commonly detected in soils were closely related to Methylocaldum spp., Methylosinus spp., Methylocystis spp., or the �forest sequence cluster� (USC ?), which has previously been detected in upland soils and is related to pmoA sequences of type II MB (Alphaproteobacteria). As well, a novel group of sequences distantly related (<75% derived amino acid identity) to those of known type I MB (Gammaproteobacteria) was often detected. This novel �upland soil cluster ?� (USC ?) was significantly more likely to be detected in soils with pH values of greater than 6.0 than in more acidic soils. To identify active MB, four selected soils were incubated with 13CH4 at low mixing ratios (<50 ppm of volume), and extracted methylated phospholipid fatty acids (PLFAs) were analyzed by gas chromatography-online combustion isotope ratio mass spectrometry. Incorporation of 13C into PLFAs characteristic for methanotrophic Gammaproteobacteria was observed in all soils in which USC ? sequences were detected, suggesting that the bacteria possessing these sequences were active methanotrophs. A pattern of labeled PLFAs typical for methanotrophic Alphaproteobacteria was obtained for a sample in which only USC ? sequences were detected. The data indicate that different MB are present and active in different soils that oxidize atmospheric methane.
Knief, Claudia; Lipski, Andre; Dunfield, Peter F.
Nutritional Environment of Tropical Peat Soils in Sarawak, Malaysia Based on Soil Solution Composition
It has been considered that natural peat soils and swamp forest ecosystems in the tropics are quite oligotrophic. This concept seems to be related to the low mineral contents in the soil solid phase of the peat soils. However, some nutritional elements such as K, Mg, Ca, and\\/or P may be abundant in the soil solution phase and could easily
Shinya Funakawa; Koyo Yonebayashi; Jong Foh Shoon; Ernest Chai Oi Khun
Investigating the impact of land cover change on peak river flow in UK upland peat catchments, based on modelled scenarios
NASA Astrophysics Data System (ADS)
Changes to land cover can influence the velocity of overland flow. In headwater peatlands, saturation means that overland flow is a dominant source of runoff, particularly during heavy rainfall events. Human modifications in headwater peatlands may include removal of vegetation (e.g. by erosion processes, fire, pollution, overgrazing) or pro-active revegetation of peat with sedges such as Eriophorum or mosses such as Sphagnum. How these modifications affect the river flow, and in particular the flood peak, in headwater peatlands is a key problem for land management. In particular, the impact of the spatial distribution of land cover change (e.g. different locations and sizes of land cover change area) on river flow is not clear. In this presentation a new fully distributed version of TOPMODEL, which represents the effects of distributed land cover change on river discharge, was employed to investigate land cover change impacts in three UK upland peat catchments (Trout Beck in the North Pennines, the Wye in mid-Wales and the East Dart in southwest England). Land cover scenarios with three typical land covers (i.e. Eriophorum, Sphagnum and bare peat) having different surface roughness in upland peatlands were designed for these catchments to investigate land cover impacts on river flow through simulation runs of the distributed model. As a result of hypothesis testing three land cover principles emerged from the work as follows: Principle (1): Well vegetated buffer strips are important for reducing flow peaks. A wider bare peat strip nearer to the river channel gives a higher flow peak and reduces the delay to peak; conversely, a wider buffer strip with higher density vegetation (e.g. Sphagnum) leads to a lower peak and postpones the peak. In both cases, a narrower buffer strip surrounding upstream and downstream channels has a greater effect than a thicker buffer strip just based around the downstream river network. Principle (2): When the area of change is equal, the size of land cover change patches has no effect on river flow for patch sizes up to 40000m2. Principle (3): Bare peat on gentle slopes gives a faster flow response and higher peak value at the catchment outlet, while high density vegetation or re-vegetation on a gentle slope area has larger positive impact on peak river flow delay when compared with the same practices on steeper slopes. These simple principles should be useful to planners who wish to determine resource efficiency and optimisation for peatland protection and restoration works in headwater systems. If practitioners require further detail on impacts of specific spatial changes to land cover in a catchment then this modelling approach can be applied to new catchments of concern.
Gao, Jihui; Holden, Joseph; Kirkby, Mike
Soil Bioengineering for Upland Slope Stabilization.
National Technical Information Service (NTIS)
The objective of the study was to provide alternatives called soil bioengineering methods for slope and shallow rapid landslide stabilization along different roadside environments. Additional objectives were to educate WSDOT personnel in site selection, s...
L. Lewis S. Hagen S. Salisbury
How does hillslope position control carbon fluxes from peat soils?
NASA Astrophysics Data System (ADS)
Peatlands represent a significant terrestrial carbon stock, with an estimated 445.69 Gtonnes of carbon stored globally (Joosten 2009). In the UK, peatlands are estimated to store 1.75 Gtonnes of carbon (Joosten 2009), yet most of the upland blanket bogs that dominate peatland forms in the UK are in a damaged condition from erosion or land management practices. As such they could be releasing carbon and their restoration could be of benefit to the UK government in terms of climate change mitigation targets through the benefits of avoided carbon losses. In order to realise any possible benefit of management intervention upon peatlands accurate carbon budget models are required to assess the carbon balance of peatlands. To reduce uncertainty in model output a greater understanding of peatland function is required (Ostle et al., 2009). As part of this, topographical and hydrological controls need to be characterised in more detail. Landscape scale features such as gullies (McNamara et al., 2008) and drainage ditches (Wallage et al., 2006; Gibson et al., 2009) have been shown to affect carbon fluxes from peatlands, but slope position and its role on carbon fluxes has not yet been considered. A 12 month field study was carried out from June 2010 - June 2011 in the Peak District, UK, to assess the role that hillslope position has upon carbon flux from peat soils. Changes in hydrology, carbon dioxide flux and dissolved organic carbon (DOC) concentration across four hillslope positions: topslope, upper midslope, lower midslope and bottomslope were observed. Results showed that there was a significant slope effect for both DOC and CO2 effluxes but that the effect upon CO2 was explained by changes in the depth to the water table across the slope.
Boothroyd, I.; Worrall, F.; Allott, T.
Evaluation of the use of soil ion exchange properties for predicting streamwater chemistry in upland catchments
NASA Astrophysics Data System (ADS)
The potential of soil ion exchange chemistry for predicting streamwater quality is evaluated using soil and streamwater chemical data from ten upland catchments in NE Scotland. The study catchments vary from those dominated by acid hill peats, alpine soils and podzols to those dominated by more base-rich soils, including cambisols and gleysols. Soil and streamwater chemical data combined with precipitation and parent material chemistry are also used to investigate sources and pathways of water movement. In all soils studied, Ca and Mg are the dominant exchangeable base cations in the surface soil horizons. In most soils, Na becomes increasingly important on the exchange complex with depth down the soil profile. Plots of the relative proportions of Na:Ca:Mg in streamwater show that, during periods of high discharge, streamwater chemistry tends to become relatively more Na-rich compared with Ca and Mg. Using triangular diagrams, streamwater chemistry can be described as a mixture of geochemically distinct packages of water derived from precipitation inputs, specific parent materials and key soil horizons, although spatially important soils within catchments may be relatively unimportant in controlling streamwater chemistry. Changes in streamwater chemistry at high flow can be explained by dilution of water derived from groundwater sources or the B/C horizon, either with laterally flowing water from the upper soil horizons, or with precipitation. In conclusion, changes in the relative proportions of Na:Ca:Mg in streamwater during storms suggest that precipitation chemistry may play a greater role than hitherto suggested in modifying solute chemistry during periods of high flow.
Billett, Michael F.; Cresser, Malcolm S.
In 2005, peat was harvested in 15 US states. Florida, Michigan and Minnesota accounted for more than 80% of the US production. Reed-sedge was the dominant variety of peat harvested in the United States. More than 56% of all peat used in the US was imported from Canada. With the growing interest in gardening, landscaping related to home construction and golf courses, peat usage is expected to remain near current levels during the next several years.
Jasinski, S. M.
Soil organic matter and nitrogen transformation mediated by plant residues of different qualities in sandy acid upland and paddy soils
Organic matter management is believed to solve many of the chemical and physical problems of coarse-textured, low fertility soils of Northeast Thailand. We tested the influence of different plant residues available in this area on soil C and N dynamics in upland (Oxic Paleustult) and lowland (Aeric Paleaquult) soils. Residues included groundnut (upland) or Sesbania rostrata stover (lowland), rice straw,
P. Vityakon; S. Meepech; G. Cadisch; B. Toomsan
Accounting for variability in soil microbial communities of temperate upland grassland ecosystems
This study aimed to determine the factors which regulate soil microbial community organisation and function in temperate upland grassland ecosystems. Soil microbial biomass (Cmic), activity (respiration and potential carbon utilisation) and community structure (phospholipid fatty acid (PLFA) analysis, culturing and community level physiological profiles (CLPP) (Biolog�)) were measured across a gradient of three upland grassland types; Festuca�Agrostis�Galium grassland (unimproved grassland,
S. J. Grayston; G. S. Griffith; J. L. Mawdsley; C. D. Campbell; R. D. Bardgett
Geomorphically based predictive mapping of soil thickness in upland watersheds
NASA Astrophysics Data System (ADS)
The hydrologic response of upland watersheds is strongly controlled by soil (regolith) thickness. Despite the need to quantify soil thickness for input into hydrologic models, there is currently no widely used, geomorphically based method for doing so. In this paper we describe and illustrate a new method for predictive mapping of soil thicknesses using high-resolution topographic data, numerical modeling, and field-based calibration. The model framework works directly with input digital elevation model data to predict soil thicknesses assuming a long-term balance between soil production and erosion. Erosion rates in the model are quantified using one of three geomorphically based sediment transport models: nonlinear slope-dependent transport, nonlinear area- and slope-dependent transport, and nonlinear depth- and slope-dependent transport. The model balances soil production and erosion locally to predict a family of solutions corresponding to a range of values of two unconstrained model parameters. A small number of field-based soil thickness measurements can then be used to calibrate the local value of those unconstrained parameters, thereby constraining which solution is applicable at a particular study site. As an illustration, the model is used to predictively map soil thicknesses in two small, �0.1 km2, drainage basins in the Marshall Gulch watershed, a semiarid drainage basin in the Santa Catalina Mountains of Pima County, Arizona. Field observations and calibration data indicate that the nonlinear depth- and slope-dependent sediment transport model is the most appropriate transport model for this site. The resulting framework provides a generally applicable, geomorphically based tool for predictive mapping of soil thickness using high-resolution topographic data sets.
Pelletier, Jon D.; Rasmussen, Craig
Genesis of peat-bog soils in the northern taiga spruce forests of the Kola Peninsula
The characteristics of soil formation processes in the Peat-Bog soils of waterlogged spruce phytocenoses on the Kola Peninsula are investigated. It is found that the ash composition of the peat layer is determined primarily by the composition of the buried plant residues. The effect of the chemical composition of water feeding the peat bogs is determined. (Refs. 7).
Nikonov, V.V.
Soil water flow dynamics in a managed cutover peat field, Quebec: Field and laboratory investigations
In this paper concerned with soil water dynamics in a managed cutover peat field, the microscale hydrological processes and parameters governing water flow and storage through variably saturated peat are investigated. An open water ditch-reservoir enhanced wetting of adjacent cutover peat, maintaining the water table depth above 43 cm during the summer, surface soil moisture above 45%, and water tension
Susanne M. Schlotzhauer; Jonathan S. Price
Phenol oxidase activity in secondary transformed peat-moorsh soils
NASA Astrophysics Data System (ADS)
The chemical composition of peat depends on the geobotanical conditions of its formation and on the depth of sampling. The evolution of hydrogenic peat soils is closely related to the genesis of peat and to the changes in water conditions. Due to a number of factors including oscillation of ground water level, different redox potential, changes of aerobic conditions, different plant communities, and root exudes, and products of the degradation of plant remains, peat-moorsh soils may undergo a process of secondary transformation conditions (Sokolowska et al. 2005; Szajdak et al. 2007). Phenol oxidase is one of the few enzymes able to degrade recalcitrant phenolic materials as lignin (Freeman et al. 2004). Phenol oxidase enzymes catalyze polyphenol oxidation in the presence of oxygen (O2) by removing phenolic hydrogen or hydrogenes to from radicals or quinines. These products undergo nucleophilic addition reactions in the presence or absence of free - NH2 group with the eventual production of humic acid-like polymers. The presence of phenol oxidase in soil environments is important in the formation of humic substances a desirable process because the carbon is stored in a stable form (Matocha et al. 2004). The investigations were carried out on the transect of peatland 4.5 km long, located in the Agroecological Landscape Park host D. Chlapowski in Turew (40 km South-West of Pozna?, West Polish Lowland). The sites of investigation were located along Wysko? ditch. The following material was taken from four chosen sites marked as Zbechy, Bridge, Shelterbelt and Hirudo in two layers: cartel (0-50cm) and cattle (50-100cm). The object of this study was to characterize the biochemical properties by the determination of the phenol oxidize activity in two layers of the four different peat-moors soils used as meadow. The phenol oxidase activity was determined spectrophotometrically by measuring quinone formation at ?max=525 nm with catechol as substrate by method of Perucci et al. (2000). In peat the highest activities of phenol oxidase was observed in the combinations marked as Shelterbelt and whereas the lowest - in Zbechy, Bridge and Hirudo. Activities of this enzyme in peat ranged from 15.35 to 38.33 ?mol h-1g d.m soil. Increased activities of phenol oxidase have been recorded on the depth 50-100cm - catotelm (21.74-38.33 ?mol h-1g d.m soil) in comparison with the depth 0-50cm - acrotelm (15.35-28.32 ?mol h-1g d.m soil). References Freeman, C., Ostle N.J., Fener, N., Kang H. 2004. A regulatory role for phenol oxidase during decomposition in peatlands. Soil Biology and Biochemistry, 36, 1663-1667. Matocha Ch.J., Haszler G.R., Grove J.H. 2004. Nitrogen fertilization suppresses soil phenol oxidase enzyme activity in no-tillage systems. Soil Science, 169/10, 708-714. Perucci P., Casucci C., Dumontet S. 2000. An improved method to evaluate the o-diphenol oxidase activity of soil. Soil Biology and Biochemistry, 32, 1927-1933. Sokolowska Z., Szajdak L., Matyka-Sarzy?ska D. 2005. Impact of the degree of secondary transformation on amid-base properties of organic compounds in mucks. Geoderma, 127, 80-90. Szajdak L., Szczepa?ski M., Bogacz A. 2007. Impact of secondary transformation of peat-moorsh soils on the decrease of nitrogen and carbon compounds in ground water. Agronomy Research, 5/2, 189-200.
Sty?a, K.; Szajdak, L.
The United States continued to be significant producer and consumer of peat for horticultural and industrial applications in 1999. Florida, Michigan and Minnesota were the largest producing states, in order of output.
Jasinski, S. M.
Microbial phototrophic fixation of atmospheric CO2 in China subtropical upland and paddy soils
NASA Astrophysics Data System (ADS)
Autotrophic microorganisms, which can fix atmospheric CO2 to synthesize organic carbon, are numerous and widespread in soils. However, the extent and the mechanism of CO2 fixation in soils remain poorly understood. We incubated five upland and five paddy soils from subtropical China in an enclosed, continuously 14CO2-labeled, atmosphere and measured 14CO2 incorporated into soil organic matter (SOC14) and microbial biomass (MBC14) after 110 days. The five upland soils supported dominant crops soils (maize, wheat, sweet potato, and rapeseed) in the region, while all paddy soils were cultivated in a regime consisting of permanently-flooded double-cropping rice cultivation. The upland and paddy soils represented typical soil types (fluvisols and ultisols) and three landforms (upland, hill, and low mountain), ranging in total carbon from low (<10 g kg-1 soil organic carbon) to medium (10-20 g kg-1) to high (>20 g kg-1). Substantial amounts of 14CO2 were fixed into SOC14 (mean 20.1 � 7.1 mg C kg-1 in upland soil, 121.1 � 6.4 mg C kg-1 in paddy soil) in illuminated soils (12 h light/12 h dark), whereas no 14C was fixed in soils incubated in continuous darkness. We concluded that the microbial CO2 fixation was almost entirely phototrophic rather than chemotrophic. The rate of SOC14 synthesis was significantly higher in paddy soils than in upland soils. The SOC14 comprised means of 0.15 � 0.01% (upland) and 0.65 � 0.03% (paddy) of SOC. The extent of 14C immobilized as MBC14 and that present as dissolved organic C (DOC14) differed between soil types, accounting for 15.69-38.76% and 5.54-18.37% in upland soils and 15.57-40.03% and 3.67-7.17% of SOC14 in paddy soils, respectively. The MBC14/MBC and DOC14/DOC were 1.76-5.70% and 1.69-5.17% in the upland soils and 4.23-28.73% and 5.65-14.30% in the paddy soils, respectively. Thus, the newly-incorporated C stimulated the dynamics of DOC and MBC more than the dynamics of SOC. The SOC14 and MBC14 concentrations were highly significantly correlated (r = 0.946; P < 0.0001). We conclude that CO2 uptake by phototrophic soil microorganisms can contribute significantly to carbon assimilation in soil, and so warrants further future study.
Ge, Tida; Wu, Xiaohong; Chen, Xiaojuan; Yuan, Hongzhao; Zou, Ziying; Li, Baozhen; Zhou, Ping; Liu, Shoulong; Tong, Chengli; Brookes, Phil; Wu, Jinshui
Peat fires as source of polycyclic aromatic hydrocarbons in soils
NASA Astrophysics Data System (ADS)
Polycyclic aromatic hydrocarbons (PAHs) arrive from pyrogenic sources including volcanism and the combustion of oil products and plant materials. The production of PAHs during the combustion of plant materials was considered in a number of publications, but their results were mainly obtained in laboratory experiments. Insufficient data are available on the hightemperature production of PAHs in environmental objects. For example, natural fires are frequently related to the PAH sources in landscapes, but very little factual data are available on this topic. On Polistovskii reserve (Russia, Pskov region) the soil series were separated depending on the damage to the plants; these series included soils of plots subjected to fires of different intensities, as well as soils of the background plots. The series of organic and organomineral soils significantly differed in their PAH distributions. In this series, the concentration of PAHs in the upper horizons of the peat soils little varied or slightly decreased, but their accumulation occurred at a depth of 5-10 or 10-20 cm in the soils after the fires. For example, in the series of high moor soils, the content of PAHs in the upper horizons remained almost constant; significant differences were observed in the subsurface horizons: from 2 ng/g in the background soil to 70 ng/g after the fire. In the upper horizons of the oligotrophic peat soils under pine forests, the total PAH content also varied only slightly. At the same time, the content of PAHs in the soil series increased from 15 to 90 ng/g with the increasing pyrogenic damage to the plot. No clear trends of the PAH accumulation were recorded in the organomineral soils. The content of PAHs in the soddy-podzolic soil subjected to fire slightly decreased (from 20 to 10 ng/g) compared to the less damaged soil. In peat fires, the access of oxygen to the fire zone is lower than in forest fires. The oxygen deficit acts as a factor of the organic fragments recombination and PAH production; therefore, larger amounts of PAHs are formed in peat fires. In addition, the peat fires occur directly in the soil layer; therefore, larger amounts of the resulting polyarenes remain in the soils of the fire sites. PAHs also can be formed at the heating of organic matter on the areas adjacent to the fire sites. After the combustion of peat in fires, phenanthrene, chrysene, benz[a]pyrene, and tetraphene accumulate in soils. This is mainly the group of 4-nuclear compounds with the participation of 3-nuclear phenanthrene and 5-nuclear benz[a]pyrene. The formation of high-molecular weight compounds like benz[a]pyrene and, in some places, benzo[ghi]perylene is possible during smoldering under a low oxygen supply.
Tsibart, Anna
Suitability of field portable XRF for the study of contaminated peat soils
NASA Astrophysics Data System (ADS)
Upland peat soils in close proximity to urban and industrial areas can be contaminated with - and act as sinks for - high concentrations of atmospherically deposited lead. Erosion of these soils has the potential to release lead to surface waters. Lead storage is not uniform across peat surfaces and significant within-site spatial variability has previously been found. In heavily degraded areas this is further complicated by gullying and the removal of surface material from bare peat flats. Quantifying lead concentrations across the surface of actively eroding peatlands is vital in order to understand lead storage and release in such systems. Field portable x-ray fluorescence (FPXRF) continues to gain acceptance in the study of metal contaminated soil; however, FPXRF has not been used to conduct field surveys of contaminated peat soils due to their high moisture content. FPXRF analysers allow a large number of samples to be processed in a relatively short time giving a high level of detail with little disturbance to the surrounding area. They also offer significant advantages over off-site laboratory analysis in terms of on-site decision making and faster turn-around of results. This study compares lead concentration data obtained in situ using a handheld Niton XL3t 900 X-Ray Fluorescence analyser with data derived from ex situ lab based analyses. In situ measurements were acquired across degraded and intact peatland sites in the Peak District, southern Pennines, UK. Field samples were then dried, homogenised and analysed again using the FPXRF before subsequent acid digestion and analysis using inductively coupled plasma atomic emission spectroscopy (ICP-OES). The moisture content of the samples was also determined and used to normalise the in situ field measurements. A good relationship was found between in situ and ex situ lead concentration data. Linear regression analysis yielded r2 values of 0.80 (in situ XRF vs. ICP-OES) and 0.82 (in situ XRF vs. ex situ XRF). These are improved slightly when in situ concentrations are normalised for moisture content. This study reveals that FPXRF can provide an accurate, rapid and cost-effective means of assessing surface lead content in contaminated peatland environments.
Shuttleworth, E. L.; Evans, M. G.; Rothwell, J. J.; Hutchinson, S. M.
Resistivity-based monitoring of biogenic gases in peat soils
NASA Astrophysics Data System (ADS)
Biogenic free-phase gas (FPG) formation was induced in a peat block (dimensions 0.28 � 0.21 � 0.21 m) extracted from a peatland in Maine. Electrical resistivity (ER), surface deformation, and methane (CH4) flux from the peat surface was monitored over a 48-day period during which the temperature remained constant at 21 � 1�C. ER measurements were made on 5 vertical electrode arrays, each containing 20 electrodes spaced at 0.01-m intervals. Surface deformation was monitored using 30 elevation rods equally spaced across the surface of the block, and average CH4 flux from the peat surface estimated by integration of measurements obtained with a portable gas detector over a 20-min time period. Pore water conductivity was recorded at three depths (0.06, 0.09, and 0.15 m) at a single point in the block. ER measurements were inverted for the ratio resistivity change relative to a background data set and corrected for changes in pore fluid conductivity, permitting an estimate of equivalent change in gas content assuming (1) insignificant surface conduction, (2) porosity changes estimated from peat surface expansion, and (3) an Archie saturation exponent n of 1.3 based on results from a parallel block experiment. The resistivity ratios reveal a pattern of FPG evolution consistent with surface deformation and CH4 flux data. During the first part of the experiment (approximately the first 24 days), a gradual buildup in FPG within a layer 4-6 cm below the peat surface (water table) occurs concurrent with modest surface deformation and low CH4 fluxes. In contrast, during the latter half of the experiment (approximately 25-48 days), a complex pattern of more pronounced gas buildup and release at multiple depths occurs concurrent with large rates of surface deformation and higher CH4 fluxes. The experiment demonstrates that ER monitoring is a viable geophysical technology for imaging and monitoring biogenic gas fluxes in peat soils. Here the resistivity clearly shows that FPG is preferentially generated in layers about 0.04-0.06 m below the peat surface and that the buildup of gas is spatially nonuniform even in a relatively small peat block. Furthermore, the experimental results suggest that factors other than temperature and atmospheric pressure must control biogenic gas accumulation and release. As the method is readily deployable at the field scale, possibly in an autonomous monitoring mode, resistivity measurements may permit significant improvements in understanding of carbon gas generation and release from northern peatlands.
Slater, Lee; Comas, Xavier; Ntarlagiannis, Dimitrios; Moulik, Maitry Roy
Effect of soil properties on peat erosion and suspended sediment delivery in drained peatlands
NASA Astrophysics Data System (ADS)
from peat extraction areas is known to cause siltation of water courses and poor water quality. However, the main soil parameters affecting peat erosion and suspended sediment (SS) yields from different catchments are not well understood. This paper used peat properties (degree of humification, peat type, ash content, porosity, moisture content, bulk density, and shear strength) and novel erosion threshold measurements from intact soil cores to explain peat erodibility and spatial variations in SS concentrations (SSCs) and SS loads (SSLs) at 20 Finnish peat extraction sites. The erosion threshold measurements suggested that critical shear stresses for particle entrainment decrease with increasing degree of humification (von Post scale) and are significantly lower in well-decomposed peat than in slightly or moderately decomposed peat. Two critical shear stresses were obtained from moderately decomposed peat samples, indicating a degree of surface armoring by coarse peat fibers. Monitored long-term average SSC was highest at study sites with well-decomposed peat, while very fine-grained mineral subsoil explained some of the highest long-term SSC in areas where drainage ditches penetrated below the upper peat layer. Average SSL (kg d-1) at the study sites was best explained (R2 = 0.89) by average discharge and surface peat decomposition level. Overall, this study provides new knowledge on peat erosion and critical shear stresses that can be used in water conservation and sediment management practices for cutover peatlands and other similar land uses.
Tuukkanen, Tapio; Marttila, Hannu; Kl�ve, Bj�rn
Soil Physicochemical and Biological Properties of Paddy-Upland Rotation: A Review
Paddy-upland rotation is an unavoidable cropping system for Asia to meet the increasing demand for food. The reduction in grain yields has increased the research interest on the soil properties of rice-based cropping systems. Paddy-upland rotation fields are unique from other wetland or upland soils, because they are associated with frequent cycling between wetting and drying under anaerobic and aerobic conditions; such rotations affect the soil C and N cycles, make the chemical speciation and biological effectiveness of soil nutrient elements varied with seasons, increase the diversity of soil organisms, and make the soil physical properties more difficult to analyze. Consequently, maintaining or improving soil quality at a desirable level has become a complicated issue. Therefore, fully understanding the soil characteristics of paddy-upland rotation is necessary for the sustainable development of the system. In this paper, we offer helpful insight into the effect of rice-upland combinations on the soil chemical, physical, and biological properties, which could provide guidance for reasonable cultivation management measures and contribute to the improvement of soil quality and crop yield.
Lv, Teng-Fei; Chen, Yong; Westby, Anthony P.; Ren, Wan-Jun
Legacy mercury and stoichiometry with C, N, and S in soil, pore water, and stream water across the upland-wetland interface: The influence of hydrogeologic setting
NASA Astrophysics Data System (ADS)
Mechanisms influencing retention, biogeochemical cycling, and release of legacy mercury within soils of forests and wetlands remain poorly understood. We quantified mercury pool size and stoichiometry with carbon, nitrogen, and sulfur across forest-wetland transects and among wetlands of different hydrogeologic settings in the Adirondack region of New York State. Average total mercury pool size in soils (to 50 cm depth) was greater in forests (17.5 mg/m2) than in wetlands (6.1 mg/m2; p < 0.010). The average mercury pool size (to 50 cm depth) in shallow-peat riparian wetlands (9.3 mg/m2) was greater than in deep-peat riparian (5.4 mg/m2; p = 0.099) or headwater wetlands (3.6 mg/m2; p = 0.046). Accumulation of mercury was enhanced at the forest-wetland interface. In mineral horizons of the forest soil and in shallow-peat riparian wetlands, mercury was positively correlated with carbon (r2 = 0.73-0.96) and nitrogen (r2 = 0.82-0.93), but not sulfur. In contrast, mercury and sulfur were strongly correlated in headwater wetland peat (r2 = 0.73). Dissolved mercury was correlated with dissolved organic carbon (DOC) in pore water and stream water of deep-peat and shallow-peat riparian wetlands (r2 = 0.46-0.73), but not in headwater wetland pore water. In headwater outlet streams, dissolved mercury was correlated with DOC (r2 = 0.62), but the slope was only one third that in riparian streams. Hydrogeologic setting influences decomposition processes, biogeochemical cycling of mercury, and hydrologic transport that in turn, govern the size and stoichiometry of mercury pools across the upland-wetland interface and among different wetland types. Ultimately, mobilization of legacy mercury into aquatic ecosystems from forest soils and wetlands likely depends upon decomposition dynamics and hydrologic flow paths.
Demers, Jason D.; Yavitt, Joseph B.; Driscoll, Charles T.; Montesdeoca, Mario R.
The United States continued as a significant producer and consumer of peat for horticultural, agricultural and industrial applications in 1997. Several operations in the Great Lakes and the Southeast regions dominated US production. Florida, Michigan and Minnesota were the largest producing states.
Jasinski, S. M.
Peat is a natural organic material of botanical origin and commercial significance. Peatlands are situated predominately in shallow wetland areas of the Northern Hemisphere. Commercial deposits are formed from the gradual decomposition of plant matter under anaerobic conditions over about a 5,000-year period.
Jasinski, S. M.
Is the blocking of drainage channels in upland peats an effective means of reducing DOC loss at the catchment scale?
NASA Astrophysics Data System (ADS)
Only 3% of the earths land surface is covered by peatland yet boreal and subarctic peatlands store approximately 15-30% of the World's soil carbon as peat (Limpens et al. 2008). In comparison British bogs store carbon equivalent to 20 years worth of national emissions. The loss of carbon from these areas in the form of dissolved organic carbon (DOC) is increasing and it is expected to have grown by up to 40% by 2018. Extensive drainage of UK peatlands has been associated with dehydration of the peat, an increase in water colour and a loss of carbon storage. It has been considered that the blocking of these drainage channels represents a means of peat restoration and a way of reducing DOC loss. This study aims to assess the effectiveness of this drain blocking at both an individual drain scale and at a larger catchment scale. Gibson et al. (2009) considered the effects of blocking at a solely individual drain scale finding that a 20% drop in DOC export was recorded post blocking however this decrease was due to a reduction in water yield rather than a reduction in DOC concentration with the concentration record showing no significant reduction. The effect of external parameters become more pronounced as the DOC record is examined at larger scales. The catchment is an open system and water chemistry will be influence by mixing with water from other sources. Also it is likely that at some point the drains will cut across slope leading to the flow of any highly coloured water down slope, bypassing the blockages, and entering the surface waters downstream. Degradation of DOC will occur naturally downstream due to the effects of light and microbial activity. There is, consequently, a need to examine the wider effects of drain blocking at a catchment scale to ensure that what is observed for one drain transfers to the whole catchment. A series of blocked and unblocked catchments were studied in Upper Teesdale, Northern England. Drain water samples were taken at least daily at nine localities. These sites were located such that individual drains could be monitored in the context of a larger catchment. Water table depth, flow and weather parameters were recorded along with the collection of runoff and soil water samples. A detailed sampling programme was undertaken in which a series of drains were studied in the 12 months prior to and post blocking. This approach has allowed the effects of blocking on the carbon budget, water balance and flow pathways to be considered. Results indicate that the blocking of zero order drainage channels leads to a decrease in DOC export on an individual drain scale. However, this is due to a reduction in water yield rather than concentration. Concentrations are seen to rise by a small yet statistically significant amount in blocked zero order streams. The effect at a larger scale is more complex. Annual export values in the unblocked control catchment show a rise from zero to first order streams indicating that water is being added to the system at this scale from external spatially variable sources. This pattern is also recognised in the blocked catchment. The DOC concentration record in blocked drains at this larger scale however indicated a reduction relative to the unblocked catchment. This reduction points to a change in flow pathways post blocking as highly coloured water re-navigates its way downstream. References: Gibson H, Worrall F, Burt TP, Adamson JK (2009) DOC budgets of drained peat catchments: implications for DOC production in peat soils, Hydrological Processes 23(13) 1901-1911 Limpens J (2008) Peatlands and the carbon cycle: from local processes to global implications- a synthesis, Biogeosciences 5 1475-1491
Turner, Kate; Worrall, Fred
Phosphorus Sorption-Desorption Characteristics of Selected Acid Upland Soils in Indonesia
Phosphorus (P) sorption-desorption isotherms were studied in several acid upland soils developed from different parent materials in Indonesia. The soils varied in their chemical and physical properties. P sorption characteristics were satisfactorily described by the Langmuir equation, which was used to determine P sorption maxima and bonding energies. The soils varied widely in their capacity to sorb P. P sorption
Arief Hartono; Shinya Funakawa; Takashi Kosaki
Can carbon offsetting pay for upland ecological restoration?
NASA Astrophysics Data System (ADS)
Upland peat soils represent a large terrestrial carbon store and as such have the potential to be either an ongoing net sink of carbon or a significant net source of carbon. In the UK many upland peats are managed for a range of purposes but these purposes have rarely included carbon stewardship. However, there is now an opportunity to consider whether management practices could be altered to enhance storage of carbon in upland peats. Further, there are now voluntary and regulated carbon trading schemes operational throughout Europe that mean stored carbon, if verified, could have an economic and tradeable value. This means that new income streams could become available for upland management. The 'Sustainable Uplands' RELU project has developed a model for calculating carbon fluxes from peat soils that covers all carbon uptake and release pathways (e.g. fluvial and gaseous pathways). The model has been developed so that the impact of common management options within UK upland peats can be considered. The model was run for a decade from 1997-2006 and applied to an area of 550 km2 of upland peat soils in the Peak District. The study estimates that the region is presently a net sink of -62 Ktonnes CO2 equivalent at an average export of -136 tonnes CO2 equivalent/km2/yr.. If management interventions were targeted across the area the total sink could increase to -160 Ktonnes CO2/yr at an average export of -219 tonnes CO2 equivalent/km2/yr. However, not all interventions resulted in a benefit; some resulted in increased losses of CO2 equivalents. Given present costs of peatland restoration and value of carbon offsets, the study suggests that 51% of those areas, where a carbon benefit was estimated by modelling for targeted action of management interventions, would show a profit from carbon offsetting within 30 years. However, this percentage is very dependent upon the price of carbon used.
Worrall, F.
Effect of soil type and fertilizer management on archaeal community in upland field soils.
The effects of soil and fertilizer types on archaeal communities were evaluated by real-time PCR and PCR-denaturing gradient gel electrophoresis (DGGE) targeting the 16S rRNA gene of total DNA directly extracted from upland field soils. Twelve experimental upland field plots containing four different soil types, i.e., Cumulic Andosol, Low-humic Andosol, Yellow Soil and Gray Lowland Soil, were maintained under three different fertilizer management systems for 8 years (chemical fertilizer, rice husks and cow manure, and pig manure, respectively). Two-way ANOVA and RDA analyses showed that the copy number and PCR-DGGE profile of archaeal 16S rRNA gene were affected mainly by soil type, especially between Andosol and non-Andosol, but were also influenced by fertilizer type. Among several soil chemical properties, total N content showed a significant correlation to archaeal community. Sequence analyses showed that most of the major DGGE bands corresponded to uncultured Crenarchaeota of Group I.1b that contained ammonia-oxidizing archaea (AOA). These sequences were separated into two clusters in the phylogenetic tree and each lineage showed a different response to total N content. PMID:21670564
Hoshino, Yuko Takada; Morimoto, Sho; Hayatsu, Masahito; Nagaoka, Kazunari; Suzuki, Chika; Karasawa, Toshihiko; Takenaka, Makoto; Akiyama, Hiroko
Application of ground-penetrating radar to the identification of subsurface piping in blanket peat
Natural soil pipes are common and significant in upland blanket peat catchments yet there are major problems in finding and defining the subsurface pipe networks. This is particularly important because pipeflow can contribute a large proportion of runoff to the river systems in these upland environments and may significantly influence catchment sediment and solute yields. Traditional methods such as digging
J. Holden; T. P. Burt; M. Vilas
In 2010, domestic production of peat, excluding Alaska, was estimated to be 612 kt (674,600 st), compared with 609 kt (671,300 st) in 2009. In 2010, imports increased to 947 kt (1.04 million st), compared with 906 kt (998,600 st) in 2009. Exports were estimated to have decreased to 69 kt (76,000 st) in 2010. U.S. apparent consumption for 2010 was estimated to have increased to 1.5 Mt (1.65 million st). World production was estimated to be about 23 Mt (25 million st) in 2010, which is 8 percent lower than in 2009.
Apodaca, L. E.
In 2009, domestic production of peat, excluding Alaska, was estimated to be 610 kt (672,000 st), compared with 615 kt (678,000 st) in 2008. In 2009, imports decreased to 906 kt (999,000 st) compared with 936 kt (1 million st) in 2008, and exports were estimated to have increased to 77 kt (85,000 st) in 2009. U.S. apparent consumption for 2009 was estimated to be about the same as in 2008. World production was estimated to be about 25 Mt (27.5 million st) in 2009, which is about the same as 2008.
Apodaca, L. E.
In 2012, domestic production of peat, excluding Alaska, was estimated to be 560 kt (617,000 st), compared with 568 kt (626,000 st) in 2011. In 2012, imports decreased to 940 kt (1 million st) compared with 982 kt (1.1 million st) in 2011, and exports were estimated to have increased to 75 kt (82,600 st) in 2012. U.S. apparent consumption for 2012 was estimated to have remained the same as that of 2011. World production was estimated to be about 27 Mt (30 million st) in 2012, which was slightly higher than 2011.
Apodaca, L. E.
In 2011, domestic production of peat, excluding Alaska, was estimated to be 605 kt (667,000 st), compared with 628 kt (629,000 st) in 2010. In 2011, imports increased to 1.1. Mt (1.2 million st) compared with 947 kt (1 million st) in 2010, and exports were estimated to have decreased to 39 kt (43,000 st) in 2011. U.S. apparent consumption for 2011 was estimated to have increased to 1.6 Mt (1.7 million st). World production was estimated to be about 22 Mt (24 million st) in 2011, which was 6 percent lower than 2010.
Apodaca, L. E.
Chemical properties of different peat-moorsh soils from the Biebrza River Valley
The relationship between soil structure and the ability of soil to stabilize soils organic matter is a key element in soil C dynamics. In this investigation the chemical properties were determined for three different peat-moorsh soils - Czarna Wie?, Otoczne and Kwatera 17 located in the Biebrza River Valley in Poland. Each considered soil, utilised as meadow, was sampled at
L. Szajdak; T. Brandyk
Water erosion impact on soil and carbon redistributions within uplands of Mekong River
This study quantified the soil and carbon fluxes caused by water erosion within the sloping uplands of the Mekong River basin, a river system carrying one of the greatest worldwide amounts of sediment to the ocean. Losses of sediment and soil organic carbon (SOC) (including black carbon, BC) were evaluated within an agricultural catchment of 62 ha with steep slopes,
Vincent A. M. Chaplot; Cornelia Rumpel; Christian Valentin
Dissolved organic carbon in soil solution of peat-moorsh soils on Kuwasy Mire
NASA Astrophysics Data System (ADS)
Key words: peat-moorsh soils, soil solution, dissolved organic carbon (DOC), temperature of soil, redox potential. The objective this study was the dissolved organic carbon concentration (DOC) in soil solution on the background of soil temperature, moisture and redox potential. The investigations were localized on the area of drained and agricultural used Kuwasy Mire, which are situated in the middle basin of Biebrza River, in North-East Poland. Research point was placed on a low peat soil of 110 cm depth managed as extensive grassland. The soil was recognized as peat-moorsh with the second degree of the moorshing process (with 20 cm of moorsh layer). The ceramic suction cups were installed in three replications at 30 cm depth of soil profile. The soil solution was continuously sampled by pomp of the automatic field station. The successive samples comprised of solution collected at the intervals of 21 days. Simultaneously, at the 20, 30 and 40 cm soil depths the measurements of temperature and determination of soil moisture and redox potential were made automatically. The mean twenty-four hours data were collected. The concentrations of DOC were determined by means of the flow colorimeter using the Skalar standard methods. Presented observations were made in 2001-2006. Mean DOC concentration in soil solution was 66 mg.dm-3 within all research period. A significant positive correlation between studied compound concentration and temperature of soil at 30 cm depth was observed; (correlation coefficient - r=0.55, number of samples - n=87). The highest DOC concentrations were observed during the season from July to October, when also a lower ground water level occurred. The DOC concentration in soil solution showed as well a significant correlation with the soil redox potential at 20 cm level. On this depth of describing soil profile a frontier layer between moorshing layer and peat has been existed. This layer is the potentially most active in the respect to biochemical transformation. On the other hand it wasn't possible to shown dependences on the DOC concentration from soil moisture. That probably results from a huge water-holding capacity of these type of peat soils, which are keeping a high moisture content even at a long time after decreasing of the groundwater table.
Jaszczy?ski, J.; Sapek, A.
Fate of (14)C-labeled dissolved organic matter in paddy and upland soils in responding to moisture.
Soil organic matter (SOM) content in paddy soils is higher than that in upland soils in tropical and subtropical China. The dissolved organic matter (DOM) concentration, however, is lower in paddy soils. We hypothesize that soil moisture strongly controls the fate of DOM, and thereby leads to differences between the two agricultural soils under contrasting management regimens. A 100-day incubation experiment was conducted to trace the fate and biodegradability of DOM in paddy and upland soils under three moisture levels: 45%, 75%, and 105% of the water holding capacity (WHC). (14)C labeled DOM, extracted from the (14)C labeled rice plant material, was incubated in paddy and upland soils, and the mineralization to (14)CO2 and incorporation into microbial biomass were analyzed. Labile and refractory components of the initial (14)C labeled DOM and their respective half-lives were calculated by a double exponential model. During incubation, the mineralization of the initial (14)C labeled DOM in the paddy soils was more affected by moisture than in the upland soils. The amount of (14)C incorporated into the microbial biomass (2.4-11.0% of the initial DOM-(14)C activity) was less affected by moisture in the paddy soils than in the upland soils. At any of the moisture levels, 1) the mineralization of DOM to (14)CO2 within 100days was 1.2-2.1-fold higher in the paddy soils (41.9-60.0% of the initial DOM-(14)C activity) than in the upland soils (28.7-35.7%), 2) (14)C activity remaining in solution was significantly lower in the paddy soils than in the upland soils, and 3) (14)C activity remaining in the same agricultural soil solution was not significantly different among the three moisture levels after 20days. Therefore, moisture strongly controls DOM fate, but moisture was not the key factor in determining the lower DOM in the paddy soils than in the upland soils. The UV absorbance of DOM at 280nm indicates less aromaticity of DOM from the paddy soils than from the upland soils. At any of the moisture levels, much more labile DOM was found in paddy soils (34.3-49.2% of the initial (14)C labeled DOM) compared with that in upland soils (19.4-23.9%). This demonstrates that the lower DOM content in the paddy soil compared with that in the upland soil is probably determined by the less complex components and structure of the DOM. PMID:24836136
Chen, Xiangbi; Wang, Aihua; Li, Yang; Hu, Lening; Zheng, Hua; He, Xunyang; Ge, Tida; Wu, Jinshui; Kuzyakov, Yakov; Su, Yirong
Rooting and Growth of Cuttings of Bursera simarouba, Gliricidia sepium, and Spondias purpurea in Upland Stony, Upland Non-Stony and Lowland Non-Stony Soils in Ciudad Colon, Costa Rica
Three indigenous Costa Rican tree species, Bursera simarouba, Gliricidia sepium, and Spondias purpurea, were grown from stem cuttings in an upland stony soil, an upland non-stony soil and a lowland non-stony soil. Cuttings were planted immediately before the rainy season. Sprouting of all three species on all three soils began within three weeks. Gliricidiacuttings were superior to the others in
A. Steven Messenger; Jose F. Di Stefano; Luis A. Fournier
Peat soil composition as indicator of plants growth environment
Exhausted milled peat areas have been left behind as a result of decades-lasting intensive peat production in Estonia and Europe. According to different data there in Estonia is 10 000 - 15 000 ha of exhausted milled peat areas that should be vegetated. Restoration using Sphagnum species is most advantageous, as it creates ecological conditions closest to the natural succession
M. Noormets; T. Tonutare; K. Kauer; L. Szajdak; R. Kolli
Natural soil pipes release peat carbon to atmosphere
NASA Astrophysics Data System (ADS)
A significant amount of organic carbon and carbon dioxide is stored within the partially decomposed plant remains that make up peatlands in northern climates. If this carbon were released to the atmosphere, it could affect climate. In peatlands, soil pipes�naturally occurring tubes of various sizes�could provide a route for deeply buried carbon to escape to the atmosphere. To learn more about the sources of carbon being emitted to the atmosphere in peatlands, Billett et al. measured carbon amounts and isotope ratios in particulate carbon, dissolved organic carbon, methane, and carbon dioxide released from three natural peat pipes and the downstream catchment outlet of a small peatland in northern England. Isotope ratios provide an indication of the source and age of the carbon; generally, deeper carbon is older.
Balcerak, Ernie
Analysing flow patterns in degraded peat soils using TiO2 dye
NASA Astrophysics Data System (ADS)
Dye tracing is a valuable method for studying the flow patterns in soils. However, limited information is available on water flow and solute transport pathways in dark colored peat soils because the frequently used Brilliant Blue FCF dye does not visibly stain the soil. In this study, we were aiming at testing the suitability of Titanium dioxide (TiO2) as a dye tracer for dark peat soils. The objectives were to quantify the physical properties of different degraded peat soils and visualize the flow patterns. Soil samples were collected from two low-lying fen sites, where the top soil was highly degraded, while lower horizons were less decomposed. Dye tracer experiments were conducted at both sites by applying a TiO2 suspension (10 g/l) with a pulse of 40 mm. Soil profiles were prepared for photo documentation the following day. It was found that the physical and hydraulic properties of peat were significantly influenced by the degree of peat decomposition and degradation. Higher decomposed and degraded peat soils had a higher bulk density, lower organic matter content and lower porosity. Moreover, higher decomposition and degradation resulted in a lower saturated hydraulic conductivity as long as investigated samples originated from the same site. In addition, degraded peat soils showed less anisotropy than un-degraded peat. It turned out that TiO2 is a suitable dye tracer to visualize the flow paths in peat soils. Although dye patterns differed within the same plot and between different plots, most of the flow patterns indicated a preferential flow situation. The distribution of TiO2 in the soil profile, as analyzed from 5 by 5 cm grid cells, compared to the distribution of bromide, which was applied along with the dye confirming the suitability of the dye tracer. Un-decomposed plant structures, such as wood branches and leaves, were identified as the major preferential flow path in un-degraded peat. For degraded peat, bio-pores, such as root and earthworm channels operated as the major transport domain.
Liu, Haojie; Lennartz, Bernd
Investigating variability of biogenic gas dynamics in peat soils using high temporal frequency hydrogeophysical methods
NASA Astrophysics Data System (ADS)
Peat soils are known to be a significant source of atmospheric greenhouse gasses. However, the releases of methane and carbon dioxide gasses from peat soils are currently not well understood, particularly since the timing of the releases are poorly constrained. Furthermore, most research work performed on peatlands has been focused on temperate to sub-arctic peatlands, while recent works have suggested that gas production rates from low-latitude peat soils are higher than those from colder climates. The purpose of the work proposed here is to introduce an autonomous Ground Penetrating Radar (GPR) method for investigating the timing of gas releases from peat soils at the lab scale utilizing samples originating from Maine and the Florida Everglades, and at the field scale in a Maine peatland. Geophysical data are supported by direct gas flux measurements using the flux chamber method enhanced by timelapse photography, and terrestrial LiDAR (TLS) monitoring surface deformation.
Wright, William J.
New Anaerobic, Ammonium-Oxidizing Community Enriched from Peat Soil? �
Anaerobic ammonium-oxidizing (anammox) bacteria have been recognized as an important sink for fixed nitrogen and are detected in many natural environments. However, their presence in terrestrial ecosystems has long been overlooked, and their contribution to the nitrogen cycling in natural and agricultural soils is currently unknown. Here we describe the enrichment and characterization of anammox bacteria from a nitrogen-loaded peat soil. After 8 months of incubation with the natural surface water of the sampling site and increasing ammonium and nitrite concentrations, anammox cells constituted 40 to 50% of the enrichment culture. The two dominant anammox phylotypes were affiliated with �Candidatus Jettenia asiatica� and �Candidatus Brocadia fulgida.� The enrichment culture converted NH4+ and NO2? to N2 with the previously reported stoichiometry (1:1.27) and had a maximum specific anaerobic ammonium oxidation rate of 0.94 mmol NH4+�g (dry weight)?1�h?1 at pH 7.1 and 32�C. The diagnostic anammox-specific lipids were detected at a concentration of 650 ng�g (dry weight)?1, and pentyl-[3]-ladderane was the most abundant ladderane lipid.
Hu, Bao-lan; Rush, Darci; van der Biezen, Erwin; Zheng, Ping; van Mullekom, Mark; Schouten, Stefan; Sinninghe Damste, Jaap S.; Smolders, Alfons J. P.; Jetten, Mike S. M.; Kartal, Boran
Seasonal influences on fungal community structure in unimprovedand improved upland grassland soils
Seasonal and management influences on the fungal communitystructure of two upland grassland soils were investigated. An upland sitecontaining both unimproved, floristically-diverse (U4a) and mesotrophic,improved (MG7b) grassland types was selected, and samples from bothgrassland types were taken at five times in one year. Soil fungalcommunity structure was assessed using fungal automated ribosomalintergenic spacer analysis (ARISA), a DNA-profiling approach. Grasslandmanagement regime was found to strongly affect fungal communitystructure, with fungal ARISA profiles from unimproved and improvedgrassland soils differing significantly. The number of fungal ribotypesfound was higher in unimproved than improved grassland soils, providingevidence that improvement may reduce the suitability of upland soil as ahabitat for specific groups of fungi. Seasonal influences on fungalcommunity structure were also noted, with samples taken in autumn(October) more correlated with change in ribotype profiles than samplesfrom otherseasons. However, seasonal variation did not obscure themeasurement of differences in fungal community structure that were due toagricultural improvement, with canonical correspondence analysis (CCA)indicating grassland type had a stronger influence on fungal profilesthan season.
Kennedy, Nabla; Brodie, Eoin; Connolly, John; Clipson, Nicholas
Controls on soil solution nitrogen along an altitudinal gradient in the Scottish uplands.
Nitrogen (N) deposition continues to threaten upland ecosystems, contributing to acidification, eutrophication and biodiversity loss. We present results from a monitoring study aimed at investigating the fate of this deposited N within a pristine catchment in the Cairngorm Mountains (Scotland). Six sites were established along an elevation gradient (486-908 m) spanning the key habitats of temperate maritime uplands. Bulk deposition chemistry, soil carbon content, soil solution chemistry, soil temperature and soil moisture content were monitored over a 5 year period. Results were used to assess spatial variability in soil solution N and to investigate the factors and processes driving this variability. Highest soil solution inorganic N concentrations were found in the alpine soils at the top of the hillslope. Soil carbon stock, soil solution dissolved organic carbon (DOC) and factors representing site hydrology were the best predictors of NO(3)(-) concentration, with highest concentrations at low productivity sites with low DOC and freely-draining soils. These factors act as proxies for changing net biological uptake and soil/water contact time, and therefore support the hypothesis that spatial variations in soil solution NO(3)(-) are controlled by habitat N retention capacity. Soil percent carbon was a better predictor of soil solution inorganic N concentration than mass of soil carbon. NH(4)(+) was less affected by soil hydrology than NO(3)(-) and showed the effects of net mineralization inputs, particularly at Racomitrium heath and peaty sites. Soil solution dissolved organic N concentration was strongly related to both DOC and temperature, with a stronger temperature effect at more productive sites. Due to the spatial heterogeneity in N leaching potential, a fine-scale approach to assessing surface water vulnerability to N leaching is recommended over the broad scale, critical loads approach currently in use, particularly for sensitive areas. PMID:22673176
Jackson-Blake, L; Helliwell, R C; Britton, A J; Gibbs, S; Coull, M C; Dawson, L
Paenibacillus humi sp. nov., isolated from peat-soil.
A Gram-positive, facultative-anaerobic, rod-shaped and endospore-forming bacterium designated as strain J30-4(T) was isolated from peat-soil collected in Russia. 16S rRNA gene sequence analysis revealed that strain belongs to the genus Paenibacillus, closely related to Paenibacillus terrigena A35(T) (98.1%) and Paenibacillus harenae B519(T) (95.5%). Chemotaxonomic analysis revealed that strain J30-4(T) possessed menaquinone MK-7 as predominant quinone and diphosphatidylglycerol, phosphatidylglycerol, phosphatidyl-ethanolamine, phosphatidyl-N-methylethanolamine and several unknown lipids were detected in the polar lipid profile. The cell wall peptidoglycan was of the A1? type (meso-diaminopimelic acid). The major fatty acids were anteiso-C??:? and iso-C??:?. The DNA G+C content of J30-4(T) was 55.5 mol%. Based on phenotypic, chemotaxonomic and phylogenetic data presented in this study, strain J30-4(T) (= KEMC 7302-014(T) = JCM 18166(T)) is indicative of a new Paenibacillus species, for which the name Paenibacillus humi sp. nov., is proposed. PMID:24646758
Kim, Hyun-Sook; Lee, Sang-Seob
Micromonospora humi sp. nov., isolated from peat swamp forest soil.
A novel actinomycete, strain P0402(T), was isolated from peat swamp forest soil collected in Thailand. Its taxonomic position was determined by using a polyphasic taxonomic approach. The chemotaxonomic characteristics of this strain matched those of the genus Micromonospora, i.e. the presence of meso-diaminopimelic acid and N-glycolyl muramic acid in the peptidoglycan, whole-cell sugar pattern D, phospholipid type II, and cellular fatty acid type 3b. Phylogenetic analysis based on 16S rRNA gene sequences revealed a close relationship between strain P0402(T) and Micromonospora coxensis JCM 13248(T) (99.0 % similarity), Micromonospora eburnea JCM 12345(T) (99.0 %), Micromonospora marina JCM 12870(T) (98.9 %), Micromonospora halophytica JCM 3125(T) (98.7 %), Micromonospora chalcea JCM 3031(T) (98.7 %), Micromonospora purpureochromogenes JCM 3156(T) (98.6 %) and Micromonospora aurantiaca JCM 10878(T) (98.5 %). It could be clearly distinguished from these type strains based on low levels of DNA-DNA relatedness and phenotypic differences. On the basis of the data presented, strain P0402(T) is suggested to represent a novel species of the genus Micromonospora, for which the name Micromonospora humi sp. nov. is proposed. The type strain is P0402(T) (?=?JCM 15292(T) ?=?PCU 315(T) ?=?TISTR 1883(T)). PMID:20562246
Songsumanus, Apakorn; Tanasupawat, Somboon; Thawai, Chitti; Suwanborirux, Khanit; Kudo, Takuji
Burkholderia eburnea sp. nov., isolated from peat soil.
A novel aerobic bacterium, designated strain RR11(T), was isolated from peat soil and was characterized by using a polyphasic taxonomic approach and identified in order to determine its taxonomic position. Strain RR11(T) is a Gram-negative, non-sporulating, motile, short-rod-shaped bacterium. 16S rRNA gene sequence analysis identified this strain as a member of the genus Burkholderia of the class Betaproteobacteria. The highest degrees of gene sequence similarity were found with Burkholderia tropica Ppe8(T) (98.0?%), B. bannensis E25(T) (97.3?%), B. ferrariae FeGI01(T) (97.1?%), B. unamae MTI-641(T) (97.1?%) and B. heleia SA41(T) (97.1?%). Strain RR11(T) had the following chemotaxonomic characteristics: the major ubiquinone was Q-8, the DNA G+C content was 60.8 mol%, the major fatty acids were C16?:?0, C19?:?0 cyclo ?8c and C17?:?0 cyclo and the polar lipid profile contained phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unknown aminophospholipid. Based on its morphological, physiological and chemotaxonomic characteristics, together with 16S rRNA gene sequence comparison results, strain RR11(T) represents a novel species, for which the name Burkholderia eburnea sp. nov. is proposed. The type strain is strain RR11(T) (?=?KEMC 7302-065(T)?=?JCM 18070(T)). PMID:24363296
Kang, Sang Rim; Srinivasan, Sathiyaraj; Lee, Sang Seob
Improving phosphorus availability in two upland soils of Vietnam using Tithonia diversifolia H
Phosphorus was added to two acidic upland soils (a Cambisol and a Ferralsol) at two rates (9�mg P kg?1 and 145�mg P kg?1) either in an inorganic P form (KH2PO4) or as a green manure (Tithonia diversifolia H. at 2.5 g kg?1 and 40 g kg?1). The effect of P source on the chemical availability of P was assessed in
Phan Thi Cong; Roel Merckx
Controls on soil solution nitrogen along an altitudinal gradient in the Scottish uplands
NASA Astrophysics Data System (ADS)
Nitrogen (N) deposition continues to threaten upland ecosystems, contributing to acidification, eutrophication and biodiversity loss. We present results from a monitoring study aimed at investigating the fate of this deposited N within a relatively pristine catchment in the Cairngorm Mountains (Scotland). Six sites were established along an elevation gradient (486 - 908 m) spanning the key habitats of temperate maritime uplands. Bulk deposition chemistry, soil carbon content, soil solution chemistry, soil temperature and soil moisture content were monitored over a 5 year period, making this the first study of its kind in a maritime Alpine environment. Results were used to assess spatial variability in soil solution N and to investigate the factors and processes driving this variability. Highest soil solution inorganic N concentrations were found in the alpine soils at the top of the hillslope. Soil carbon stock, dissolved organic carbon concentration and factors representing site hydrology were the best predictors of nitrate concentration. These factors act as proxies for changing net biological uptake and soil/water contact time, and support the hypothesis that spatial variations in soil solution nitrate are controlled by habitat N retention capacity. Soil percent carbon was a better predictor of soil solution N concentration than mass of carbon. Ammonium was less affected by soil hydrology than nitrate and showed the effects of net mineralization inputs, particularly at Racomitrium heath and peaty sites. We hypothesize that high ammonium concentrations at the Racomitrium heath are related to the mineralization of microbial cell tissue during times of stress, largely in the absence of plant uptake. Due to the spatial heterogeneity in N leaching potential, a fine-scale approach to assessing surface water vulnerability to N leaching is recommended over the broad scale, critical loads approach currently in use, particularly for sensitive areas.
Jackson-Blake, L.; Helliwell, R. C.; Britton, A. J.; Gibbs, S.; Coull, M. C.; Dawson, L.
Long term monitoring of biogenic gasses in peat soils using electromagnetic (EM) measurements
NASA Astrophysics Data System (ADS)
Peatlands are a critical component of the global carbon cycle and play a major role in atmospheric fluxes. Peat soils are considered one of the largest natural sources for greenhouse gas emissions (e.g. methane and carbon dioxide) to the atmosphere, but the mechanisms of formation and spatial distribution of these gasses within the soil matrix still remain uncertain. In this work we investigate the use of ground penetrating radar (GPR) as a geophysical tool to estimate the long term temporal evolution and spatial variability of biogenic gasses at the field scale. We performed high resolution EM measurements over a large section (4m x 4m x 6m) of a northern peatland (Caribou Bog, Maine) for almost an entire year. Methane emissions and surface peat deformation were concurrently monitored. All measurements were performed along a platform built to avoid disturbance of the peat surface and consistently revealed large shifts in gas content. Our results demonstrate that GPR measurements are a totally non-invasive way of investigating long term gas evolution without any disturbance to the natural gas regime (such as inserting monitoring probes), and provide unique information on the spatial distribution of biogenic gasses in peat soils. These findings also have implications for climate modeling efforts as related to biogenic gas emissions in peat soils and its impact on global warming.
Comas, X.; Slater, L.; Reeve, A.
Peat soil flows in Bah�a del Buen Suceso, Tierra del Fuego (Argentina)
NASA Astrophysics Data System (ADS)
On the southeastern edge of Tierra del Fuego, a mountainous area with a cold humid oceanic climate, peat soils cover not only flat areas but also steep hillslopes under an evergreen Nothofagus betuloides forest. Peat flows in the form of chutes are very frequent on these hillslopes. Some data were gathered on the field for 11 of these movements and from aerial photographs for 21 of them. The results suggest that peat soils become unstable when thickness exceeds a critical value which depends on the slope. This critical slope depends on the altitude and aspect regardless of soil thickness. A temporal analysis carried out by tree-ring counting demonstrated that the occurrence of these movements is not random though there are some periods of higher hazard, the probable triggering mechanisms being heavy snowfalls or earthquakes.
Gallart, Francesc; Clotet-Perarnau, N�ria; Bianciotto, Oscar; Puigdef�bregas, Joan
The relationship between microbial community structure and functional stability, tested experimentally in an upland pasture soil.
Soil collected from an upland pasture was manipulated experimentally in ways shown previously to alter microbial community structure. One set of soil was subjected to chloroform fumigation for 0, 0.5, 2, or 24 h and the other was sterilised by gamma-irradiation and inoculated with a 10(-2), 10(-4), 10(-6), or 10(-8) dilution of a soil suspension prepared from unsterilized soil. Following incubation for 8 months, to allow for the stabilization of microbial biomass and activity, the resulting microbial community structure (determined by PCR-DGGE of bacterial specific amplification products of total soil DNA) was assessed. In addition, the functional stability (defined here as the resistance and resilience of short-term decomposition of plant residues to a transient heat or a persistent copper perturbation) was determined. Changes in the active bacterial population following perturbation (determined by RT-PCR-DGGE of total soil RNA) were also monitored. The manipulations resulted in distinct shifts in microbial community structure as shown by PCR-DGGE profiles, but no significant decreases in the number of bands. These shifts in microbial community structure were associated with a reduction in functional stability. The clear correlation between altered microbial community structure and functional stability observed in this upland pasture soil was not evident when the same protocols were applied to soils in other studies. RT-PCR-DGGE profiles only detected a shift in the active bacterial population following heat, but not copper, perturbation. We conclude that the functional stability of decomposition is related to specific components of the microbial community. PMID:15259275
Griffiths, B S; Kuan, H L; Ritz, K; Glover, L A; McCaig, A E; Fenwick, C
Gamma ray attenuation in the soils of Northern Ireland, with special reference to peat.
This study considers gamma ray attenuation in relation to the soils and bedrock of Northern Ireland using simple theory and data from a high resolution airborne survey. The bedrock is considered as a source of radiogenic material acting as parent to the soil. Attenuation in the near-surface is then controlled by water content in conjunction with the porosity and density of the soil cover. The Total Count radiometric data together with 1:250 k mapping of the soils and bedrock of Northern Ireland are used to perform statistical analyses emphasising the nature of the low count behaviour. Estimations of the bedrock response characteristics are improved by excluding areas covered by low count soils (organic/humic). Equally, estimations of soil response characteristics are improved by excluding areas underlain by low count bedrock (basalt). When the spatial characteristics of the soil-classified data are examined in detail, the low values form spatially-coherent zones (natural clusters) that can potentially be interpreted as areas of increased water content for each soil type. As predicted by theory, the highest attenuation factors are associated with the three organic soil types studied here. Peat, in particular, is remarkably skewed to low count behaviour in its radiometric response. Two detailed studies of blanket bogs reveal the extent to which peat may be mapped by its radiometric response while the intra-peat variations in the observed response may indicate areas of thin cover together with areas of increased water content. PMID:22858640
Beamish, David
Impact of drainage on wettability of fen peat-moorsh soils
NASA Astrophysics Data System (ADS)
High water retention in peat is attributed to structural voids (macro-pores) due to the partial degradation of the structure of peat-forming plants, and molecular absorption sites (micro-pores) associated with the formation of humic substances. Water retention by the heterogeneously-structured system in peat organic matter depends on the chemical structure of solid surfaces. These naturally wet solids, if dried sufficiently, lose the ability to rewet quickly when immersed in water. The ability of peat surfaces to attract and hold water is attributed to hydrophilic functional groups which characterize the organic substances of peat. The investigations of chemical and physical properties were performed for three different peat-moorsh soils located in the Biebrza River Valley in Poland. All examined soils were used as meadow. Soil samples were taken from two depths: 5-10 cm (moorsh) and 50-80 cm (peat). Total organic carbon (TOC), dissolved organic carbon (DOC) and humic acids (HA) extracted from these samples were analysed. Also basic physical properties such as ash content and bulk density were measured. Wetting behavior of soils was quantified using water drop penetration time test (WDPT) and measured values of the soil-water contact angle using sessile drop method. The measurements were conducted on air-dry soil samples which volumetric moisture content was not exceeding 7%. The significant differences in the concentrations of TOC, DOC and properties of HA between two investigated depth of among peat and moorsh samples were observed. The measured concentrations of total organic carbon in the considered soils ranged from 37.2 to 45.6%. Generally, the decrease of total organic carbon concentration with depth of profiles was observed. The contents of dissolved organic carbon in the soils ranged from 5.3 to 19.4%. The quantities of dissolved organic carbon decreased simultaneously with E4/E6 values and with the depth of the soil profiles. For the investigated peat's, an increase of the depth is accompanied by the decrease in the degree of humification or an increase in chemical maturity of HA. The measured values of the contact angle for investigated soils were in the range from 81.4? to 114.3? what indicates their high water repellency. The WDPT was positively correlated with total organic carbon, organic matter and humic acids content while ash content, soil bulk density, pH and absorbance were correlated negatively. The highest value of correlation coefficient (statistically significant) was obtained for relation between WDPT and ash content. The soil water contact angle was less correlated with peat-moorsh soil properties in comparison with WDPT with one exception pH. The pH against the contact angle indicates tendency of increasing the contact angle with decreasing pH.
Szajdak, L.; Szaty?owicz, J.; Brandyk, T.
[Responses of soil organic carbon content and fractions to land-use conversion from paddy field to upland].
Natural 13C abundance determination method coupled with physical fractionation of soil organic carbon (SOC) was used to evaluate the responses of SOC and its fractions to long-term land-use conversion from paddy field to upland field (corn cultivation). Results showed that land-use conversion from paddy field to upland field led to significant decreases in the contents of SOC and total nitrogen (TN). Concentrations of total organic carbon (TOC) and TN were respectively greater by 76.7% and 47.6% in the paddy field than those in the corn field. Concentrations of occluded particulate organic matter (oPOM) and mineral-associated organic matter (MOM) on a whole soil basis were two times higher in the paddy field than those in the upland field, while no significant difference was found in free particulate organic matter (fPOM). Carbon concentrations of oPOM and MOM fractions on their own weight basis were significantly greater in the paddy field than those in the upland field, especially the oPOM fraction, which was 6 times higher in the former than that in the latter. It could be concluded that SOC protection exerted by soil aggregates in paddy soil was greater than that in upland soil. After a 19-year conversion from paddy field to corn field, delta13C values of SOC fractions significantly increased. Maize-derived carbon (C) accounted for 54.6%, 24.7%, and 19.0% in fPOM, oPOM and MOM, respectively. Mean residence time (MRT) of the initial rice-derived C increased in the order fPOM (24 a) < oPOM (67 a) < MOM (90 a). The above results further indicate that paddy field soil owns greater capability of carbon sequestration than upland soil mainly through increasing the contents of oPOM and MOM in the fractions of SOC. PMID:19545021
Huang, Shan; Rui, Wen-Yi; Peng, Xian-Xian; Liu, Wu-Ren; Zhang, Wei-Jian
Sorption and leaching of diuron on natural and peat-amended calcareous soil from Spain
The sorption and leaching processes of diuron from a 0.02M CaCl2 aqueous solution at 25�C, by a calcareous soil from the Southeastern of Spain after organic carbon (OC) amendment with a commercial peat (from 0.18% to 4.61%) have been studied by using batch and soil column experiments. The experimental sorption isotherms may be classified as L type of the Giles
E. Gonz�lez-Pradas; M. Villafranca-S�nchez; M. Fern�ndez-P�rez; M. Soc??as-Viciana; M. D. Ure�a-Amate
Transport of lead and diesel fuel through a peat soil near Juneau, AK: a pilot study.
A set of peat column experiments was used to determine the transport potential of lead (Pb) and diesel range organics (DRO) in palustrine slope wetlands near Juneau, AK. This project is important to southeast Alaskan communities because limited land resources are forcing development of regional wetlands. This study was instigated by concerns that proposed modifications to a nearby rifle range using DRO-contaminated soil posed a potential risk to an anadromous fish-bearing stream 250 m from the site. Three pairs of peat columns were extracted from the rifle range for analysis, one pair along and two pairs across the natural bedding planes of the soil. One column in each pair was spiked with Pb and DRO and the other was used as a control. Approximately 1-year worth of water (171 cm) was passed through each column and leachate was collected at regular intervals. The results showed that substantial DRO transport only occurred along the bedding planes. Leads was surprisingly mobile, both along and across the bedding planes with estimated soil-water partition coefficients several orders of magnitude lower than commonly published values, probably because the peat was heavily Pb-loaded by lead from bullets and because the peat's acidic, organic-rich environment enhanced Pb mobility. The chemical outflow behavior agreed with a simple macropore transport model. These results underscore the need for caution when developing regional wetlands. PMID:15358484
Deiss, Julian; Byers, Carl; Clover, Dave; D'Amore, Dave; Love, Alan; Menzies, Malcolm A; Powell, Jim; Walter, M Todd
Differential Effects of Surface and Peat Fire on Soil Constituents in a Degraded Wetland of the Northern Florida Everglades
alterations can be quite variable. In some cases, nutrient levels increase after fire (Kutiel and Shaviv, 1993; Mar- The effects of surface (aboveground) and peat (belowground) fire ion et al., 1991; Tomkins et al., 1991), while in others on a number of soil constituents were examined within a hydrologically altered marsh in the northern Florida Everglades. Peat fire resulted no
Stephen M. Smith; Susan Newman; Patrick B. Garrett; Jennifer A. Leeds
Application of ground-penetrating radar to measure near-saturation soil water content in peat soils
NASA Astrophysics Data System (ADS)
The presence and flux of biogenic methane-rich free phase gas that is eventually released to the atmosphere influence water content (?) of peat soils below the water table. Small variations in gas content in peat soils at near-saturation ? could be inferred by changes in dielectric permittivity, but detailed measurements in that range of ? needed to develop calibration functions are lacking. Our experiment uses a new method for varying ? in the sample using elevated pressure to reduce the naturally occurring volumetric gas content in a manner similar to what occurs in situ under atmospheric pressure change, which relevant to understanding carbon gas cycling in peatlands. We recorded dielectric permittivity using a 1.6 MHz ground-penetrating radar antenna at multiple water contents between 0.87 and 0.95 m3 m-3 on four peat monoliths with varying levels of humification and with <5% gas content as is commonly observed in the field. We identified empirical equations that were linear over the range of ? investigated and optimized a dielectric mixing model for estimating ? from GPR. These results indicate that there are differences in the permittivity-? relationships developed between peat samples and suggest that variability in dielectric relationships may be attributed to peat structure and particle orientation. The empirical relationships developed in this study confirm the utility of previously applied multiphase mixing models for estimating peat properties using methods sensitive to dielectric permittivity. This work is relevant to studies of gas content in peat and the role of peatlands in the carbon cycle.
Parsekian, Andrew D.; Slater, Lee; Gim�Nez, Daniel
Continuous measurements of CO2 emission from cultivated peat soil - effect of tillage intensity
NASA Astrophysics Data System (ADS)
Peatlands process and transfer significant quantities of greenhouse gases (GHG) such as CO2, CH4 and N2O. Most natural water-saturated peatlands sequester large amounts of CO2 from the atmosphere and emit CH4. Drainage and cultivation of peat soils increase soil aeration and reverse the carbon flux into net CO2 emissions, while CH4 emissions decrease and cultivated peat soils may even act as sinks for CH4. Fertile peat soils are potential sources of N2O when drained. In this investigation we used automatic dark chambers (ADC BioScientific Ltd) to measure CO2 emissions from plots with different soil tillage intensities. The field trial is located on the island Gotland east of the Swedish main land (57.584825N 18.47691E) and the soil is a peat soil with high pH (7.5) and organic content of 46.4 % (loss on ignition). The set-up was 4 treatments repeated in 4 blocks. Each plot was 18 by 25 meters and the following treatments were tested: A. Ploughing every year B. Ploughing 1 out of 4 years C. Only stubble cultivation D. Permanent ley One chamber was put in each plot and connected to a master control unit to create a network with 16 chambers. Measurements were made every hour during most of 2012 (17/4- 6/11 with some gaps) and every second hour during 2013 (22/4-27/6). Higher emissions could be observed just after cultivation and that effect lasted for about one day. The average emission was highest from treatment D during 2012 (4.53 ?mol m-2 s-1) and treatment C and D during 2013 (3.85 ?mol m-2 s-1).
Berglund, �rjan; Berglund, Kerstin
Assessing the Impact of Land Management on Organic Matter Composition in Peat Soils
NASA Astrophysics Data System (ADS)
Peatlands are seen as important stores of terrestrial carbon, accounting for up to one-third of global soil carbon stocks. In some cases peatlands are shown to be emitters of carbon, in other cases carbon sinks depending on the site conditions and nature of degradation. However, carbon budget calculations carried out to date have a number of uncertainties associated with them and the composition of the carbon is generally not considered when determining carbon budgets. Carbon cycling in peat is driven by four key factors (Laiho, 2006):, environmental conditions (e.g. temperature, water table level), substrate quality (e.g. how recalcitrant the peat is), nutrients (e.g. nitrogen required to synthesis the carbon stocks) and microbial community (e.g. are the microbes present able to utilise the available substrate). Land management is also recognised as an additional driver, but the impacts of many types of management are poorly understood. Among the four drivers listed by Laiho (2006) substrate quality is seen as the most significant. To date, little work has been carried out to characterise the quality of organic matter in peat soils; rather crude estimates have been made as to the quantity of carbon that is stored in peatlands, yet without understanding the composition of the peat, limitations are imposed on calculations of rates of carbon loss from peatlands. This work seeks to examine how variations in the chemical composition of organic matter in peat varies with land use. The method published by Wieder and Starr (1998) was followed to determine eight fractions: soluble fats and waxes, hot water soluble, hollocellulose, cellulose, soluble phenolics, acid insoluble carbohydrates, water soluble carbohydrates and lignin. Samples were taken from burnt, grazed, drained, afforested and undisturbed sites at the Moor House UNESCO Biosphere Reserve in Northern England. The method was used to identify if differences were present in the recalcitrance of the peat and linked to gaseous carbon emissions data collected during fortnightly monitoring. R. Laiho (2006) Decomposition in peatlands: Reconciling seemingly contrasting results on the impacts of lowered water levels Soil Biology & Biochemistry, 38, 2011-2024. R.K. Wieder & S.T. Starr (1998) Quantitative determination of organic fractions in highly organic, Sphagnum peat soils Communications in Soil Science and Plant Analysis, 29, 847-857.
Savage, A.; Holden, J.; Wainwright, J.
Determination of native ionic copper concentrations and copper complexation in peat soil extracts
In acid peaty soils most of the copper in the soil solution is present as organic complexes. This paper describes methods for measuring total soil solution copper by flameless atomic absorption spectroscopy and estimating the proportion of this copper that is complexed using copper titration and a copper ion selective electrode. With these acidic peats of diverse origin, total copper in solution at natural pH values (3.4 to 3.5) ranged from 0.14 to 0.2 ..mu.. M. Of this, 60 to 90% was complexed. Raising the pH of aqueous extracts to about 6.0 increased the degree of complexation of soluble copper in extracts of all three peats to > 98%. The results are discussed in relation to current thinking about the nature of copper complexation by humic and fulvic acids. 18 references, 5 figures, 2 tables.
Kerven, G.L.; Edwards, D.G.; Asher, C.J.
Binding of atrazine to humic substances from soil, peat and coal related to their structure.
Partition coefficients for the binding affinities of atrazine to 16 different humic materials were determined by the ultrafiltration HPLC technique. Sources included humic acids (HA), fulvic acids (FA), and combined humic and fulvic fractions (HF) from soil, peat, and coal humic acid. Each of the humic materials was characterized by elemental composition, molecular weight, and composition of main structural fragments determined by 13C solution-state NMR. The magnitude of K(OC) values varied from 87 to 575 L/kg of C, demonstrating relatively low binding affinity of humic substances (HS) for atrazine. On the basis of the measured K(OC) values, the humic materials can be arranged in the following order: coal HA approximately = gray wooded soil HA > chernozemic soil HA and HF > sod-podzolic soil HA approximately = peat HF > sod-podzolic soil FA > peat dissolved organic matter. The magnitude of the K(OC) values correlated strongly with the percentage of aromatic carbon in HS samples (r = 0.91). The hydrophobic binding was hypothesized as the key interaction underlying the binding of atrazine to HS. PMID:12322743
Kulikova, Natalia A; Perminova, Irina V
Production of dissolved organic carbon (DOC) and trihalomethane (THM) precursor from peat soils.
Water passing through the Sacramento-San Joaquin Delta contains elevated concentrations of dissolved organic carbon (DOC) and trihalomethane (THM) precursor relative to upstream waters from the Sacramento River and the San Joaquin River. Drainage from agricultural peat soils has been identified as one of the major sources of DOC and THM precursor. A series of controlled laboratory experiments were conducted to evaluate abiotic and biotic effects on the quantity and the nature of DOC and THM precursors produced from oxidized surface and reduced subsurface soils in the Delta. For abiotic effects, DOC was extracted from both soils with synthetic solutions containing a range of salinity (0-4 dS/m) and sodicity (0 to infinity ). The results showed that an increase in salinity significantly decreased the concentration of DOC in the soil-water from both soils but increased its aromaticity, as indicated by specific ultraviolet absorbance at 254 nm (SUVA). For biotic effects, peat soils were incubated over a range of temperatures (10 degrees C, 20 degrees C and 30 degrees C) and soil moisture contents (0.3-10 g water/g soil). After 8 weeks of incubation, only extracted DOC from flooded conditions and flooded and non-flooded cycles showed an increase in DOC. These findings indicate that neither salinity nor sodicity is the major factor for DOC production, but both can affect the solubility and mobility of DOC in the Delta soils. We believe wetting processes in oxidized peat soils produce significant amounts of DOC found in agricultural drainage discharged into the Delta waters. PMID:14511718
Chow, Alex T; Tanji, Kenneth K; Gao, Suduan
Mississippi Basin Carbon Project; upland soil database for sites in Yazoo Basin, northern Mississippi
The conversion of land from its native state to an agricultural use commonly results in a significant loss of soil carbon (Mann, 1985; Davidson and Ackerman, 1993). Globally, this loss is estimated to account for as much as 1/3 of the net CO2 emissions for the period of 1850 to 1980 (Houghton et al, 1983). Roughly 20 to 40 percent of original soil carbon is estimated to be lost as CO2 as a result of agricultural conversion, or 'decomposition enhancement', and global models use this estimate along with land conversion data to provide agricultural contributions of CO2 emissions for global carbon budgets (Houghton and others, 1983; Schimel, 1995). As yet, erosional losses of carbon are not included in global carbon budgets explicitly as a factor in land conversion nor implicitly as a portion of the decomposition enhancement. However, recent work by Lal et al (1995) and by Stallard (1998) suggests that significant amounts of eroded soil may be stored in man-made reservoirs and depositional environments as a result of agricultural conversion. Moreover, Stallard points out that if eroding soils have the potential for replacing part of the carbon trapped in man-made reservoirs, then the global carbon budget may grossly underestimate or ignore a significant sink term resulting from the burial of eroded soil. Soil erosion rates are significantly (10X) higher on croplands than on their undisturbed equivalents (Dabney et al, 1997). Most of the concern over erosion is related to diminished productivity of the uplands (Stallings, 1957; McGregor et al, 1993; Rhoton and Tyler, 1990) or to increased hazards and navigability of the lowlands in the late 1800's to early 1900's. Yet because soil carbon is concentrated at the soil surface, with an exponential decline in concentration with depth, it is clear that changes in erosion rates seen on croplands must also impact soil carbon storage and terrestrial carbon budgets as well.
Harden, J. W.; Fries, T. L.; Huntington, T. G.
Morphometrics, Erosion Processes and the influence of Climate on Upland Soil-Mantled Landscapes
NASA Astrophysics Data System (ADS)
Hillslope morphology reflects processes of sediment transport and offers key insight into controlling mechanisms on landscape evolution. Here, we examine how climate influences landscape form, using remotely sensed data from an upland soil-mantled region of the Sierra Nevada, California. Previous work in this field area has quantified rates of landscape lowering by cosmogenic 10Be and dominant processes of soil transport by fallout radionuclides and field measurements including incidence of tree throw, burrow density, root density and soil surface exposure. Here, we examine high resolution Light Distance and Ranging (LiDAR) and coarser scale Shuttle Radar Topography (SRTM) data for four distinct climate zones along the western front of the southern Sierra Nevada range. We quantify slope and curvature distributions and metrics of surface roughness, ruggedness, drainage density and relief. Furthermore, we couple hillslope profiles with calculated denudation rates and soil transport processes to examine climate modulated control of erosion and weathering on landscape morphology. Our morphometric examination demonstrates the sensitivity of variables such as hillslope curvature to distinct processes of soil transport across the climate gradient.
Dixon, J. L.; Heimsath, A. M.; Finnegan, D. C.; Amundson, R.
Investigating methane flux dynamics in subtropical peat soils of the Everglades using hydrogeophysical methods
NASA Astrophysics Data System (ADS)
Methane is a dynamic atmospheric gas with high radiative forcing that directly influences climatic patterns. Peat soils are well recognized sources for atmospheric methane, and although the number of studies on methane dynamics has increased during the last two decades, most have focused on boreal peatlands. For that reason, low-latitude systems like the Everglades have traditionally been less studied, and have focused on discrete point measures (such as gas chambers) that provide little information on temporal patterns in methane flux variability. In this study, we present an array of hydrogeophysical techniques to investigate the temporal variability of methane dynamics in peat soils of the Everglades. Ground penetrating radar (GPR) is used here to estimate temporal changes in methane fluxes at different scales ranging from low frequency measurements in the field (1- 10 m), to high frequency measurements in peat blocks at the laboratory scale (<1 m). Discrete measurements in the field are combined with continuous measurements using a unique autonomous rail system at the laboratory scale to further constrain timing of methane releasing events. GPR measurements are paired with other techniques, including direct methods such as time-lapse cameras, gas traps and gas chromatography, and other indirect methods, such as capacitance probes. Our results show the potential of hydrogeophysical techniques to better understand: 1) the internal biogenic gas dynamics within the peat's matrix (i.e. methane production vs. release), 2) the temporal variability in methane gas releases (i.e. steady vs. episodic ebullition); and 3) the effect of atmospheric pressure on regulating ebullitive methane events. Our results suggest that ebullitive events in peat soils of the Everglades resulting in large rapid fluxes of methane to the atmosphere may occur during periods of high atmospheric pressure due to decreases in the bubble volume and subsequent increases in bubble mobility.
Comas, X.; Wright, W. J.; Heij, G.
The response of caribbean pine, green panic, and siratro to fertiliser on soils of the 'Eua Uplands, Tonga
Fertiliser experiments were conducted on soils fom the uplands of 'Eua, Tonga, which are being developed for forest farming (pastures under trees). Glasshouse pot trials were used to demonstrate nutrient deficiencies and the likely level of fertiliser input for the satisfactory growth of caribbean pine (Pinus caribaea), green panic (Panicum maximum var. trichoglume), and siratro (Macroptilium atropurpureum) on Houma silty
P. B. S. Hart; J. P. Widdowson
Mercury in vegetation and organic soil at an upland boreal forest site in Prince Albert National Park, Saskatchewan, Canada
We studied an upland boreal forest plot located in the Prince Albert National Park, Saskatchewan, Canada, to measure the total mercury content in vegetation and organic soil with a view to assessing the potential for mercury release during forest fires. The study area consists of two stands of vegetation regrown after fires 39 and 130 years ago, with different carbon
H. R. Friedli; L. F. Radke; N. J. Payne; D. J. McRae; T. J. Lynham; T. W. Blake
Correlation of Methane Production and Functional Gene Transcriptional Activity in a Peat Soil ?
The transcription dynamics of subunit A of the key gene in methanogenesis (methyl coenzyme M reductase; mcrA) was studied to evaluate the relationship between process rate (methanogenesis) and gene transcription dynamics in a peat soil ecosystem. Soil methanogen process rates were determined during incubation of peat slurries at temperatures from 4 to 37�C, and real-time quantitative PCR was applied to quantify the abundances of mcrA genes and transcripts; corresponding transcriptional dynamics were calculated from mcrA transcript/gene ratios. Internal standards suggested unbiased recovery of mRNA abundances in comparison to DNA levels. In comparison to those in pure-culture studies, mcrA transcript/gene ratios indicated underestimation by 1 order of magnitude, possibly due to high proportions of inactive or dead methanogens. Methane production rates were temperature dependent, with maxima at 25�C, but changes in abundance and transcription of the mcrA gene showed no correlation with temperature. However, mcrA transcript/gene ratios correlated weakly (regression coefficient = 0.76) with rates of methanogenesis. Methanogen process rates increased over 3 orders of magnitude, while the corresponding maximum transcript/gene ratio increase was only 18-fold. mcrA transcript dynamics suggested steady-state expression in peat soil after incubation for 24 and 48 h, similar to that in stationary-phase cultures. mcrA transcript/gene ratios are therefore potential in situ indicators of methanogen process rate changes in complex soil systems.
Freitag, Thomas E.; Prosser, James I.
Changes in soil fungal:bacterial biomass ratios following reductions in the intensity of management of an upland grassland
In this study we examined the effect on soil fungal:bacterial biomass ratios of withholding fertiliser, lime, and sheep-grazing from reseeded upland grassland. The cessation of fertiliser applications on limed and grazed grassland resulted in a reduction in soil pH from 5.4 to 5.1. The cessation of fertiliser applications and liming on grazed grassland resulted in a fall in pH from
Richard D. Bardgett; Philip J. Hobbs; �sa Frosteg�rd
Acetate repression of methane oxidation by supplemental Methylocella silvestris in a peat soil microcosm.
Methylocella spp. are facultative methanotrophs that grow on methane and multicarbon substrates, such as acetate. Acetate represses transcription of methane monooxygenase of Methylocella silvestris in laboratory culture. DNA stable-isotope probing (DNA-SIP) using (13)C-methane and (12)C-acetate, carried out with Methylocella-spiked peat soil, showed that acetate also repressed methane oxidation by Methylocella in environmental samples. PMID:21515721
Rahman, M Tanvir; Crombie, Andrew; Moussard, H�l�ne; Chen, Yin; Murrell, J Colin
Acetate Repression of Methane Oxidation by Supplemental Methylocella silvestris in a Peat Soil Microcosm ? �
Methylocella spp. are facultative methanotrophs that grow on methane and multicarbon substrates, such as acetate. Acetate represses transcription of methane monooxygenase of Methylocella silvestris in laboratory culture. DNA stable-isotope probing (DNA-SIP) using 13C-methane and 12C-acetate, carried out with Methylocella-spiked peat soil, showed that acetate also repressed methane oxidation by Methylocella in environmental samples.
Rahman, M. Tanvir; Crombie, Andrew; Moussard, Helene; Chen, Yin; Murrell, J. Colin
Permafrost controls on soil C storage and turnover in upland black spruce ecosystems of interior Alaska
NASA Astrophysics Data System (ADS)
Permafrost soils in northern latitudes have functioned as important reservoirs for organic carbon (OC) since the last glacial maximum. In particular, the formation of permafrost through syngenetic processes (e.g. aeolian loess deposition) allows for high rates of OC burial and stabilization. Recent warming at northern latitudes has resulted in warming and thawing of permafrost in many regions, which may mobilize OC stocks from deep soil reservoirs via decomposition, leaching or erosion. Furthermore, in the boreal region, increased wildfire frequency and severity may promote rapid permafrost thaw and soil OC loss from forested ecosystems. Release of OC stocks from permafrost as carbon dioxide or methane may function as a strong positive feedback to atmospheric warming. Here, we examine patterns of OC storage in active layer and permafrost soils across a fire chronosequence of upland black spruce stands near Hess Creek, interior Alaska. Our research objective was to evaluate how post-fire changes in organic horizon thickness and consequently, changes in active layer thickness, influence rates of OC turnover in deep mineral soil. We used a finite-difference numerical model (GIPL2) to simulate permafrost dynamics and a steady-state radiocarbon model to estimate carbon turnover. To calibrate the permafrost model, we monitored soil temperature, soil moisture, snow depth, and active layer thickness at four sites across the fire chronosequence. To evaluate soil carbon dynamics, we measured OC stocks and radiocarbon inventories from zero to two meters below the ground surface across the chronosequence. Preliminary results from field observations and model runs indicate that active layer thickness was closely linked to fire severity, as reflected by organic horizon thickness. Total carbon storage to two meters averaged 35 � 6 kg m-2 across the chronosequence, with between 42 and 67 % of these stocks below the permafrost table. Radiocarbon ages of soil OC at two meters ranged from 20,000 to 28,000 years before present, and generally increased with depth. Input rates of OC to surface organic horizons (via moss net primary productivity and litterfall) and to deep mineral soil (via charcoal, dissolved organics and roots) were similar, collectively averaging 0.010 kg C m-2 y-1. However, decomposition constants were an order of magnitude different between surface organic and deep mineral soils, averaging 0.010 and 0.001 yr-1 respectively. Together, these field observations and modeling approaches will allow us to evaluate the effects of future fire and climate conditions on permafrost degradation and carbon loss from northern soils.
O'Donnell, J. A.; Harden, J. W.; Romanovsky, V. E.; Kanevskiy, M. Z.; Jorgenson, T.; Xu, X.; Ewing, S. A.; McGuire, D.; Shur, Y.
Vertical transfer of 137 Cs in peat soils fallen out as a consequence of the chernobyl accident
On the basis of measurements of the specific radioactivity of soil specimens sampled with a small step along their deposition, depth profiles are plotted for the curves of the vertical change in137Cs in peat soils not treated since the Chernobyl accident. A theoretical analysis is provided for the plotted profiles that shows that the vertical transfer of137Cs in these soils
N. M. Olekhnovich; G. I. Makovetskii; A. I. Galyas; O. I. Pashkovskii; G. M. Severin; G. A. Turtsevich; K. I. Yanushkevich
The influence of different types of grassland on soil quality in upland areas of Czech Republic.
The diversity of grassland in upland areas of Czech Republic was studied on selected soil characteristics of these biotopes. In the first phase, 44 soil characteristics were studied and mutual correlations were found between many of them. In the following phase characteristics were chosen which correlated most with other soil characteristics and, at the same time, were easy to evaluate in practise. A great number of correlations were also evidenced between many soil characteristics and the content of humus and nitrogen, which are closely linked to organic matter in soil. In studying these characteristics on selected areas with different types of grassland and consequential cluster analysis and further evaluation, the grassland plots were divided into three groups, from newly established vegetation to species-rich communities. Non-parametric analysis was carried out on the results and a statistically significant difference was proved between the species rich and poorvegetation and carbon and nitrogen content of the soil. Slightly different humus quality (higher amount of HA) was also found under richer vegetation. These results show that at 0-20 cm layer, 58.9 tonnes of carbon ha?� was measured under species-poor pastureland and 106.1 tonnes of carbon ha under species-rich vegetation. The results showed that besides supporting species diversity, the described quality change can also be important for carbon sequestration. The difference of about 40-50 tonnes of carbon ha and converting 10% of grassland in the Czech Republic to species-rich vegetation would mean sequestration of about 3.9 Mt carbon. If only agroenvironmentally subsidized areas are converted, carbon sequestration in such vegetation could amountto 1.7 Mt. PMID:24812999
Sarapatka, B; Cizkova, S
Dissolved Organic Carbon and Disinfection By-Product Precursor Release from Managed Peat Soils
A wetland restoration demonstration project examined the effects of a permanently flooded wetland on subsidence of peat soils. The project, started in 1997, was done on Twitchell Island, in the Sacramento-San Joaquin Delta of California. Conversion of agricultural land to a wetland has changed many of the biogeochemical processes controlling dissolved organic carbon (DOC) release from the peat soils, relative to the previous land use. Dissolved organic C in delta waters is a concern because it reacts with chlorine, added as a disinfectant in municipal drinking waters, to form carcinogenic disinfection byproducts (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs). This study explores the effects of peat soil biogeochemistry on DOC and DBP release under agricultural and wetland management. Results indicate that organic matter source, extent of soil organic matter decomposition, and decomposition pathways all are factors in THM formation. The results show that historical management practices dominate the release of DOC and THM precursors. However, within-site differences indicate that recent management decisions can contribute to changes in DOC quality and THM precursor formation. Not all aromatic forms of carbon are highly reactive and certain environmental conditions produce the specific carbon structures that form THMs. Both HAA and THM precursors are elevated in the DOC released under wetland conditions. The findings of this study emphasize the need to further investigate the roles of organic matter sources, microbial decomposition pathways, and decomposition status of soil organic matter in the release of DOC and DBP precursors from delta soils under varying land-use practices.
Fleck, J. A.; Bossio, D. A.; Fujii, R.
A cost-efficient method to assess carbon stocks in tropical peat soil
NASA Astrophysics Data System (ADS)
Estimation of belowground carbon stocks in tropical wetland forests requires funding for laboratory analyses and suitable facilities, which are often lacking in developing nations where most tropical wetlands are found. It is therefore beneficial to develop simple analytical tools to assist belowground carbon estimation where financial and technical limitations are common. Here we use published and original data to describe soil carbon density (kgC m-3; Cd) as a function of bulk density (gC cm-3; Bd), which can be used to rapidly estimate belowground carbon storage using Bd measurements only. Predicted carbon densities and stocks are compared with those obtained from direct carbon analysis for ten peat swamp forest stands in three national parks of Indonesia. Analysis of soil carbon density and bulk density from the literature indicated a strong linear relationship (Cd = Bd � 495.14 + 5.41, R2 = 0.93, n = 151) for soils with organic C content > 40%. As organic C content decreases, the relationship between Cd and Bd becomes less predictable as soil texture becomes an important determinant of Cd. The equation predicted belowground C stocks to within 0.92% to 9.57% of observed values. Average bulk density of collected peat samples was 0.127 g cm-3, which is in the upper range of previous reports for Southeast Asian peatlands. When original data were included, the revised equation Cd = Bd � 468.76 + 5.82, with R2 = 0.95 and n = 712, was slightly below the lower 95% confidence interval of the original equation, and tended to decrease Cd estimates. We recommend this last equation for a rapid estimation of soil C stocks for well-developed peat soils where C content > 40%.
Warren, M. W.; Kauffman, J. B.; Murdiyarso, D.; Anshari, G.; Hergoualc'h, K.; Kurnianto, S.; Purbopuspito, J.; Gusmayanti, E.; Afifudin, M.; Rahajoe, J.; Alhamd, L.; Limin, S.; Iswandi, A.
The xanthine oxidase activity in different of secondary transformed peat-moorsh soils
NASA Astrophysics Data System (ADS)
The investigations were carried out on the transect of peatland 4.5 km long, located in the Agroecological Landscape Park host D. Chlapowski in Turew (40 km South-West of Pozna?, West Polish Lowland). The sites investigation were located along Wysko? ditch. The following material was taken from four chosen sites marked as Zb?chy, Bridge, Shelterbelt and Hirudo in two layers: acrotelm (0-50 cm) and catotelm (50-100 cm). The object of this study was to characterize the biochemical properties by the determination of the xanthine oxidase activity in two layers (acrotelm and catotelm) of the four different peat-moorsh soils used as meadow. The xanthine oxidase activity was determined spectrophotometrically by measuring uric acid formation at ?max=290 nm with xanthine as substrate. In peat-moorsh soil the highest activities of xanthine oxidasewas observed in the Shelterbelt and whereas the lowest - in Zb?chy, Bridge and Hirudo. Activities of this enzyme in peat-moorsh soil ranged from 5.96 to 19.51 ?mol h-1g d.m soil. Increased activities of xanthine oxidase have been recorded on the depth 50-100 cm - catotelm (from 11.71 to 19.51 ?mol h-1g d.m soil) in comparison with the depth 0-50 cm - acrotelm (from 5.96 to 14.64 ?mol h-1g d.m soil). This work was supported by a grant No. N N305 3204 36 founded by Polish Ministry of Education.
Sty?a, Katarzyna; Wojciech Szajdak, Lech
Carbon monoxide fluxes of different soil layers in upland Canadian boreal forests
NASA Astrophysics Data System (ADS)
Dark or low-light carbon monoxide fluxes at upland Canadian boreal forest sites were measured on-site with static chambers and with a laboratory incubation technique using cores from different depths at the same sites. Three different upland black spruce sites, burned in 1987, 1992 and 1995 and a control site, were chosen to determine the effects of fire, temperature, soil structure and soil covers on CO fluxes. Three different surfaces were observed at the sites � bare mineral soil with little living moss cover; burned feather mosses 5 30cm deep; and unburned, living, green feather mosses. The static chamber measurements indicated similar deposition velocities for the burned and unburned feather moss sites [(1.54�0.64)� 102cm s1 ; (1.83�0.63).102cm s1], but significantly lower rates for sites that had burned down to the mineral soil [(1.08�0.53).102cm s1, excluding data with net CO emission]. This finding was confirmed by results from the incubation measurements and shows that fire intensities determine the long-term, post-fire effect on soil-atmosphere fluxes of CO. Temperature studies with the cores showed that CO consumption rates increased from (2�1)% at -15�C to -13�C to (43�20)% at 0�C to 1.5�C and (68�15)% at 4�C to 5�C of the deposition velocity values obtained at 20�C. This temperature dependence was consistent with results obtained from the static chamber measurements. The temperature range studied and the dark or low-light conditions were representative for the night-time of nearly the whole six snow-free months in the boreal ecosystem. In nearly all cases, deposition velocities determined for cores from the top 5cm with the incubation technique were the same, within experimental errors, as those determined with the static chambers. Soil CO concentration profiles taken in situ, moreover, did not show any clear trend below 5cm. Thus we conclude that the top 5cm of soils are determining the dark soil-atmosphere CO fluxes at these sites. The top 5cm of soil columns are most exposed to temperature (and probably moisture) variations and are most affected by fires as well.
Kuhlbusch, Thomas A. J.; Zepp, R. G.; Miller, W. L.; Burke, R. A., Jr.
Complexes of the antimicrobial ciprofloxacin with soil, peat, and aquatic humic substances.
Natural organic matter (NOM) is implicated in the binding of antibiotics by particles in soils and waters. The authors' previous computational study revealed structural rearrangement of both hydrophilic and hydrophobic moieties of NOM to favor H-bonding and other intermolecular interactions, as well as both competition with ion-exchange reactions and bridging interactions by NOM-bound divalent cations. The importance of these interactions was investigated using fluorescence-quenching spectroscopy to study the adsorption of ciprofloxacin (Cipro), a fluoroquinolone antibiotic, on 4 reference humic substances (HSs): Elliott soil humic acid (HA), Pahokee peat HA, and Suwannee river HA and fulvic acid. A simple affinity spectrum HS model was developed to characterize the cation-exchange capacity and the amount of H-bond donor moieties as a function of pH. The adsorption results stress the influence of both pH conditions and the type of HS: both soil HA and peat HA exhibited up to 3 times higher sorption capacity than the aquatic HS at pH???6, normalizing to the aromatic C content accounted for the differences among the terrestrial HS, and increasing the concentration of divalent cations led to a decrease in adsorption on aquatic HA but not on soil HA. In addition, the pH-dependent speciation models of the Cipro-HS complexes illustrate an increase in complexation due to an increase in deprotonation of HS ligands with increasing pH and, at circumneutral and alkaline pH, enhanced complexation of zwitterionic Cipro only in the presence of soil HA and peat HA. The findings of the present study imply that, in addition to electrostatic interactions, van der Waals interactions as facilitated by aromatic structures and H-bond donating moieties in terrestrial HS may facilitate a favorable binding environment. Environ Toxicol Chem 2013;32:1467-1478. � 2013 SETAC. PMID:23456646
Aristilde, Ludmilla; Sposito, Garrison
Biochar as a Substitute for Peat in Greenhouse Growing Media: Soil Water Characteristics and Carbon Leaching Dynamics
NASA Astrophysics Data System (ADS)
Biochar (charcoal derived from waste biomass via pyrolysis) has the potential to be used as part of regional scale carbon sequestration strategies. By providing a stable form of carbon that is resistant to decay in soils, biochar can be utilized in a wide range of applications to improve the sustainability of land use management practices. Due to its high water holding capacity, surface area and charge density, it could provide a substitute for peat that is widely used in horticultural activities. Globally, peat production in 2010 amounted to 23.4 Mt, with more than a third of this used for horticulture. In Canada, essentially all peat produced is used for horticulture, with each ton of peat extracted also contributing about 0.7 t CO2e in combined greenhouse gas emissions related to production, transportation and use of peat. We evaluated biochar produced on farm from red alder as a peat substitute in terms of soil water characteristics and carbon leaching in greenhouse growing media (e.g. potting mix). Biochar mixing ratios of 10% (v/v) and greater provided water holding capacity equivalent to peat-based potting mixes. We also present results from a laboratory wetting experiment in which we characterized leachate for dissolved organic carbon (DOC) concentration and DOC characteristics using spectral methods (uV-Vis and fluorescence spectroscopy).
Johnson, M. S.; Hilbert, I.; Jollymore, A. J.
Dark or low-light carbon monoxide fluxes at upland Canadian boreal forest sites were measured on-site with static chambers and with a laboratory incubation technique using cores from different depths at the same sites. Three different upland black spruce sites, burned in 1987,199...
Fate and transport of ambient mercury and applied mercury isotope in terrestrial upland soils: insights from the METAALICUS watershed.
The fate of mercury (Hg) deposited on forested upland soils depends on a wide array of biogeochemical and hydrological processes occurring in the soil landscape. In this study, Hg in soil, soilwater, and streamwater were measured across a forested upland subcatchment of the METAALICUS watershed in northwestern Ontario, Canada, where a stable Hg isotope (spike Hg) was applied to distinguish newly deposited Hg from Hg already resident in the watershed (ambient Hg). In total, we were able to account for 45% of the total mass of spike Hg applied to the subcatchment during the entire loading phase of the experiment, with approximately 22% of the total mass applied now residing in the top 15 cm of the mineral soil layer. Decreasing spike Hg/ambient Hg ratios with depth in the soil and soilwater suggest that spike Hg is less mobile than ambient Hg over shorter time scales. However, the transport of spike Hg into the mineral soil layer is enhanced in depressional areas where water table fluctuation is more extreme. While we expect that this pool of Hg is now effectively sequestered in the mineral horizon, future disturbance of the soil profile could remobilize this stored Hg in runoff. PMID:24383823
Oswald, Claire J; Heyes, Andrew; Branfireun, Brian A
Swelling of peat soil samples as determined by 1H NMR relaxometry
NASA Astrophysics Data System (ADS)
The swelling of soil organic matter (SOM) rich samples like peat soils may affect sorption and desorption of nutrients and contaminants. In the course of swelling the state of water may change and SOM may form a gel phase. Two peat soil samples in different degradation states from one location in Germany were saturated with water. Their swelling kinetics were studied at 5�C, 19�C and 30�C using 1H NMR relaxometry at 7.5 MHz. CPMG pulse sequence and the inversion recovery method were used to determine transverse (T2) and longitudinal (T1) relaxation time distributions, respectively. The gel phase and the state of water were both characterized with 1H NMR relaxometry, Cryo-NMR and differential scanning calorimetry (DSC). Three types of water were found in both peats: Non-freezing bound water and two types of freezable water which showed a splitting of the melting peak in the DSC thermogram. The stepwise water drainage of the peat samples by centrifugation revealed increasing T1/T2 ratios, which were not caused by proton relaxation, due to spin diffusion in internal field gradients. It can be assumed that both the splitting of the melting peak and the increasing T1/T2 ratios were caused by a phase separation of the "free" freezable water as found for conventional biopolymers like starch. Due to the organic surfaces one phase of the freezable water is structured which affects the rotational motion of water molecules, and thus caused different T1 and T2 values. From the swelling kinetics three processes (fast, medium, slow) of water dislocation from larger to smaller T2 values were distinguished. The time constants of the processes were found to be in the range of minutes (fast), hours (medium) and days/weeks (slow). The activation energies ranged between 15 - 50 KJ mol-1 suggesting that physical and physical/chemical processes are governing the swelling of SOM like a sterical re-orientation of SOM macromolecules, the water-structuring and hydration of SOM.
Jaeger, F.; Schaumann, G. E.
Technical Note: Development of an automated lysimeter for the calculation of peat soil actual evapotranspiration
NASA Astrophysics Data System (ADS)
A limited number of publications in the literature deal with the measurement of actual evapotranspiration (AET) from a peat soil. AET is an important parameter in the description of water pathways of an ecosystem. In peatlands, where the water table is near the surface and the vegetation is composed of nonvascular plants without stomatal resistance, the AET measurement represents a challenge. This paper discusses the development of an automated lysimeter installed between 12 and 27 July 2010, at a 11-ha bog site, Pont-Rouge (42 km west of Quebec City, Canada). This system was made of an isolated block of peat, maintained at the same water level as the surrounding water table by a system of submersible pressure transmitters and pumps. The change in water level in millimetres in the isolated block of peat was used to calculate the water lost through evapotranspiration (ET) while accounting the precipitation. The rates of AET were calculated for each day of the study period. Temperature fluctuated between 17.2 and 23.3 �C and total rainfall was 43.76 mm. AET rates from 0.6 to 6.9 mm day-1 were recorded, with a ?AET/?P ratio of 1.38. The estimated potential ET (PET) resulting from Thornthwaite's semi-empirical formula suggested values between 2.8 and 3.9 mm day-1. The average AET/PET ratio was 1.13. According to the literature, the results obtained are plausible. This system, relatively inexpensive and simple to install, may eventually be used to calculate AET on peaty soils in the years to come.
Proulx-McInnis, S.; St-Hilaire, A.; Rousseau, A. N.; Jutras, S.; Carrer, G.; Levrel, G.
Heavy metal contamination from historic mining in upland soil and estuarine sediments of Egypt Bay, Maine, USA
NASA Astrophysics Data System (ADS)
Concentrations of Cd, Cu, Pb and Zn in sediments of Egypt Bay in Hancock County, Maine, are elevated above background levels. The source of the contamination is Cu mining that occurred in the uplands adjacent to Egypt Stream between 1877 and 1885. Egypt Stream is a tributary to Egypt Bay. Egypt Bay is part of the Taunton Bay estuary system. The Hagan Mine was one of the mines extracting metals from the sulfide deposits in Downeast Maine north of Penobscot Bay. Metal concentrations were determined using ICP-AES after sample digestion with nitric acid. Soil collected from the coarse textured mine tailings pile contained elevated concentrations of Cd, Cu, Pb and Zn, but the majority of the surface soils at the Hagan Mine site were not contaminated. Estuary sediments from the surface to 100 cm depth were collected in four locations within Egypt Bay. Below 40 cm, metal concentrations in sediments were similar to those in uncontaminated upland soils. Metal concentrations in the estuary sediments between the surface and 26 cm were above background levels. According to 210Pb dating, the sediment at 26-34 cm depth was likely to have been deposited at the time the historic mines were in operation. Concentrations of Cd, Cu, Pb, and Zn in sediment from the 32-34 cm depth interval are similar to concentrations in the upland soil sample from the mine tailings pile. Elevated Pb concentrations in sediments from the surface to 24 cm are from atmospheric Pb deposition from anthropogenic sources. Sediment in the top 10 cm of the estuary has been mixed both by the polychaete worm Nereis virens and by those harvesting the worms for sale as fish bait.
Osher, L. J.; Leclerc, L.; Wiersma, G. B.; Hess, C. T.; Guiseppe, V. E.
The influence of aeration and temperature on the structure of bacterial complexes in high-moor peat soil
NASA Astrophysics Data System (ADS)
The number and taxonomic structure of the heterotrophic block of aerobic and facultative anaerobic bacteria were studied in monoliths from a high-moor peat (stored at room temperature and in a refrigerator) and in the peat horizons mixed in laboratory vessels. The monitoring lasted for a year. In the T0 horizon, spirilla predominated at room and low temperatures; in the T1 and T2 horizons, bacilli were the dominants. The continuous mixing of the peat layers increased the oxygen concentration and the peat decomposition; hence, the shares of actinomycetes and bacilli (bacteria of the hydrolytic complex) increased. In the peat studied, the bacilli were in the active state; i.e., vegetative cells predominated, whose amount ranged from 65 to 90%. The representatives of the main species of bacilli (the facultative anaerobic forms prevailed) hydrolyzed starch, pectin, and carboxymethylcellulose. Thus, precisely sporiferous bacteria can actively participate in the decomposition of plant polysaccharides in high-moor peat soils that are characterized by low temperatures and an oxygen deficit. The development of actinomycetes is inhibited by low temperatures; they can develop only under elevated temperature and better aeration.
Kukharenko, O. S.; Pavlova, N. S.; Dobrovol'Skaya, T. G.; Golovchenko, A. V.; Pochatkova, T. N.; Zenova, G. M.; Zvyagintsev, D. G.
Biogenic Gas Dynamics in Peat Soil Blocks using Ground Penetrating Radar: a Comparative Study in the Laboratory between Peat Soils from the Everglades and from two Northern Peatlands in Minnesota and Maine
NASA Astrophysics Data System (ADS)
Peatlands cover a total area of approximately 3 million square kilometers and are one of the largest natural sources of atmospheric methane ( CH4) and carbon dioxide (CO 2). Most traditional methods used to estimate biogenic gas dynamics are invasive and provide little or no information about lateral distribution of gas. In contrast, Ground Penetrating Radar (GPR) is an emerging technique for non-invasive investigation of gas dynamics in peat soils. This thesis establishes a direct comparison between gas dynamics (i.e. build-up and release) of four different types of peat soil using GPR. Peat soil blocks were collected at peatlands with contrasting latitudes, including the Everglades, Maine and Minnesota. A unique two-antenna GPR setup was used to monitor biogenic gas buildup and ebullition events over a period of 4.5 months, constraining GPR data with surface deformation measurements and direct CH 4 and CO2 concentration measurements. The effect of atmospheric pressure was also investigated. This study has implications for better understanding global gas dynamics and carbon cycling in peat soils and its role in climate change.
Cabolova, Anastasija
Use of Computer-Aided Tomography (CT) Imaging for Quantifying Coarse Roots, Rhizomes, Peat, and Particle Densities in Marsh Soils
Computer-aided Tomography (CT) imaging was utilized to quantify wet mass of coarse roots, rhizomes, and peat in cores collected from organic-rich (Jamaica Bay, NY) and mineral (North Inlet, SC) Spartina alterniflora soils. Calibration rods composed of materials with standard dens...
Electron paramagnetic resonance (EPR) studies on stable and transient radicals in humic acids from compost, soil, peat and brown coal
Quantitative EPR method was applied to characterise four types of humic acids (HA) derived from composts, soil, peat and soft brown coal. For each sample of HA the level of native (indigenous) radicals was estimated. Interactions of the HA with various gaseous agents and organic solvents were investigated. Strong effects of gaseous ammonia and aliphatic amines on spin concentration enhancement
Adam Jezierski; Franciszek Czechowski; Maria Jerzykiewicz; Yona Chen; Jerzy Drozd
Impact of secondary transformation of peat-moorsh soils on the decrease of nitrogen and carbon compounds in ground water
The study of peatland is used to show the water quality functioning with respect to different forms of nitrogen and carbon. In this paper, the purification of ground water by the transect of 4.5 km length consisting of organic soils (peat-moorsh soils) was investigated. The transect is located in the Agroecological Landscape Park in Turew, 40 km South-West of Pozna?,
L. Szajdak; M. Szczepa?ski; A. Bogacz
Nitrous Oxide (N2O) Production and Consumption after the Rewetting of Soils in Isolated Wetlands and Surrounding Pasture Upland
NASA Astrophysics Data System (ADS)
Nitrous oxide (N2O) is one of the most potent greenhouse gases and the highest N2O emissions from pasture lands are always found after the rewetting of soils which is caused by events, such as rainfall and irrigation. The N2O emission peaks are attributed to denitrification because of the anaerobic condition in the soil created by rewetting and the accumulated substrates (nitrate and labile organic carbon) during the drying period. Therefore, the N2O emissions after rewetting represent the difference between N2O production and N2O consumption by denitrification. Isolated wetlands, which have no surface water connectivity with nearby water bodies, are common feature in many pasture ecosystems. They act as water and nutrient storage systems at landscape scale and have distinct biogeochemical features with the surrounding pasture uplands. An isolated wetland located in cow-grazing pasture was selected as our study site. Study area has been stratified into three zones according to the vegetative communities and basin morphology: wetland center zone (Center), transient edge zone (Edge) and pasture upland zone (Upland). Six transects extended from the center of wetland to surrounding pasture upland have been set up, in which 3 transects have been fenced aiming for excluding the cow and calf grazing. Soil samples (0-10 cm) were collected in each zone along each transects. Soil biogeochemical properties were characterized on soil subsamples. A laboratory incubation study was performed to quantify N2O production and consumption rates of the rewetted soils. Our results indicated that the N2O production process normally had a biphasic pattern, with a low production rates in 6 h after rewetting, followed by a faster production rate between 6 h to the time when accumulated N2O began to be consumed. In the first 6 h after rewetting, soils from Edge had the highest production rates because of the relative higher nitrate content. Nitrous oxide production rates were significantly increased by the nitrate enrichment while glucose enrichment did not have significant effect on production rates. With nitrate enriched, soils from Center had the fastest N2O production rates. The incubation treatments with nitrate enriched and with both nitrate and glucose enriched had obvious second phase during N2O production process. Nitrous oxide accumulated during production process began to be consumed after the N2O concentration reaching the highest point (H point). Soils from Edge had the latest H point and highest N2O consumption rates. Glucose enriched treatment had earlier H point and faster N2O consumption while nitrate enriched treatment did not reach the H point during the incubation. In the treatment with both nitrate and glucose enriched, soils from Center had the earliest H point but the N2O consumption rates were not significantly different in soils from different zones.
Hu, J.; Inglett, K.; Inglett, P.; Clark, M.; Reddy, R.
pp iii Transport of lead and diesel fuel through a peat soil near Juneau, AK: a pilot study
NASA Astrophysics Data System (ADS)
A set of peat column experiments was used to determine the transport potential of lead (Pb) and diesel range organics (DRO) in palustrine slope wetlands near Juneau, AK. This project is important to southeast Alaskan communities because limited land resources are forcing development of regional wetlands. This study was instigated by concerns that proposed modifications to a nearby rifle range using DRO-contaminated soil posed a potential risk to an anadromous fish-bearing stream 250 m from the site. Three pairs of peat columns were extracted from the rifle range for analysis, one pair along and two pairs across the natural bedding planes of the soil. One column in each pair was spiked with Pb and DRO and the other was used as a control. Approximately 1-year worth of water (171 cm) was passed through each column and leachate was collected at regular intervals. The results showed that substantial DRO transport only occurred along the bedding planes. Leads was surprisingly mobile, both along and across the bedding planes with estimated soil-water partition coefficients several orders of magnitude lower than commonly published values, probably because the peat was heavily Pb-loaded by lead from bullets and because the peat's acidic, organic-rich environment enhanced Pb mobility. The chemical outflow behavior agreed with a simple macropore transport model. These results underscore the need for caution when developing regional wetlands.
Deiss, Julian; Byers, Carl; Clover, Dave; D'Amore, Dave; Love, Alan; Menzies, Malcolm A.; Powell, Jim; Todd Walter, M.
The influence of environmental factors on the CO2 emission from the surface of oligotrophic peat soils in West Siberia
NASA Astrophysics Data System (ADS)
The influence of various ecological factors (air and soil temperature, atmospheric pressure, level of peatland waters, and the content of CO2 in the atmosphere) on the emission of CO2 from the surface of a peat deposit of an oligotrophic peatland in the south taiga subzone of West Siberia was studied. On the basis of the investigations, day and seasonal dynamics of the emission of CO2 from the surface of the peat deposit were revealed. A detailed correlation analysis allowed us to describe the dependences of the CO2 flux from the surface of the peat deposit on the environmental parameters at various levels of averaging: hour, day, and month. It was shown that the temperature of the air and surface of the peat deposit have a reliable impact on the emission of CO2 on all time scales. The atmospheric pressure, as a factor that changes relatively slowly, influences the emission of CO2 weakly. The performed studies did not allow us to draw an unambiguous conclusion about the influence of the level of bog waters on the emission of CO2 from the surface of a peat deposit.
Golovatskaya, E. A.; Dyukarev, E. A.
A coupled molecular and field-based approach to study microbial controls on methane flux in upland soils
NASA Astrophysics Data System (ADS)
Predicting the responses of ecosystems to global change depends, in part, on understanding how soil microbial communities respond to external controls. To address this question, we are studying a relatively simple biogeochemical process: methane consumption in upland (i.e., well-drained, oxic) soils. In this process, methane molecules diffuse from the atmosphere into the soil, where they are consumed by methanotrophic bacteria. Because of the simplicity of this process, we have been able to develop a reaction-diffusion model that allows us to directly quantify methanotroph activity in situ from chamber-based measures of flux and diffusivity. Moreover, because the bacteria that oxidize methane come from a phylogenetically cohesive group, we can use molecular tools to quantify the size of methanotroph community and determine its species composition. Our application of these approaches on the Shortgrass Steppe Long-Term Ecological Research (SGS LTER) site in northeastern Colorado has revealed strong temporal and spatial patterns in methane uptake rates that are driven primarily by methanotroph activity, and very little by soil diffusivity. The temporal patterns in methanotroph activity follow seasonal changes in soil temperature and water content, with sharp reductions in activity associated with hot, dry conditions. Spatial patterns in activity follow differences in soil texture, with sandier soils expressing a greater range of methanotroph activity than clay soils. Although methanotroph abundances did not vary across soil types, the phylogenetic structure of the methanotroph communities differed significantly between clay and sand soil types. In addition, we found that the majority of methanotrophs were not the usual Type I or Type II, but instead were of the JR2 and JR3 types previously found only in a dry California grassland by Horz et al. AEM (2005). Together, these observations suggest that the species composition of methanotroph communities reflects changes in the physical environment. Given the potential for specialization among methanotrophs (e.g., for desiccation tolerance, or for methane affinity), we anticipate that the specific phylogenetic and physiological characteristics of methane oxidizer communities will modulate the responses of upland methane fluxes to climate change.
Judd, C. R.; von Fischer, J. C.; Fierer, N.
Vegetation Affects the Relative Abundances of Dominant Soil Bacterial Taxa and Soil Respiration Rates in an Upland Grassland Soil
Plant-derived organic matter inputs are thought to be a key driver of soil bacterial community composition and associated\\u000a soil processes. We sought to investigate the role of acid grassland vegetation on soil bacterial community structure by assessing\\u000a bacterial diversity in combination with other soil variables in temporally and spatially distinct samples taken from a field-based\\u000a plant removal experiment. Removal of
Bruce C. Thomson; Nick Ostle; Niall McNamara; Mark J. Bailey; Andrew S. Whiteley; Robert I. Griffiths
Coevolution of topography, soils, and vegetation in upland landscapes: Using cinder cones to elucidate ecohydrogeomorphic feedback mechanisms
NASA Astrophysics Data System (ADS)
The study of landscape evolution in upland environments requires analysis of complex interactions among topography, soil development, and vegetation cover under changing climatic conditions. Earth surface scientists lack a comprehensive understanding of these interactions in part due to their interdisciplinary nature, our limited ability to reconstruct the progression of landscape states through time, and the limited spatially-distributed data available for paleoclimate conditions. In this study, we investigate the interactions and feedbacks among topography, soil development, and vegetation cover in upland environments using remote sensing, geochemistry, and numerical modeling. We focus on quantifying the evolution of late Quaternary cinder cones within several volcanic fields, spanning a range of climates, as a function of age and microclimate, which varies with elevation and slope aspect. Cinder cones are excellent natural laboratories for studying the evolution of upland landscapes because they begin their evolution at a known time in the past (i.e. many cinder cones have been radiometrically dated) and because they often have unusually uniform initial conditions (i.e. they form close to the angle of repose and are comprised of well-sorted volcaniclastic parent materials). As such, cinder cones of different ages with similar size and climatic history can provide an approximate time progression illustrating how a dated hillslope has evolved over geologic time scales. Data suggest that rates of soil development and fluvial erosion are low on younger cones, which have surfaces consisting mostly of permeable cinders, but increase significantly after eolian deposits reduce the permeability of the cone surface. Further, data demonstrate that microclimatic differences between north and south facing slopes lead to systematic variations in biomass. Additionally, north-facing slopes on cinder cones are found to be steeper than corresponding south-facing slopes. The observed asymmetries in hillslope morphology are not present initially, but appear to develop over time as a result of differences in post-emplacement processes that may be attributed to aspect-induced microclimatic effects on long-term sediment transport rates. Results provide additional constraints on the timing and magnitude of feedback mechanisms among topography, biomass, and soil development as well as improve our understanding of cinder cone evolution within different climates.
McGuire, L.; Pelletier, J. D.; Rasmussen, C.
Carbon dioxide and methane fluxes from drained peat soils, southern Quebec
NASA Astrophysics Data System (ADS)
Fluxes of CO2 and CH4 were determined by a static chamber technique at eight drained swamp peatland sites, with crop and forest covers. Over a 6- month period (May - October, 1991), CH4fluxes ranged from -5 to 7 mg CH4 m-2 d-1 and were not correlated with either soil temperature or water table position. Integrated seasonal emissions were -0.40 to 0.04 g CH4 m-2 over 147 days; the sites with a forest or grass cover were a small sink of CH4 whereas the sites with horticultural crops showed no significant flux. Laboratory incubations showed that the highest CH4 consumption rates (3 to 9 ?g CH4 g-1 d-1) occurred in the least disturbed soils. The results, when compared with CH4 fluxes from nearby swamps which have been unaffected by drainage, suggest that drainage of temperate peatlands has reduced emissions of CH4 to the atmosphere by 0.6 - 1 � 1012g CH4 yr-1. CO2 fluxes ranged from 0 to 16 g CO2 m-2 d-1 and were correlated with the seasonal pattern of temperature in the upper part of the soil profile. Integrated seasonal fluxes for the sites in which root respiration was an unimportant contribution were 0.6 - 0.8 kg CO2 m-2 over 181 days. Aerobic laboratory incubations revealed CO2 production rates of 0.2 - 1.4 mg CO2 g-1 d-1, an average of 5 times the rate under anaerobic conditions. Using bulk density and loss-on-ignition data, we found that the seasonal CO2 fluxes translate into surface lowering of the peat of about 2 mm yr-1, whereas the commonly observed lowering in these cultivated peatlands is 20 mm yr-1. These data suggest that processes other than direct oxidation, such as shrinkage and aeolian erosion, are the major contributor to the surface lowering of the peat.
Glenn, Shannon; Heyes, Andrew; Moore, Tim
Effect of long-term paddy-upland yearly rotations on rice (Oryza sativa) yield, soil properties, and bacteria community diversity.
A 10-year-long field trial (between 2001 and 2010) was conducted to investigate the effect of paddy-upland rotation on rice yield, soil properties, and bacteria community diversity. Six types of paddy-upland crop rotations were evaluated: rice-fallow (control; CK), rice-rye grass (RR), rice-potato with rice straw mulches (RP), rice-rapeseed with straw incorporated into soil at flowering (ROF), rice-rapeseed incorporated in soil after harvest (ROM), and rice-Chinese milk vetch (RC). Analysis of terminal restriction fragment length polymorphism (T-RFLP) was used to determine microbial diversity among rotations. Rice yield increased for upland crops planted during the winter. RC had the highest average yield of 7.74 t/ha, followed by RR, RP, ROM, and ROF. Soil quality differences among rotations were found. RC and RP improved the soil mean weight diameter (MWD), which suggested that rice rotated with milk vetch and potato might improve the paddy soil structure. Improved total nitrogen (TN) and soil organic matter (SOM) were also found in RC and RP. The positive relationship between yield and TN/SOM might provide evidence for the effect of RC rotation on rice yield. A strong time dependency of soil bacterial community diversity was also found. PMID:22919301
Chen, Song; Zheng, Xi; Wang, Dangying; Chen, Liping; Xu, Chunmei; Zhang, Xiufu
Impact of drainage on wettability of fen peat-moorsh soils
High water retention in peat is attributed to structural voids (macro-pores) due to the partial degradation of the structure of peat-forming plants, and molecular absorption sites (micro-pores) associated with the formation of humic substances. Water retention by the heterogeneously-structured system in peat organic matter depends on the chemical structure of solid surfaces. These naturally wet solids, if dried sufficiently, lose
L. Szajdak; J. Szatylowicz; T. Brandyk
Hydrochemical heterogeneity in an upland catchment: further characterisation of the spatial, temporal and depth variations in soils, streams and groundwaters of the Plynlimon forested catchment, Wales
The heterogeneous nature of upland hard-rock catchments in terms of geology, geomorphology, superficial deposits, soil type and land use gives rise to a range of hydrochemical characteristics in stream waters. This is further complicated by the large and often rapid changes in stream flow typical of storm events. The sources of solutes and flow pathways in hard-rock catchments are still
P. Shand; A. H. Haria; C. Neal; K. J. Griffiths; D. C. Gooddy; A. J. Dixon; T. Hill; D. K. Buckley; J. E. Cunningham
Influence of oil and stratal water contamination on the ash composition of oligotrophic peat soils in the oil-production area (the Ob' region)
NASA Astrophysics Data System (ADS)
The mineral contamination of peat soils in the oil-production area differs considerably in the places of oil or stratal water spills. The time elapsed since the spill occurred is also an important factor of the changes in the chemical composition of the peat ash. The ash content rises drastically in the oil-contaminated peat, and the peat ash becomes rich in heavy metals (Mn, Ni, and Sr) and lanthanides (La and Ce). The content of K and Fe decreases, and that of P, S, Mg, Ca, Ni, and Pb increases with time at the site of old oil contamination. In the course of the self-rehabilitation of oil-contaminated peat, the content of Cl decreases more intensely than that of the heavier halogen Br. The ash content rises to a lesser extent in the peat contaminated with stratal water. The ash of the salinized peat is enriched in heavy alkaline-earth elements, i.e., Ba and Sr. Although most of the elements are leached with time, the content of Ba and Sr still remains 4-6 times higher than the background one even after long-term (more than 10 years) leaching. The concentrations of halogens rise considerably in the salinized peat, that of Cl in the peat ash decreases by 10 times, and the content of Ba virtually remains the same.
Vodyanitskii, Yu. N.; Avetov, N. A.; Savichev, A. T.; Trofimov, S. Ya.; Shishkonakova, E. A.
Function of peatland located on secondary transformed peat-moorsh soils on groundwater purification processes and the elution of soil organic matter
NASA Astrophysics Data System (ADS)
The investigation of peatland is used to show the water quality functioning with respect to different forms of nitrogen and carbon. The purification of ground water by the transect of 4.5 km long consisting organic soils (peat-moorsh soils) was estimated. This transect is located in the Agroecological Landscape Park in Turew, 40 km South-West of Poznan, West Polish Lowland. There is this transect along Wysko? ditch. pH, the contents of total and dissolved organic carbon, total nitrogen, N-NO3-, N-NH4+ was measured. Additionally C/N factors of peats were estimated. The investigation has shown the impact of the peatland located on the secondary transformed peat - moorsh soils on the lowering of total nitrogen, ammonium, and nitrates as well as total and dissolved organic carbon in ground water. Peat-moorsh soils were described and classified according to Polish hydrogenic soil classification and World Reference Base Soil Notation. There are these investigated points along to Wyskoc ditch. Two times a month during entire vegetation season the following material was taken from four chosen sites marked as Zbechy, Bridge, Shelterbelt and Hirudo: samples of peat, from the depth of 0-20 cm, samples of water from the ditch, samples of ground water from wells established for this investigation. Samples of peat-moorsh soils were collected at the depth 0-20 cm. Soils were sampled two times a month from 10 sites of each site. Samples were air dried and crushed to pass a 1 mm-mesh sieve. These 10 sub-samples were mixed for the reason of preparing a "mean sample", which used for the determination of pH (in 1M KCl), dissolved organic carbon (DOC), total organic carbon (TOC), total nitrogen (Ntotal), and N-NO3- as well as N-NH4+. In water from Wysko? ditch pH, Ntotal, N-NO3-, N-NH4+, DTC (dissolved total carbon) and DOC (dissolved organic carbon) was measured. Ground water samples were collected from four wells established for this investigation. The water was filtered by the middle velocity separation and pH, N-total, N-NO3-, N-NH4+, DTC (dissolved total carbon) and DOC (dissolved organic carbon) ware measured. Peatland located on the secondary transformed peat - moorsh soils has revealed the lowering in ground water: nitrates 38.5%, N-organic 10%, N-total 24.5%, ammonium 38.7%, dissolved total carbon 33.1%, dissolved total inorganic carbon 10%, and dissolved organic carbon 57.5%. The dissolution of soil organic matter from peat-moorsh soils in broad range of pH and ionic strength was investigated. The rates of the reaction were calculated from the kinetics of first order reaction model. The investigations have shown the impact of the properties of secondary transformed peat-moorsh soils on the rates of the dissolution of organic matter.
Szczepa?ski, M.; Szajdak, L.; Bogacz, A.
Function of peatland located on secondary transformed peat-moorsh soils on groundwater purification processes and the elution of soil organic matter
The investigation of peatland is used to show the water quality functioning with respect to different forms of nitrogen and carbon. The purification of ground water by the transect of 4.5 km long consisting organic soils (peat-moorsh soils) was estimated. This transect is located in the Agroecological Landscape Park in Turew, 40 km South-West of Poznan, West Polish Lowland. There
M. Szczepanski; L. Szajdak; A. Bogacz
EPR investigations of structure of humic acids from compost, soil, peat and soft brown coal upon oxidation and metal uptake
Free radical concentration and theirg-values in humic acids (HA) isolated from various sources were studied by quantitative EPR technique. EPR data for HA formed\\u000a during composting and natural humification processes occurring in soil, peat and brown coal are given. In more detail the\\u000a EPR data were analyzed for brown coal HA under carbonization, air oxidation (150�C) as well as metal
A. Jezierskit; F. Czechowski; M. Jerzykiewicz; J. Drozd
Hydrological, fine sediment and water colour response of managed upland wetlands
NASA Astrophysics Data System (ADS)
Many upland peats in the UK have been subject to artificial drainage mainly involving the cutting of ditches. The aim was to drain the ground for grazing and game but there is little evidence of any improvement for these purposes. Instead moorland ditching has been blamed for causing a wide range of problems including: increased flooding, decreased low flows, increased water discolouration (or loss of dissolved organic carbon), accelerated erosion and associated destruction of in-stream and wetland habitats and the removal of the terrestrial carbon store. However, there is conflicting evidence for the hydrological response of peatlands to drainage and little is known about the exact nature of the hydrological, fine sediment and water colour production, transport and storage processes involved. This poster presents the research outline for a new three year project that aims to examine the effects of wetland management (including ditch blocking and natural revegetation) on the production of runoff, fine sediment and water discolouration in upland blanket peats. Detailed process-based measurements will be combined with simultaneously collected yield data measured at a range of spatial and temporal scales. For example, monitoring of catchment outlets will be combined with measurement of hillslope flow processes including overland flow, subsurface pipeflow, and soil pore matrix and macropore flows. It is envisaged that the project will be extended to deal with the science of a detailed process-based carbon budget for managed upland peats.
Holden, J.
Exploring the potential of the permanganate oxidation method as a tool to monitor soil quality in agricultural upland systems of Southeast Asia
NASA Astrophysics Data System (ADS)
The transition to more intensified upland systems is having an impact on the soil quality, defined as the ability of a soil to both provide and maintain essential services to an ecosystem. As many tropical upland soils are inherently low in quality, it is essential that impacts be monitored. Soil quality is assessed by using a combination of parameters that serve as indicators and cover the soil chemical, biological and physical properties. An ideal indicator should be sensitive to changes in the environment and management practices and should be widely accessible, meaning low resource requirement (i.e. time and equipment). Total organic carbon (TOC) content is a commonly used indicator of soil quality as it is linked to many soil functions and processes; however analysis is costly and requires access to advanced instrumental facilities, rendering it unsuited for many developing countries. An alternative indicator is the soil fraction dominated by easily decomposable carbon; this may be measured by treating soil samples with 0.2M potassium permanganate (KMnO4), an oxidizing agent which is thought to mimic the enzymes released by the soil microbial community. The advantage of this method is that it is accessible: it is fast, requires little resource input and is field appropriate. There is no consensus however as to which soil carbon fraction the method targets. Furthermore Skjemstad et al. (2006) has indicated that KMnO4 may oxidise charcoal, a component of the non-labile carbon pool; this has implications for the suitability of the method when used for soils of shifting cultivation systems. The purpose of this study was to investigate the potential of permanganate oxidizable carbon (Pox C) as a reliable indicator of soil quality in agricultural upland systems in Northern Lao PDR. Focus was placed on the relations between Pox C and other soil quality parameters (bulk density, pH, CEC, TOC, total N, exchangeable K, plant available P) and upland rice yields. The ability of KMnO4 to oxidize charcoal was also a focus however, as the study is still in its initial stage, no results can be discussed. Volumetric soil samples (at the surface and at 10 cm) and upland rice yield measurements were taken from three fields with three plots that were previously left fallow for five years (n=9; soil n=81). Pearson's Correlation test and Stepwise Regression analysis was done using SPSS v 16.0 for Windows. Results show that Pox C is significantly correlated to the measured soil parameters in a manner similar to TOC. Both are positively correlated to the soil nutrients: Total N %, P Avail and K Exch; Pox C however had a stronger correlation to K Exch than TOC. This affirms the important role of Pox C in soil processes in the biological, chemical and physical spheres. Furthermore, the regression analysis identified Pox C as an influencing factor for the variations seen in upland rice yields. It is concluded that Pox C is a suitable indicator for soil quality and may be useful in monitoring changes in the soil quality of agricultural upland systems.
Hepp, Catherine M.; Bruun, Thilde Bech; de Neergaard, Andreas
Uncertainties in peat volume and soil carbon estimated using ground penetrating radar and probing
We evaluate the uncertainty in calculations of peat basin volume using high-resolution data . to resolve the three-dimensional structure of a peat basin using both direct (push probes) and indirect geophysical (ground penetrating radar) measurements. We compared volumetric estimates from both approaches with values from literature. We identified subsurface features that can introduce uncertainties into direct peat thickness measurements including the presence of woody peat and soft clay or gyttja. We demonstrate that a simple geophysical technique that is easily scalable to larger peatlands can be used to rapidly and cost effectively obtain more accurate and less uncertain estimates of peat basin volumes critical to improving understanding of the total terrestrial carbon pool in peatlands.
Parsekian, Andrew D. [Rutgers University; Slater, Lee [Rutgers University; Ntarlagiannis, Dimitrios [Rutgers University; Nolan, James [Rutgers University; Sebestyen, Stephen D [USDA Forest Service, Grand Rapids, MN; Kolka, Randall K [USDA Forest Service, Grand Rapids, MN; Hanson, Paul J [ORNL
Biogeochemistry of carbon and related major and trace elements in peat bog soils of the middle taiga of Western Siberia (Russia).
NASA Astrophysics Data System (ADS)
Global climate changes impact the status of wetland ecosystems shifting the balances of the carbon, macro-, and microelements cycles. This study aims to establish the features of accumulation and distribution of major- and trace elements in the organic layer of peat bog soils, belonging to different ecosystems of the oligotrophic bog complex located in the middle taiga of Western Siberia (Khanty-Mansiysk region, Russia). Key areas which are selected for this study include the following bog conjugate elementary ecosystems: higher ryam, lower ryam, ridge-hollow complex, and oligotrophic poor fen as characterized previously [1]. We have sampled various peat types along the entire length of the soil column (every 10 cm down to 3 m). Peat samples were analyzed for a wide range of macro- and microelements using an ICP-MS technique following full acid digestion in a microwave oven. These measurements allowed quantitative estimates of major- and trace elements in the peat deposits within the whole bog complex and individual elementary landscapes. Based on the data obtained, the lateral and radial geochemical structures of the bog landscapes were determined and clarified for the first time for middle taiga of the West Siberian plain. The similar regime of mineral nutrition during the complete bog landscape formation was detected for the peat deposits based on the measurements of some major- and trace elements (Ca, Fe, Mg, etc.). The vertical distribution of some major and some trace elements along the profile of peat column is rather uniform with relatively strong increase in the bottom organic layers. This strongly suggests the similarity of the processes of element accumulation in the peat and relatively weak post depositional redistribution of elements within the peat soil profile. Overall, obtained corroborate the existing view on chemical composition of peats being determined by botanical peat's components (which forms this peat deposit), atmospheric precipitation, position of ecosystems in the landscape (lateral migration) and types of bedrocks [2]. The results allow better understanding of the coupling between biogeochemical cycles of carbon and major and trace elements in peat soils in order to predict the future changes in both concentrations and stocks of chemical elements in the Western Siberia peat bog systems under climate warming.
Stepanova, V. A.; Mironycheva-Tokareva, N. P.; Pokrovsky, O. S.
The effect of anaerobicity and temperature on N2 and N2O dynamics in forestry drained boreal peat soils
NASA Astrophysics Data System (ADS)
Molecular nitrogen (N2) is the dominant end-product of microbial denitrification in soils; however, due to difficulties in measuring N2 exchange, the emissions of N2 from terrestrial ecosystems are largely unknown. In boreal peatland soils, the combination of high soil carbon and nitrogen contents, fluctuating water-table and high decomposition activity of the peat make these soils potentially large emitters of N gases via microbial denitrification processes. This motivated us to quantify the N2 and nitrous oxide (N2O) losses from boreal drained peat soils varying in fertility status. Soil samples were collected from two drained peatland forests: a nutrient-rich (Lettosuo) and a nutrient-poor (Kalevansuo) site, both located in the boreal zone of Southern Finland. N2 and N2O emissions from intact soil cores were measured using the helium gas flow soil core method. Two incubation experiments were conducted focusing on the effects of anaerobicity and temperature on N2 and N2O dynamics of the top-soil (experiment 1), and the effect of anaerobicity on N2 and N2O dynamics in the peat profile (experiment 2). Soil samples in experiment 1 were incubated under 1) cold (2� C) aerobic (20% O2, 80% He), 2) cold (2� C) anaerobic (0% O2, 100% He), and 3) warm (15� C) anaerobic conditions, while those in experiment 2 were incubated under 1) warm aerobic and 2) warm anaerobic conditions. Dynamics of N2 and N2O fluxes for each incubation condition were followed until fluxes stabilized. In general, the N2 and N2O fluxes in the nutrient-rich Lettosuo peat were higher and more variable than those at the nutrient-poor Kalevansuo peat. In the nutrient-rich Lettosuo, both the N2 and N2O emissions increased dramatically after the change from aerobic to anaerobic conditions, and again after the temperature rise from 2 to 15� C. This latter peak in emissions was followed by a switch from N2O production to N2O consumption and a simultaneous sharp decrease in N2 emissions. Although, the N2 and N2O fluxes in the nutrient-poor Kalevansuo peat were small and close to the detection limit, the change from the aerobic to anaerobic conditions induced significant N2O uptake, which was even more pronounced under warm anaerobic conditions. At the nutrient-rich Lettosuo, all the three soil layers (10-15 cm, 15-20 cm, 40-45 cm) were equally active in N2 and N2O production or consumption. Overall, N2 emissions from both sites always exceeded N2O emissions, and when the fluxes were positive and above their detection limits, the ratio of N2:N2O ranged between 1 and 180.
Pihlatie, Mari; Hongisto, Isto; Dannenmann, Michael; Georg, Willibald; Rainer, Gasche; Klaus, Butterbach-Bahl
Soil evolution and climate dynamics in dry steppes of the Privolzhskaya Upland during the last 3500 years
NASA Astrophysics Data System (ADS)
The investigation of paleosols of different ages buried under archaeological monuments of the Bronze (16th-15th centuries BC), Early Iron (2nd-3rd centuries AD), and Medieval (14th century AD) ages demonstrated that the evolution of chestnut soils and solonetzes in the dry steppes of the southern part of the Privolzhskaya Upland during the past 3500 years manifested itself at the level of the genus and species characteristics of the soils, such as the degree of the solonetzicity, the humus content, and the content and composition of the soluble salts. The revealed regularities of the variations of the morphological, chemical, and microbiological soil properties in time allowed reconstructing the secular dynamics of the climatic humidity in the region. It was found that the humidization of the climate with a decrease in the degree of the climatic continentality took place in the middle of the second millennium BC. The Late Sarmatian Time (2nd-3rd centuries AD) was characterized by arid climatic conditions, whereas the Golden Horde time (13th-14th centuries AD) was marked by the general humidization of the climate. A gradual aridization of the climate began in the second half of the 14th century and continued in the 15th century AD.
Demkin, V. A.; Demkina, T. S.; Khomutova, T. E.; El'tsov, M. V.
Effects of soils and grazing on breeding birds of uncultivated upland grasslands of the Northern Great Plains
The principal use of uncultivated upland grasslands in the northern Great Plains is for livestock production. However, on lands set aside for wildlife or for scientific or recreational use, grazing by livestock may be used as a management measure to enhance populations of game species or to create conditions that increase the diversity of plant or animal species. To determine the effects of grazing on the avifauna of various types of Great Plains grasslands, we conducted bird censuses and plant surveys during 1974-78 on 615 plots of lightly, moderately, or heavily grazed native rangeland.Numbers of horned lark (Eremophila alpestris), western meadowlark (Sturnella neglecta), lark bunting (Calamospiza melanocorys), and chestnut-collared longspur (Calcarius ornatus) accounted for 65-75% of the total bird population, regardless of grazing intensity. For the entire area sampled (600,000 km2), horned lark, western meadowlark, and chestnut-collared longspur were the dominant birds. Major differences in composition of the dominant species and species richness occurred among the major soils. Increased mean annual soil temperature seemingly had a greater negative influence on avian species richness than did decreased soil moisture or organic matter content. Differences in total bird density were not significant among soils and among grazing intensities within most soils. For the area as a whole, light or moderate grazing resulted in increased species richness. Of the 29 species studied, 2 responded significantly to grazing for the area as a whole and 6 others to grazing on the soil in which peak densities occurred. Response of several other species to grazing effects evidently varied among strata.A list of plants with mean cover values of more than 1% in any of the 18 combinations of soils and grazing intensities contained less than 25 species, attesting to the relative simplicity of the grassland vegetation in the northern Great Plains. Agropyron spp. and Bouteloua gracilis were the dominant plants that provided greater than average cover on the best habitat for the most bird species. Optimum habitat for each bird species is given in terms of grazing, soils, and dominant plant species. Increased soil temperature probably had a negative effect on plant species richness, especially among soils with a high organic matter content that supported perennial grasses and other mesophytes.
Kantrud, H. A.; Kologiski, R. L.
Catchment disturbance and stream metabolism: Patterns in ecosystem respiration and gross primary production along a gradient of upland soil and vegetation disturbance
Catchment characteristics determine the inputs of sediments and nutrients to streams. As a result, natural or anthropogenic disturbance of upland soil and vegetation can affect instream processes. The Fort Benning Military Installation (near Columbus, Georgia) exhibits a wide range of upland disturbance levels because of spatial variability in the intensity of military training. This gradient of disturbance was used to investigate the effect of upland soil and vegetation disturbance on rates of stream metabolism (ecosystem respiration rate [ER] and gross primary production rate [GPP]). Stream metabolism was measured using an open-system, single-station approach. All streams were net heterotrophic during all seasons. ER was highest in winter and spring and lowest in summer and autumn. ER was negatively correlated with catchment disturbance level in winter, spring, and summer, but not in autumn. ER was positively correlated with abundance of coarse woody debris, but not significantly related to % benthic organic matter. GPP was low in all streams and generally not significantly correlated with disturbance level. Our results suggest that the generally intact riparian zones of these streams were not sufficient to protect them from the effect of upland disturbance, and they emphasize the role of the entire catchment in determining stream structure and function. ?? 2005 by The North American Benthological Society.
Houser, J. N.; Mulholland, P. J.; Maloney, K. O.
[Mercury in the peat bog ecosystem in Xiaoxing'an mountain in China].
The mercury content in Tangwang River forested catchment of Xiaoxingan Mountain in Northeast of China was studied. The average total mercury (THg) in peat profile ranged from 65.8 ng/g to 186.6 ng/g with the highest in the depth of 5-10 m. THg in the peat surface was higher than the background in Heilongjiang province, and higher than the Florida Evergrade in America and Birkeness in Sweden. MeHg ranged from 0.16 ng/g to 1.86 ng/g with the highest in the depth of 10-15 cm. MeHg was 0.2-1.2% of THg. They all decreased with the depth. There was no strong significant correlation between the THg and MeHg (p = 0.05, r = 0.28). THg in upland mor layer of soil (0-20 cm) was comparable to the peat surface (0-20 cm), but in deeper layer THg in peat was much higher than the forested mineral soil. THg in the peat bog increased, but MeHg decreased after it was drained 30 years ago. THg in plant was different, THg in the moss (119 ng/g, n = 12) was much larger than the herbage, the arbor and the shrub. The peat bog was contaminated by mercury coming from the atmosphere to some degree. PMID:12371089
Liu, Ruhai; Wang, Qichao; L�, Xianguo; Ma, Zhuangwei; Fang, Fengman
Simulating the effect of land use and climate change on upland soil carbon stock of Wales using ECOSSE
NASA Astrophysics Data System (ADS)
Within Wales soils hold between 400-500 MtC, over half of this carbon is stored in organic and organo-mineral soil which cover less than 20% of the land area of Wales. It has been predicted that climate change will increasingly have an impact on the C stock of soils in Wales. Higher temperatures will increase the rate of decomposition of organic matter, leading to increased C losses. However increased net primary production (NPP), leading to increased inputs of organic matter, may offset this. Land use plays a major role in determining the level of soil C and the direction of change in status (soil as a source or sink). We present here an assessment of the effect of land use change and climate change on the upland soil carbon stock of Wales in 3 different catchments i.e. Migneint, Plynlimon and Pontbren using a process-based model of soil carbon and nitrogen dynamics, ECOSSE. The uncertainties introduced in the simulations by using only the data available at national scale are determined. The ECOSSE model (1,2) has been developed to simulate greenhouse gas emissions from both organic and mineral soils. ECOSSE was derived from RothC (3) and SUNDIAL (4,5) and predicts the impacts of changes in land use and climate on emissions and soil carbon stock. Simulated changes in soil C are dependent on the type of land use change, the soil type where the land use change is occurring, and the C content of soil under the initial and final land uses. At Migneint and Plynlimon, the major part of the losses occurs due to the conversion of semi-natural land to grassland. Reducing the land use change from semi-natural to grassland is the main measure needed to mitigate losses of soil C. At Pontbren, the model predicts a net gain in soil C with the predicted land use change, so there is no need to mitigate. Simulations of future changes in soil C to 2050 showed very small changes in soil C due to climate compared to changes due to land use change. At the selected catchments, changes in soil C due to the impacts of land use change were predicted to be up to 1000 times greater than the changes predicted due to climate change. This is encouraging, as it illustrates the great potential for C losses due to climate change to be mitigated by changing land use. 1. Smith P, et al 2007. SEERAD Report. ISBN 978 0 7559 1498 2. 166pp. 2. Smith JU, et al 2009. RERAD Report. In press. 3. Coleman K & Jenkinson DS 1996. In: Evaluation of Soil Organic Matter Models Using Existing, Long-Term Datasets, NATO ASI Series I, Vol.38 (eds Powlson DS, Smith P, Smith JU), pp. 237-246. Springer-Verlag, Heidelberg, Germany. 4. Bradbury NJ, et al 1993. Journal of Agricultural Science, Cambridge 121, 363-379. 5. Smith JU, et al 1996. Agronomy Journal 88, 38-42.
Rani Nayak, Dali; Gottschalk, Pia; Evans, Chris; Smith, Pete; Smith, Jo
Does elevated nitrogen deposition or ecosystem recovery from acidification drive increased dissolved organic carbon loss from upland soil? A review of evidence from field nitrogen addition experiments
Dissolved organic carbon (DOC) concentrations have risen in upland waters across large areas of Europe and North America.\\u000a Two proposed drivers of these increases are (1) deposition of atmospheric pollutant nitrogen (N) with consequent effects on\\u000a plant and decomposer carbon dynamics, and (2) soil recovery from acidification associated with decreasing sulphur deposition.\\u000a Examination of 12 European and North American field
Chris D. Evans; Christine L. Goodale; Simon J. M. Caporn; Nancy B. Dise; Bridget A. Emmett; Ivan J. Fernandez; Chris D. Field; Stuart E. G. Findlay; Gary M. Lovett; Henning Meesenburg; Filip Moldan; Lucy J. Sheppard
Acidification of soil-water in low base-saturated sand soils of the superior uplands under acid and normal precipitation.
Lakes and streams are acidified by direct precipitation and water channeled through nearby soils, but water in low base-saturation soils can produce highly acidic percolate after prolonged contact and subsequent degassing in surface waters. Theories advanced by Reuss (1983), Reuss and Johnson (1985), and Seip and Rustad (1984) suggest that soils with less than 15% base saturation are susceptible to soil-water pH depression of up to 0.4 unit, which is sufficient to cause negative alkalinity in soil solutions. High concentrations of mobile anions (notably sulfate) are responsible for the negative alkalinity and these solutions on CO2 degassing in surface waters can retain acidities equivalent to a pH value of 5.0 or less. This mechanism purports to explain why some lakes acidify when they are surrounded by acid soils and cation leaching is not required.Ambient precipitation set to pH 5.4 and pH 4.2 was applied to columns of low base-saturated, sand, soils, starting in 1985. The columns (15 cm diameter and 150 cm long) were collected from soils with base saturations falling into one of three groups (0-10, 10-20, and 20-40%) from national forests in the Superior Uplands area (includes Boundary Waters Canoe Area, Rainbow Lakes, Sylvania, Moquah Barrens, and other Wilderness and Natural areas). The soils were Haplorthods and Udipsamments mainly from outwash plains.The soil columns were instrumented and reburied around a subterranean structure used to collect leachate water and to maintain natural temperature, air, and light conditions. Three humus treatments were applied to soil column (none, northern hardwood, and jack pine) to measure the effect of natural acidification compared to acidification by acid precipitation. The cores were treated with precipitation buffered to pH 5.4 to simulate natural rain and pH 4.2 to simulate acid rain.Columns were treated in 1985 and 1986 with approximately 200 cm of buffered precipitation each year over the frost-free season. Data is now being analyzed for the 1986 treatment year. In leachate collected from the upper horizons of the soil colums, there was a significant difference in pH, alkalinity, nitrate, and sulfate concentrations between the pH 5.4 and pH 4.2 precipitation treatments. This difference, however, disappears at the bottom of the columns. This could be partly due to exchange reactions in the B horizon. The pH and alkalinities are higher in bottom leachate. Chloride and nitrate also increased significantly due mainly to concentrating effects. Even with a pickup of sulfate in the B horizon, sulfate adsorption decreased bottom leachate concentrations well below surface values.Alkalinity, pH, and sulfate concentration in the leachate decreased over the treatment season. Nitrate concentration increased by 4- to 5-fold over the season. Leachate from the bottom of the soil columns is becoming more acidic with time with negative alkalinities appearing more frequently in columns with soils of lower base saturation. There were some significant alkalinity differences due to humus treatments; however, these were not consistent between pH treatments, and need further study. This research will eventually answer whether soil processes can be important to the acidification of lakes in poor, sandy, outwash plains of the Superior Uplands, and whether a reduction in acid sulfate deposition will reverse the percolate alkalinity from negative to positive. PMID:24249061
Harris, A R
Is soil degradation unrelated to deforestation? Examining soil parameters of land use systems in upland Central Sulawesi, Indonesia
It is generally assumed that declining soil fertility during cultivation forces farmers to clear forest. We wanted to test this for a rainforest margin area in Central Sulawesi, Indonesia. We compared soil characteristics in different land-use systems and after different length of cultivation. 66 sites with four major land-use systems (maize, agroforestry, forest fallow and natural forest) were sampled. Soils
Georg Dechert; Edzo Veldkamp; Iswandi Anas
Influence of Chemical Properties on Soil Carbon Storage of a Tropical Peat Swamp Forest
Problem statement: It is important to investigate the seriousness of degradation of peat swamp forest caused by skidding system in terms of its function as a carbon sink. In this study, we formulated assumptions that conditions of our resea rch site before the introduction of skidding system were in their natural states, thus that changes mea sured are clearly caused
Anton Eko Satrio; Seca Gandaseca; Osumanu Haruna Ahmed; Nik Muhamad Ab. Majid
Soil archives of the Westerkoggepolder (West Friesland, North-Holland); relicts of a peat cover that disappeared by historical land management.
NASA Astrophysics Data System (ADS)
In a large part of the Westerkoggepolder the surficial Holocene peat deposit of several meters thickness disappeared in historical time due to historical land use. Drainage of the original histosols and crop production promoted bio-oxidation of the organic matrix and consequently lowering of the land surface. Relicts of this peat occur below old farm houses. In many soil sections a thin organic horizon is present in the stratigraphical position between older and younger clay deposits. This horizon can easily be interpreted as a relict of a peat deposit, truncated by marine transgression. In the Westerkoggepolder some lots show a typical micro relief. This is the result of local historical small scale peat digging and relief inversion afterwards. Land owners, responsible for this form of peat digging were obliged to fill the excavated trenches with material to restore the land surface. They used clay that they dredged up in the existing drain channels. That is also the reason that in the present landscape some of these channels are relatively broad. Due to relief inversion, these trenches are now visible as small ridges in the landscape. In the flat part of the landscape, a surficial clay layer covers the remnants of the excavated trenches. Pollen analysis indicates that the surficial clay layer must be interpreted as an eluvial alteration horizon. This surficial clay cover is a relict of the former peat bog.
van Mourik, Jan; Ligtendag, Wim
Sorption of selected organic compounds from water to a peat soil and its humic-acid and humin fractions: Potential sources of the sorption nonlinearity
The sorption isotherms of ethylene dibromide (EDB), diuron (DUN), and 3,5-dichlorophenol (DCP) from water on the humic acid and humin fractions of a peat soil and on the humic-acid of a muck soil have been measured. The data were compared with those of the solutes with the whole peat from which the humic-acid (HA) and humin (HM) fractions were derived and on which the sorption of the solutes exhibited varying extents of nonlinear capacities at low relative concentrations (C(e)/S(w)). The HA fraction as prepared by the density-fractionated method is relatively pure and presumably free of high- surface-area carbonaceous material (HSACM) that is considered to be responsible for the observed nonlinear sorption for nonpolar solutes (e.g., EDB) on the peat; conversely, the base-insoluble HM fraction as prepared is presumed to be enriched with HSACM, as manifested by the greatly higher BET- (N2) surface area than that of the whole peat. The sorption of EDB on HA exhibits no visible nonlinear effect, whereas the sorption on HM shows an enhanced nonlinearity over that on the whole peat. The sorption of polar DUN and DCP on HA and HM display nonlinear effects comparable with those on the whole peat; the effects are much more significant than those with nonpolar EDB. These results conform to the hypothesis that adsorption onto a small amount of strongly adsorbing HSACM is largely responsible for the nonlinear sorption of nonpolar solutes on soils and that additional specific interactions with the active groups of soil organic matter are responsible for the generally higher nonlinear sorption of the polar solutes.
Chiou, C. T.; Kile, D. E.; Rutherford, D. W.; Sheng, G.; Boyd, S. A.
Scale effect of climate on soil organic carbon in the Uplands of Northeast China
Purpose��Climate factors, considered significant factors in regulating soil organic carbon (SOC), are not equally important at all\\u000a spatial scales. However, the scale which provides the optimal relationship between climate and SOC and how that relationship\\u000a varies at multiple scales are still unclear. Thus, it is crucial to study the relationship between climate factors and SOC\\u000a at multiple scales when attempting
Dan-Dan Wang; Xue-Zheng Shi; Hong-Jie Wang; David C. Weindorf; Dong-Sheng Yu; Wei-Xia Sun; Hong-Yan Ren; Yong-Cun Zhao
NASA Technical Reports Server (NTRS)
Humics, Inc. already had patented their process for separating wet peat into components and processing it when they consulted NERAC regarding possible applications. The NERAC search revealed numerous uses for humic acid extracted from peat. The product improves seed germination, stimulates root development, and improves crop yields. There are also potential applications in sewage disposal and horticultural peat, etc.
Time-lapse ground penetrating radar (GPR) measurements for exploring biogenic gas distribution and releases from peat soils in the Florida Everglades
NASA Astrophysics Data System (ADS)
Peat soils are known to release significant amounts of methane (CH4) and carbon dioxide (CO2) to the atmosphere. However, uncertainties still remain regarding the spatio-temporal distribution of gas accumulations and the triggering mechanisms of gas releasing events. Furthermore, most peatland gas dynamics research has historically been focused on high latitude peatlands, while recent works have suggested that gas production rates from low-latitude peat soils may be higher than those from colder climates. Ground penetrating radar (GPR) is a geophysical tool that has successfully been used in the past to non-invasively investigate the release of biogenic gasses from peat soils. This study is conducted in the Loxahatchee Impoundment Landscape Assessment (LILA), a hydrologically controlled, landscape scale (30 HA) model of the Florida Everglades. Here, temporal and spatial heterogeneity of gas releases from peat soil at the plot scale (<100 m2) are shown using a time series of three-dimensional (3D) GPR measurements. GPR data are supported by direct gas flux measurements using flux chambers combined with time-lapse photography, and surface deformation measurements using terrestrial LiDAR scanning and differential leveling.
Wright, W. J.; Comas, X.; Berber, M.
Metal and arsenic impacts to soils, vegetation communities and wildlife habitat in southwest Montana uplands contaminated by smelter emissions. 1: Field evaluation
Concentrations of arsenic and metals in soils surrounding a smelter in southwest Montana were correlated with vegetative community structure and composition and wildlife habitat quality. Soils in the uplands surrounding the smelter were highly enriched with arsenic and metals. Concentrations of these analytes decreased with distance from the smelter and with soil depth, suggesting that the smelter is the source of the enrichment. In enriched areas, marked modifications to the native vegetation community structure and composition were observed. These included replacement of evergreen forest with bare unvegetated ground; species impoverishment and increased dominance by weed species in grasslands; and reductions in the vertical complexity of the habitat. Significant negative correlations existed between soil arsenic and metals concentrations and the extent of vegetative cover and the vertical diversity of plant communities. Loss of vegetative cover in the affected areas has been accompanied by reductions in their capacity to support indigenous wildlife populations.
Galbraith, H.; LeJeune, K.; Lipton, J. [Hagler Bailly Consulting, Inc., Boulder, CO (United States)
Methane and carbon dioxide exchange potentials of peat soils in aerobic and anaerobic laboratory incubations
Samples (140) of peat collected from bogs, fens and swamps in boreal, subarctic and temperate regions of Canada were incubated at 15 or 20�C for 5 d in the laboratory to determine potential rates of CO2 and CH4 exchange under aerobic and anaerobic conditions. Rates of CO2 production ranged between 0.07 and 5.0 mg g?1 d?1, with means of 1.0
T. R. Moore; M. Dalva
Effects of atmospheric nitrogen deposition on ericoid mycorrhizal infection of Calluna vulgaris growing in peat soils
In a greenhouse experiment, Calluna moorland peat microcosms from five sites along a pollution gradient (2�10 kg N ha?1 year?1 in wet deposition) have been subjected over 18 months to uniform amounts of simulated polluted precipitation with compositions appropriate to each microcosm sampling site, thus eliminating temperature and precipitation amount as variables. Maximum mycorrhizal infection (80.5% � 3.11) occurred at
Laila Yesmin; Shimna M. Gammack; Malcolm S. Cresser
The effects of ecological restoration, on soil-pore water quality and DOC concentrations, on a British upland blanket bog.
NASA Astrophysics Data System (ADS)
Polluted by past atmospheric deposition, eroded and burnt, the Bleaklow plateau (Peak district National Park, UK) has long been degraded. Peatlands are important carbon reservoirs and can act as sources or sinks of carbon. Dissolved organic carbon (DOC) is carbon lost from peatlands via the fluvial pathway and as the major component of water colour it is costly to remove during water treatment processes. The Bleaklow Summit peatlands, were subjected to a large wildfire in 2003 devegetating 5.5km2. This fire prompted stakeholders to initiate a large-scale programme of restoration of the plateau. This study considered restoration techniques across four sites: all four sites were seeded with lawn grass, limed and fertilised; to raise the pH and allow establishment of vegetation. In addition to these interventions, one site also had a mulch of Calluna vulgaris applied to the surface to allow soil stabilisation and promote vegetation establishment and another site had biodegradable geojute textile mesh installed, to stabilize the steep gully surfaces. Another site had a gully block installed, to reduce peat desiccation and erosion. This study will compare the four restored sites to two types of comparators: bare soil sites where no restoration was undertaken and a naturally vegetated site unaffected by the 2003 wildfire. Each site had six replicate dipwells, installed in two groups of three. The depth to the water table was monitored and soil water samples collected for analysis, monthly for 5 years, from Nov 2006 - Jan 2012. No significant difference in DOC concentration was found between control and treated sites. There was, however, a significant difference in DOC composition between sites and over the 5 year period of monitoring. UV-vis absorbance of the samples is used to quantify the fulvic to humic components of DOC. The vegetated control was not significantly different to the bare sites; however the vegetated control had a significantly greater humic fraction of than the seeded, limed and fertilised only site, as well as the seeded, limed, C. vulgaris mulched site. This is possibly related to vegetation and litter layer establishment. A suite of water quality data (conductivity, pH and cation data) are now being analysed in combination with DOC to increase understanding of the relationship between bare site re-vegetation and DOC compositional change.
Qassim, Suzane; Dixon, Simon; Rowson, James; Worrall, Fred; Evans, Martin
Geobotanical indication of the trophic status and moistening of reclaimed oil-polluted oligotrophic peat soils in the middle reaches of the Ob River
Changes in the trophic status and moistening of oligotrophic peat soils subjected to oil pollution and subsequent reclamation in the middle reaches of the Ob River are discussed. The main plants-indicators are listed. Numerical estimates of the trophic level and the degree of moistening of natural and transformed soils of the widespread bog biogeocenoses---pine-dwarf-shrub-sphagnum, complex ridged-hollow, and cotton grass-sphagnum bogs---are
N. A. Avetov
Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes
NASA Astrophysics Data System (ADS)
The diversity of ecosystems across boreal landscapes, successional changes after disturbance and complicated permafrost histories, present enormous challenges for assessing how vegetation, water and soil carbon may respond to climate change in boreal regions. To address this complexity, we used a chronosequence approach to assess changes in vegetation composition, water storage and soil organic carbon (SOC) stocks along successional gradients within four landscapes: (1) rocky uplands on ice-poor hillside colluvium, (2) silty uplands on extremely ice-rich loess, (3) gravelly-sandy lowlands on ice-poor eolian sand and (4) peaty-silty lowlands on thick ice-rich peat deposits over reworked lowland loess. In rocky uplands, after fire permafrost thawed rapidly due to low ice contents, soils became well drained and SOC stocks decreased slightly. In silty uplands, after fire permafrost persisted, soils remained saturated and SOC decreased slightly. In gravelly-sandy lowlands where permafrost persisted in drier forest soils, loss of deeper permafrost around lakes has allowed recent widespread drainage of lakes that has exposed limnic material with high SOC to aerobic decomposition. In peaty-silty lowlands, 2-4 m of thaw settlement led to fragmented drainage patterns in isolated thermokarst bogs and flooding of soils, and surface soils accumulated new bog peat. We were not able to detect SOC changes in deeper soils, however, due to high variability. Complicated soil stratigraphy revealed that permafrost has repeatedly aggraded and degraded in all landscapes during the Holocene, although in silty uplands only the upper permafrost was affected. Overall, permafrost thaw has led to the reorganization of vegetation, water storage and flow paths, and patterns of SOC accumulation. However, changes have occurred over different timescales among landscapes: over decades in rocky uplands and gravelly-sandy lowlands in response to fire and lake drainage, over decades to centuries in peaty-silty lowlands with a legacy of complicated Holocene changes, and over centuries in silty uplands where ice-rich soil and ecological recovery protect permafrost.
Torre Jorgenson, M.; Harden, Jennifer; Kanevskiy, Mikhail; O'Donnell, Jonathan; Wickland, Kim; Ewing, Stephanie; Manies, Kristen; Zhuang, Qianlai; Shur, Yuri; Striegl, Robert; Koch, Josh
On the applicability of unimodal and bimodal van Genuchten-Mualem based models to peat and other organic soils under evaporation conditions
NASA Astrophysics Data System (ADS)
Soil moisture is one of the key parameters controlling biogeochemical processes in peat and other organic soils. To understand and accurately model soil moisture dynamics and peatland hydrological functioning in general, knowledge about soil hydraulic properties is crucial. As peat differs in several aspects from mineral soils, the applicability of standard hydraulic functions (e.g. van Genuchten-Mualem model) developed for mineral soils to peat soil moisture dynamics might be questionable. In this study, the hydraulic properties of five types of peat and other organic soils from different German peatlands have been investigated by laboratory evaporation experiments. Soil hydraulic parameters of the commonly-applied van Genuchten-Mualem model and the bimodal model by Durner (1994) were inversely estimated using HYDRUS-1D and global optimization. The objective function included measured pressure heads and cumulative evaporation. The performance of eight model set-ups differing in the degree of complexity and the choice of fitting parameters were evaluated. Depending on the model set-up, botanical origin and degree of peat decomposition, the quality of the model results differed strongly. We show that fitted �tortuosity� parameters ? of the van Genuchten-Mualem model can deviate very much from the default value of 0.5 that is frequently applied to mineral soils. Results indicate a rather small decrease of the hydraulic conductivity with increasing suction compared to mineral soils. Optimizing ? did therefore strongly reduce the model error at dry conditions when high pressure head gradients occurred. As strongly negative pressure heads in the investigated peatlands rarely occur, we also reduced the range of pressure heads in the inversion to a �wet range� from 0 to -200 cm. For the �wet range� model performance was highly dependent on the inclusion of macropores. Here, fitting only the macropore fraction of the bimodal model as immediately drainable additional pore space seems to be a practical approach to account for the macropore effect, as the fitting of the full bimodal model led to only marginal further improvement of model performance. This keeps the number of parameters low and thus provides a model that is more easily managed in pedotransfer function development and practical applications like large scale simulations. Our findings point out first options to improve the performance of the frequently-used simple single-domain models when they are applied to organic soils. We suggest further performance evaluation of these models during wetting periods when they are known to fail to describe preferential and non-equilibrium flow phenomena.
Dettmann, Ullrich; Bechtold, Michel; Frahm, Enrico; Tiemeyer, B�rbel
Sorption and desorption rates of carbon tetrachloride and 1,2-dichlorobenzene to three organobentonites and a natural peat soil
The sorption and desorption rates of carbon tetrachloride (CCl{sub 4}) and 1,2-dichlorobenzene (1,2-DCB) to and from three organobentonites of varying alkyl-chain length were quantified. The effects of solute structure, organobentonite structure, and solute-sorbent contact time on the rates of solute mass-transfer were investigated. For each solute, the rate of sorption was compared to the rate of desorption. In addition, the rate of 1,2-DCB sorption to a natural peat soil was quantified. The experimental data were simulated using a two-site model and a model incorporating a continuous distribution of mass-transfer rate coefficients. Based on a statistical analysis of the model simulations, the following conclusions were made: (1) The rate of 1,2-DCB sorption to the organobentonites was significantly faster than the rate of 1,2-DCB sorption to the peat soil. (2) The rate of mass-transfer during sorption and desorption was greater for CCl{sub 4} than for 1,2-DCB. (3) The alkyl-chain lengths of the organobentonites did not affect the rate of mass-transfer during sorption; however, the rate of 1,2-DCB desorption decreased as the length of the organobentonite alkyl-chain increased. (4) The rate of solute desorption was slower than the rate of solute uptake for two of the three organobentonites. (5) For most environmental applications using the organobentonites studied here, a local equilibrium assumption will satisfactorily describe CCl{sub 4} and 1,2-DCB sorption and desorption.
Deitsch, J.J.; Smith, J.A.; Arnold, M.B.; Bolus, J. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Civil Engineering] [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Civil Engineering
Copper tolerance of the biomass crops Elephant grass (Pennisetum purpureum Schumach), Vetiver grass (Vetiveria zizanioides) and the upland reed (Phragmites australis) in soil culture.
Pot trials were conducted to study the influence of copper (Cu) on the growth and biomass of Elephant grass (EG, Pennisetum purpureum Schumach), Vetiver grass (VG, Vetiveria zizanioides) and the upland reed (UR, Phragmites australis). Cu toxicity in EG, VG and UR was positively correlated with the total and bioavailable Cu concentrations in the soil. Based on the EC50, dry weights, Cu contents, chlorophyll contents and photosynthesis rates, the Cu tolerance of the three species followed the trend EGNVGNUR. There were no significant differences in the unit calorific values among the different plants, though the total calorific values of EG were higher than those of VG and UR due to its higher biomass. The addition of KH2PO4 to the soil decreased the bioavailability of Cu and the Cu uptake by plants. EG could therefore be a good candidate for growth on Cu-contaminated soils, especially those improved by phosphate. PMID:19393734
Liu, Xinghua; Shen, Yixing; Lou, Laiqing; Ding, Chenglong; Cai, Qingsheng
Influence of geology, regolith and soil on fluid flow pathways in an upland catchment in central NSW, Australia
NASA Astrophysics Data System (ADS)
Influence of geology, regolith and soil on fluid flow pathways in an upland catchment in central NSW, Australia. Tony Bernardi and Leah Moore Dryland Salinity Hazard Mitigation Program (DSHMP), University of Canberra, ACT 2601, AUSTRALIA The diversity of salt expression in central NSW has defied classification because salt expression, mobilisation and transport is highly variable and is typically site specific. Hydrological models are extensively used to simulate possible outcomes for a range of land use changes to mitigate the mobilisation and transport of salt into the streams or across the land surface. The ability of these models to mimic reality can be variable thereby reducing the confidence in the models outputs and uptake of strategic management changes by the community. This study focuses on a 250 ha semi-arid sub-catchment of Little River catchment in central west NSW in the Murray-Darling Basin, Australia. We propose that an understanding the structure of the landforms and configuration of rock, regolith and soil materials at the study site influences fluid flow pathways in the landscape and can be related to observed variations in the chemical composition and salinity of surface and aquifer water. Preliminary geological mapping of the site identified the dominant rock type as a pink and grey dacite and in localised mid-slope areas, a coarsely crystalline biotite-phyric granodiorite. Samples were taken at regular intervals from natural exposures in eroded stream banks and in excavations made during the installation of neutron moisture meter tubes. In order to establish mineral weathering pathways, samples were taken from the relatively unweathered core to the outer weathered 'onion skins' of corestones on both substrates, and then up through the regolith profile, including the soil zone, to the land surface. X-ray diffraction (XRD) analysis and X-ray fluorescence (XRF) was conducted on the rock and soil/saprock samples. Electromagnetic induction (EMI) profile data were compiled from previous work with colleagues in this area. Preliminary interpretation of the mapping and the geophysics is that there is a three-layer framework for groundwater modelling: fractured granitic rock with an irregular upper surface, finer-grained (volcanic) rock that has either mantled the older granite or has been intruded into, and a weathering profile developed in relation to the land surface. More careful interpretation of the intervals that shallow and deep piezometers and shallow and deep bores are sampling indicates that variability in water chemistry between holes can, in part, be explained because they are sampling different materials in the sub-surface geology/regolith geology. Quartz is a relatively resistant phase throughout the profiles. For both substrates there is a decrease in the feldspar in increasingly weathered regolith materials, with a corresponding increase in kaolinite clay. There is increased homogenisation of the profile, and some horizonation due to pedogenic processes (e.g. bioturbation, illuviation of fines down profile) nearer the land surface. This results in a concentration of more resistant phases (quartz and remnant primary feldspar as sands) at the land surface over the granitic substrate, however kaolinite persists in the profile over the finer substrate. The presence of measurable ferruginous oxides and sesquioxides relates to localised percolation of oxidising fluids through the profiles. Understanding the configuration and composition of rocks and regolith materials in the Baldry catchment facilitates interpretation of observed patterns in hydrological analyses.
Bernardi, Tony
Geobotanical indication of the trophic status and moistening of reclaimed oil-polluted oligotrophic peat soils in the middle reaches of the Ob River
NASA Astrophysics Data System (ADS)
Changes in the trophic status and moistening of oligotrophic peat soils subjected to oil pollution and subsequent reclamation in the middle reaches of the Ob River are discussed. The main plants-indicators are listed. Numerical estimates of the trophic level and the degree of moistening of natural and transformed soils of the widespread bog biogeocenoses�pine-dwarf-shrub-sphagnum, complex ridged-hollow, and cotton grass-sphagnum bogs�are suggested on the basis of the ecological scales developed by L.G. Ramenskii. These estimates have been grouped into several classes used to describe the ecological conditions in natural biogeocenoses of the middle taiga subzone. The main tendencies in the transformation of ecological conditions are revealed. Indicative characteristics of the anthropogenic salinization of peat soils are established.
Avetov, N. A.
Soil organic carbon sequestration in upland soils of northern China under variable fertilizer management and climate change scenarios
NASA Astrophysics Data System (ADS)
determined the historical change in soil organic carbon (SOC) stocks from long-term field trials that represent major soil types and climatic conditions of northern China. Soil carbon and general circulation models were validated using these field trial data sets. We then applied these models to predict future change in SOC stocks to 2100 using two net primary production (NPP) scenarios (i.e., current NPP or 1% year-1 NPP increase). The conversion rate of plant residues to SOC was higher in single-cropping sites than in double-cropping sites. The prediction of future SOC sequestration potential indicated that these soils will be a net source of carbon dioxide (CO2) under no fertilizer inputs. Even when inorganic nutrients were applied, the additional carbon input from increased plant residues could not meet the depletion of SOC in parts of northern China. Manure or straw application could however improve the SOC sequestration potential at all sites. The SOC sequestration potential in northern China was estimated to be -4.3 to 18.2 t C ha-1 by 2100. The effect of projected climate change on the annual rate of SOC change did not differ significantly between climate scenarios. The average annual rate of SOC change under current and increased NPP scenarios (at 850 ppm CO2) was approximately 0.136 t C ha-1 yr-1 in northern China. These findings highlight the need to maintain, and where possible increase, organic carbon inputs into these farming systems which are rapidly becoming inorganic fertilizer intensive.
Jiang, Guiying; Xu, Minggang; He, Xinhua; Zhang, Wenju; Huang, Shaomin; Yang, Xueyun; Liu, Hua; Peng, Chang; Shirato, Yasuhito; Iizumi, Toshichika; Wang, Jinzhou; Murphy, Daniel V.
Peat surface GHG fluxes related to peat hydrology in various tropical peat land uses
NASA Astrophysics Data System (ADS)
It is generally accepted that the gradual increase in the mean temperature of the Earth's surface is primarily due to rising concentrations of greenhouse gases (GHG), especially carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in the atmosphere. Tropical peatlands are an important component of the global peatland resource, contributing to terrestrial carbon storage in both their above-ground biomass (peat swamp forest) and underlying thick deposits of peat, which both participate soil-atmosphere carbon exchange processes. In their natural state, these forests have the ability to sequester carbon from the atmosphere during photosynthesis, retain this in plant biomass and store part of it in the peat. This process occurs mainly because of the frequent waterlogged condition of the peat, which reduces organic matter decomposition significantly and this causes the rate of organic matter production to exceed its breakdown. Peatland development, however, requires drainage, brings about changes in the vegetation type C-sequestration capacity and leads to changes in peat organic matter dynamics. Drainage promotes the depth of oxic conditions deeper in peat profile and thus speeds up peat stored organic matter mineralization. Aerobic conditions and high redox potentials created by drainage are known to favour microbial activity, which can enhance C and N losses by peat mineralization. Large areas of tropical peat have been drained, resulting in an abrupt and permanent shift in the ecosystem carbon balance from sink to source. Discussion of the current role of tropical peatlands in regional and global climate change processes is based mostly on circumstantial and secondary evidence, largely because total ecosystem carbon balance studies are very few and unsatisfactory. Peat surface GHG flux data are spatially very fragmented and have not usually been collected over entire diurnal or seasonal cycles. Interpretation of the impact of biophysical factors of tropical peat on tropical peat carbon dynamics is very difficult because of variations in environmental conditions (especially peat hydrology), peat and vegetation that are not collected systematically or reported adequately in studies. In this paper we (i.) compare the most important greenhouse gases, i.e. CO2, CH4, and N2O, related to peatland hydrology in typical land use types and peat drainage intensities, and (ii.) assess gaps existing in currently available GHG data collected from tropical peat in South-East Asia. Presented information is derived from our established GHG flux monitoring programs and reviewed values from literature. Land use types in GHG comparisons include selectively logged non-drained and drainage affected peat swamp forests, plantations, agricultural peat, and mismanaged abandoned peatlands. The results are discussed on basis of GHG dynamics controlling factors in various tropical peat land uses.
Jauhiainen, Jyrki; Silvennoinen, Hanna; Limin, Suwido; Vasander, Harri
Is it clean or contaminated soil? Using petrogenic versus biogenic GC-FID chromatogram patterns to mathematically resolve false petroleum hydrocarbon detections in clean organic soils: a crude oil-spiked peat microcosm experiment.
The Canadian Council of Ministers of the Environment (CCME) reference method for the Canada-wide standard (CWS) for petroleum hydrocarbon (PHC) in soil provides chemistry analysis standards and guidelines for the management of contaminated sites. However, these methods can coextract natural biogenic organic compounds (BOCs) from organic soils, causing false exceedences of toxicity guidelines. The present 300-d microcosm experiment used CWS PHC tier 1 soil extraction and gas chromatography-flame ionization detector (GC-FID) analysis to develop a new tier 2 mathematical approach to resolving this problem. Carbon fractions F2 (C10-C16), F3 (C16-C34), and F4 (>C34) as well as subfractions F3a (C16-C22) and F3b (C22-C34) were studied in peat and sand spiked once with Federated crude oil. These carbon ranges were also studied in 14 light to heavy crude oils. The F3 range in the clean peat was dominated by F3b, whereas the crude oils had approximately equal F3a and F3b distributions. The F2 was nondetectable in the clean peat but was a significant component in crude oil. The crude oil�spiked peat had elevated F2 and F3a distributions. The BOC-adjusted PHC F3 calculation estimated the true PHC concentrations in the spiked peat. The F2:F3b ratio of less than 0.10 indicated PHC absence in the clean peat, and the ratio of greater than or equal to 0.10 indicated PHC presence in the spiked peat and sand. Validation studies are required to confirm whether this new tier 2 approach is applicable to real-case scenarios. Potential adoption of this approach could minimize unnecessary ecological disruptions of thousands of peatlands throughout Canada while also saving millions of dollars in management costs. PMID:23703885
Kelly-Hooper, Francine; Farwell, Andrea J; Pike, Glenna; Kennedy, Jocelyn; Wang, Zhendi; Grunsky, Eric C; Dixon, D George
Dissolved organic carbon concentrations and compositions, and trihalomethane formation potentials in waters from agricultural peat soils, Sacramento-San Joaquin Delta, California; implications for drinking-water quality
Water exported from the Sacramento-San Joaquin River delta (Delta) is an important drinking-water source for more than 20 million people in California. At times, this water contains elevated concentrations of dissolved organic carbon and bromide, and exceeds the U.S. Environmental Protection Agency's maximum contaminant level for trihalomethanes of 0.100 milligrams per liter if chlorinated for drinking water. About 20 to 50 percent of the trihalomethane precursors to Delta waters originates from drainage water from peat soils on Delta islands. This report elucidates some of the factors and processes controlling and affecting the concentration and quality of dissolved organic carbon released from peat soils and relates the propensity of dissolved organic carbon to form trihalomethanes to its chemical composition.Soil water was sampled from near-surface, oxidized, well-decomposed peat soil (upper soil zone) and deeper, reduced, fibrous peat soil (lower soil zone) from one agricultural field in the west central Delta over 1 year. Concentrations of dissolved organic carbon in the upper soil zone were highly variable, with median concentrations ranging from 46.4 to 83.2 milligrams per liter. Concentrations of dissolved organic carbon in samples from the lower soil zone were much less variable and generally slightly higher than samples from the upper soil zone, with median concentrations ranging from 49.3 to 82.3 milligrams per liter. The dissolved organic carbon from the lower soil zone had significantly higher aromaticity (as measured by specific ultraviolet absorbance) and contained significantly greater amounts of aromatic humic substances (as measured by XAD resin fractionation and carbon-13 nuclear magnetic resonance analysis of XAD isolates) than the dissolved organic carbon from the upper soil zone. These results support the conclusion that more aromatic forms of dissolved organic carbon are produced under anaerobic conditions compared to aerobic conditions. Dissolved organic carbon concentration, trihalomethane formation potential, and ultraviolet absorbance were all highly correlated, showing that trihalomethane precursors increased with increasing dissolved organic carbon and ultraviolet absorbance for whole water samples. Contrary to the generally accepted conceptual model for trihalomethane formation that assumes that aromatic forms of carbon are primary precursors to trihalomethanes, results from this study indicate that dissolved organic carbon aromaticity appears unrelated to trihalomethane formation on a carbon-normalized basis. Thus, dissolved organic carbon aromaticity alone cannot fully explain or predict trihalomethane precursor content, and further investigation of aromatic and nonaromatic forms of carbon will be needed to better identify trihalomethane precursors.
Fujii, Roger; Ranalli, Anthony J.; Aiken, George R.; Bergamaschi, Brian A.
Restoration of a Freshwater Wetland on Subsided Peat Soils: Potential Effects on Release of Dissolved Organic Carbon and Disinfection Byproduct Precursors
NASA Astrophysics Data System (ADS)
In 1997, a wetland restoration demonstration project began on Twitchell Island in the Sacramento-San Joaquin Delta (Delta), California, to examine the effects of a permanently flooded, freshwater wetland on peat soil subsidence. Conversion from agriculture to wetland has changed many of the biogeochemical processes controlling dissolved organic carbon (DOC) production, release, and transport from the peat soils, relative to the previous agricultural land uses. This study explores the effects of agricultural and wetland management on peat soil biogeochemistry of DOC and disinfection byproduct (DBP) precursor release. DBPs [e.g. trihalomethanes (THMs)] form when chlorine reacts with the natural organic matter present in source drinking water. Many DBPs are carcinogenic and mutagenic and pose a potential threat to more than 22 million Californians whose drinking water is diverted from the Delta. Results indicate that previous drainage practices substantially affected the quantity of water-soluble DOC currently extractable from Delta peat soils and ranged from 0.40 mg C (carbon)/g soil for well-drained soils to 0.76 mg C/g soil for poorly drained soils. Present management also affects the propensity of this DOC to form DBPs. The following values for DBP formation were measured for a variety of soil types and depths (all values are medians in mmole THMs produced/mole C): well-drained agricultural field (7.7 plow layer, 7.9 below plow layer), poorly drained agricultural field (7.0 plow layer, 8.7 below plow layer), open-water wetland (12.8 sediment, 10.1 underlying soil), and vegetated wetland (11.3 sediment, 7.7 underlying soil). Sources of organic matter inputs and decomposition pathways seem to be important factors in DBP precursor formation and release when DOC loadings are of similar magnitude. These results indicate that soil conditions have a greater effect on DOC and DBP loadings than any differences caused by conversion from agriculture to wetland, which is of great importance in Delta restoration efforts.
Fleck, J.; Fujii, R.; Bossio, D.
The assessment of the organic matter state in drained peat soils as related to the environmental conditions by the methods of multidimensional statistics
NASA Astrophysics Data System (ADS)
The specificity of the group and fraction composition of the organic matter in peat soils drained to a different extent that have developed for a 20-to 25-year period of hydro-and forest amelioration was characterized using the methods of multidimensional statistics. The differences in the organic matter of the soils studied are mainly determined by the contents of humic and fulvic acid of fractions 1 and 3, as well as of hemicelluloses and cellulose. The degree and depth of the humification are inversely related to the soil moisture and directly related to the peroxidase activity.
Efremova, T. T.; Ovchinnikova, T. M.
Impact of managed moorland burning on peat nutrient and base cation status
NASA Astrophysics Data System (ADS)
Controlled 'patch' burning of moorland vegetation has been used for decades in the UK to stimulate growth of heather (Calluna vulgaris) for game bird habitat and livestock grazing. Typically small patches (300-900 m2) are burned in rotations of 8-25 years. However, our understanding of the short-to-medium term environmental impacts of the practice on these sensitive upland areas has so far been limited by a lack of scientific data. In particular the effect of burning on concentrations of base cations and acid-base status of these highly organic soils has implications both for ecosystem nutrient status and for buffering of acidic waters. As part of the EMBER project peat chemistry data were collected in ten upland blanket peat catchments in the UK. Five catchments were subject to a history of prescribed rotational patch burning. The other five catchments acted as controls which were not subject to burning, nor confounded by other detrimental activities such as drainage or forestry. Soil solution chemistry was also monitored at two intensively studied sites (one regularly burned and one control). Fifty-centimetre soil cores, sectioned into 5-cm intervals, were collected from triplicate patches of four burn ages at each burned site, and from twelve locations at similar hillslope positions at each control site. At the two intensively monitored sites, soil solution chemistry was monitored at four depths in each patch. Across all sites, burned plots had significantly smaller cation exchange capacities, lower concentrations of exchangeable base cations and increased concentrations of exchangeable H+ and Al3+ in near-surface soil. C/N ratios were also lower in burned compared to unburned surface soils. There was no consistent trend between burn age and peat chemistry across all burned sites, possibly reflecting local controls on post-burn recovery rates or external influences on burn management decisions. At the intensively monitored site, plots burned less than two years prior to sampling had significantly smaller exchange capacities and lower concentrations of soil base cations in surface soils relative to plots burned 15-25 years previously. In contrast, surface soil solutions in recently burned plots were enriched in base cations relative to older plots and relative to the control site, possibly due to enhanced leaching at bare soil surfaces. The results offer evidence for an impact of burning on peat nutrient and acid-base status, but suggest that soils recover given time with no further burning.
Palmer, Sheila; Gilpin, Martin; Wearing, Catherine; Johnston, Kerrylyn; Holden, Joseph; Brown, Lee
Economic incentives for farmers in the Philippine uplands to adopt hedgerow intercropping
Land degradation in the Philippine uplands is severe and widespread. Most upland areas are steep, and intense rainfall on soils disturbed by intensive agriculture can produce high rates of soil loss. This has serious implications for the economic welfare of a growing upland population with few feasible livelihood alternatives. Hedgerow intercropping can greatly reduce soil loss from annual cropping systems
R. A Nelson; R. A Cramb
Effect of Logging Operation on Soil Carbon Storage of a Tropical Peat Swamp Forest
Problem statement: Since heavy machinery are used in the logging oper ation activity for extracting the logs on sensitive forest site with p eat soil, environment destruction should be the oth er concern during its processes especially on its impo rtant function as soil carbon storage. The objectiv e of this study was to determine whether logging oper ation affect
Anton Eko Satrio; Seca Gandaseca
Trihalomethane Reactivity of Water and Sodium Hydroxide�Extractable Organic Carbon Fractions from Peat Soils
Certain organic carbon moieties in drinking source waters of the Sacramento-San Joaquin Delta can react with chlorine during dis- infection to form potentially carcinogenic and mutagenic trihalometh- anes. The properties of reactive organic carbon in Delta waters, partic- ularly those of soil origin, have been poorly understood. This study attempts to characterize trihalomethane reactivity of soil organic car- bon from
Alex T. Chow; Fengmao Guo; Suduan Gao; Richard S. Breuer
The objectives of this investigation were: (1) to locate potential peat deposits in Costa Rica; (2) to estimate as closely as possible by representative sampling the amount of peat present in each deposit, and (3) to make a preliminary evaluation of the quality of the peat in each deposit. With information from soil maps and a 3-week survey of Costa Rica, it is estimated that a potential area of about 1000 km{sup 2} is covered by peat. Most of the peat area (about 830 km{sup 2}) is in northeastern Costa Rica in the Tortuguero area. An aerial survey identified the potential peat areas by the exclusive presence of the Yolillo palm. The next largest potential area of peat (about 175 km{sup 2}) is in the cloud-covered areas of the Talamanca Mountains. Some reconnaissance has been done in the Talamanca Mountains, and samples of the peat indicate that it is very similar to the sphagnum peat moss found in Canada and the northern US. Smaller bogs have been discovered at Medio Queso, El Cairo, Moin, and the Limon airport. Two bogs of immediate interest are Medio Queso and El Cairo. The Medio Queso bog has been extensively sampled and contains about 182,000 metric tons (dry) of highly decomposed peat, which is being used as a carrier for nitrogen-fixing bacteria. The El Cairo bog is sparsely sampled and contains about 1,300,000 metric tons of slightly decomposed dry peat. Plans are to use this peat in horticultural applications on nearby farms. 10 refs., 11 figs., 7 tabs.
Obando A, L.; Malavassi R, L.; Ramirez E, O. (RECOPE, San Jose (Costa Rica)); Cohen, A. (South Carolina Univ., Columbia, SC (USA). Dept. of Geological Sciences); Raymond, R. Jr.; Thayer, G.R. (Los Alamos National Lab., NM (USA))
Measurement of Entrapped Biogenic Gas Bubbles in Northern Peat Soils: Application of Resistivity and X-ray Computed Tomography.
NASA Astrophysics Data System (ADS)
Peatlands are the largest natural source per annum of CH4 emissions to the atmosphere. CH4 is lost from peatlands via diffusion or active transport through vascular plants, and as bubbles moving to the peatland surface - ebullition. The build up and ebullition of biogenic gas bubbles within northern peatlands is spatially variable and depends on the rate of CH4 production, the transport of dissolved CH4 to bubbles through pore water, and the physical properties of the peat. Recent measurements suggest a threshold bubble volume must be reached to trigger episodic or cyclic ebullition, which is assumed to be dependent on peat type. However, this threshold theory lacks a secure physical basis and therefore cannot be applied to simulate methane ebullition from northern peatlands with any confidence. We develop an approach to examine the structural attributes of the peat that cause and promote the trapping and release of bubbles by combining resistivity and X-ray computed tomography (CT). The spatial and temporal variation in the biogenic gas content of peat cores are identified from resistivity measurements. Areas of high and low entrapped gas content are subsequently correlated with the pore structure of the peat samples, characterised using CT. The CT images of the peat structure are vectorised to allow them to be analysed for metrics which relate to the ability of the peat to trap bubbles: e.g. stem length and width, number of branches, angle of branches. Difficulties applying these approaches within northern peatlands are examined. The low pore water conductivity of poorly decomposed near surface peat can hamper resistivity measurements at the laboratory scale, and electrolytic reactions induce the development of artificial gas bubbles. The similarity in linear attenuations between poorly decomposed Sphagnum and pore water also makes the peat structure indistinguishable from the pore water within standard CT scans. The peat samples must, therefore, first be doped with a solution of lead(II) nitrate which is adsorbed by the peat fibres, making them visible.
Kettridge, N.; Binley, A.; Baird, A.
Understanding barite and gypsum precipitation in upland acid-sulfate soils: An example from a Lufkin Series toposequence, south-central Texas, USA
NASA Astrophysics Data System (ADS)
Although low-temperature barite precipitation has been previously documented in soils and paleosols, pedogenic barite precipitation remains poorly understood. This study characterizes the micromorphology, elemental trends, and stable isotope geochemistry of sulfates in a barite-bearing soil (Lufkin Series) toposequence using optical microscopy, XRD, ICP-MS, and stable S and O isotope data. Synthesized data indicate that fluctuating redox processes and microbial activity resulting from epiaquatic and evaporative conditions lead to the precipitation of sulfates in the Lufkin soils. Stable sulfur and oxygen isotopes indicate that the primary source of sulfur is the partial dissolution of jarosite during microbial sulfate reduction. Barium-rich parent material provides adequate barium for barite precipitation. Barium is mobilized and concentrated in Btg horizons ~ 100-160 cm below the surface. The presence of humic acids in profiles lower on the landscape prevents barite precipitation and drives the precipitation of gypsum between saturated, anoxic conditions (November to May) and drier, more oxic conditions (May to November). Barite precipitation is a slow, punctuated process. Micromorphological data reveal that barite precipitates first along evacuated macropores and then in the adjacent matrix. In general, optimal conditions for pedogenic barite precipitation in upland wetland acid-sulfate soils are: 1) warm soil temperature that supports active sulfur-reducing and sulfur oxidizing microbes; 2) distinct wet/dry seasons that allow alternating redox conditions; 3) low-gradient landscape; 4) parent material that contains barium- and sulfur-rich constituents; and 5) a long-lived, stable landscape.
Jennings, Debra S.; Driese, Steven G.
The accumulation of zinc in oat grown in soils treated by incubated sewage sludge with peat and straw
The effect of addition of treated sewage sludge on the accumulation of Zn in plants was tested in pot experiment. The additions of eight months preincubated sewage sludge at temperature of 20�C under aerobic and anaerobic conditions with addition of peat and straw were tested. Two different combinations were designed: first consisted of 50% sludge + 35% peat and 15%
J. Bal�k; D. Pavl�kov�; J. ?ern�
Thermal properties of peat, marshy and mineral soils in relation to soil moisture status in Polesie and Biebrza wetlands
NASA Astrophysics Data System (ADS)
Knowledge of thermal properties of soil helps in estimating heat fluxes as an important component of the heat balance. The research was conducted to evaluate spatial distribution of the soil thermal properties (thermal conductivity, heat capacity and thermal diffusivity) in relation to soil wetness and bulk density in wetland soils of Polesie and Biebrza regions (Poland). Soil moisture content and bulk density together with soil temperature and texture data, were used for determination of thermal properties. The thermal conductivity was measured, by KD2 Pro Decagon, and calculated by the physical-statistical model of Usowicz, and the heat capacity - was calculated with empirical formulae, and the thermal diffusivity was determined by the ratio of thermal conductivity to the heat capacity. The thermal conductivity of wetland and marsh soils increases with increasing moisture content and density of the soil to higher extent in soils richer in minerals - mostly quartz. Maximum thermal conductivity of the wetland soils at different density did not exceed the value of the thermal conductivity of water. However, for mineral soil at the natural density (1.31 Mg m-3) and with the quartz content of 96%, the thermal conductivity is about four times greater than the thermal conductivity of water. This is due to that the thermal conductivity of quartz is sixteen times greater than that of water. Dependence of the soil thermal conductivity on moisture content is non-linear and the shape of the non-linearity largely depends on the density of the soil. Particular components of soil bring their contribution to the conductivity respectively to their fractions and compounds being dominant in the ground contribute mostly to the effective slope of the thermal conductivity versus the water content at a given soil density. The heat capacity of the soil substrate is linearly dependent on the water content. Soils containing more organic matter within low specific densities, usually are characterized by less or minimal available heat capacity values in dry conditions, while they can also be characterized by highest or maximal heat capacity values, in highly wet conditions approaching the saturation with water. The increase in soil density caused a parallel shift of the characteristics of the heat capacity in the direction of higher values. This was associated with an increase in solids content per unit volume of the substrate and the reduction of the water content and the specific heat capacity of the individual components of the soil. Thermal diffusivity of soils exhibits characteristic extremes. In organic soils characteristic minimal or maximal extremes may occur, while mineral soils achieve only maximal diffusivity values on regular basis. Extremes of the thermal diffusivity are mainly due to the changes in the intensity of the thermal conductivity of the substrate due to change in soil moisture content and density. The heat capacity of the soil increases with increasing moisture content at the constant rate. The value of soil thermal diffusivity depends highly on quartz content. Thermal diffusivity of the soil with the same moisture content was greater for the higher densities, and minimum or maximum thermal diffusivity tends to move toward the lower moisture content for higher densities. The observed extremes are so distinctive that they determine the value of soil moisture and density, at which the temperature wave travels the slowest and the fastest in the soil. The question of determining and sensing the water capacity is also affected by the texture and porosity. Simple volumetric measures of porosity are used, but with distinguishing the volume of pores filled by air and other part filled with water. Practically, porosity is treated simply and is included to assessments by effects on the thermal properties. We prove that thermal properties are very good variables for a sensitive indicator of the water content, and accounting the impact from porosity. Thermal properties gather effects from the texture and porosity cumulatively. Therefo
Usowicz, Boguslaw; ?ukowski, Mateusz; Marczewski, Wojciech; Usowicz, Jerzy B.; Lipiec, Jerzy; Stankiewicz, Krystyna
Soil microbial respiration from various microhabitats in Arctic landscape: impact of soil type, environmental conditions and soil age
NASA Astrophysics Data System (ADS)
Soil respiration is the second largest C flux between atmosphere and terrestrial ecosystems after gross primary production. Carbon dioxide released from soils is thus a major contributor to the atmospheric CO2 concentration. Despite the global importance, soil respiration and its components (heterotrophic and autotrophic respiration) remain poorly understood and not well constrained fluxes of the terrestrial C cycle. This is particularly true for the Arctic, where huge amounts of the Earth's soil carbon is stored. Here, we report on heterotrophic soil respiration rates from various Arctic tundra microhabitats measured in situ. The study site was Seida (67�07'N, 62�57'E, 100 m a.s.l.) which is characterized by typical sub-arctic permafrost landscape which comprises raised, vegetated permafrost peat plateaus, interspersed with spots of bare peat surfaces (peat circles), and upland mineral soils. We used isotope partitioning approach based on differences in natural abundance of 14C between soil and plants to separate sources of soil-respired CO2. In addition, the tradition trenching approach was employed. Complementary laboratory incubations with homogenized soil were conducted to assess primary decomposability of the soils and to identify age of the CO2 released and thus get more information on the nature of the sources of respiration. The major aim was to link SMR rates with of soil type, land cover class, soil physic-chemical properties (e.g. water content), soil C stocks and age of soil. Results show that, despite profound differences in soil characteristics and primary decomposability of organic matter, surface CO2 fluxes derived from soil microbial respiration rates were rather similar between microhabitats. The only factor which influenced, at least to some extent, the respiration rates was total soil C (and N) stocks in surface soils. There was some evidence for reduced soil-related CO2 emissions from peatlands, though results were not consistent between the methods applied. It seems that the lower decomposability of peat is largely outweighed by higher C stocks at field conditions. Surprisingly, the bare surfaces (peat circles) with 3500 years old C at the surface exhibited about the largest soil microbial respiration rates among all sites as shown by both methods. This is likely due to the immature status of the peat which was during the bulk of its developmental time protected by permafrost, together with high C-densities. The observation is particularly relevant for decomposition of deeper peat at the permafrost-active layer interface in the large vegetated peat plateaus, where soil material similar to the bare surfaces can be found. The results suggest that the chemical nature and high age of the soil SOC in deep peat does not solely guarantee for resistance to decay. Thus, the study highlights risks for potential re-mobilization of C in deep peat soils following thawing. Soil microbial respiration rates need to be better known when predicting the overall carbon sink/source character of tundra ecosystems in a warming climate. Biasi C., Jokinen S., Marushchak M., H�m�l�inen K., Trubnikova T., Oinonen M., Martikainen P. (2013). Microbial respiration in Arctic upland and peat soils as source of CO2. Ecosystems. DOI: 10.1007/s10021-013-9710-z.
Biasi, Christina; Jokinen, Simo; Marushchak, Maija; Trubnikova, Tatiana; H�m�l�inen, Kai; Oinonen, Markku; Martikainen, Pertti
Mycobiota of peat-gleyic soils during the process of recultivation
NASA Astrophysics Data System (ADS)
The experiments on the recultivation of oil-polluted soils and their self-rehabilitation were laid in 1995 at sites contaminated with oil in the area of Usinsk region, Komi Republic, Russia. There were taken different plots for the experiment with various amounts of contaminant. The investigations continued some years after the contamination. At this point, the concentration of residual oil in these areas significantly decreased. Microbiological activity increased 2-3 times in the most contaminated soil. We should note that the micromycets were marked only in the layer 0-5sm in contrast to background soil. There were 10 species of micromycets and most of them characterized as dark colored species, the dominants were Aspergillus fumigatus. Penicillium funiculosum, P. paxilli, P. lanosum, P. tardum, usual for contaminated anthropogenic soils. The same highly oil-polluted soil, where recultivation was held, is characterized with the wider specter of different physiological groups of microorganisms. Micobiota is quite reach, it represents 20 species from 8 types. In the composition of micromycets 40% are the representatives of Penicillium, sterile mycelium presents as dark colored forms so as light colored ones. But the micobiota is still reach in micromycets typical for disturbed anthropogenic soils. The most microbiologically active plot was a territory with low-contaminated self-recovered soil. The micobiota is represented of great amount of microorganisms and consists of 21 species, mostly formed with dark colored forms of sterile mycelium. During the process of recultivation the structure of micromyctes changed: regrouping of species and increase of biodiversity. We assume that a process of self-purification started. However we should notice that activation of biological processes doesn't occur deeper than 0-5sm. At the same time the roots of high plants are seen till the depth 7-10sm, they also participate in the cleaning of oil polluted soil. There was used a Zhakkar coefficient of similarity to show the difference of mycobiota structure of rehabilitated ecosystems. The greatest similarity was observed between the communities of soil micromycetes from recultivated area and the area with low pollution (42.8%), the smallest - mycobiota of a non-polluted and heavily contaminated soil (5.4%). Mikobiota of virgin soil is characterized with the richest biodiversity of micromycetes species; rates of similarity coefficient between the mycobiota of virgin soils and oil-polluted here have the lowest value. In summary, we want to mark that micromycet complexes are changing in soils under the influence of oil pollution: first, a reduction in the diversity of fungal complexes in the soil, compared with the background, and secondly, there is an increase of dominant and often encountered species and reducing the number of rare species. There is also the appearance of fungi, which are typical for the more southern regions. Influenced by oil pollution the investigated soils become a sphere of accumulation of potentially hazardous to human species of micromycetes: Aspergillus fumigatus, Paecilomyces variotii, etc.
Ibatullina, I.; Khabibullina, F.
Electron paramagnetic resonance (EPR) studies on stable and transient radicals in humic acids from compost, soil, peat and brown coal
NASA Astrophysics Data System (ADS)
Quantitative EPR method was applied to characterise four types of humic acids (HA) derived from composts, soil, peat and soft brown coal. For each sample of HA the level of native (indigenous) radicals was estimated. Interactions of the HA with various gaseous agents and organic solvents were investigated. Strong effects of gaseous ammonia and aliphatic amines on spin concentration enhancement were observed; additionally, higher values of g-value were found to be associated with the formed 'transient' radicals. Correlation of copper(II) ions uptake by different HA with effect diminishing primary spin concentration was established. It was recognised that the radical centres, which are enhanced by 'ammonia effect' are quenched in the formed HA-Cu(II) complexes. The both opposite effects are competitive from each other, where 'copper(II) quenching effect' prevails. Reaction of nitrogen dioxide with the humic acids was also examined. The presence of diketones and/or other compounds with active methylene group results in formation of the iminoxy radicals; these radicals are immobilized in the solid (macromolecular) matrix of the humic acids.
Jezierski, Adam; Czechowski, Franciszek; Jerzykiewicz, Maria; Chen, Yona; Drozd, Jerzy
Electron paramagnetic resonance (EPR) studies on stable and transient radicals in humic acids from compost, soil, peat and brown coal.
Quantitative EPR method was applied to characterise four types of humic acids (HA) derived from composts, soil, peat and soft brown coal. For each sample of HA the level of native (indigenous) radicals was estimated. Interactions of the HA with various gaseous agents and organic solvents were investigated. Strong effects of gaseous ammonia and aliphatic amines on spin concentration enhancement were observed; additionally, higher values of g-value were found to be associated with the formed 'transient' radicals. Correlation of copper(II) ions uptake by different HA with effect diminishing primary spin concentration was established. It was recognised that the radical centres, which are enhanced by 'ammonia effect' are quenched in the formed HA-Cu(II) complexes. The both opposite effects are competitive from each other, where 'copper(II) quenching effect' prevails. Reaction of nitrogen dioxide with the humic acids was also examined. The presence of diketones and/or other compounds with active methylene group results in formation of the iminoxy radicals; these radicals are immobilized in the solid (macromolecular) matrix of the humic acids. PMID:10727156
Jezierski, A; Czechowski, F; Jerzykiewicz, M; Chen, Y; Drozd, J
Geobotanical indication of the trophic status and moistening of reclaimed oil-polluted oligotrophic peat soils in the middle reaches of the Ob River
Changes in the trophic status and moistening of oligotrophic peat soils subjected to oil pollution and subsequent reclamation\\u000a in the middle reaches of the Ob River are discussed. The main plants-indicators are listed. Numerical estimates of the trophic\\u000a level and the degree of moistening of natural and transformed soils of the widespread bog biogeocenoses�pine-dwarf-shrub-sphagnum,\\u000a complex ridged-hollow, and cotton grass-sphagnum bogs�are
N. A. Avetov
Soil Phosphorus in Relation to Surface and Ground Water Phosphorus in Harvested and Forested Portions of a Sub-humid Boreal Aspen Upland
NASA Astrophysics Data System (ADS)
Soil moisture and phosphorus measured across a toposequence from upland to wetland in both harvested (clearcut) and forested sections of an aspen-dominated catchment in central Alberta were related to surface and ground water phosphorus. Topographic position explained most of the variance in the moisture and phosphorus contents of surface soils (0-20 cm) and there was little difference between harvested and forested areas. Soil phosphorus was inversely related to soil moisture throughout the catchment. Soil moisture was low and soil phosphorus was high in upslope areas compared to low-lying areas and wetlands. Surface organic soils (0 -10 cm) are high in extractable phosphorus (> 70 ? g g-1) and total phosphorus pools (> 1000 ? g g-1) whereas mineral soils are low in extractable phosphorus (< 2 ? g g-1) and total phosphorus pools (< 300 ? g g-1). Phosphorus buffering capacity was low in organic surface soils (EPC > 5000 ? g l-1) and high in subsoils (EPC =100-400 ? g l-1 in A horizon; EPC < 100 ? g l-1 in B horizon). This is reflected in total dissolved phosphorus concentrations in surface water and ground water throughout the catchment. Total dissolved phosphorus concentrations were high in surface water (85 ? g l-1) and soil water (202 ? g l-1) where organic soils were present and low in ground water where mineral soils were prevalent (23 ? g l-1). Changes in ground water phosphorus following a harvest are unlikely in this catchment due to the high adsorption affinity of mineral subsoils. Phosphorus-rich surface soils have a high potential for phosphorus release to surface water but this does not differ between harvested and forested sections of the catchment. Natural climatic variability in this sub-humid area often prevents surface runoff and discharge from occurring. The effects of harvesting may be dampened in sub-humid areas such as the Boreal Plain due to the moisture deficit. However, our ability to evaluate the effects of harvesting on phosphorus dynamics in this region is confounded by natural climatic variability and spatial variability within catchments.
Macrae, M. L.; Devito, K. J.; Redding, T.; Creed, I. F.; Bell, W.
Chemically enhanced mixed region vapor stripping of TCE-contaminated saturated peat and silty clay soils
The objective of this study was to conduct further testing of MRVS, chemically enhanced with calcium oxide conditioning, on field- contaminated soils collected from beneath the NASA Michoud Rinsewater Impoundment. In this study, residual soil VOC levels as a function of vapor stripping time were measured to quantify VOC removal rates. Physical and chemical soil parameters expected to affect MRVS efficiency were measures. The effects of varying the calcium oxide loadings as well as varying the vapor stripping flow rates on VOC removal were also evaluated. The results of this study will be used to determine whether acceptable removals can be achieved within reasonable treatment times, remediation costs being directly proportional to the latter. The purpose of this report is to document the experimental results of this study, as well as to address issues that were raised after completion of the previous Michoud treatability work.
West, O.R.; Cameron, P.A.; Lucero, A.J.; Koran, L.J. Jr.
Nitrogen Turnover Processes in Low Temperatures in an Agricultural Peat Soil
Nitrogen (N) cycling in agricultural soils has a key impact on the environment. Agricultural ecosystems are the most important sources of nitrous oxide (N2O), an important greenhouse gas, to the atmosphere. Additionally N fertilizers used to improve plant growth lead to enhanced N leaching and thereby to eutrophication of surrounding aquatic ecosystems. Microbial processes are normally enhanced by increase in
H. M. Silvennoinen; R. H�m�l�inen; H. T. Koponen; P. J. Martikainen
Dissipation of racemic mecoprop and dichlorprop and their pure R-enantiomers in three calcareous soils with and without peat addition.
Two racemic herbicides, mecoprop (R,S-MCPP) and dichlorprop (R,S-DCPP), as well as their enantiopure R-forms, were incubated in three calcareous soils at 15 degrees C and 80% of their field capacity to try to elucidate their behaviour in soil and compare the dissipation rates when racemic and enantiopure compounds are used. Quantitation of pesticides is made by HPLC and the R/S ratio by GC-MS. The inactive S-enantiomer from the racemic forms persists longer than the R-forms in silt and sandy loam soils, but for shorter time in the clay loam soil. The pure R-enantiomers, both for MCPP and DCPP, after incubation in soil, are partially converted into their S-forms. In all cases, the dissipation of racemic and pure enatiomeric forms is lower in the clay loam soil than in the silt and sandy loam soils. The R-forms' peristence, in the three soils, is approximately two times lower when they are incubated alone than when they are incubated as racemic compounds. When peat is added, the persistence of these herbicides in the silt and sandy loam soils increases, while in the clay loam soil it decreases. Besides, in the clay loam soil, the enantiomeric ratio (ER) changes from its S-preferential degradation to a preferential degradation of its R-form, so an increase in the persistence of the inactive S-form occurs. PMID:11202724
Romero, E; Matallo, M B; Pe�a, A; S�nchez-Rasero, F; Schmitt-Kopplin, P; Dios, G
Carbon dioxide and methane fluxes from drained peat soils, southern Quebec
Fluxes of CO2 and CH4 were determined by a static chamber technique at eight drained swamp peatland sites, with crop and forest covers. Over a 6- month period (May - October, 1991), CH4fluxes ranged from ?5 to 7 mg CH4 m?2 d?1 and were not correlated with either soil temperature or water table position. Integrated seasonal emissions were ?0.40 to
Shannon Glenn; Andrew Heyes; Tim Moore
Carbon dioxide and methane fluxes from drained peat soils, southern Quebec
Fluxes of CO2 and CH4 were determined by a static chamber technique at eight drained swamp peatland sites, with crop and forest covers. Over a 6-month period (May-October, 1991), CH4 fluxes ranged from -5 to 7 mg CH4 m-2 d-1 and were not correlated with either soil temperature or water table position. Integrated seasonal emissions were -0.40 to 0.04 g
Shannon Glenn; Andrew Heyes; Tim Moore
Metagenomic Insights into Anaerobic Metabolism along an Arctic Peat Soil Profile
A metagenomic analysis was performed on a soil profile from a wet tundra site in northern Alaska. The goal was to link existing biogeochemical knowledge of the system with the organisms and genes responsible for the relevant metabolic pathways. We specifically investigated how the importance of iron (Fe) oxides and humic substances (HS) as terminal electron acceptors in this ecosystem is expressed genetically, and how respiratory and fermentative processes varied with soil depth into the active layer and into the upper permafrost. Overall, the metagenomes reflected a microbial community enriched in a diverse range of anaerobic pathways, with a preponderance of known Fe reducing species at all depths in the profile. The abundance of sequences associated with anaerobic metabolic processes generally increased with depth, while aerobic cytochrome c oxidases decreased. Methanogenesis genes and methanogen genomes followed the pattern of CH4 fluxes : they increased steeply with depth into the active layer, but declined somewhat over the transition zone between the lower active layer and the upper permafrost. The latter was relatively enriched in fermentative and anaerobic respiratory pathways. A survey of decaheme cytochromes (MtrA, MtrC and their homologs) revealed that this is a promising approach to identifying potential reducers of Fe(III) or HS, and indicated a possible role for Acidobacteria as Fe reducers in these soils. Methanogens appear to coexist in the same layers, though in lower abundance, with Fe reducing bacteria and other potential competitors, including acetogens. These observations provide a rich set of hypotheses for further targeted study.
Lipson, David A.; Haggerty, John Matthew; Srinivas, Archana; Raab, Theodore K.; Sathe, Shashank; Dinsdale, Elizabeth A.
The decomposition of vegetation and soil in marginal peat-forming landscapes: climate simulations to quantify gaseous and dissolved carbon fluxes and the effects on peat accumulation and drinking water treatment
NASA Astrophysics Data System (ADS)
Peatlands in the UK represent a large proportion of the soil carbon store, however there is concern that some systems may be switching from sinks to sources of carbon. The accumulation of organic material in peatlands results from the slow rates of decomposition typically occurring in these regions. Climate change may lead to faster decomposition which, if not matched by an equivalent increase in net primary productivity and litter fall, may tip the balance between source and sink. Recent trends have seen a greater flux of dissolved organic matter (DOM) from peatlands to surface waters and a change in DOM character, presenting challenges to water treatment, for example in terms of increased production of disinfectant by-products (DBPs). Peat systems border a large proportion of reservoirs in the UK so uncertainty regarding DOM quantity and quality is a concern for water utilities. This study considered five peatland vegetation types (Sphagnum spp., Calluna vulgaris, Molinea caerulea, peat soil and mixed litter) collected from the Exmoor National Park, UK where it is hypothesised that peat formation may be strongly affected by future changes to climate. A factorial experiment design to simulate climate was used, considering vegetation type, temperature and rainfall amount using a current baseline and predictions from the UKCP09 model. Gaseous fluxes of carbon were monitored over a two month period to quantify the effect on carbon mineralisation rates while 13C NMR analysis was employed to track which classes of compounds decayed preferentially. The DOM collected was characterised using UV and fluorescence techniques before being subject to standard drinking water treatment processes (coagulation/flocculation followed by chlorination). The effect of the experimental factors on DOM amenability to removal and propensity to form DBPs was then considered, with both trihalomethane (THM) and haloacetonitrile (HAN) DBP classes monitored. Initial results have shown a statistically significant (Mann-Whitney U) difference in THM formation (p<0.05) as well as the amount of DOM produced and specific UV absorption at 254nm (p<0.01) between vegetation classes.
Ritson, J.; Bell, M.; Clark, J. M.; Graham, N.; Templeton, M.; Brazier, R.; Verhoef, A.; Freeman, C.
Effect of peat on mycorrhizal colonization and effectiveness of the arbuscular mycorrhizal fungus Gigaspora margarita
The influence of the addition of Chinese peat and Canadian peat on arbuscular mycorrhizal colonization, mycorrhizal effectiveness and host-plant growth was investigated in a pot experiment. Chinese peat or Canadian peat was mixed with Masa soil (weathered granite soil) at different levels (0, 25, 50, 100, 150 or 200�g�kg) into which an arbuscular mycorrhizal fungus (AMF) Gigaspora margarita Becker &
Nan Ma; Kazuhira Yokoyama; Takuya Marumoto
Low-cost removal of trace metals from copper-nickel mine stockpile drainage. Volume II - Trace metal sequestration by peat, other organics, tailings, and soils
This report describes a two-phase experimental program to examine the feasibility of removing trace metals (Cu, Mi, Co, Zn) from stockpile effluent using readily available materials in low-cost, low-maintenance systems. Volume II is a literature review of several low-cost materials that might be used for removing trace metals from stockpile drainage. The materials included peat, humic acid, fulvic acid, other organics, soils, and tailings. The methods employed in the investigations review ranged from laboratory experiments to field-scale studies. Trace metal removal mechanisms and capacities were addressed.
Lapakko, K.A.; Strudell, J.D.; Eger, A.P.
The Late Quaternary peat, vegetation and climate history of the Southern Oceanic Islands of New Zealand
NASA Astrophysics Data System (ADS)
Seven oceanic island groups (Chatham, Bounty, Snares, Antipodes, Auckland, Campbell and Macquarie) lie to the south and east of the southern New Zealand mainland between the Subtropical Convergence and the Antarctic Convergence. They are highly oceanic, experiencing moist, cool, cloudy and windy climates. Deep peat soils cover most of the islands, except for steep slopes and exposed high altitude sites. The three large island groups (Chatham, Auckland and Campbell) support forest and tall scrub in the lowlands, in the latter two grading with altitude through shrubland and grassland to upland tundra. Macrophyllous forbs create luxuriant herbfields in nutrient-rich coastal sites and also, as stunted forms, dominate upland tundra associations. The southernmost island, Macquarie has no woody species, and is covered with tussock grassland, herbfield and tundra. Vegetation cover is highly sensitive to soil saturation and exposure to the strong westerly winds of this region. Extensive oligotrophic bogs occur where drainage is poor and exposure high, and forest and tall scrub are abundant only in sheltered, well-drained lowland sites. Glacial cirque levels indicate mean annual temperatures fell by 5-6�C during the Last Glacial Maximum. A depression of 6-10�C in sea surface temperatures is suggested by deep-sea core analyses, but this seems incompatible with terrestrial evidence. Auckland and Campbell Islands were extensively glaciated, and grassland, herbfield and tundra landscapes prevailed. Glaciers retreated by 15,000 yr BP, and landscapes had stabilised and peat soils begun forming by 12,000 yr BP. By the beginning of the Holocene, oligotrophic bog, grassland and shrubland were dominant. Scrub and low forest spread slowly during the early Holocene in the Chatham, Auckland and Campbell Islands, inhibited by cloudy, moist climates, low insolation and wet soils. Maximum extent of forest and scrub occurred between 6000 and 2000 yr BP, most probably linked with a drying of the soils and increasing summer insolation. Upland sites and those exposed to westerly gales on Auckland and Campbell Islands remained in grassland, herbfield and bog throughout the Holocene. Wind-blown sand and stones in cliff edge peat profiles on Auckland and Campbell Island from 8000 yr BP suggest strengthening westerly winds.
McGlone, M. S.
Use of Computed Tomography Imaging for Qualifying Coarse Roots, Rhizomes, Peat, and Particle Densities in Marsh Soils
Computed tomography (CT) imaging has been used to describe and quantify subtidal, benthic animals such as polychaetes, amphipods, and shrimp. Here, for the first time, CT imaging is used to successfully quantify wet mass of coarse roots, rhizomes, and peat in cores collected from...
Physicochemical sensitivities of tropical peat to electrokinetic environment
Tropical peat is unconsolidated superficial deposits with high non-crystalline colloid (humus) content, constituting the subsurface of wetland systems. Laboratory experiments were carried out on a very slightly decomposed fibric and a highly decomposed amorphous, undisturbed tropical peat soils, to determine the physicochemical effects on the peats due to electrokinetic (EK) treatment in terms of mechanisms and resulting effects in the
Afshin Asadi; Bujang B. K. Huat; Mohamed M. Hanafi; Thamer A. Mohamed; Nader Shariatmadari
Nitrogen mineralization, nitrification and denitrification in upland and wetland ecosystems
Nitrogen mineralization, nitrification, denitrification, and microbial biomass were evaluated in four representative ecosystems in east-central Minnesota. The study ecosystems included: old field, swamp forest, savanna, and upland pin oak forest. Due to a high regional water table and permeable soils, the upland and wetland ecosystems were separated by relatively short distances (2 to 5 m). Two randomly selected sites within
Donald R. Zak; David F. Grigal
Reducing sediment inputs to Scottish streams: a review of the efficacy of soil conservation practices in upland forestry.
The historical process by which a soil conservation strategy has evolved within the UK forestry industry is briefly reviewed. Particular attention is given to the development of practical and effective guidelines to prevent both soil damage and sediment entering water courses. It is concluded that the 'Forest and Water Guidelines', together with other forest industry manuals, largely provide adequate protection for aquatic habitats from pre-afforestation cultivation and from harvesting activities. The problem of soil erosion owing to ploughing of open furrows has largely been obviated by improved drainage network design coupled with the use of vegetated buffer strips and sediment catchpits. Alternative site preparation techniques, such as 'moling' or 'dolloping' of afforestation sites, are now preferred. However, the effects on slope hydrology and the improved soil conservation associated with these methods require quantifying. Additional understanding of effective buffer strip function, for example, on a variety of slope angles, soil types and vegetation associations would be beneficial. The design of forest roads and the associated network of drains, culverts and sediment catchpits is addressed in forestry guidelines. Future potential in this area may involve the use of Geographical Information Systems in the effective design of road networks which minimise adverse effects on slope hydrology. Similarly computer simulation of flow routing might aid in the design of road drain networks. At the more local scale there remains scope for further research aimed at minimising soil disturbance by machinery. Consideration should also be given to the long-term sustainability of the soil structure through second and subsequent crop rotations. PMID:11227267
Carling, P A; Irvine, B J; Hill, A; Wood, M
Ash contents of Costa Rican peat deposits
Fourteen sites within 6 Costa Rican peat localities were sampled using MacCaulay samplers and soil augers. Sample localities included high mountain (>2500 meters), river floodplain, and Gulf coastal plain. Peat deposits ranged from as thin as 20 cm to greater than 460 cm. Within the peat deposits, ash (that material which will remain following combustion) occurs both dispersed within the peat layers and as layers containing nearly 100% inorganic material interstratified with the peat layers. Ash in Costa Rican peats includes material derived from both organic and inorganic origins. The predominant inorganically derived material is volcanic and may result from direct volcanic ashfall into the peat environment or as detritus transported into the peat areas. Volcanic ash is rapidly altered within the peats, leaving little if any relict structures. Alteration products are pedominantly kaolin and smectite clays and gibbsite. Unaltered minerals identified by x-ray diffraction include quartz, cristobalite, plagiolase feldspar, and anatase. Hematite and bassanite (identified by x-ray diffraction) are present but result from the alteration of iron-bearing minerals and organic sulfur or gypsum during sample preparation. Pyrite is present as a very minor component of some Costa Rican peats. Organically-derived ash constituents in Costa Rican peats include siliceous diatoms, siliceous sponge spicules, and silica phytoliths. The type and abundance of ash constituents within Costa Rican peats can be evaluated based on geographic location of the peat deposits, the geologic conditions affecting their deposition, and the plant communities existing during deposition. 6 refs., 11 figs., 3 tabs.
Raymond, R. Jr.; Cohen, A.D.; Bish, D.L.
Small scale soil carbon and moisture gradients in a drained peat bog grassland and their influence on CO2, CH4 and N2O fluxes
NASA Astrophysics Data System (ADS)
Due to the UNFCCC report requirements of each country on the emissions of greenhouse gases from key sources the joint research project "Organic Soils" was established in Germany. The project's objective is to improve the data set on greenhousegas emissions from organic soils in Germany. Within 12 German Project Catchments emissions from different types of organic soils, e.g. under different land uses and hydrological conditions, are measured. At the location "Gro�es Moor" near Gifhorn (Lower Saxony) the effects of small-scale soil organic carbon and groundwater level gradients on the GHG fluxes (CO2, CH4 and N2O) are quantified. The study area is located within a former peat bog altered by drainage and peat cutting, which is currently grassland under extensive agricultural use. The focus of the study is on the acquisition of CO2, CH4 and N2O fluxes on six sites via manual closed chambers. In order to calculate the annual CO2 exchange rate, values are interpolated on a 0.5 hour scale between measurement campaigns. In combination with continually logged meteorological parameters, such as the photosynthetic active radiation as well as air and soil temperatures, we calculate the daily CO2 ecosystem exchange of the different sites. During the 2011 campaign, CO2 was determined as the most important greenhouse gas. The groundwater table was the dominant variable influencing gas emissions. Another important factor was the vegetation composition. In detail, highest CO2 emissions occurred with a water table of 40-50 cm below ground level, temperatures above 10�C and low plant biomass amounts. Due to the more complex formation of N2O by a number of processes, each being promoted by different soil conditions, the measurement of N2O fluxes in the field was complemented by a laboratory experiment. In this, the use of stable isotope tracer techniques enabled us to quantify the contribution of single biochemical pathways to the overall formation of N2O under controlled conditions. This together with the prediction of the systems CO2 exchange, gives valuable information on how degraded peatlands can be restored best or at least be cultivated in a way to achieve climate neutral conditions. Thus, our study improves the prediction, how peatland soils will react to changes of soil and climate conditions with respect to their greenhouse gas emissions.
Leiber-Sauheitl, K.; Fu�, R.; Freibauer, A.
Nitrate turnover in a peat soil under drained and rewetted conditions: results from a [(15)N]nitrate-bromide double-tracer study.
Under natural conditions, peatlands are generally nitrate-limited. However, recent concerns about an additional N input into peatlands by atmospheric N deposition have highlighted the risk of an increased denitrification activity and hence the likelihood of a rise of emissions of the greenhouse gas nitrous oxide. Therefore, the aim of the present study was to investigate the turnover of added nitrate in a drained and a rewetted peatland using a [(15)N]nitrate-bromide double-tracer method. The double-tracer method allows a separation between physical effects (dilution, dispersion and dislocation) and microbial and chemical nitrate transformation by comparing with the conservative Br(-) tracer. In the drained peat site, low NO3(-) consumption rates have been observed. In contrast, NO3(-) consumption at the rewetted peat site rises rapidly to about 100% within 4 days after tracer application. Concomitantly, the (15)N abundances of nitrite and ammonium in soil water increased and lead to the conclusion that, besides commonly known NO3(-) reduction to nitrite (i.e. denitrification), a dissimilatory nitrate reduction to ammonium has simultaneously taken place. The present study reveals that increasing NO3(-) inputs into rewetted peatlands via atmospheric deposition results in a rapid NO3(-) consumption, which could lead to an increase in N2O emissions into the atmosphere. PMID:24313368
Russow, Rolf; Tauchnitz, Nadine; Spott, Oliver; Mothes, Sibylle; Bernsdorf, Sabine; Meissner, Ralph
Combined Systems SOD Peat - Milled Peat.
National Technical Information Service (NTIS)
One of the purposes of this study, is to study how much milled peat a producer can get between and right after the sod peat harvests. The purpose of the study is also to identify the effect on the drying of the sod peat if the producer harvests the milled...
J. Sauli E. Jonsson A. Teljing
Function of peatland located on secondary transformed peat-moorsh soils on the purification processes of groundwater and the impact of pH on the rates of the elution of organic matter
The investigation of peatland is used to show the water quality functioning with respect to different forms of nitrogen and carbon. The purification of ground water by the transect of 4.5 km long consisting organic soils (peat-moorsh soils) was estimated. This transect is located in the Agroecological Landscape Park in Turew, 40 km South-West of Poznan, West Polish Lowland. There
Lech Wojciech Szajdak; Marek Szczepanski
Properties and structure of raised bog peat humic acids
NASA Astrophysics Data System (ADS)
Humic substances form most of the organic components of soil, peat and natural waters, and their structure and properties differ very much depending on their source. The aims of this study are to characterize humic acids (HAs) from raised bog peat, to evaluate the homogeneity of peat HAs within peat profiles, and to study peat humification impact on properties of HAs. A major impact on the structure of peat HAs have lignin-free raised bog biota (dominantly represented by bryophytes of different origin). On diagenesis scale, peat HAs have an intermediate position between the living organic matter and coal organic matter, and their structure is formed in a process in which more labile structures (carbohydrates, amino acids, etc.) are destroyed, while thermodynamically more stable aromatic and polyaromatic structures emerge as a result of abiotic synthesis. However, in comparison with soil, aquatic and other HAs, aromaticity of peat HAs is much lower. Comparatively, the raised bog peat HAs are at the beginning of the transformation process of living organic matter. Concentrations of carboxyl and phenolic hydroxyl groups change depending on the peat age and decomposition degree from where HAs have been isolated, and carboxylic acidity of peat HAs increases with peat depth and humification degree.
Klavins, Maris; Purmalis, Oskars
Heavy metal contents in surface soils along the Upper Scheldt river (Belgium) affected by historical upland disposal of dredged materials.
For several decades, periodical dredging of river sediments has been necessary to allow for shipping traffic on the river Scheldt. Sediments were disposed along the shores in the alluvial plain without concern for the potential presence of contaminants. The aim of this study was to survey the alluvial plains of the Upper Scheldt river in Belgium for the presence of old dredged sediment landfills, and to appraise the heavy metal contamination at these sites. Up to 82% of the areas that were affected by dredged sediment disposal was found to be polluted by at least one of the metals Cd, Cr, Zn or Pb. Concentrations of Cd, Cr and Zn were, in 10% of the cases, higher than 26, 1900 and 2800 mg/kg, respectively. Cu and Ni concentrations were of no environmental concern on any site. Trends in metal concentrations as a function of location and time were explored and discussed. The highest average concentrations of Cd, Cr, Cu, Pb and Zn were found in the most downstream quarter of the Upper Scheldt. Contents of Pb and Cu were significantly lower for sediments disposed after 1965, but no indication for improvement of the sediment quality with time was observed for Cd, Cr and Zn. The pollution levels encountered warrant for caution as most of the soils affected by historical dredged sediment disposal are currently in use for agriculture, nature development or forestry. PMID:12083701
Vandecasteele, Bart; De Vos, Bruno; Tack, Filip M G
Coupling of groundwater, river flow and rainfall in an upland floodplain
NASA Astrophysics Data System (ADS)
Upland floodplains provide an important function in regulating river flows and controlling the coupling of hillslope runoff with rivers. To investigate the responses of floodplain groundwater to river flows and rainfall events, a small floodplain in an upland area of the River Tweed catchment, Scotland, was characterised using geophysics, 3D geological mapping and hydrogeological testing; and monitoring undertaken from September 2011 to February 2013 of: groundwater levels in five pairs of piezometers; river stage and flow at the upstream and downstream limits of the study site; soil moisture on the adjacent hillslope; and meteorological parameters. Periodical groundwater chemistry and residence data were also collected. The floodplain aquifer is permeable throughout but partially stratified, comprising dominantly alluvial and glaciofluvial sandy gravels between 8 and 15m interspersed with thin, intermittent layers of low permeability silts, clays and peats. Overlying the gravel aquifer is a partial thin cover of low permeability alluvial silts, and it is underlain dominantly by low permeability glaciolacustrine silts and clays. High permeability solifluction deposits mantle much of the adjacent hillslope and provide a rapid connection to the floodplain aquifer. The unusually wet year of 2012 provides a good example of how a temperate upland floodplain responds to consistently high rainfall. Statistical analysis and graphical interpretation of groundwater level, rainfall, soil moisture and river stage demonstrates that: 1) dominant groundwater flow within the floodplain is in the same direction as the river, from up-valley to down-valley; 2) soil moisture in the hillslope is strongly correlated with local rainfall, but groundwater across much of the floodplain is more strongly influenced by river stage; except 3) groundwater near the edge of floodplain, which responds more slowly to local rainfall and river stage changes ; and 4) subsurface flow from the hillslope to the floodplain occurs during high rainfall events. A detailed investigation of three flood events, when the river rose above bank level and flooded adjacent fields and groundwater became artesian in parts of the floodplain, suggests that antecedent moisture conditions can partly explain the differences in groundwater response during different flood events, where high intensity or long duration rainfall can cause saturated soil conditions, reducing soil water storage capacity and hence promoting flood conditions. A conceptual model based on field data of groundwater flow after storm events during antecedent unsaturated and saturated soil conditions is presented.
Archer, Nicole; Dochartaigh, Brighid �.; MacDonald, Alan; Bonell, Mike; Black, Andrew; Coles, Neil
Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield
The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemistry parameters were evaluated for two separate years: 2005 and 2006. Results show agreement with other studies where watershed area, lake water pH, nutrient levels (specifically dissolved NO3--N) and dissolved iron are important factors controlling and/or predicting fish THg level. Exceeding all was the strong dependence of yellow perch THg level on soil A-horizon THg and, in particular, soil O-horizon THg concentrations (Spearman ?? = 0.81). Soil B-horizon THg concentration was significantly correlated (Pearson r = 0.75) with lake water THg concentration. Lakes surrounded by a greater percentage of shrub wetlands (peatlands) had higher fish tissue THg levels, thus it is highly possible that these wetlands are main locations for mercury methylation. Stepwise regression was used to develop empirical models for the purpose of predicting the spatial variation in yellow perch THg over the studied region. The 2005 regression model demonstrates it is possible to obtain good prediction (up to 60% variance description) of resident yellow perch THg level using upland soil O-horizon THg as the only independent variable. The 2006 model shows even greater prediction (r2 = 0.73, with an overall 10??ng/g [tissue, wet weight] margin of error), using lake water dissolved iron and watershed area as the only model independent variables. The developed regression models in this study can help with interpreting THg concentrations in low trophic level fish species for untested lakes of the greater Superior National Forest and surrounding Boreal ecosystem. ?? 2009 Elsevier B.V.
Gabriel, M. C.; Kolka, R.; Wickman, T.; Nater, E.; Woodruff, L.
Changes in the relationship between soil erosion and N loss pathways after establishing soil conservation systems in uplands of Northeast Thailand
Slow establishment of green barriers together with competition for nutrients and water between crops and contour hedges hamper their acceptance by rural communities in tropical mountainous regions. Alternatively, a combination of hedges\\/barriers and minimum tillage may shift the pathway of N losses from water erosion towards leaching. In Northeast Thailand, run-off, soil loss, N leaching (by resin cores) and crop
W. Pansak; T. H. Hilger; G. Dercon; T. Kongkaew; G. Cadisch
Artificial Dewatering of Peat.
National Technical Information Service (NTIS)
New information produced by a study of the literature and by outstanding experimental research is presented is this publication. The subjects dealt with are peat production methods based on artificial dewatering, peat structure, and the waterbinding prope...
M. Aho P. Pirkkonen R. Thun T. Peltola V. M. Luukkainen
Impact of fire on macropore flow and the hydraulic conductivity of near-surface blanket peat
NASA Astrophysics Data System (ADS)
Peatlands can be subject to wildfire or deliberate burning in many locations. Wildfires are known to impact soil properties and runoff production in most soil types but relatively little work has been conducted on peatlands. Furthermore in large parts of the UK uplands prescribed vegetation burning on peat has taken place at regular intervals (e.g. every 8-25 years) on patches of around 300-900 sq. metres over the past century to support increased grouse populations for sport shooting. However, there have been few studies on how these prescribed fires influence near-surface hydrology. It is known that macropores transport a large proportion of flow in near-surface peat layers and we investigated their role in flow transport for fire sites using tension infiltrometers. Measurements were performed, at replicated hillslope positions to control for slope position effects, on unburnt peat (U) and where prescribed burning had taken place two years (P2), four years (P4) and >15 years (P15+) prior to sampling. For the prescribed burning plots, vegetation burning had also occurred at around a 15-20 year interval for most of the past century. We also sampled a nearby wildfire site (W) with the same sampling design where wildfire had occurred four months prior to sampling. Both the contribution of macropore flow to overall infiltration, and the saturated hydraulic conductivity, were significantly lower in the recently burnt sites (W, P2, P4), compared to P15+ and U. There was no significant difference in macropore flow contributions, effective macroporosity and saturated hydraulic conductivity between P15+ and U. The results suggest fire influences the near-surface hydrological functioning of peatlands but that 'recovery' for some hydrological processes to prescribed vegetation burning may be possible within two decades if there are no further fires.
Holden, Joseph; Wearing, Catherine; Palmer, Sheila; Jackson, Benjamin; Johnston, Kerrylyn; Brown, Lee
National Technical Information Service (NTIS)
The MTT-12 peat loader is an improvement on the KTG-1A peat loader. A number of the parts of the latter are interchangeable with the MTT-12. The metal structure and hydraulic system have been improved. The output of the new peat loader is 25% greater than...
B. I. Bobrov D. I. Markov
Chemical properties of peat used in balneology
NASA Astrophysics Data System (ADS)
The physiological activity of peats is observed in human peat-bath therapy and in the promotion of growth in some plants. Balneological peat as an ecologically clean and natural substance is perceived as being more 'human friendly' than synthetic compounds. Poland has a long tradition of using balneological peat for therapeutic purposes. Balneological peat reveals a physical effect by altering temperature and biochemical effects through biologically active substances. It is mainly used for the treatment of rheumatic diseases that are quite common in Poland. Peat represents natural product. Physico-chemical properties of peat in particular surface-active, sorption and ion exchanges, defining their biological function, depend mainly on the chemical composition and molecular structure of humic substances representing the major constituent of organic soil (peat). The carbon of organic matter of peats is composed of 10 to 20% carbohydrates, primarily of microbial origin; 20% nitrogen-containing constituents, such as amino acids and amino sugars; 10 to 20% aliphatic fatty acids, alkanes, etc.; with the rest of carbon being aromatic. For balneology peat should be highly decomposed (preferably H8), natural and clean. The content of humic acids should exceed 20% of dry weight, ash content will be less than 15 15% of dry weight, sulphur content less than 0.3% of dry weight and the amount of water more than 85%. It will not contain harmful bacteria and heavy metals. Humic substances (HS) of peat are known to be macromolecular polydisperse biphyllic systems including both hydrophobic domains (saturated hydrocarbon chains, aromatic structural units) and hydrophilic functional groups, i. e having amphiphilic character. Amphiphilic properties of FA are responsible for their solubility, viscosity, conformation, surfactant-like character and a variety of physicochemical properties of considerable biologically practical significance. The chemical composition of peats depends significantly on the genesis of peatlands and the depth of sampling. The chemical properties of peat fulvic acids (FA) have some genetic peculiarities due to the specific conditions of the process of humification of peat-forming plants in mires. The process of humification in mires takes place in the top-forming layer under amphibious moisture conditions. Substances of microbial origin are water-soluble and can participate in the formation of peat FA to a little extent. So a main source of structural units for the peat HA and FA is suggested to be organic constituents of peat forming plants of various botanical composition. The content of aromatic units in peat FA was shown to depend on the content of lignin in peat-forming plants and also of the aromatization of polysaccharides mainly due to the transformation of cellulose. FA characterized lower than humic acids molecular weight (1000-30,000). FA's are composed of a series of highly oxidized aromatic rings with a large number of side chains. Building blocks are benzene carboxylic acids and phenolic acids. These are held together by hydrogen bonding van der Waals' forces and ionic bonding. FA contains larger concentrations of nitrogen. This fraction also contains a great deal of polysaccharide materials, as well as low molecular fatty acids and cytoplasmic constituents of microorganisms. These compounds are linear, flexible colloids at low concentrations, and spherical colloids at high solution concentrations and low pH values. A more adequate knowledge of the chemical structure of humic materials will assist us in better understanding the physiological effects and also the function of these macromolecules on the health that these materials are know to exert. This improved knowledge provides us better information on chemical structure of humic substances from peats, which are responsible for pharmacotherapeutic, pharmacokinetic and biopharmaceutical effect. This structure of FA creates proper conditions for uptake of nutrient as well as bioavailability of biologically active substances. The solubilization in water by
Szajdak, L.; H?ado?, T.
Peat, the precursor of coal, is composed primarily of plant components and secondarily of inorganic matter derived from a variety of sources. The elemental, mineralogic, and petrographic composition of a peat is controlled by a combination of both its botanical and depositional environment. Inorganic contents of peats can vary greatly between geographically separated peat bogs as well as vertially and horizontally within an individual bog. Predicting the form and distribution of inorganic matter in a coal deposit requires understanding the distribution and preservation of inorganic matter in peat-forming environments and diagenetic alterations affecting such material during late-stage peatification and coalification processes. 43 refs., 4 figs., 3 tabs.
Raymond, R. Jr.; Bish, D.L.; Cohen, A.D.
Function of peatland located on secondary transformed peat-moorsh soils on the purification processes of groundwater and the impact of pH on the rates of the elution of organic matter
NASA Astrophysics Data System (ADS)
The investigation of peatland is used to show the water quality functioning with respect to different forms of nitrogen and carbon. The purification of ground water by the transect of 4.5 km long consisting organic soils (peat-moorsh soils) was estimated. This transect is located in the Agroecological Landscape Park in Turew, 40 km South-West of Poznan, West Polish Lowland. There is this transect along Wysko? ditch. pH, the contents of total and dissolved organic carbon, total nitrogen, N-NO3-, N-NH4+ was measured. Additionally C/N factors of peats were estimated. The investigation has shown the impact of the peatland located on the secondary transformed peat - moorsh soils on the lowering of total nitrogen, ammonium, and nitrates as well as total and dissolved organic carbon in ground water. Peat-moorsh soils were described and classified according to Polish hydrogenic soil classification and World Reference Base Soil Notation. There are four investigated points along to Wyskoc ditch. Two times a month during entire vegetation season the following material was taken from this four chosen sites: samples of peat, from the depth of 0-20 cm, samples of water from the ditch, samples of ground water from wells established for this investigation. Samples of peat-moorsh soils were collected at the depth 0-20 cm. Soils were sampled two times a month from 10 sites of each site. Samples were air dried and crushed to pass a 1 mm-mesh sieve. These 10 sub-samples were mixed for the reason of preparing a 'mean sample', which used for the determination of pH (in 1M KCl), dissolved organic carbon (DOC), total organic carbon (TOC), total nitrogen (Ntotal), and N-NO3- as well as N-NH4+. In water from Wysko? ditch pH, Ntotal, N-NO3-, N-NH4+, DTC (dissolved total carbon) and DOC (dissolved organic carbon) was measured. Ground water samples were collected from four wells established for this investigation. The water was filtered by the middle velocity separation and pH, N-total, N-NO3-, N-NH4+, DTC (dissolved total carbon) and DOC (dissolved organic carbon) ware measured. Peatland located on the secondary transformed peat - moorsh soils has revealed the lowering in ground water: nitrates 38.5%, N-organic 10%, N-total 24.5%, ammonium 38.7%, dissolved total carbon 33.1%, dissolved total inorganic carbon 10%, and dissolved organic carbon 57.5%. The elution of soil organic matter from peat-moorsh soils in broad range of pH and ionic strength was investigated. The rates of the reaction were calculated from the kinetics of first order reaction model. All experiments were repeated at different pH 6.0, 6.5, 7.0, 8.0, 8.5 of 0.5 M ammonium acetate buffer solution. The investigations have shown the impact of the properties of secondary transformed peat-moorsh soils on the rates of the dissolution of organic matter. The rates of organic matter elution for all samples of peats were significant different at four used wavelengths ?=272 nm, ?=320 nm, ?=465 nm, and ?=665 nm. It was observed that the rates increased between ?=272 nm and ?=320 nm and decreased from ?=465 nm to ?=665 nm. Although, the lowest values of the pseudo first-order rate constants measured at ?=665 nm for all samples of peats from four places ranged from 1.9524 10-4 s-1 to 2.7361 10-4 s-1. Therefore, the highest values of t0.5 ranged from 42.2 to 59.2 min for all samples from Zb?chy, Shelterbelt, Mostek and Hirudo. This work was supported by a grant No. N N305 3204 36 founded by Polish Ministry of Education.
Wojciech Szajdak, Lech; Szczepa?ski, Marek
Peat dewatering: solvent extraction
The objective of this program is to determine the preliminary technical and economic feasibility of using IGT's solvent-extraction process for the dewatering of peat. Parallel objectives of the program are to: identify organic solvents that can be readily used to dewater raw peat by IGT's solvent-extraction process; design, construct, and operate bench-scale equipment for testing the most promising solvents; and estimate the preliminary economics of the process for a commerical-scale peat dewatering plant using a selective solvent. The results indicate that: solvent-extraction dewatering can remove up to 90% of the water in peat; and diethyl ketone (DEK) and benzene appear to dewater peat better than the other solvents tested. A preliminary economic evaluation of solvent-extraction dewatering of peat with DEK shows that the cost of this type of dewatering method is not currently competitive with other peat dewatering methods. (DWC)
Paganessi, J.E.; Mensinger, M.C.; Tsaros, C.L.; Arora, J.
Solidphase 31 P NMR spectra of peat and mineral soils, humic acids and soil solution components: influence of iron and manganese
Solid-phase31P nuclear magnetic resonance (NMR) offers a direct means to determine the chemical environment of P present in soil and soil\\u000a fractions. Iron is often a major component in soil and it has been thought that the presence of paramagnetic Fe and Mn in\\u000a soil components is responsible for loss of resolution in NMR spectra. We have found that the
C. A. Shand; M. V. Cheshire; C. N. Bedrock; P. J. Chapman; A. R. Fraser; J. A. Chudek
CO2 Efflux from Cleared Mangrove Peat
BackgroundCO2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils.Methodology\\/Principal FindingsWe measured CO2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance
Catherine E. Lovelock; Roger W. Ruess; Ilka C. Feller; Simon Thrush
Review of pre-treated peat applied in treating domestic wastewaters and oily waters
Peat is commonly used as a combustible fuel for energy and as an addictive to soil in horticulture. For hundreds of years, peat was widely used as a green energy source for heating in the northern parts of Europe and North America. Nowadays, people tend to lay decomposed peat on lawns or gardens as a top layer because of its
Xiao Jiang; Cynthia A. Coles; Emmanuel S. Asapo
Peat Archives: The Key To Unravel The Influence Of Peat Compaction On Delta Evolution
NASA Astrophysics Data System (ADS)
Peat is most compressible of all natural soils. Therefore, compaction of peat layers leads to substantial amounts of land subsidence. In Holocene deltas, which are often densely populated, subsidence due to peat compaction is caused by anthropogenic processes such as loading by construction works and groundwater level lowering, but also, a significant amount of compaction is caused by natural processes. However, there is a lack of knowledge concerning effects of peat compaction on the evolution of deltas, which is mainly due to a lack of field data and suitable methods to quantify peat compaction in fluvial-deltaic settings on Holocene time scales (100-103 years). Therefore, new field methods to measure the amount of peat compaction in fens and swamps are developed. These methods are based on 1) dry bulk density and organic matter content measurements in vertical peat profiles, 2) 14C dating and 3) detailed analysis of sediment sequence stratigraphy based on logged boreholes. A new coring device has been developed to collect sufficiently large samples of uncompacted (modern) peat, without disturbing the internal structure. We present data obtained with these methods from the Rhine-Meuse delta (The Netherlands), the Cumberland Marshes (Canada) and the Biebrza National Park (Poland). Values of up to about 50 % of compaction (percentage of the initial thickness) are observed at sites where the peat layer is relatively thick, has a high organic matter content and is overlain by a meters thick sediment overburden. It is hypothesized that accommodation space created by peat compaction is an important mechanism controlling the development of natural levees of low gradient rivers. Peat compaction underneath natural levees, and crevasse splay deposits, fixes river channels and prevents renewed avulsion, arguable the most important process controlling sediment distribution in deltas. Herewith, we contradict the hypothesis stating that subsidence due to peat compaction creates changes in cross-valley gradient which possibly drives avulsion. Avulsions in peatlands are controlled by other mechanisms than peat compaction. Results of this ongoing study are of high value for predicting sites of severe subsidence due to peat compaction and to determine its influence of delta evolution.
van Asselen, S.; Stouthamer, E.
Peat resource estimation in South Carolina. Final report, Year 2
South Carolina has few indigenous energy resources. Most widely known and utilized are hydropower, wood, and solar. Peat is a material composed of partially decomposed organic matter that, after burial for long periods of time, may eventually become coal. Peat is utilized as an energy resource for the production of electricity and for home heating in Europe and the Soviet Union. There are peat deposits in South Carolina, but peat has never been used as an energy resource within the state. This report presents the results of the two years of a planned four-year study of the quantity and energy potential of peat in South Carolina. In this year's survey two activities were undertaken. The first was to visit highly probable peat deposits to confirm the presence of fuel-grade peat. The second was to survey and characterize in more detail the areas judged to be of highest potential as major resources. The factors carrying the greatest weight in our determination of priority areas were: (1) a description of peat deposits in the scientific literature or from discussions with state and federal soil scientists; (2) mention of organic soils on soil maps or in the literature; and (3) information from farmers and other local citizens.
Holmes, M.; Andrejko, M.; Corvinus, D.; Tisdale, M.
An analysis of commercial vegetable farms in relation to sustainability in the uplands of Southeast Asia
Commercial vegetable production systems in the uplands of Southeast Asia are important to supplement the demand for fresh vegetables in lowland Asian cities. A farm survey and soil sampling was done to characterise and identify major factors limiting vegetable productivity in the uplands of the Manupali watershed, Mindanao, the Philippines. Large yield differences were found among the four most common
D. D. Poudel; D. J. Midmore; W. L. Hargrove
Peat, horticulture and environment
Peat-based growing media underpin the horticultural industry in the UK, although production sites cover less than 0.5% of the total peatland area. In recent years Peat Producer's Association members have released over 20% of their holdings to English Nature, representing virtually all the areas of current conservation value. The Association is now engaged in the assessment and development of restoration
R. A. Robertson
Peat biogasification development program
NASA Astrophysics Data System (ADS)
The design and operation of a peat anaerobic digestion process development unit is considered. Five areas are addressed: pretreatment information; anaerobic digestion; evaluation of waste streams; process model development and economic analysis; and planning for the process development unit. Data were taken for the development of the predictive process model. A number of batch and continuous pretreatment experiments were completed and analyzed. The four samples analyzed through solvent extration were completed, and the results are presented. Work on high pressure liquid chromatography continued, and the development of the gradient elution solvent system was completed with encouraging results. Pretreated peat was batch fermented; the continuously oxidized peat show conversions of close to 30 percent. This is significantly higher than the conversion for the batch oxidized peat. A predictive process model for the three phases of peat biogasification, solubilization, oxidation, and fermentation was developed.
Wise, D. L.
Oxidative ratio (OR) of UK peats
NASA Astrophysics Data System (ADS)
The oxidative ratio (OR) is the amount of CO2 sequestered in the terrestrial biosphere for each mol of O2 produced. The OR governs the effectiveness of a terrestrial biome to mitigate the impact of anthropogenic CO2 emissions and it has been used to calculate the balance of terrestrial and oceanic carbon sinks across the globe. However, few studies have investigated the controls of the variability in OR. What factors affect OR - climate? Soil type? Vegetation type? N deposition? Land use? Land use change? Small shifts in OR could have important implications in the global partitioning of CO2 between the atmosphere, biosphere, and oceans. This study looks at peat soils (Histosols) from a series of sites representing a climatic transect across the UK. Duplicate peat cores were taken, along with samples of above-ground vegetation and litter, from sites in northern Scotland (Forsinard), southern Scotland (Auchencorth), northern England (Moor House; Thorne Moor) through the Welsh borders (Whixhall Moss) and Somerset levels (Westhay Moor) to Dartmoor and Bodmin Moor in the south west of England. Sub-samples of the cores were analysed for their CHNO concentrations using a Costech ECS 4010 Elemental combustion system. Using the method of Masiello et al. (2008), OR values could be calculated from these elemental concentrations. Initial results show that OR values of UK peats varied between 0.94 and 1.1 with a median value of 1.05 which similar to the median value of World soils but the range is at the more reduced end. There was significant variation between peat cores, even between peat cores on the same site and the peat showed significant reduction in OR with depth in the core.
Clay, G. D.; Worrall, F.; Masiello, C. A.
Filling Holes in Regional Carbon Budgets: Predicting Peat Depth and Volume in a North- Temperate Lake District
NASA Astrophysics Data System (ADS)
Peat deposits are estimated to contain 1/6 of all terrestrial fixed carbon (C) globally, and C in peat far exceeds that in live vegetation in many north-temperate and boreal landscapes. Because surface peat is more vulnerable to oxidation than deeply-buried peat, knowledge of peat depth distribution is required in order to judge the vulnerability of a region's peat C stores. However, regional estimates of C stored in peatlands are typically uncertain, largely because variation in peat depth is not well understood. To estimate the amount and spatial distribution of peat C in the Northern Highlands Lake District (NHLD) in northern Wisconsin, which contains 20% peatlands by area, we sampled 21 peatlands during summer 2008. Our study addressed two questions: (1) How spatially variable are peat depth and volume within and among peatlands of the NHLD? (2) To what degree can peat depth and volume be predicted from available spatial and/or field data? In each peatland (area range 0.4 to 24 ha), peat depth was measured on a regular grid, and interpolated to calculate total peatland volume and mean peat depth. Among the 21 peatlands, mean peat depth ranged from 0.2 to 5.1 m, with an average of 1.9 m, while volume varied by 3 orders of magnitude. Peat depth varied more within than among peatlands, and the maximum measured depth was >15 m. Mean and maximum peat depth could be predicted from local slope at the peatland-upland interface, measured either in the field or using digital elevation (DEM) data. Strikingly, field measurements (water chemistry, water table depth, vegetation cover) failed to substantially improve slope-based models. As the DEM data are widely available, this technique has the potential to considerably improve regional estimates of C stored in peatlands.
Buffam, I.; Turner, M. G.; Yeck, W.; Hanson, P. C.; Carpenter, S. R.
Seasonal use of wetlands by upland wildlife is common; when uplands are dis� turbed. wildlife may use we I lands year�round. The structure and form of vegetation in wetlands is more important than species composition 10 upland wildlife. Wetlands may provide upland wildlife with food. escape cover. protection from inclement weather. and reproductive habitat. There has been little documentation of
Frank Schiloskey. Jr
An evaluation of SPOT-simulation imagery for land-use mapping and ecological investigations in upland areas of Northern Ireland
In Northern Ireland peat and marginal land dominate uplands, form significant cover in lowlands and, together with the small-scale intricate nature of field systems, result in a landscape unlike many other parts of the United Kingdom.Four cover types are considered in the analysis of SPOT-simulated imagery �peat, marginal land, forests and improved grassland. Results suggest potential use of SPOT in
N. L. Betts; M. M. Cruickshank; R. W. Tomlinson
Anthropogenic transformation of soils in the northern Ergeni Upland (studies at the first experimental plot of the Arshan'-Zelmen Research Station)
NASA Astrophysics Data System (ADS)
The results of soil studies performed in 2005-2009 at the first experimental plot of the Arshan'-Zelmen Research Station of the Institute of Forest Science of the Russian Academy of Sciences are discussed. The post-reclamation state (about 55 years after reclamation) of the soils under forest shelterbelts and adjacent croplands in the rainfed agriculture was studied. The long-term efficiency of forest reclamation and crop-growing technologies developed in the 1950s by the Dokuchaev Soil Science Institute and the Institute of Forest to reclaim strongly saline solonetzic soils was proved. In 55 years, strongly saline sodic solonetzes with sulfate-chloride and chloride-sulfate composition of salts were replaced by agrogenic soils with new properties. Under forest shelterbelts, where deep (40-60 cm) plowing was performed, the soils were transformed into slightly saline solonetzic agrozems with slight soda salinization in the upper meter and with dealkalized plowed and turbated horizons (0-20(40) cm). Under the adjacent cropland subjected to the influence of the shelterbelts on the soil water regime, strongly saline solonetzes were transformed into solonchakous agrosolonetzes with slight soda salinization in the upper 50 cm. In the plow layer, the content of exchangeable sodium decreased to 4-12% of the sum of exchangeable cations. An increased alkalinity and the presence of soda were found in the middle-profile horizons of the anthropogenically transformed soils.
Novikova, A. F.; Konyushkova, M. V.
The effects of salinization on aerobic and anaerobic decomposition and mineralization in peat meadows: The roles of peat type and land use.
Peat soils comprise a large part of the western and northern Netherlands. Drainage for agriculture has caused increased soil aeration which has stimulated decomposition and, hence, soil subsidence, currently amounting to 1-2�cm/yr. River water is supplied to these peat areas in summer to prevent drying out of the peat soils. Saltwater intrusion and evaporation make this surface water slightly brackish during drought periods. In addition, brackish seepage can surface more easily during such dry periods. We performed an incubation experiment in which the effects of salinization on aerobic decomposition and mineralization of shallow peat samples and anaerobic decomposition and mineralization of deep peat samples were studied. We considered four different types of peat samples: peat sampled in agricultural peat meadows and in nature reserves, originally formed under either eutrophic or oligotrophic conditions. The aerobic decomposition was approximately reduced by 50% after salinization, whereas the anaerobic decomposition rates remained unchanged. Remarkably, the response to salinization did not differ between the peat types and land uses. Ammonium concentrations increased while nitrate concentrations decreased after salinization, probably as a result of reduced nitrification. Especially in the oligotrophic peat, ammonium concentrations increased substantially. Phosphate concentrations increased, possibly caused by changes in desorption and adsorption processes due to higher ion concentrations. DOC concentrations decreased in the brackish samples due to precipitation. Furthermore, the eutrophic peat samples showed increasing sulfate concentrations, both in oxic and anoxic incubations, which was attributed to pyrite oxidation. Independently of salinization, nitrification rates were higher in the agricultural, fertilized, peat soils. In conclusion, while salinization might reduce subsidence rates, it will have adverse effects on water quality. PMID:24837279
Brouns, Karlijn; Verhoeven, Jos T A; Hefting, Mariet M
Inter-Specific Competition, but Not Different Soil Microbial Communities, Affects N Chemical Forms Uptake by Competing Graminoids of Upland Grasslands
Evidence that plants differ in their ability to take up both organic (ON) and inorganic (IN) forms of nitrogen (N) has increased ecologists� interest on resource-based plant competition. However, whether plant uptake of IN and ON responds to differences in soil microbial community composition and/or functioning has not yet been explored, despite soil microbes playing a key role in N cycling. Here, we report results from a competition experiment testing the hypothesis that soil microbial communities differing in metabolic activity as a result of long-term differences to grazing exposure could modify N uptake of Eriophorum vaginatum L. and Nardus stricta L. These graminoids co-occur on nutrient-poor, mountain grasslands where E. vaginatum decreases and N. stricta increases in response to long-term grazing. We inoculated sterilised soil with soil microbial communities from continuously grazed and ungrazed grasslands and planted soils with both E. vaginatum and N. stricta, and then tracked uptake of isotopically labelled NH4+ (IN) and glycine (ON) into plant tissues. The metabolically different microbial communities had no effect on N uptake by either of the graminoids, which might suggest functional equivalence of soil microbes in their impacts on plant N uptake. Consistent with its dominance in soils with greater concentrations of ON relative to IN in the soluble N pool, Eriophorum vaginatum took up more glycine than N. stricta. Nardus stricta reduced the glycine proportion taken up by E. vaginatum, thus increasing niche overlap in N usage between these species. Local abundances of these species in mountain grasslands are principally controlled by grazing and soil moisture, although our results suggest that changes in the relative availability of ON to IN can also play a role. Our results also suggest that coexistence of these species in mountain grasslands is likely based on non-equilibrium mechanisms such as disturbance and/or soil heterogeneity.
Medina-Roldan, Eduardo; Bardgett, Richard D.
Predicting soil respiration from peatlands.
This study considers the relative performance of six different models to predict soil respiration from upland peat. Predicting soil respiration is important for global carbon budgets and gap filling measured data from eddy covariance and closed chamber measurements. Further to models previously published new models are presented using two sub-soil zones and season. Models are tested using data from the Bleaklow plateau, southern Pennines, UK. Presented literature models include ANOVA using logged environmental data, the Arrhenius equation, modified versions of the Arrhenius equation to include soil respiration activation energy and water table depth. New models are proposed including the introduction of two soil zones in the peat profile, and season. The first new model proposes a zone of high CO(2) productivity related to increased soil microbial CO(2) production due to the supply of labile carbon from plant root exudates and root respiration. The second zone is a deeper zone where CO(2) production is lower with less labile carbon. A final model allows the zone of high CO(2) production to become dormant during winter months when plants will senesce and will vary depending upon vegetation type within a fixed location. The final model accounted for, on average, 31.9% of variance in net ecosystem respiration within 11 different restoration sites whilst, using the same data set, the best fitting literature equation only accounted for 18.7% of the total variance. Our results demonstrate that soil respiration models can be improved by explicitly accounting for seasonality and the vertically stratified nature of soil processes. These improved models provide an enhanced basis for calculating the peatland carbon budgets which are essential in understanding the role of peatlands in the global C cycle. PMID:23178842
Rowson, J G; Worrall, F; Evans, M G; Dixon, S D
The effects of ecological restoration on CO2 fluxes from a climatically marginal upland blanket bog
NASA Astrophysics Data System (ADS)
A legacy of gully incision, deposition of industrially-derived aerial pollutants, inappropriate management and wildfire has left large expanses of the topographic Bleaklow Plateau (Peak District National Park, England, UK) bare of vegetation and susceptible to massive erosion of the peat soils. The consequence of such degradation has been to decrease the capacity of the peatland on the plateau to provide important ecosystem services including; loss of net C sink function, discolouration of surface waters, mobilisation to surface waters of stored heavy metals and infilling of upland reservoirs with peat-derived sediment. In response to on-going and worsening degradation a programme of ecological restoration has been undertaken. Restoration methods include: seeding with a lawn grass mix; liming; fertilisation; slope stabilisation; and gully blocking. This talk will present data from a five-year, observational-study of CO2 fluxes from eight sites, with four sites sampling different restoration treatments and four sampling bare and least disturbed areas. The results of the analysis reveal that sites with revegetation alongside slope stabilisation were most productive and were the largest net (daylight hours) sinks of CO2. Unrestored, bare sites, while having relatively low gross fluxes of CO2 were the largest net sources of CO2. Revegetation without slope stabilisation took longer (~18 months) to show an impact on CO2 flux in comparison to the sites with slope stabilisation. Binary logistic regression indicated that a ten centimetre increase in water table depth decreases the odds of observing a net CO2 sink, on a given site, by up to 30%. Sites with slope stabilisation were between 5-8x more likely to be net CO2 sinks than the bare sites. Sites without slope stabilisation were only 2-2.3x more likely to be net CO2 sinks compared to the bare sites. The most important conclusion of this research is that revegetation appears to be effective at increasing the likelihood of net CO2 behaviour on degraded, climatically marginal blanket peat, with revegetation alongside slope stabilisation having the greatest impact.
Dixon, Simon; Qassim, Suzane; Rowson, James; Worrall, Fred; Evans, Martin
Environmental Controls over Peat Accumulation in Arctic Alaska
NASA Astrophysics Data System (ADS)
Wide spread accumulation of peat (paludification) began on Alaska's North Slope during the Pleistocene/Holocene transition starting ca. 12,000 14C years ago and established this region as a carbon sink. Its status as a C sink is in question today because of rapid climate change. Our project's focus is on the relationship between peat, microclimate, and topography in a portion of the Arctic Foothills 300-350 km south of Point Barrow on the northern flank of the Brooks Range. Our objectives are 1) Quantify how varying microclimate factors found along a climosequence determine the thickness of the thin surface peats (<50 cm) that have developed during the Holocene; 2) Estimate peat accumulation rates on level, initially well-drained geomorphic surfaces using a 3,000 year old chronosequence on river point bars; 3) Quantify how peat accumulation affects soil temperature regimes; 4) Develop a GIS-based peat-prediction model for a 50 km2 study area and estimate this area's pool of standing carbon. We used a combination of remotely sensed data, field measurements, and a GIS to gather data regarding slope, aspect, elevation, near-ground temperature, soil moisture, temperature at the organic/mineral horizon interface, solar radiation, upslope drainage area, and lastly, peat thickness. Peat is defined here as any near-surface soil horizon containing >25% organic carbon by volume. We employ statistical analyses to examine how each factor independently influences peat thickness and what suite of factors best explains peat distribution and thickness across the landscape. Results show a significant inverse relationship (R2 = 0.27, p-value <<.001) between slope and peat thickness, with an increase in steepness accompanying a decrease in peat thickness. There is a less significant relationship (R2 = 0.03, p-value = .02) between aspect and peat thickness. There is a significant positive relationship (R2 = 0.81, P-value <<.001) between peat thickness and July active layer thickness, indicating that peat thickness and below ground temperature regimes are highly correlated. We estimated time to paludification to be 300-600 years. Initial peat accumulation rates are 0.015 - 0.031 cm/yr (R2 = 0.56, P-value <<.001). There appears to be a temporal threshold along the chronosequence at approximately 400 years. After this point the peat accumulation rate is near zero and statistically insignificant (R2 = 0.02, P-value = 0.49). This could indicate that landscapes in the Arctic Foothills approach a stable state with regards to peat development rather quickly on the geologic time scale and challenges the idea of continuous peat accumulation. Results from this project will inform a geospatial model linking peat dynamics to climate change in arctic Alaska.
Baughman, C. A.; Mann, D. H.; Heiser, P. A.; Kunz, M. L.
Dynamic properties of Sherman Island peat
The dynamic properties of peat have been identified as a major source of uncertainty in the evaluation of seismic hazards throughout the Sacramento-San Joaquin Delta in northern California. This paper summarizes the results of a laboratory study of the dynamic properties of a layer of peaty organic soil underlying the south levee on Sherman Island near the western side of the delta. Conventional Shelby tube sampling procedures were able to obtain high-quality samples because of the compactness of this peat layer, located between depths of 9 and 16 m. The samples tested were very fibrous and had ash contents of 35--56%. Staged cyclic triaxial loading was used to measure the stress-strain behavior of several specimens under cyclic shear strains ranging from about 0.0005% to 10%. Other tests included piezo-ceramic bender element tests to measure the shear wave velocity of specimens within the triaxial device, and undrained monotonic triaxial compression and extension tests. The effects of loading frequency, cyclic degradation, consolidation stress history, and structural anisotropy are evaluated. The resulting modulus reduction and damping relationships for the Sherman Island peat are compared with published results for other peats, solid waste materials, and mineral soils.
Boulanger, R.W.; Arulnathan, R. [Univ. of California, Davis, CA (United States). Dept. of Civil and Environmental Engineering; Harder, L.F. Jr.; Torres, R.A.; Driller, M.W. [California Dept. of Water Resources, Sacramento, CA (United States)
Fluvial entrainment of low density peat blocks (block carbon)
NASA Astrophysics Data System (ADS)
In many fluvial environments low density materials are transported in significant quantities and these form an important part of the stream load and /or have a distinct impact on sedimentation in these environments. However, there are significant gaps in understanding of how these materials are entrained and transported by streams and rivers. Eroding upland peatland environments in particular, frequently have fluvial systems in which large eroded peat blocks, often exceeding 1 m in length; form an important component of the stream material flux. Transport of this material is significant in determining rates of erosion but also has important impacts in terms of damage to infrastructure and carbon loss. This paper describes a field experiment designed to establish for the first time the conditions under which large peat blocks (c. > 0.1 m b axis) are initially entrained from a rough gravel bed. The field site is Trout Beck, in the North Pennines, Northern England which is an upland wandering river channel with occasional lateral and mid channel bars. Mean low flow stage is typically 0.2 m but during flood can rapidly rise, in one to two hours, to over 1.5 m. To study peat block entrainment a bespoke data acquisition system consisting of two pressure transducers, four release triggers and time lapse camera was set up. The pressure transducers provided a record of local depth and the release triggers were embedded in peat blocks to record initial motion and arranged on the rough stream bed. The time lapse camera provided verification of timing of block entrainment (during daylight hours) and also provided information on the mechanism of initial movement. Peat blocks were cut from a local source and were equidimensional, ranging in size from 0.1 to 0.7 m. The derived entrainment function is related to a critical depth of entrainment. Results demonstrate that peat blocks are entrained when the local depth approximates the height of the peat block. Blocks frequently shift position prior to entrainment but once entrained are rapidly transported downstream. Because of the rough stream bed local depth, measured on the four sides of the block varies markedly and needs to be considered in developing an appropriate entrainment function and; is useful in explaining initial movement prior to entrainment. In some experiments a small accelerometer (HOBO Pendant G data logger) was used to investigate transport dynamics following entrainment. Further work will seek to improve the entrainment function by extending the size range of tests, developing a shear stress related function and investigating the importance of block shape (rounding) on entrainment.
Warburton, Jeff
Production of SOD Peat. Handbook.
National Technical Information Service (NTIS)
The aim of the study is to create a kind of handbook on sod peat production. The book would include all stages of sod peat production from selection of the bog to the transport and delivery of sod peat to users. The references used are mainly from Finnish...
A. Leinonen V. M. Luukkainen
Peat gasification: an experimental study
The United States has the second largest peat reserves in the world. The total energy contained in the peat resources (about 120 billion tons) is equivalent to 1440 quads or 240 billion barrels of oil. These enormous energy reserves in peat are greater than those estimated to be available from the reserves of uranium, oil shale, lignite, anthracite or natural
D. V. Punwani; S. P. Nandi; L. W. Gavin; J. L. Johnson
Temperature and peat type control CO2 and CH4 production in Alaskan permafrost peats.
Controls on the fate of ~277�Pg of soil organic carbon (C) stored in permafrost peatland soils remain poorly understood despite the potential for a significant positive feedback to climate change. Our objective was to quantify the temperature, moisture, organic matter, and microbial controls on soil organic carbon (SOC) losses following permafrost thaw in peat soils across Alaska. We compared the carbon dioxide (CO2 ) and methane (CH4 ) emissions from peat samples collected at active layer and permafrost depths when incubated aerobically and anaerobically at -5, -0.5, +4, and +20��C. Temperature had a strong, positive effect on C emissions; global warming potential (GWP) was >3� larger at 20��C than at 4��C. Anaerobic conditions significantly reduced CO2 emissions and GWP by 47% at 20��C but did not have a significant effect at -0.5��C. Net anaerobic CH4 production over 30�days was 7.1���2.8�?g CH4 -C gC(-1) at 20��C. Cumulative CO2 emissions were related to organic matter chemistry and best predicted by the relative abundance of polysaccharides and proteins (R(2) �=�0.81) in SOC. Carbon emissions (CO2 -C�+�CH4 -C) from the active layer depth peat ranged from 77% larger to not significantly different than permafrost depths and varied depending on the peat type and peat decomposition stage rather than thermal state. Potential SOC losses with warming depend not only on the magnitude of temperature increase and hydrology but also organic matter quality, permafrost history, and vegetation dynamics, which will ultimately determine net radiative forcing due to permafrost thaw. PMID:24616169
Treat, C C; Wollheim, W M; Varner, R K; Grandy, A S; Talbot, J; Frolking, S
The short-term effects of ecological restoration on carbon dioxide fluxes from a Molinia caerulea dominated marginal upland blanket bog.
NASA Astrophysics Data System (ADS)
Peat soils in the UK represent a significant long-term carbon store. Despite this the annual imbalance between uptake and release is small and susceptible to change in response to land management, atmospheric deposition and climate change. The shallow marginal peatlands of Exmoor, southwest England, have historically been subject to extensive drainage and are known to be vulnerable to future changes in climate as they lie at the southern edge of the ombrotrophic peatland climatic envelope. However little is known about the processes that drive CO2 fluxes from degraded Molinia caerulea dominated upland mires or the potential effect that restoration through drainage blocking will have. The Mires-on-the-Moors project (www.upstreamthinking.org), funded by South West Water aims to restore the eco-hydrological functionality to over 2000 hectares of drained mire by April 2015. We hypothesised that such mire restoration will return these upland mires to peat forming/carbon sequestering systems. Partitioned below-ground respiration fluxes as well as biotic and abiotic variables, were collected on various dates in 2012 and 2013 along six transects adjacent to three pairs of drainage ditches. One of each pair was restored by blocking with peat dams in spring 2013 whilst the other remained unrestored to act as a control. Monitoring locations were arranged along transects to investigate the spatial variation in gas fluxes with respect to the drainage ditches. By partitioning below-ground fluxes it was possible to monitor root-derived (autotrophic) and more importantly soil-derived (heterotrophic) respiration providing an insight to the effects of ditch blocking on the long term carbon store. Here we present CO2 fluxes for the growing seasons at two critical stages in the restoration process: (a) immediately pre-restoration and (b) immediately post- restoration, and discuss the temporally and spatially variable processes driving below-ground CO2 fluxes. Respiration rates were comparatively low in these shallow humified peats, with daily mean total, heterotrophic and autotrophic respiration reached 1.34, 0.60 and 0.23 ?molCm-2s-1 respectively. As expected soil temperature had a significant control on respiration rates, once this was accounted for water level showed a weak effect on total and heterotrophic respiration. Distinguishing the effects of ecological restoration between a wetter baseline period and a drier post-restoration period had its challenges. However, by expressing the respiration rates in the restored sites as a proportion of that observed in the control sites, the confounding effect of climate variability could be accounted for. This allowed us to determine that heterotrophic respiration decreased at the restored sites comparative to the control sites following restoration, indicating the immediate effect of restoration was to reduce decomposition of the peat store, with implications for carbon sequestration rates.
Gatis, Naomi; Luscombe, David; Grand-Clement, Emilie; Hartley, Iain; Anderson, Karen; Brazier, Richard E.
Uplands and Land Use Decision Making.
ERIC Educational Resources Information Center
This material includes student guide sheets, reference material, and tape script for the audio-tutorial unit on uplands. A set of 35mm slides and an audio tape are used with the materials. The material is designed for use with Connecticut schools, but can be adapted to other localities. The materials consider types of uplands, ecology of uplands,�
Smith, Dwight G.
Ryholms torv. (Ryholm's Peat).
National Technical Information Service (NTIS)
The purpose was to develop a system for production of dry peat fuel year around. An essential part in the system was to be the fluidized bed dryer developed by ABB STAL. Between the autumn of 1984 until the summer of 1985 the first stage of the project wa...
R. Matsson J. Wilde
Peat semicoking and hydrocracking
This work deals with thermochemical conversion of peat into solvent-soluble oil and volatile gaseous products by using pyrolysis and catalytical hydrocracking methods. Distribution of liquid compounds between solubilized in water, benzene, and in acetone was determined and as a result the oil yield as total solubles was calculated. Chromatographic and FTIR-spectroscopic methods were used to characterize the composition of conversion
Hans Luik; Vilja Palu; Lea Luik; Julia Sokolova; J�rgen Bojesen-Koefoed
Alfred P. Dachnowski and the scientific study of peats
Botanist Alfred Paul Dachnowski (1875�1949) was a major contributor to efforts at mapping organic soils in the United States during the early 20th century. He began his career at The Ohio State University, and spent most of his professional life at the U.S. Department of Agriculture in Washington, DC. His work spanned a diversity of topics, including bog ecology and the ecosystem services provided by wetlands, the mapping and chemical characterization of peat, and the commercial applications of peat. We present a biography and overview of his work. Dachnowski is best known today for the peat sampler that bears his name. The details of its operation are described here, and its place in modern peat studies is discussed.
Landa, E. R.; Cohen, K. M.
The Sonoran Desert, Arizona Upland
NSDL National Science Digital Library
This tutorial explains the ecosystem of the Arizona Upland region of the Sonoran Desert and describes the plants and animals that live there. Students will discover the interactions of the living and non-living parts of the ecosystem. There is an interactive glossary within the text.
Peat has been identified in Cost Rica, and an economic analysis of energy applications for peat has been done. About 1000 km{sup 2} of Cost Rica has the potential of being covered by peat. The Talamanca Mountains and the northeastern plains contain most of the Costa Rican peat. Specific bogs have been identified by the Medio Queso River in north-central Costa Rica and near El Cairo, Moin, and the Limon airport in northeastern Costa Rica. The Medio Queso bog, which is supplying peat for use as a carrier for nitrogen-fixing bacteria, and the El Cairo bog, which has been identified as a source of horticultural peat for nearby ornamental plant farms, are of special interest. The economics of three energy applications of peat were examined -- as a fuel in large boilers, as a fuel in small boilers, and as an oil substitute in a cement plant. A facility using coal would have the same total costs as one using peat if coal prices were $45 and $30 per metric ton (used for large boilers and a cement plant, respectively). A facility using Bunker C or diesel would have the same total cost as one using peat if oil prices were $0.11, $0.08, and $0.06 per liter (used for large boilers, small boilers, and a cement plant, respectively). In all three cases, the costs for peat were comparable or less than the costs for coal and oil at 1987 prices. 6 refs., 8 figs.
Thayer, G.R.
Not less than 2% of the Earth's land surface is peat-covered, so it is important to try to understand the dynamics of peat accumulation. Peat-forming systems (mires) accumulate peat because conditions within them impede the decay of the plant material produced by their surface vegetation. This paper concerns the rate of peat production and some unexpected consequences of the processes
R. S. Clymo
Chemical properties of peat used in balneology
The physiological activity of peats is observed in human peat-bath therapy and in the promotion of growth in some plants. Balneological peat as an ecologically clean and natural substance is perceived as being more 'human friendly' than synthetic compounds. Poland has a long tradition of using balneological peat for therapeutic purposes. Balneological peat reveals a physical effect by altering temperature
L. Szajdak; T. Hladon
Water source utilization and foliar nutrient status differs between upland and flooded plant communities in wetland tree islands
Tree islands in the Everglades wetlands are centers of biodiversity and targets of restoration, yet little is known about\\u000a the pattern of water source utilization by the constituent woody plant communities: upland hammocks and flooded swamp forests.\\u000a Two potential water sources exist: (1) entrapped rainwater in the vadose zone of the organic soil (referred to as upland soil\\u000a water), that
Amartya K. SahaLeonel da Silveira; Leonel da Silveira O�Reilly Sternberg; Michael S. Ross; Fernando Miralles-Wilhelm
Processes and mechanisms controlling consumption of CFC11 and CFC12 by peat from a conifer-swamp and black spruce-tamarack bog in New York State
We evaluated the potential consumption of chlorofluorocarbons CFC-11 and CFC-12 by peat soil from a conifer swamp and a temperate bog in New York State in order to assess whether extensive northern peatlands might serve as a sink for atmospheric CFCs. Intact peat cores maintained with an anoxic headspace over the peat surface consumed CFC-11 and minor amounts of CFC-12.
M. R. Bauer; J. B. Yavitt
Chemical and mineralogical weathering rates and processes in an upland granitic till catchment in Scotland
Weathering in an upland granitic till catchment receiving an intermediate level of acidic deposition has been studied by chemical and mineralogical analyses of soil profiles and chemical analysis of precipitation and streamwater. Long-term weathering rates for base cations calculated from analyses of soil profile horizons using Zr as an internal, immobile, index element are similar for alpine podzols and peaty
D. C. Bain; A. Mellor; M. J. Wilson; D. M. L. Duthie
Physical and thermochemical properties of uncontaminated and diesel-contaminated peat
Peat, plant matter that is partially fossilized, is formed in poorly oxygenated wetlands where the rate at which the plant matter accumulates is greater than the rate at which it decomposes. Peat is a common solid fuel ranking among coal, coke, wood, and sugarcane bagasse. It has also been used to recover oil during the remediation processes of contaminated water and soil. Because of its high moisture content, peat has a high potential as biofuel material for gasification. However, proper understanding of the physical and thermochemical properties of peat is necessary for the design of thermochemical conversion systems. This study provides information on moisture content, bulk density, particle size, heating values, proximate analysis, ultimate analysis, ash composition, and ash fusibility characteristics of uncontaminated and diesel-contaminated peat. The moisture content of uncontaminated peat was 7.10%, whereas that of diesel-contaminated peat ranged from 8.65% to 10.80%. The bulk density for the uncontaminated peat was 151 kg/m{sup 3}, which increased to 391--534 kg/m{sup 3} due to diesel contamination. Most of the particles (60%) were in the form of dust. The results also showed an ash content of 3.23% and the lower heating value of 17.65 MJ/kg (dry weight basis) for the uncontaminated peat. The ash content decreased substantially, whereas the lower heating value increased due to diesel contamination. The ash fusion temperature of the peat was found to be over 1100 C.
Ghaly, R.A.; Pyke, J.B.; Ghaly, A.E.; Ugursal, V.I. [Dalhousie Univ., Halifax, Nova Scotia (Canada)
The legacy of wetland drainage on the remaining peat in the Sacramento San Joaquin Delta, California, USA
Throughout the world, many extensive wetlands, such as the Sacramento-San Joaquin Delta of California (hereafter, the Delta), have been drained for agriculture, resulting in land-surface subsidence of peat soils. The purpose of this project was to study the in situ effects of wetland drainage on the remaining peat in the Delta. Peat cores were retrieved from four drained, farmed islands and four relatively undisturbed, marsh islands. Core samples were analyzed for bulk density and percent organic carbon. Macrofossils in the peat were dated using radiocarbon age determination. The peat from the farmed islands is highly distinct from marsh island peat. Bulk density of peat from the farmed islands is generally greater than that of the marsh islands at a given organic carbon content. On the farmed islands, increased bulk density, which is an indication of compaction, decreases with depth within the unoxidized peat zone, whereas, on the marsh islands, bulk density is generally constant with depth except near the surface. Approximately 5580 of the original peat layer on the farmed islands has been lost due to land-surface subsidence. For the center regions of the farmed islands, this translates into an estimated loss of between 29005700 metric tons of organic carbon/hectare. Most of the intact peat just below the currently farmed soil layer is over 4000 years old. Peat loss will continue as long as the artificial water table on the farmed islands is held below the land surface. ?? 2009 The Society of Wetland Scientists.
Drexler, J. Z.; De Fontaine, C. S.; Deverel, S. J.
Peat-Fired Electric Power Plants.
National Technical Information Service (NTIS)
The Swedish resources of peat are of significance for the energy supply in the country. Peat is now successively being taken into use especially for district heating. Considerable parts of the peat resources are, however, located far from densely populate...
R. Hardell
Land-Use Sustainability of Composite Swiddening in the Uplands of Northern Vietnam: Nutrient Balances of Swidden Fields during the Cropping Period and Changes of Soil Nutrients over the Swidden Cycle
This study examined the sustainability of the swidden component of the composite swiddening system practiced by the Tay ethnic minority in Tat hamlet, Hoa Binh province in Northern Vietnam. This farming system is thought to be suitable for the uplands where land degradation is a serious problem. The common swidden rotation of two years of rice, two years of cassava
N. T. Lam; A. Patanothai; V. Limpinuntana; P. Vityakon
Biochemical processes of oligotrophic peat deposits of Vasyugan Mire
NASA Astrophysics Data System (ADS)
The problem of peat and mire ecosystems functioning and their rational use is the main problem of biosphere study. This problem also refers to forecasting of biosphere changes results which are global and anthropogenic. According to many scientists' research the portion of mires in earth carbon balance is about 15% of world's stock. The aim of this study is to investigate biochemical processes in oligotrophic deposits in North-eastern part of Vasyugan Mire. The investigations were made on the territory of scientific-research ground (56�? 03� and 56�? 57� NL, 82�? 22� and 82�? 42� EL). It is situated between two rivers Bakchar and Iksa (in outskirts of the village Polynyanka, Bakchar region, Tomsk oblast). Evolution of investigated mire massif began with the domination of eutrophic phytocenosis - Filicinae, then sedge. Later transfer into oligotrophic phase was accompanied by formation of meter high-moor peat deposit. The age of three-meter peat deposit reaches four thousand years. Biochemical processes of carbon cycle cover the whole peat deposit, but the process activity and its direction in different layers are defined by genesis and duration of peat formation. So, the number of cellulose-fermenting aerobes in researched peat deposits ranges from 16.8 to 75.5 million CFU/g, and anaerobic bacteria from 9.6 to 48.6 million CFU/g. The high number of aerobes is characteristic for high water levels, organizing by raised bog peats. Their number decreases along the profile in 1.7 - 2 times. The number of microflora in peat deposit is defined by the position in the landscape profile (different geneses), by the depth, by hydrothermic conditions of years and individual months. But microflora activity shows along all depth of peat deposit. We found the same in the process of studying of micromycete complex structure. There was revealed either active component micromycete complex - mycelium, or inert one - spores in a meter layer of peat deposit. If mushrooms spores are observed in all deposit layers, mycelium of mushrooms deepens into the peat deposit (to 2 meters) within the limits of aerobic (meter) zone and only in particular months of dry years. The existence of seasonal dynamics of eukaryotic cells, and also capability of yeast and other groups of micromycetes for growth, testifies about vital activity of a number of eukaryotic cells at a depth of 2 meters. Researched peat deposits are biochemically active along the whole profile. But they are different in a microflora number of individual physiological groups either in items of the landscape, or in deposit depth. The largest quantity of aerobic cellulose-fermenting microorganisms is marked during dry years. Anaerobic cellulose-fermenting microorganisms dominate during wet years. The quantity of microbe biomass increases in bottom lifts of peat deposits. This fact testifies about viable condition of microbe complex at depth. The formation process of carbon dioxide in peat deposits of Vasyugan Mire actively occurs during dry years and is defined by hydrothermic conditions of a meter layer of peat deposit. The intensity of CO2 isolation for certain correlates with the temperature in horizon of 0 - 50 sm. and with bog waters level. The study of gas composition for the three years showed that the largest concentration of carbon dioxide in peat soils is marked along the whole profile during a dryer year (0.08 - 2.65 millimole/l), increasing other years' level in about 1.5 0 2 times. Emission of carbon dioxide in peat
Inisheva, L. I.; Sergeeva, M. A.
Understanding fine sediment and phosphorous delivery in upland catchments
NASA Astrophysics Data System (ADS)
The uplands of UK are heavily impacted by land management including; farming and forestry operations, moorland burning, peat extraction, metal mining, artificial drainage and channelisation. It has been demonstrated that such land management activity may modify hillslope processes, resulting in enhanced runoff generation and changing the spatial distribution and magnitude of erosion. Resultantly, few upland river systems of the UK are operating in a natural state, with land management activity often resulting in increased fluxes of suspended sediment (< 2 mm) and associated pollutants (such as phosphorous). Most recent Environment Agency (EA) data reveals that 60% of monitored water bodies within upland areas of the UK are currently at risk of failing the Water Framework Directive (WFD) due to poor ecological status. In order to prevent the continual degradation of many upland catchments, riverine systems and their diverse ecosystems, a range of measures to control diffuse pollution will need to be implemented. Future mitigation options and measures in the UK may be tested and targeted through the EA's catchment pilot scheme; DEFRA's Demonstration Test Catchment (DTC) programmes and through the catchment restoration fund. However, restoring the physical and biological processes of past conditions in inherently sensitive upland environments is extremely challenging requiring the development of a solid evidence base to determine the effectiveness of resource allocation and to enable reliable and transparent decisions to be made about future catchment operations. Such evidence is rarely collected, with post-implementation assessments often neglected. This paper presents research conducted in the Morland sub-catchment of the River Eden within Cumbria; UK. 80% of this headwater catchment is in upland areas and is dominated by improved grassland and rough grazing. The catchment is heavily instrumented with a range of hydro-meteorological equipment. A high-tech monitoring station at the 12.5 km2 outlet provides flow, turbidity, total phosphorous (TP), total reactive phosphorous (TRP), conductivity, temperature and pH measurements at 15-minute intervals. Within this catchment, two additional monitoring stations along adjacent tributaries with catchment areas of 2.3 km2 and 3.8 km2 provide continuous flow and turbidity data with soluble reactive phosphorous and TP collected during storms. Collection and analysis of this data over two full hydrological years has proved effective in; a) producing load estimates; b) producing better assessments of the magnitude and duration of aquatic organisms exposure to detrimental levels of suspended sediment and phosphorous; c) exploring the processes responsible for the delivery and transfer of fine sediment and phosphorous to and from the channel and; d) enhancing our understanding and prediction of the fluvial sediment system. The process understanding achieved using this monitoring framework has facilitated the production of a mitigation plan for the Morland catchment. Following this plan, a range of measures are currently being implemented to reduce the movement of diffuse pollutants across the hillslopes and channels whilst in-stream monitoring continues. The adopted mitigation measures may act as a trial for other upland catchments facing similar pressures.
Perks, M. T.; Reaney, S. M.
Dissipation of racemic mecoprop and dichlorprop and their pure R-enantiomers in three calcareous soils with and without peat addition
Two racemic herbicides, mecoprop (R,S-MCPP) and dichlorprop (R,S-DCPP), as well as their enantiopure R-forms, were incubated in three calcareous soils at 15�C and 80% of their field capacity to try to elucidate their behaviour in soil and compare the dissipation rates when racemic and enantiopure compounds are used. Quantitation of pesticides is made by HPLC and the R\\/S ratio by
E Romero; M. B Matallo; A Pe�a; F S�nchez-Rasero; Ph Schmitt-Kopplin; G Dios
Peat respiration at low temperatures
The peatlands of northern latitudes represent an enormous store of organic carbon. The decomposition of peat and the release of carbon dioxide is expected to increase with temperature as a result of climate change. CO2 emission and O2 uptake were measured during laboratory incubations of homogenised peat samples from 15 sites in Scotland. These were made either at fixed temperatures
S. J. Chapman; M. Thurlow
Transport and fate of trifluoroacetate in upland forest and wetland ecosystems.
Although trifluoroacetate (TFA), a breakdown product of chlorofluorocarbon replacements, is being dispersed widely within the biosphere, its ecological fate is largely unknown. TFA was added experimentally to an upland, northern hardwood forest and to a small forest wetland ecosystem within the Hubbard Brook Experimental Forest in New Hampshire. Inputs of TFA were not transported conservatively through these ecosystems; instead, significant amounts of TFA were retained within the vegetation and soil compartments. More TFA was retained by the wetland ecosystem than by the upland forest ecosystem. Using simulation modeling, TFA concentrations were predicted for soil and drainage water until the year 2040. PMID:9114018
Likens, G E; Tartowski, S L; Berger, T W; Richey, D G; Driscoll, C T; Frank, H G; Klein, A
Climate sensitivity and macronutrient regulation of peat decomposition
NASA Astrophysics Data System (ADS)
Organic soils act as vital global carbon stores maintained in northern latitudes by climate and nutrient limited rates of organic matter decomposition. Peatland decomposition rates are sensitive to climate change, however predicting the magnitude of the microbial respiratory response is complex due to unknown interactions between climate and substrate quality. The nutrient status of peatlands varies widely from mineral rich fens to nutrient poor ombrotrophic bogs, which have the potential to respond differently to climate driven changes in temperature and carbon (C) inputs. In this work we examine the links between peatland macronutrient C, phosphorus (P) and nitrogen (N) stoichiometry, microbial community structure and the microbial response to direct and indirect effects of climate change. Using total soil C:N and C:P ratios to define nutrient gradients in organic soils from Svalbard and Finland we investigated the interaction between the microbial response to temperature and nutrient limitation of decomposition. In organic rich soils from Svalbard we found there was a significant relationship between increasing temperature sensitivity of respiration and decreasing total soil P concentrations. Further investigation of the potential direct link between P limitation of decomposition and increased temperature sensitivity along a minerotrophic-ombroptrophic gradient in Finland was performed using multi-factorial P limitation assays. These showed that despite varying degrees of P limitation across four peatland soils there was no relationship between P limitation and increased temperature sensitivity of soil respiration. Throughout this study we found consistently high temperature sensitivity of decomposition in organic rich soils with Q10 values ranging between 2 to 4.5, indicating potentially higher vulnerability of these C stores to warming than is currently predicted using a globally invariant Q10. Following on from this we examined the interaction between peatland nutrient status and the potential for labile C substrates to stimulate (prime) decomposition of the peat organic matter. Using 13C labelled glucose and hemicellulose compounds we observed significant differences in the amount and rate of microbial substrate use between peats with differing nutrient status. Nutrient addition experiments were used with labelled C substrates to investigate the role of N and P limitation in enhancing or restricting priming effects. This is one of the first studies to use 13C substrates to examine potential priming effects in peat soil and it provides an insight into the importance of priming mechanisms in peat decomposition. This work explicitly links soil microbial responses to temperature and nutrient manipulations with microbial community structure allowing us to observe how microbial communities mediate soil C losses in peat soils. Disentangling the complex interactions between soil microbial community, C and nutrient limitation of decomposition is essential for predicting the vulnerability of different peatland ecosystems to climate driven changes.
Marshall, Rachel; Ostle, Nick; McNamara, Niall; Baggs, Elizabeth
Pollutants dynamics in a rice field and an upland field during storm events
NASA Astrophysics Data System (ADS)
We investigated the dynamics of pollutants such as total nitrogen (TN), total phosphorous (TP), biochemical oxygen demand (BOD), chemical oxygen demand (COD), and suspended sediment (SS) in runoff from a rice field and an upland field near the upper stream of the Han river in South Korea for multiple storm events. The upland field was cropped with red pepper, sweet potato, beans, and sesame. Runoff from the rice field started later than that from the upland field due to the water storage function of rice field. Unlike the upland field, runoff from the rice field was greatly affected by farmers' water management practices. Overall, event mean concentrations (EMCs) of pollutants in runoff water from the upland field were higher than those from the rice field. Especially, EMCs of TP and SS in runoff water from the upland field were one order of magnitude higher than those from the rice field. This may be because ponding condition and flat geographical features of the rice field greatly reduces the transport of particulate phosphorous associated with soil erosion. The results suggest that the rice field contributes to control particulate pollutants into adjacent water bodies.
Kim, Jin Soo; Park, Jong-Wha; Jang, Hoon; Kim, Young Hyeon
Age Determination of the Remaining Peat in the Sacramento-San Joaquin Delta, California, USA
Introduction The Sacramento-San Joaquin Delta of California was once a 1,400 square kilometer (km2) tidal marsh, which contained a vast layer of peat ranging up to 15 meters (m) thick (Atwater and Belknap, 1980). Because of its favorable climate and highly fertile peat soils, the majority of the Delta was drained and reclaimed for agriculture during the late 1800s and early 1900s. Drainage of the peat soils changed the conditions in the surface layers of peat from anaerobic (having no free oxygen present) to aerobic (exposed to the atmosphere). This change in conditions greatly increased the decomposition rate of the peat, which consists largely of organic (plant) matter. Thus began the process of land-surface subsidence, which initially was a result of peat shrinkage and compaction, and later largely was a result of oxidation by which organic carbon in the peat essentially vaporized to carbon dioxide (Deverel and others, 1998; Ingebritsen and Ikehara, 1999). Because of subsidence, the land-surface elevation on farmed islands in the Delta has decreased from a few meters to as much as 8 m below local mean sea level (California Department of Water Resources, 1995; Steve Deverel, Hydrofocus, Inc., written commun., 2007). The USGS, in collaboration with the University of California at Davis, and Hydrofocus Inc. of Davis, California, has been studying the formation of the Delta and the impact of wetland reclamation on the peat column as part of a project called Rates and Evolution of Peat Accretion through Time (REPEAT). The purpose of this report is to provide results on the age of the remaining peat soils on four farmed islands in the Delta.
Drexler, Judith Z.; de Fontaine, Christian S.; Knifong, Donna L.
Second technical contractors' conference on peat
This conference reported the status of the US Department of Energy Peat Program. The program includes peat resource surveys of eleven states, peat gasification process and equipment studies, dewatering studies, and environmental and socioeconomic factors in the development of peat technology. Separate abstracts were prepared for selected papers. (CKK)
Not Available
Runoff generation and water table fluctuations in blanket peat: evidence from UK data spanning the dry summer of 1995
Understanding of the hydrology of upland blanket peatlands has been limited both by the logistical difficulties of obtaining data from such environments and by technical difficulties with plot scale investigations of peat hydrology. The relative importance of infiltration-excess and percolation-excess as runoff generating mechanisms as opposed to the saturation-excess mechanism remains unclear. This study uses catchment-scale runoff data, in combination
M. G. Evans; T. P. Burt; J. Holden; J. K. Adamson
The authors compare the competitive position of peat for energy with coal, oil, and cogenerative systems in gasifiers and solid-fuel boilers. They also explore the possibility for peat use in industry. To identify the major factors, they analyze costs using a Los Alamos levelized cost code, and they study parametric costs, comparing peat production in constant dollars with interest rates and return on investment. They consider costs of processing plant construction, sizes and kinds of boilers, retrofitting, peat drying, and mining methods. They examine mining requirements for Moin, Changuinola, and El Cairo and review wet mining and dewatering methods. Peat can, indeed, be competitive with other energy sources, but this depends on the ratio of fuel costs to boiler costs. This ratio is nearly constant in comparison with cogeneration in a steam-only production system. For grate boilers using Costa Rican high-ash peat, and for small nonautomatic boilers now used in Costa Rica, the authors recommend combustion tests. An appendix contains a preliminary mining plan and cost estimate for the El Cairo peat deposit. 8 refs., 43 figs., 19 tabs.
Thayer, G.R.; Williamson, K.D. Jr. (Los Alamos National Lab., NM (USA)); Ramirez, O. (RECOPE, San Jose (Costa Rica))
An overview of peat gasification
NASA Astrophysics Data System (ADS)
Thermal and biological peat gasification processes are reviewed, with research showing that peat is high in both oxygen and hydrogen, and also nitrogen, which can be used to form ammonia as a byproduct. The hydrogen-carbon ratio of peat has been shown to exceed that of subbituminous coal, indicating less of a need to supply more hydrogen in the formation of gaseous fuels. The gasification process involves crushing the peat into particles smaller than 2 mm, which cascade through drying air into a gasifier, where gases from the hydrogasifier induce hydropyrolysis. The char then flows into a reactor with steam and oxygen to make synthesis gas. Minnesota peat has shown the highest hydrocarbon yields in the U.S., and economic comparisons show peak gasification has economic parity with other means of producing SNG. Experiments have also shown the feasibility of wet peat conversion using a peat-water slurry in an anaerobic digestor to produce methane. Building of pilot plants is suggested as necessary to verify existing processes.
Punwani, D. V.
What controls the oxidative ratio of UK peats? A multi-site study of elemental CHNO concentrations in peat cores
NASA Astrophysics Data System (ADS)
The oxidative ratio (OR) is the amount of CO2 sequestered in the terrestrial biosphere for each mol of O2 produced. The OR governs the effectiveness of a terrestrial biome to mitigate the impact of anthropogenic CO2 emissions and it has been used to calculate the balance of terrestrial and oceanic carbon sinks across the globe. However, few studies have investigated the controls of the variability in OR. What factors affect OR - climate? Soil type? Vegetation type? N deposition? Land use? Land use change? Small shifts in OR could have important implications in the global partitioning of CO2 between the atmosphere, biosphere, and oceans. This study looks at peat soils from a series of sites representing a climatic transect across the UK. Duplicate peat cores were taken, along with samples of above-ground vegetation and litter, from sites in northern Scotland (Forsinard), southern Scotland (Auchencorth), northern England (Moor House; Thorne Moor) through the Welsh borders (Whixhall Moss) and Somerset levels (Westhay Moor) to Dartmoor and Bodmin Moor in the south west of England. Sub-samples of the cores were analysed for their CHNO concentrations using a Costech ECS 4010 Elemental combustion system. Using the method of Masiello et al. (2008), OR values could be calculated from these elemental concentrations. Results show that OR values of UK peats varied between 0.82 and 1.27 with a median value of 1.08 which is within the range of world soils. There were significant differences in OR of the peat between sites with the data falling into two broad groupings - Group 1: Forsinard, Auchencorth, Dartmoor and Bodmin Moor; Group 2: Moor House, Thorne Moor, Westhay Moor, Whixhall Moss. Whilst there were significant changes (p < 0.05) in elemental ratios with increasing peat depth (increasing C:N ratio and decreasing O:C ratio) there was no significant difference overall in OR with depth. This paper will explore some of the possible controlling factors on these ratios. Local vegetation was also sampled along with agricultural soils from the local area of the peat cores to compare the relative differences in different mediums. Significant differences (p < 0.01) between vegetation, agricultural soils and surface peat layers were found where vegetation had OR values of 1.03 � 0.04 and agricultural soils had OR values of 1.15 � 0.04. Further discussion of these results from these comparisons is also presented in this study.
Clay, Gareth; Worrall, Fred; Masiello, Carrie
Dewatering Peat With Activated Carbon
NASA Technical Reports Server (NTRS)
Proposed process produces enough gas and carbon to sustain itself. In proposed process peat slurry is dewatered to approximately 40 percent moisture content by mixing slurry with activated carbon and filtering with solid/liquid separation techniques.
Rohatgi, N. K.
Miehittaemaetoen turvetuotanto. (Unoccupied peat production).
National Technical Information Service (NTIS)
Methods needed for automation of milled peat production are reviewed in this report. The main targets of the research were the utilization possibilities of the tractors available on the Finnish vehicle markets, the suitabilities of different positioning m...
P. Hirvonen V. Aho A. Leinonen
Cumulative Impacts of Peat Mining.
National Technical Information Service (NTIS)
Three alternative 20-year peat mining development scenarios were constructed for Hyde, Tyrrell and Washington Counties, North Carolina. Probable cumulative environmental and economic impacts on agriculture; forest products; fish; wildlife; recreation; sur...
J. A. Gale D. A. Adams
Analyzing the ability of peat to trap gas bubbles
NASA Astrophysics Data System (ADS)
Peatlands, thick deposits of partially decayed plant matter, are a globally important carbon store. Peat soils make up one third of the global soil carbon pool and provide one of the largest natural sources of methane to the atmosphere. Bubbles of methane, an important greenhouse gas, are produced by the decomposition of peat under waterlogged conditions. These bubbles increase in size until their buoyancy exceeds the forces keeping them in place, at which point methane bubbles move upward through the soil and are released at the surface in what is known as an ebullition event. These ebullition events are important because they may account for a large proportion of methane lost from peatlands. (Journal of Geophysical Research Biogeosciences, doi:10.1029/2010JG001478, 2011)
Tretkoff, Ernie
Prescribed burning as a natural, long-term experiment in biochar addition - Can prescribed burns contribute to carbon storage in peat soils?
NASA Astrophysics Data System (ADS)
Prescribed burning is a common land management of UK peatlands where Calluna-vulgaris dominated vegetation is burnt on a cycle of 8 - 25 years. The burning of Calluna by prescribed burning does produce char and thus presents a long-term experiment in biochar addition to a soil. This study will discuss the impacts of biochar additions on soil structure, hydrology, water quality and carbon fluxes from a number of experiments including a study of a chronosequence of nine years. This study proposes that although prescribed burning of moorland dominated by Calluna represents a direct loss of carbon to the atmosphere during the burn itself and destruction of litter production after the burn this loss of carbon is outweighed by the production of both dead biomass and refractory black carbon (char) during the burn itself. The study has produced a model of carbon stock in a peatland under a range of burn frequencies (5- 25 years) and compared this to the carbon stocks of a Calluna-dominated peatland at steady-state biomass. The model was run stochastically with all input parameters being allowed to vary by 50% and run over a period of 51 years. The study shows that: i) In the few years immediately following a burn, there is elevated water colour in soil pore water, but that this is not matched by a rise in dissolved organic carbon (DOC) concentration i.e. the composition varies rather than the absolute concentration. ii) Whilst all the sites examined were net sources of carbon but burnt sites were smaller sources than unburnt sites, i.e. a relative sink was achieved by burning. iii) The conditions under which burning results in a greater annual average sink of carbon than an unburnt site was controlled by the maturity of the Calluna and the extent of severe burning, i.e. the destruction of long term carbon reserves in litter and soil layers. iv) The annual average C flux on an unburnt sink was -8.7 � 2.6 gC/m2/yr compared to -13.3 � 2.7 gC/m2/yr for a site burnt every 25 years (equivalent to 100% of the Calluna steady state biomass). The study shows that significant carbon savings could be achieved not by bringing areas of Calluna dominated peatland under burn management but by changing the burn frequency on areas already under burn management and extending it to be as close as possible to the maximum steady-state biomass for the site.
Worrall, F.; Clay, G. D.
Differential peat deformation, compressibility, and water storage between peatland microforms: Implications for ecosystem function and development
NASA Astrophysics Data System (ADS)
Because peat is elastic, the daily to seasonal swelling and shrinking of the peat surface not only affects water storage but also alters peatland hydraulics and the biogeochemical and thermal properties of peat. Due to different botanical origins and degrees of decomposition, we hypothesized that different peatland microforms (ridges and lawns) display a large variation in peat deformation and compressibility. Here we examined the spatial variation of peat surface movement, peat strength, and volumetric water content at a low lawn (LL), upper lawn (UL), and ridge (R) along a 5 m transect in a peatland in Quebec, Canada. The average seasonal amplitude in peat surface level was 9, 6, and 2 cm at the LL, UL, and R sites, respectively. The surface layers in each of these sites were fairly rigid with the largest changes in peat thickness occurring between 20 and 60 cm depth in the peat profile. Compressibility varied among microforms but was not correlated to other properties within the layer in individual soil layers. However, when average profile compressibility was considered, it was significantly correlated to peat depth, von Post humification, distance to hollow, and peat strength. The total water storage by dilation below the water table was about the same as the water deficit (precipitation minus evapotranspiration) for LL, while the storage deficit for UL and especially R was lower. Including changes in entrapped gas content over the season reduced estimates of changes in water storage at all sites. Because microform type and position were significant predictors of hydrophysical properties, we argue that this suggests that peatland microtopography is self-reinforcing through ecohydrological feedbacks. Including the variability in these properties in peatland ecohydrological models will be key for predicting the response of peatland ecosystems to disturbance.
Waddington, J. M.; Kellner, E.; Strack, M.; Price, J. S.
Revegetation processes and environmental conditions in abandoned peat production fields in Estonia
NASA Astrophysics Data System (ADS)
As a result of peat extraction, peat production has been finished in Estonia at different times in 154 peat production areas and 9,500 ha (~1% of peatlands) are abandoned, although the peat reserves are not exhausted yet; besides, several areas are not properly recultivated. In addition 12,000 ha of fens (oligotrophic peat layers) are drained and used as grasslands. If the abandoned and non-recultivated peat production areas are not vegetated, their CO2 emission is considerable and peat mineralises in such areas. The aim of the study was to find out specific ecological and geological factors, which affect recovering of peatlands and influence the recultivation. During the revision the amount and quality of the remained reserves, as well as the state of water regime, drainage network and revegetation was assessed in all 154 abandoned peat production areas. The study showed that the state of them is very variable. Some of them are covered with forest, prevailingly with birches at former drainage ditches, later supplemented by pine trees. In the others predominate grasses among plants, and various species of moss (Cladonia rei, Bryum caespiticum, Sphagnum ripariuma, Sphagnum squarrosum) occur as well. Besides, some abandoned areas are completely overgrown with cotton grass. Open abandoned peat areas, which are not covered by vegetation, are much rarer. We found out, that water regime among the factors plays most important role. Moreover abandoned peat production fields, where the environmental conditions have changed - are appropriate for growth of several moss species, which cannot inhabit the areas already occupied by other species. The most interesting discovers were: second growing site of Polia elongata in West-Estonia and Ephemerum serratum, last found in Estonia in the middle of the 19th century, was identified in central Estonia. Also Campylopus introflexus, what was unknown in Estonia. However, the changes in environmental conditions influence the peat layers structure and technical characteristics of organic soils that affect the vegetation of peatlands.
Orru, M.; Orru, H.
Properties and structure of peat humic acids depending on humification and precursor biota in bogs
NASA Astrophysics Data System (ADS)
Humic substances form most of the organic component of soil, peat and natural waters, but their structure and properties very much differs depending on their source. The aim of this study is to characterize humic acids from raised bog peat profiles to evaluate the homogeneity of humic acids isolated from the bog bodies and study peat humification impact on properties of humic acids. A major impact on the structure of peat humic acids have raised bog biota (dominantly represented by bryophytes of different origin) void of lignin. For characterization of peat humic acids their elemental (CHNOS), functional (-COOH, phenolic OH) analysis, spectroscopic characterization (UV, fluorescence, FTIR, 1H NMR, CP/MAS 13C NMR, ESR) and degradation studies (Py-GC/MS) were done. Peat humic acids (HA) have an intermediate position between the living organic matter and coal organic matter and their structure is formed in a process in which more labile structures (carbohydrates, amino acids, etc.) are destroyed, but thermodynamically more stable aromatic and polyaromatic structures emerge. Comparatively, the studied peat HAs are at the start of the transformation process of living organic matter. Concentrations of carboxyl and phenolic hydroxyl groups changes depending on the depth of peat from which HAs have been isolated: and carboxylic acidity is increasing with depth of peat location and the humification degree. The ability to influence the surface tension of peat humic acids isolated from a well-characterized bog profile demonstrates dependence on age and humification degree. With increase of the humification degree and age of humic acids, their molecular complexity and ability to influence surface tension decreases; even so, the impact of the biological precursor (peat-forming bryophytes and plants) can be identified.
Klavins, Maris; Purmalis, Oskars
Phosphorus storages in historically isolated wetland ecosystems and surrounding pasture uplands
Historically isolated wetland ecosystems may provide a phosphorus (P) storage sink for runoff from agricultural pastures. Four historically isolated wetlands were characterized on two cow-calf ranches in the Lake Okeechobee Basin, Florida, to (i) quantify P storage in ecosystem compartments (plant biomass, litter, and soil) of historically isolated wetlands and surrounding improved pasture uplands, (ii) determine if a P storage
E. J. Dunne; J. Smith; D. B. Perkins; M. W. Clark; J. W. Jawitz; K. R. Reddy
The Biogeochemistry of Dissolved Organic Carbon: Isotopic and Spectroscopic Insights From an Upland Mediterranean Catchment
In upland catchments, allochthonous inputs of dissolved organic carbon (DOC) represent the major source of reduced energy to the aquatic ecosystem. The concentration and chemistry of this stream DOC is a primarily controlled by a complex interplay between soil biogeochemical cycling and hydrologic routing. Here we present results from an intensive field and laboratory examination of DOC fluxes and chemistry
J. Sanderman; R. Amundson; J. Baldock
Catchment and in-stream influences on iron-deposit chemistry, algal-bacterial biomass and invertebrate richness in upland streams, Northern Ireland.
NASA Astrophysics Data System (ADS)
The density and composition of upland stream bed iron-deposits is affected by physical, chemical and biological processes. The basic chemical processes producing ochre deposits are well known. Mobilisation of iron and manganese is influenced by bedrock weathering, the presence of acidic and/or reducing conditions and the concentration of dissolved organic carbon. Ferromanganese-depositing bacteria are significant biogenic agents and can cause/enhance the deposition of metals in streams as (hydr)oxides. Metal concentrations from stream waters in two geological blocks in Northern Ireland were compared to determine the contributions of catchment characteristics and in-stream conditions. One block is composed of metamorphosed schist and unconsolidated glacial drift, with peat or peaty podzol (mainly humic) soils, while the other block consists of tertiary basalt with brown earth and gley soils. Water samples were collected from 52 stream sites and analysed for iron, manganese and aluminium as well as a range of other chemical determinands known to affect metal solubility. Stone deposit material was analysed for metal concentrations, organic matter content and epilithic algae, chlorophyll a concentration. Invertebrates were collected by area-standardised kick samples and animals identified to family and numbers counted. Higher conductivities and concentrations of bicarbonate, alkalinity, calcium and magnesium occurred on basalt than on schist. Despite higher iron and manganese oxide concentrations in basalt-derived non-humic soils, stream water concentrations were much lower and stone deposit concentrations only one third of those occurring on schist overlain by humic soils. Peat-generated acidity and the limited acid neutralising capacity of base-poor metamorphosed schist has resulted in elevated concentrations of metals and ochre deposit in surface waters. Algal biomass was determined by catchment level factors whereas in-stream conditions affected bacterial biomass. Strong, non-linear, relations occurred between estimated bacterial biomass and deposit metal concentrations, with iron and manganese becoming relatively more important and algal biomass declining above a threshold deposit/bacterial density. Invertebrate community structure was altered above a deposit density of 10 mg cm-2, when invertebrate richness and diversity declined. These changes are driven by an increase in estimated bacterial biomass.
Macintosh, Katrina Ann; Griffiths, David
Comparison of the litterfall and forest floor organic matter and nitrogen dynamics of upland forest ecosystems in north central Wisconsin
It has been suggested that a feedback exists between the vegetation and soil whereby fertile (vs infertile) sites support species with shorter leaf life spans and higher quality litter which promotes rapid decomposition and higher soil nutrient availability. The objectives of this study were to (1) characterize and compare the C and N dynamics of dominant upland forest ecosystems in
Karins S. Fassnacht; Stith T. Gowerr
A delta13C record of late Quaternary climate change from tropical peats in southern India
STABLE-ISOTOPE ratios of carbon in soils or lake sediments1-3 and of oxygen and hydrogen in peats4,5 have been found to reflect past moisture variations and hence to provide valuable palaeoclimate records. Previous applications of the technique to peat have been restricted to temperate regions, largely because tropical climate variations are less pronounced, making them harder to resolve. Here we present
R. Sukumar; R. Ramesh; R. K. Pant; G. Rajagopalan
A conceptual model of volume-change controls on the hydrology of cutover peats
Modeling hydrological processes in certain peats requires a detailed understanding of short-term changes in soil volume and it's influence on the system's hydraulic properties. A study of cutover sites abandoned for 7-years (H92) and 2-years (H97), and an undisturbed section of the Lac Saint-Jean (LSJ) cutover bog was conducted to characterize peat volume changes and its associated hydrological behaviour. Shrinkage
G. W. Kennedya
The role of fungi in the Sphagnum peat wastewater treatment system
The lack of suitable soils and the increased building in rural areas has led to the need for alternative onsite wastewater treatment systems. One alternative system utilizes Sphagnum peat to provide a high quality effluent (<10 mg\\/l BOD5, <6 mg\\/l nitrate N, and <1 fecal coliform bacteria\\/100 ml). Treatment efficiencies were greatest when the temperature of the peat was 0-10°C.
The microbilogy of cut-away peat
Summary��A description is given of several surveys of fungal habitats in bare cut-away peat. These surveys are related to one another and to the general surveys of the peat microflora reported in an earlier paper of this series. The response of the peat myco-flora to cultivation of cut-away peat is reported and the colonisation of fresh organic material added to
M. Dooley; C. H. Dickinson
Piston corers for peat and lake sediments
Two pistons corers are described which are successful in cuting the wood or undecomposed fibrous peat that characterizes many peat deposits. These modified corers are equipped with a serrated cutting edge, along with modifications to permit the core tube to be rotated back and forth, so that undecomposed fibers and roots can be cut. Complete sections of peat and even
H. E. Jr. Wright; D. H. Mann; P. H. Glaser
Metal removal from wastewater using peat
Peat has been investigated by several researchers as a sorbent for the capture of dissolved metals from wastestreams. Besides being plentiful and inexpensive, peat possesses several characteristics that make it an effective media for the removal of dissolved metal pollutants. The mechanism of metal ion binding to peat remains a controversial area with ion-exchange, complexation, and surface adsorption being the
P. A Brown; S. A Gill; S. J Allen
Code of Federal Regulations, 2013 CFR
... 5 2013-10-01 2013-10-01 false Peat moss. 148.290 Section 148.290 Shipping...Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow...
Production and Use of Peat Coke.
National Technical Information Service (NTIS)
The properties of peat coke are fairly similar to those of wood charcoal. A high reactivity, a porous structure and a low sulphur content are typical characteristics of peat coke. The phosphorus content of peat coke is usually high and the strength low co...
J. Brandt K. Sipilae R. Thun
Arbuscular mycorrhizal colonization of tree species grown in peat swamp forests of Central Kalimantan, Indonesia
Arbuscular mycorrhizas improve the growth and nutrient uptake of plants and are formed in 80% of all land plants. Little information is available on the status of arbuscular mycorrhizas in tropical soils. The objective of this study was to clarify mycorrhizal colonization of tree species grown in tropical peat soils. Seedlings of 22 tree species in 14 families grown in
K. Tawaraya; Y. Takaya; M. Turjaman; S. J. Tuah; S. H. Limin; Y. Tamai; J. Y. Cha; T. Wagatsuma; M. Osaki
Peat Depth Assessment Using Airborne Geophysical Data for Carbon Stock Modelling
NASA Astrophysics Data System (ADS)
The Kyoto Agreement demands that all signatory countries have an inventory of their carbon stock, plus possible future changes to this store. This is particularly important for Ireland, where some 16% of the surface is covered by peat bog. Estimates of soil carbon stores are a key component of the required annual returns made by the Irish and UK governments to the Intergovernmental Panel on Climate Change. Saturated peat attenuates gamma-radiation from underlying rocks. This effect can be used to estimate the thickness of peat, within certain limits. This project examines this relationship between peat depth and gamma-radiation using airborne geophysical data generated by the Tellus Survey and newly acquired data collected as part of the EU-funded Tellus Border project, together encompassing Northern Ireland and the border area of the Republic of Ireland. Selected peat bog sites are used to ground truth and evaluate the use of airborne geophysical (radiometric and electromagnetic) data and validate modelled estimates of soil carbon, peat volume and depth to bedrock. Data from two test line sites are presented: one in Bundoran, County Donegal and a second line in Sliabh Beagh, County Monaghan. The plane flew over these areas at different times of the year and at a series of different elevations allowing the data to be assessed temporally with different soil/peat saturation levels. On the ground these flight test lines cover varying surface land use zones allowing future extrapolation of data from the sites. This research applies spatial statistical techniques, including uncertainty estimation in geostatistical prediction and simulation, to investigate and model the use of airborne geophysical data to examine the relationship between reduced radioactivity and peat depth. Ground truthing at test line locations and selected peat bog sites involves use of ground penetrating radar, terrestrial LiDAR, peat depth probing, magnetometry, resistivity, handheld gamma-ray spectrometry, moisture content and rainfall monitoring combined with a real-time Differential Global Positioning System (DGPS) to monitor temporal and spatial variability of bog elevations. This research will assist in determining the accuracy and limitations of modelling soil carbon and changes in peat stocks by investigating the attenuation of gamma-radiation from underlying rocks. Tellus Border is supported by the EU INTERREG IVA programme, which is managed by the Special EU Programmes Body in Northern Ireland, the border Region of Ireland and western Scotland. The Tellus project was funded by the Northern Ireland Development of Enterprise Trade and Investment and by the Rural Development Programme through the Northern Ireland Programme for Building Sustainable Prosperity.
Keaney, Antoinette; McKinley, Jennifer; Ruffell, Alastair; Robinson, Martin; Graham, Conor; Hodgson, Jim; Desissa, Mohammednur
Ecological study of peat landforms in Canada and Alaska
NASA Technical Reports Server (NTRS)
Over 20 percent of the land surface of Canada and Alaska is covered by peatlands, which may be defined as any waterlogged ecosystem with a minimum thickness of 20 cm of organic matter in the soil. Past investigations have demonstrated the value of aerial photographs in identifying the major vegetation types and analyzing the biotic and hydrogeologic processes that control the development of these peatlands. In the present study, LANDSAT TM imagery was used in conjunction with field studies to determine the utility of this satellite sensor for detecting these important processes. Although the vegetation landforms within these major peat basins are visible on aerial photographs, LANDSAT TM imagery provides essential new evidence for their analysis. Spectral data from the LANDSAT TM system provides: (1) synoptic views of the patterns across large portions of these peat basins, indicating important physiographic controls on peatland development, (2) more sensitive detection of the major vegetation types, allowing rapid quantitative estimates to be made of their distribution and aerial extent, (3) discrimination of bog areas with potentially rapid or slow rates of peat accumulation, (4) identification of discharge zones for groundwater, which apparently represents the most important source of alkalinity in these peat basins, and (5) detection of flow patterns in water tracks that appear nearly uniform on standard aerial photographs.
Glaser, Paul H.
Classifying and mapping wetlands and peat resources using digital cartography
Digital cartography allows the portrayal of spatial associations among diverse data types and is ideally suited for land use and resource analysis. We have developed methodology that uses digital cartography for the classification of wetlands and their associated peat resources and applied it to a 1:24 000 scale map area in New Hampshire. Classifying and mapping wetlands involves integrating the spatial distribution of wetlands types with depth variations in associated peat quality and character. A hierarchically structured classification that integrates the spatial distribution of variations in (1) vegetation, (2) soil type, (3) hydrology, (4) geologic aspects, and (5) peat characteristics has been developed and can be used to build digital cartographic files for resource and land use analysis. The first three parameters are the bases used by the National Wetlands Inventory to classify wetlands and deepwater habitats of the United States. The fourth parameter, geological aspects, includes slope, relief, depth of wetland (from surface to underlying rock or substrate), wetland stratigraphy, and the type and structure of solid and unconsolidated rock surrounding and underlying the wetland. The fifth parameter, peat characteristics, includes the subsurface variation in ash, acidity, moisture, heating value (Btu), sulfur content, and other chemical properties as shown in specimens obtained from core holes. These parameters can be shown as a series of map data overlays with tables that can be integrated for resource or land use analysis.
Cameron, Cornelia, C.; Emery, David, A.
Thermal degradation of diesel-contaminated peats in an air atmosphere
Peat, plant matter that is partially fossilized, is formed in poorly oxygenated wetlands where the rate at which the plant matter accumulates is greater than the rate at which it decomposes. Peat is a common solid fuel ranked among coal, coke, wood, and sugarcane bagasse. Peat has also been used to recover oil during the soil and water remediation processes. However, industrial utilization of peat in thermochemical conversion systems to liberate energy requires the knowledge of its thermal characteristics. In this study, the thermal behavior of peat (both uncontaminated and diesel-contaminated) was examined at three heating rates (10, 20, and 50 C/min) in a stationary air atmosphere using a thermogravimetric analysis technique between ambient temperature (25 C) and 600 C. The thermal degradation rate in active and passive pyrolysis zones, the initial degradation temperature, and the residual weight at 600 C were determined. Increasing the heating rate increased both the thermal degradation rate and the residual weight at 600 C and decreased the initial degradation temperature. The residual weight at 600 C was less than the ash content in all of the peat samples indicating the burnout of some of the mineral oxides, which have low melting and boiling temperatures, such as K{sub 2}O and P{sub 2}O. The results provide useful information about utilization of diesel-contaminated peat in thermochemical conversion systems, especially gasifiers, because of its high energy content and low ash content.
Ghaly, R.A.; Ugursal, V.I.; Ghaly, A.E.; Mansaray, K.G. [Dalhousie Univ., Halifax, Nova Scotia (Canada)
Degradation of 2, 4-D, 2, 4, 5-T, and picloram in two Philippine soils
The degradation of 2, 4-D, 2, 4, 5-T, and picloram in two Philippine soils was investigated under upland and flooded (submerged) conditions. These herbicides degraded in both upland and flooded Maahas clay and Luisiana clay soils. The rate of degradation of the herbicides was more rapid in the Maahas clay soil than in the Luisiana clay soil. Among the three
Tomio Yoshida; T. F. Castro
The role of condensed organic matter in the nonlinear sorption of hydrophobic organic contaminants by a peat and sediments.
This study examines the effect of soil organic matter heterogeneity on equilibrium sorption and desorption of phenanthrene, naphthalene, 1,3,5-trichlorobenzene (1,3,5-TCB), and 1,2-dichlorobenzene (1,2-DCB) by soils and sediments. Two estuary sediments, a Pahokee peat (PP; Euic, hyperthermic Lithic Haplosaprist), and two subsamples (base- and acid-treated peat [TP] and acid-treated peat [FP]) of the peat were used as the sorbents. The contents of black carbon particles were quantified with a chemical extraction method. Petrographical examinations revealed the presence of the condensed soil and sediment organic matter (SOM) in Pahokee peat. The Freundlich isotherm model in two different forms was used to fit both sorption and desorption data. The results show that the sorption and desorption isotherms are generally nonlinear and that the apparent sorption-desorption hysteresis is present for phenanthrene and TCB. Detailed analysis of sorption data for the tested sorbent-sorbate systems indicates that black carbon is probably responsible for sorption isotherm nonlinearity for the two sediments, whereas the humic substances and kerogen may play the dominant role in nonlinear sorption by the peat. This investigation suggests that the microporosity of SOM is important for the hydrophobic organic contaminant (HOC) sorption capacity on the peat. PMID:12469845
Ran, Yong; Huang, Weilin; Rao, P S C; Liu, Dehan; Sheng, Guoying; Fu, Jiamo
An exploratory study of peat and sawdust as enhancers in the (bio)degradation of n-dodecane.
Current practice for dealing with oil spills involves the use of adsorbent materials to contain the pollution prior to bioremediation of the contaminated soil and adsorbent. This work presents a study of the effects of bioavailable carbon sources in the adsorbents peat and sawdust as organic nutrients for microorganisms specialized in degrading n-dodecane in soil and sawdust contaminated with hydrocarbon mixtures. An experimental bioremediation system was developed using n-dodecane, biomass adapted to n-dodecane, inorganic nutrients and the two adsorbents (sterilized). Bioreactors containing peat enhanced cell growth the most and also evolved more CO(2). An advantage of peat is that its soluble carbon sources can sustain higher cell densities compared to sawdust, and this may prove decisive when cultivating endogenous microorganisms for the aerobic bioremediation of soils contaminated with hydrocarbons. However, at the end of the 68-day experiment slightly higher n-dodecane removal was identified in the system containing sawdust-n-dodecane (99.6%) than in that with peat-n-dodecane (98.5%), evidencing the higher hydrocarbon retention capacity of peat. Based on this study, the use of sawdust instead of peat is recommended when an adapted inoculum is available for aerobic bioremediation of organic contaminants, whereas the use of peat is advisable to boost cell densities in order to improve the probability of sustaining a viable biomass in unfavorable conditions. PMID:17960486
S�ez-Navarrete, C�sar; Gelmi, Claudio A; Reyes-Bozo, Lorenzo; Godoy-Fa�ndez, Alex
Mercury methylation in forested uplands; how important is it?
NASA Astrophysics Data System (ADS)
Episodic fluxes of mercury during high flows at the headwater catchment at the Sleepers River Research Watershed in Vermont indicate that uplands are an important source of total mercury (Hg) to known downstream methylation sites (i.e. large wetlands). Methylmercury (MeHg) behavior in streamwater, soil water, and sediment porewater coupled with high potential methylation rates suggests that forested uplands may be significant source areas for MeHg as well. In a July 2003 incubation, potential Hg methylation rates exceeded potential demethylation rates by factors of 1.6 each in shallow (0-4 cm) swamp and riparian soils and by 19.6 in anoxic stream sediments. The stream sediment had the greatest methylation rate of 7.5 ng/ g of wet sediment / day. However, MeHg concentrations in filtered (0.4 um) porewater at these sites ranged only from 0.07 to 0.37 ng/ L, similar to the range at low-lying wetland sites elsewhere in Vermont (0.06 to 0.56 ng/L). In Sleepers River headwaters as well as larger Vermont rivers, most of the MeHg export occurs during snowmelt and summer / fall storms, with nearly all of the MeHg occurring in the particulate phase. Stream total Hg and MeHg concentrations were consistently correlated, suggesting a common source, probably soil organic matter. The methylation efficiency (ratio MeHg / total Hg) was near 2% in the Sleepers River headwaters, similar to that in Vermont rivers draining large wetland systems, indicating that the methylation process originates in the headwaters.
Shanley, J. B.; Marvin-Dipasquale, M.; Schuster, P. F.; Chalmers, A.; Reddy, M. M.
Evaluation of a peat moss plus soybean oil (PMSO) technology for reducing explosive residue transport to groundwater at military training ranges under field conditions
An evaluation of peat moss plus crude soybean oil (PMSO) for mitigation of explosive contamination of soil at military facilities was performed using large soil lysimeters under field conditions. Actual range soils were used, and two PMSO preparations with different ratios of peat moss:soybean oil (1:1, PO1; 1:2, PO2) were compared to a control lysimeter that received no PMSO. PMSO
Mark E. Fuller; Charles E. Schaefer; Robert J. Steffan
Tropical organic soils ecosystems in relation to regional water resources in southeast Asia
Tropical organic soils have functioned as natural sinks for carbon, nitrogen, slfur and other nutrients for the past 4000 years or more. Topographic evolution in peat swamp forests towards greater oligotrophy has concentrated storage of the limited nutrient stock in surface soils and biota. Tropical peat systems thus share common ecosystem characteristics with northern peat bogs and certain tropical oligotrophic
Interdependence of peat and vegetation in a tropical peat swamp forest.
The visual uniformity of tropical peat swamp forest masks the considerable variation in forest structure that has evolved in response to differences and changes in peat characteristics over many millennia. Details are presented of forest structure and tree composition of the principal peat swamp forest types in the upper catchment of Sungai Sebangau, Central Kalimantan, Indonesia, in relation to thickness and hydrology of the peat. Consideration is given to data on peat geochemistry and age of peat that provide evidence of the ombrotrophic nature of this vast peatland and its mode of formation. The future sustainability of this ecosystem is predicted from information available on climate change and human impact in this region.
Page, S E; Rieley, J O; Shotyk, W; Weiss, D
Microbial Communities in Long-Term Heavy Metal Contaminated Ombrotrophic Peats
High concentrations of heavy metals are known to be toxic to many soil organisms. The effects of long-term exposure to lower\\u000a levels of metals on the soil microbial community are, however, less well understood. The southern Pennines of the U.K. are\\u000a characterised by expanses of ombrotrophic peat soils that have experienced deposition of high levels of heavy metals since\\u000a the
Patricia E. Linton; Laura Shotbolt; Andrew D. Thomas
Recent atmospheric dust deposition in an ombrotrophic peat bog in Great Hinggan Mountain, Northeast China.
Recent deposition of atmospheric soil dust (ASD) was studied using (210)Pb-dated Sphagnum-derived peat sequences from Great Hinggan Mountain in northeast China. Physicochemical indices of peat including dry bulk density, water content, ash content, total organic carbon and mass magnetic susceptibility were measured. Acid-insoluble concentration of lithogenic metals (Al, Ca, Fe, Mn, V and Ti) were measured using ICP-AES. The basic physicochemical properties were used to assess the peat trophic status and indicated that the sections above 45-60 cm are rain-fed peat. A continuous record of ASD fluxes over the past 150 years was reconstructed based on the geochemical data obtained from the ombrotrophic zone, and the average input rate of ASD is 13.4-68.1 g m(-2) year(-1). The source of soil dust deposited in peat was dominated by the long-range transport of mineral aerosol from the drylands in north China and Mongolia. The temporal variation of ASD fluxes in the last 60 years coincides well with the meteorological records of dust storm frequency during 1954-2002 in north China. This suggests that the reconstructed sequence of atmospheric dust deposition is reliable and we can look back in time at the dust evolution before 1949. Dust storm events were observed occasionally in the late Qing dynasty, and their frequency and intensity were smaller than dust weather occurring in recent times. Four peaks of ASD fluxes were distinguished and correlated with the historical events at that time. This study presents the first atmospheric soil dust data in peat records in northeast China, and complements a global database of peat bog archives of atmospheric deposition. The results reflect the patterns of local environmental change over the past century in north China and will be helpful in formulating policies to achieve sustainable and healthy development. PMID:22664536
Bao, Kunshan; Xing, Wei; Yu, Xiaofei; Zhao, Hongmei; McLaughlin, Neil; Lu, Xianguo; Wang, Guoping
Smouldering fires and environmental reconstructions using ombrotrophic peat cores
NASA Astrophysics Data System (ADS)
Peatlands are the soil organic matter-rich ecosystem most affected by fire. When they burn, the dominating phenomenon is not flaming but rather smouldering combustion. Recent estimates suggest that mean annual greenhouse gas emissions from smouldering peat fires are equivalent to 15% of global anthropogenic emissions. Furthermore, warmer temperatures at high latitudes are already resulting in unprecedented permafrost thaw, leaving large organic C pools exposed to fires for the first time in millennia. Much of our knowledge of past fire events is based on the abundance of charcoal particles in fossil and sub-fossil records. The combustion of char by the smouldering process implies that the record of past fires in peat cores may be entirely hidden. Three Sphagnum peat columns (26 cm deep) having different initial moisture contents (MC, in dry weight basis), i.e., 50, 100 and 200%MC, were prepared for this study. In a previous work, we tried to identify palaeofires by the physical and chemical signature that they leave behind in the soil profile. In the present one, we employ solid-state Nuclear Magnetic Resonance (NMR) and Isotope-Ratio Mass Spectroscopy (IRMS) characterization of peat organic matter, as well as results regarding and measure polycyclic aromatic hydrocarbons (PAH) production and metal concentration changes following smouldering fires. The 15N spectrum of fresh peat (FP) used as control shows only an amide signal, which is in agreement with the 13C NMR spectrum where mainly signals of carbohydrates and alkyl C can be observed. Further signals can be observed in the aromatic region, most probably due to lignin derivatives. Following the smouldering event, selected peat samples from both the 50% and 100% MC series show signals supporting the occurrence of fire. In detail, the 15N-signals between -200 and -250 ppm are typical for pyrrole or indole type N. This is in accordance with the 13C NMR spectra showing considerable intensity in the aromatic region, most likely from char residues. The isotopic signature of ?13C seems to be slightly affected by smouldering, although the information about vegetational changes are preserved, whereas the ?15N shows a trend positively correlated with the relative N enrichment observed in smouldered peat samples, as also supported by 15N NMR. Compared to flaming fires, smouldering fires produce much lower concentrations of PAH. Furthermore, PAH detected in peat following smouldering fires consist mainly of those with lower molecular weights (i.e., naphthalene, acenaphthene and fluorene). Finally, although concentrations of As, Hg, and Pb increase compared to the FP, their enrichment, relative to Ti, decreases. Such a trend regards mainly the surface layers. These data that suggest smouldering fires may be an important cause of variations observed in peat cores.
Zaccone, Claudio; Rein, Guillermo; Ciavatta, Claudio; Knicker, Heike; Shotyk, William; Miano, Teodoro M.
ERIC Educational Resources Information Center
PricewaterhouseCoopers (PwC) is giving the Chicago Bulls a run for their money when it comes to three-peats. The professional services firm scored the top spot on the Training Top 125 for a record third year in a row. So, just how did PwC nail No. 1 again? For starters, it met and exceeded a hefty challenge in fiscal year 2009: cutting training�
Freifeld, Lorri
A model of multi-purpose ecosystem management for degraded Mediterranean uplands
In order to reconcile the need for conserving and improving neglected Mediterranean upland ecosystems with socio-economic advancement, new concepts of integrated landscape management are required. For this purpose a mode of a closely interwoven network of multiple land-use patterns is suggested, based on vegetation management and manipulation of the soil-plant-animal complex and on multi-purpose environmental landscaping and afforestation. The latter
Zev Naveh
History and Vulnerability of Permafrost in Upland and Lowland Boreal Landscapes (Invited)
NASA Astrophysics Data System (ADS)
The history of permafrost aggradation and degradation in boreal landscapes can be interpreted through surface geomorphology, ground-ice characteristics, geochemistry, and ecological indicators. This history, which varies greatly in relation to topography, surficial materials, and ecological succession, can be simplified into four basic patterns involving rocky uplands, loamy uplands, gravelly-sandy lowlands, and peaty-loamy lowlands. In rocky uplands, permafrost conditions reflect fluctuations only over decades to century-long periods due to low latent heat of ice-poor soils and frequent fires, and history is poorly preserved. In loamy uplands with loess, water-shedding slopes, surface thermal properties, ecological recovery, and high latent heat in underlying massive ice make permafrost highly resilient. Consequently, permafrost history is well preserved as cryostructures, isotopic signatures, and buried soils. Permafrost can persist over tens to perhaps hundreds of thousands of years. In gravelly-sandy lowlands with fluvial gravels and eolian sand sheets, permafrost presence fluctuates over century periods, but because permafrost can affect surface and groundwater, changing water levels leave a legacy of plant macrofossils from aquatic and terrestrial ecosystems that can be used interpreting permafrost history. In peaty-loamy lowlands with lowland loess and abandoned floodplain deposits, water-impounding topography and permafrost-inducing soil thermal properties are conducive to permafrost fluctuations over decadal, century, and millennial periods that leave a rich legacy of plant materials indicative of specific conditions of permafrost formation and degradation. These varying responses of permafrost to environmental changes complicate the assessment of the role of permafrost in the sequestration and release of soil carbon into the atmosphere and surface waters.
Jorgenson, M. T.; Kanevskiy, M. Z.; Shur, Y.; Harden, J. W.; O'Donnell, J.; Wickland, K. P.; Ewing, S. A.; Striegl, R. G.; Zhuang, Q.
Cropping intensity and rainfall effects on upland rice yields in northern Laos
In northern Laos, upland rice is grown as a subsistence crop under rainfed conditions with no fertilizer inputs. It has traditionally\\u000a been grown under slash-and-burn systems with long fallows, which restore soil fertility and reduce insect and weed pressure.\\u000a However, increasing population density and government policies aimed at reducing the area under slash-and-burn have reduced\\u000a fallows to as little as
K. Saito; B. Linquist; B. Keobualapha; K. Phanthaboon; T. Shiraiwa; T. Horie
Woody debris along an upland chronosequence in boreal Manitoba and its impact on long-term carbon storage
This study investigated the role of fire-killed woody debris as a source of soil carbon in black spruce (Picea mariana (Mill.) BSP) stands in Manitoba, Canada. We measured the amount of standing dead and downed woody de- bris along an upland chronosequence, including wood partially and completely covered by moss growth. Such woody debris is rarely included in measurement protocols
K. L. Manies; J. W. Harden; B. P. Bond-Lamberty; K. P. O'Neill
Freshwater peat on the continental shelf
Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is now the continental shelf in an unbroken extension from the adjacent land areas to the north and west.
Emery, K. O.; Wigley, R. L.; Bartlett, A. S.; Rubin, M.; Barghoorn, E. S.
Artificial Water Removal from Peat, Part 1. Water Binding Properties of Peat.
National Technical Information Service (NTIS)
Water can be bound in peat in many different ways since peat contains large pores, capillars, colloids, plant cells and inorganic material. There are several theories in literature concerning different binding forms of water in peat. The number of the for...
K. Kantola M. Aho
Hydrogasification PDU studies on Florida peat and peat dewatered by various methods
In this program, hydrogasification tests are being conducted in two separate tasks. The objective of Task 1 is to study the gasification characteristics of peats from Florida and Alaska. The objective of Task 2 is to determine the effects of dewatering methodologies on the gasification characteristics of peat. Peats dewatered by three methods have been selected for testing in this task. These are: North Carolina peat harvested by the sod peat method, Minnesota peat dewatered in a sulzer belt press and thermally dried at approx. 300/sup 0/F in a Sulzer fluidized-bed dryer, and Minnesota peat dewatered in a Sulzer belt press and thermally dried in a tray dryer at 250/sup 0/F. To date a total of four hydrogasification tests have been conducted with a reed sedge peat from Florida (Seffner, Florida) completing the planned tests. The tests were conducted with hydrogen, steam and hydrogen, and hydrogen and nitrogen mixtures, at a pressure of 250 psia, and at maximum coil temperatures ranging from 1080/sup 0/ to 1510/sup 0/F. The operating conditions and results of these tests are summarized in Table 1. A typical chemical analysis of the Florida peat is compared with that of a Minnesota, North Carolina, and a Maine peat in Table 2. The Florida peat had a calorific value similar to that of the Minnesota peat. Its ash content was higher than that of the others, but its oxygen content was lower.
Mensinger, M.C.; Lau, F.S.; Punwani, D.V.
Altitude or slope position - gaseous carbon cycling on UK blanket peat bogs
NASA Astrophysics Data System (ADS)
Blanket peat accounts for 87% of Britain's total peatlands and represents one of the UK's largest terrestrial carbon stores. For peatlands to accumulate carbon the net ecosystem exchange of CO2 (NEE) must be negative with respect to the atmosphere. Unlike many other peatlands, upland blanket peat bogs in the UK are draped across hillsides and so it could be that both altitude and slope position are significant controls upon the magnitude and direction of NEE. The role that altitude and slope position play on NEE in upland blanket peat is poorly constrained on a local scale. Thus a hillslope transect was set up to measure how the gaseous exchange of CO2 varies across altitude and with slope position. The slope-transect consisted of 4 sites, in the English Peak District, with three replicates per site. The transect spanned the entire margin of peat occurrence on the hillside, from the summit (447m ASL) to the lowest occurrence of peat at (378m ASL). The sites were positioned to sample each of the distinct points of the variation in slope from the flat top, to the point of slope steepening, to the point of slope leveling to the final flattening out of the slope. Each site was located in Calluna vulgaris of similar age and in the same growth phase (degenerate). Data were gathered for a year in order to sample a complete seasonal cycle. The results of analysis by ANOVA showed that altitudinal effects were either not present or so small as to be masked by other effects. However both NER and GPP seemed to be linked to slope position. ANOVA and post hoc Tukey testing showed that only the site on the point of slope steepening was significantly different to the other sites with NER being 47% higher and GPP being 63% greater than the average of the other sites. But the elevated rates of GPP and NER cancelled each other out resulting in a non-significant 3% greater rate of overall NEE from the point of slope steepening. Another slope position effect observed was that of hill foot shading. This created markedly less variable readings than on the hill top sites, with the coefficients of variation being 70%, 40% and 36% greater on the hill top sites than hill foot sites for NEE, NER and GPP respectively. This suggests shading provides a more stable environment leading to more a spatially uniform gaseous carbon cycle within a single vegetation type.
Dixon, Simon; Rowson, James; Worrall, Fred
Peat combustion and enhancement by wet oxidation
A new technique, using partial oxidation and wet carbonization pretreatments at low temperatures (190 C), is described for improving the dewatering characteristics of peat. Experimental evidence is presented that shows these pretreatment processes solubilize 10% of the peat as carbon, and a solid peat fuel is recovered after mechanical dewatering. The solubilized carbon exits the process as a filtrate that is biodegradable under anaerobic conditions with methane as a by-product. Some of the peat-processing methods summarized are: biogasification, wet oxidation, solar drying, solvent extraction, wet carbonization, and partial oxidation.
Bettinger, J.A.; Baillod, C.R.; Lamparter, R.A.
Effects of mulching and catch cropping on soil temperature, soil moisture and wheat yield on the Loess Plateau of China
Soil management can notably influence crop production under dryland farming in semiarid areas. Field experiments were conducted, from October 2001 to September 2004, with an attempt to evaluate the effects of field management regimes on thermal status at an upland site; and soil water and wheat production in a winter wheat (Triticum aestivum L.) system at upland, terrace land and
Shulan Zhang; Lars L�vdahl; Harald Grip; Yanan Tong; Xueyun Yang; Quanjiu Wang
Self-organizing patterns of peat decomposition in mires and implications for greenhouse gas emissions
NASA Astrophysics Data System (ADS)
In many peatlands occurring in both permafrost and temperate terrain, vegetation develops in the form of spatially heterogeneous patterns or pools. Because GHG fluxes and their responses to allogenic forcing from different elements of mire patterns (eg., pools and raised peat strings) can vary, quantifying the role of peatlands in climate change may require using models for the dynamics of patterns. To this end, we investigate patterns of consistently-spaced ? 2 m diameter pools that occur in permafrost mires across a 4500 y chronosequence at Espenberg, NW Alaska. Pools first occur in small groups (<5) on 1200 y old mires where peat depth is ? 1 m, and pool patterns increase in size thereafter. Dissolved oxygen in pool water and peat stratigraphy in pool walls and floors are consistent with formation by peat decomposition amplified by thaw-derived subsidence of ice-rich organic soil. Natural patterns are reproduced by a model in which new pools principally initiate in ? 3 m wide annuli around existing pools, as evaluated using Kolmogorov-Smirnov tests of pool spacing distributions. Models encapsulating spatially random mechanisms for pool formation cannot reproduce natural patterns. Pool replication occurs by suppression of peat accumulation adjacent to 0.2--1.0 m high frost-heaved peat rings by drifting snow that persists into the growing season. Because pool initiation depends on distribution of earlier pools, rates and patterns of peat decomposition in the mire may nonlinearly depend upon, and have intrinsic time-scales exceeding, external influences on decomposition such as climate. Variations in peat accumulation or decomposition, and hence carbon accumulation or release, are localized in pools rather than occurring as a bulk change across a peatland surface. The influence of emergent pattern dynamics in this environment, and others, such as the patterned peatlands of Cape Breton, Nova Scotia, will be discussed.
Plug, L. J.; Tae, K. E.; Werner, B. T.
Impacts of peatland restoration on dissolved carbon loss from eroded upland peatlands in the UK
NASA Astrophysics Data System (ADS)
Upland blanket peatlands in the UK are severely degraded by extensive gully erosion. Large areas have experienced complete vegetation loss. In the last decade landscape scale approaches to the restoration of eroded and bare peat have been developed in the Peak District National Park in northern England. Bare peat is re-vegetated with a nurse crop of grasses established by the aerial application of lime, seed, and fertiliser. The approach has successfully re-vegetated large areas of eroded bog a nd has been shown to dramatically reduce particulate carbon losses in runoff. The impacts of the treatment on water quality and dissolved carbon loss have not previously been fully assessed. This paper reports results from a small catchment study assessing the impacts of restoration practice in the Peak District. Data from five small catchments are presented one re-vegetated, one intact and three eroded/bare catchments. Bi-weekly water samples have been taken from the catchments between January 2011 and February 2012 and during July 2012 two of the bare sites were treated with lime, seed, and fertiliser. The data show that there are significant spikes in nutrient flux post treatment and marked effects on dissolved carbon which include initial spikes in in DOC concentration but longer term reductions in DOC concentration. Monitoring is ongoing at these sites but the evidence to date points to at least a short term benefit in DOC flux reduction from this form of peatland restoration.
Evans, M.; Stimson, A.; Allott, T. E. H. A.; Holland, N.
Ecohydrological Controls on Peat Consumption During Wildfire
NASA Astrophysics Data System (ADS)
Peat oxidation by smouldering combustion during wildfire represents a carbon flux, though episodic, able to release over 3 kg C ^{m-2} to the atmosphere, along with numerous trace-gas by-products of combustion. In peatlands, smouldering is dominated by a vertical heat transfer and combustion mechanism. We conducted laboratory and modelling studies to examine the interaction of peatland microtopography and hydrology on depth of burn during wildfire. Many peat profiles show a distinct thermodynamic resistance to combustion. Except in cases of extreme drought, Sphagnum fuscum hummocks have sufficiently high water retention such that more energy is required to drive off the water in the upper moss layers than is derived by the combustion of the dry peat. Although our model runs suggest if hummocks of S. fuscum are dry enough to burn the uppermost moss layers (2-3 cm), there is a higher probability of deep ( 30 cm) burning in the hummock due to a 'chain reaction' of combustion through the physically similar peat layers underneath. Enhanced summer water table draw-down and fire intensity serves to increase depth of burn only slightly into deeper humic peat layers in the presence of a water table and hydrostatic equilibrium. However, laboratory water retention analyses show that this humified peat retains less water per unit mass, despite being of greater average bulk density to less humified peat. Thus, smouldering combustion of humic peat has the potential to be more severe compared to less humified peat given the same distance from the water table. In shallow peatlands where the water table can fall beyond the basal mineral layer, evaporative demand is entirely satisfied by loss of water stored in the unsaturated zone. Similarly, in peatlands drained for forestry, transpiration can draw water out of the rooting zone in excess of rates of capillary rise, resulting in non-equilibrium conditions and enhanced risk of deep combustion. In both cases, upper peat horizons can become out of equilibrium with deeper peat and dry preferentially. In instances where peat moisture reaches equilibrium with the atmosphere, deep burning is much easier to achieve in peatlands. This has implications in shallow peatlands, where the water table routinely falls below the basal peat horizons during dry summers. The vulnerability of shallow peatlands is furthered by an increase in the abundance humified peat closer to the surface compared to deeper peatlands. This enhanced risk of deep combustion in shallow peatlands could help explain the relative scarcity of shallow peatlands less than 50 cm found in peat depth databases in the boreal plain.
Thompson, D. K.; Wotton, M.; Turetsky, M. R.; Flannigan, M.; Benscoter, B.; Waddington, J. M.
Upland disturbance affects headwater stream nutrients and suspended sediments during baseflow and stormflow
Because catchment characteristics determine sediment and nutrient inputs to streams, upland disturbance can affect stream chemistry. Catchments at the Fort Benning Military Installation (near Columbus, Georgia) experience a range of upland disturbance intensities due to spatial variability in the intensity of military training. We used this disturbance gradient to investigate the effects of upland soil and vegetation disturbance on stream chemistry. During baseflow, mean total suspended sediment (TSS) concentration and mean inorganic suspended sediment (ISS) concentration increased with catchment disturbance intensity (TSS: R 2 = 0.7, p = 0.005, range = 4.0-10.1 mg L-1; ISS: R 2 = 0.71, p = 0.004, range = 2.04-7.3 mg L-1); dissolved organic carbon (DOC) concentration (R 2 = 0.79, p = 0.001, range = 1.5-4.1 mg L-1) and soluble reactive phosphorus (SRP) concentration (R 2 = 0.75, p = 0.008, range = 1.9-6.2 {micro}g L-1) decreased with increasing disturbance intensity; and ammonia (NH4 +), nitrate (NO3 -), and dissolved inorganic nitrogen (DIN) concentrations were unrelated to disturbance intensity. The increase in TSS and ISS during storms was positively correlated with disturbance (R 2 = 0.78 and 0.78, p = 0.01 and 0.01, respectively); mean maximum change in SRP during storms increased with disturbance (r = 0.7, p = 0.04); and mean maximum change in NO3 - during storms was marginally correlated with disturbance (r = 0.58, p = 0.06). Soil characteristics were significant predictors of baseflow DOC, SRP, and Ca2+, but were not correlated with suspended sediment fractions, any nitrogen species, or pH. Despite the largely intact riparian zones of these headwater streams, upland soil and vegetation disturbances had clear effects on stream chemistry during baseflow and stormflow conditions.
Houser, Jeffrey N [ORNL
Upland disturbance affects headwater stream nutrients and suspended sediments during baseflow and stormflow
Because catchment characteristics determine sediment and nutrient inputs to streams, upland disturbance can affect stream chemistry. Catchments at the Fort Benning Military Installation (near Columbus, Georgia) experience a range of upland disturbance intensities due to spatial variability in the intensity of military training. We used this disturbance gradient to investigate the effects of upland soil and vegetation disturbance on stream chemistry. During baseflow, mean total suspended sediment (TSS) concentration and mean inorganic suspended sediment (ISS) concentration increased with catchment disturbance intensity (TSS: R2 = 0.7, p = 0.005, range = 4.0-10.1 mg L-1; ISS: R2 = 0.71, p = 0.004, range = 2.04-7.3 mg L-1); dissolved organic carbon (DOC) concentration (R2 = 0.79, p = 0.001, range = 1.5-4.1 mg L-1) and soluble reactive phosphorus (SRP) concentration (R2 = 0.75, p = 0.008, range = 1.9-6.2 ??g L-1) decreased with increasing disturbance intensity; and ammonia (NH 4+), nitrate (NO3-), and dissolved inorganic nitrogen (DIN) concentrations were unrelated to disturbance intensity. The increase in TSS and ISS during storms was positively correlated with disturbance (R2 = 0.78 and 0.78, p = 0.01 and 0.01, respectively); mean maximum change in SRP during storms increased with disturbance (r = 0.7, p = 0.04); and mean maximum change in NO3- during storms was marginally correlated with disturbance (r = 0.58, p = 0.06). Soil characteristics were significant predictors of baseflow DOC, SRP, and Ca 2+, but were not correlated with suspended sediment fractions, any nitrogen species, or pH. Despite the largely intact riparian zones of these headwater streams, upland soil and vegetation disturbances had clear effects on stream chemistry during baseflow and stormflow conditions. ?? ASA, CSSA, SSSA.
Houser, J. N.; Mulholland, P. J.; Maloney, K. O.
Monitoring the effects of manure policy in the Peat region, Netherlands
NASA Astrophysics Data System (ADS)
Total N concentrations in farm ditches in the Peat region of the Netherlands are on the average twice as high as the Good Ecological Potential value of the Water Framework Directive. Since ditches are connected to regional surface water, they may contribute to eutrophication. The minerals policy aims to improve the water quality. In the Netherlands, the effectiveness of the minerals policy on water quality is evaluated with data from the National Minerals Policy Monitoring Programme (LMM). This regards farm data on the quality of water leaching from the root zone and on farm practices. The soil balance nitrogen surpluses decreased between 1996 and 2003 on dairy farms in the Peat region. However, no effect on root zone leaching was found. This study aims to show how monitoring in the Peat region can be improved in order to link water quality to agricultural practice. Contrary to the other Dutch regions, nitrate concentrations in root zone leaching on farms in the Peat region are often very low (90% of the farms below 25 mg/l) due to the reduction of nitrate (denitrification). The main nitrogen (N) components in the peat region waters are ammonium and organic N. Total N is therefore a better measure for N concentrations in the Peat region. The ammonium concentration in groundwater in Dutch peat soils increases with depth. It is assumed that the deeper ammonia-rich water is older and relates to anaerobic peat decomposition instead of agricultural practice. Recent infiltrated low-ammonium water, lies like a thin freshwater lens on the older water. In the Peat region, root zone leaching is monitored by taking samples from the upper meter of groundwater. Unintended, often both lens water and older water are sampled and this distorts the relation between agricultural practice and water quality. In the Peat region, the N surplus is transported with the precipitation surplus to ditches. The relation between the N surplus and the total N in ditch water is therefore better than between N surplus and total N in root zone leaching. The precipitation surplus flows to ditches directly or via open field drains. However, the ditches may be fed partly with older water (seepage of groundwater). In the open field drain only recent water will occur. We expect that monitoring the water quality of the open field drains may even better reflect changes in agricultural practices. These data may also improve the understanding of contribution of agricultural nitrogen and natural nitrogen, necessary to develop measures to decrease the total-N concentration in ditch water.
Hooijboer, Arno; Buis, Eke; Fraters, Dico; Boumans, Leo; Lukacs, Saskia; Vrijhoef, Astrid
A 70 year upland record of climate change in the UK
NASA Astrophysics Data System (ADS)
Most long-term meteorological records in the UK are confined to the lowlands. Climate change in the UK uplands is important because their peaty soils are key carbon stores, they contain internationally important ecological habitats and are source areas for water supply. The temperature record for Moor House meteorological station, north Pennines, UK, at 556 m altitude provides a rare long-term framework for analysing past temperature in an upland location in Britain. Earlier examination of these data suggested that there was no evidence in the uplands for the recent warming which has been identified in lowland Britain. This paper shows that, in line with lowland records, there has been a long-term warming trend in the north Pennine uplands over the past seven decades. Indeed recent annual warming at Moor House has been greater than experienced at the nearby Durham station at an altitude some 450 m lower suggesting localised changes to lapse rates. Most of the annual warming is concentrated during winter months. Winters have warmed significantly by 1.5-2.0 deg C while no significant temperature changes have been recorded during summers. Milder winters could be crucial in upland areas because where temperatures are close to freezing for much of the winter slight warming may result in changes to frost frequency. The occurrence of frost is a key biological and geomorphological control and an important indicator of climate change. The mean number of days with air frost has significantly reduced at Moor House by 24 % over the last 10 years in the context of the 70-year record. This has been accompanied by a decrease in the number of days when the temperature is both above and below freezing (geomorphologically active days) and by a reduction in the number of days with snow cover. Mean annual minimum temperatures have increased significantly but mean maxima have not. The result is a decrease in the average diurnal temperature range and in the mean seasonal temperature range.
Holden, J.; Adamson, J. K.
Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams
Delivery of water, sediments, nutrients, and organic matter to stream ecosystems is strongly influenced by the catchment of the stream and can be altered greatly by upland soil and vegetation disturbance. At the Fort Benning Military Installation (near Columbus, Georgia), spatial variability in intensity of military training results in a wide range of intensities of upland disturbance in stream catchments. A set of 8 streams in catchments spanning this upland disturbance gradient was selected for investigation of the impact of disturbance intensity on hydrodynamics and nutrient uptake. The size of transient storage zones and rates of NH4+ uptake in all study streams were among the lowest reported in the literature. Upland disturbance did not appear to influence stream hydrodynamics strongly, but it caused significant decreases in instream nutrient uptake. In October 2003, coarse woody debris (CWD) was added to 1/2 of the study streams (spanning the disturbance gradient) in an attempt to increase hydrodynamic and structural complexity, with the goals of enhancing biotic habitat and increasing nutrient uptake rates. CWD additions had positive short-term (within 1 mo) effects on hydrodynamic complexity (water velocity decreased and transient storage zone cross-sectional area, relative size of the transient storage zone, fraction of the median travel time attributable to transient storage over a standardized length of 200 m, and the hydraulic retention factor increased) and nutrient uptake (NH4+ uptake rates increased). Our results suggest that water quality in streams with intense upland disturbances can be improved by enhancing instream biotic nutrient uptake capacity through measures such as restoring stream CWD. ?? 2007 by The North American Benthological Society.
Roberts, B. J.; Mulholland, P. J.; Houser, J. N.
Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams
Delivery of water, sediments, nutrients, and organic matter to stream ecosystems is strongly influenced by the catchment of the stream and can be altered greatly by upland soil and vegetation disturbance. At the Fort Benning Military Installation (near Columbus, Georgia), spatial variability in intensity of military training results in a wide range of intensities of upland disturbance in stream catchments. A set of 8 streams in catchments spanning this upland disturbance gradient was selected for investigation of the impact of disturbance intensity on hydrodynamics and nutrient uptake. The size of transient storage zones and rates of NH4+ uptake in all study streams were among the lowest reported in the literature. Upland disturbance did not appear to influence stream hydrodynamics strongly, but it caused significant decreases in instream nutrient uptake. In October 2003, coarse woody debris (CWD) was added to of the study streams (spanning the disturbance gradient) in an attempt to increase hydrodynamic and structural complexity with the goals of enhancing biotic habitat and increasing nutrient uptake rates. CWD additions had positive short-term (within 1 mo) effects on hydrodynamic complexity (water velocity decreased and transient storage zone cross-sectional area, relative size of the transient storage zone, fraction of the median travel time attributable to transient storage over a standardized length of 200 m, and the hydraulic retention factor increased) and nutrient uptake (NH4+ uptake rates increased). Our results suggest that water quality in streams with intense upland disturbances can be improved by enhancing instream biotic nutrient uptake capacity through measures such as restoring stream CWD.
Roberts, Brian J [ORNL; Mulholland, Patrick J [ORNL; Houser, Jeffrey N [ORNL
The Late Quaternary peat, vegetation and climate history of the Southern Oceanic Islands of New Zealand
Seven oceanic island groups (Chatham, Bounty, Snares, Antipodes, Auckland, Campbell and Macquarie) lie to the south and east of the southern New Zealand mainland between the Subtropical Convergence and the Antarctic Convergence. They are highly oceanic, experiencing moist, cool, cloudy and windy climates. Deep peat soils cover most of the islands, except for steep slopes and exposed high altitude sites.
M. S. McGlone
Upland forests of the American/Pacific islands: Research opportunities in Micronesia and American Samoa. Forest Service general technical report (Final)
The Upland forests of Micronesia and American Samoa can provide many social, ecological, and esthetic benefits for island inhabitants. Substantial upland areas (the majority of acreage on some islands) are now occupied by secondary and grassland/savanna vegetation: such areas represent opportunities for restoration, with both native forest cover and plantations of introduced species. The review briefly describes characteristics of the islands and the nature of existing and potential upland forests, including the most common upland tree species. Principal information needs and research opportunities are discussed for 10 subjects: watershed rehabilitation, forest restoration in secondary vegetation areas, basic ecology, soils and nutrient relationships, damaging agents, forest inventory and productivity assessment, silvicultural systems, valuation of forest products and services, threatened and endangered species, and description and protection of native forest habitats.
DeBell, D.S.; Whitesell, C.D.
National Technical Information Service (NTIS)
The full-depth method is a method of peat harvesting in which conventional contractor equipment is used. In a centrally located terminal at the bog the peat is prepared and mechanically dewatered. Then it will be formed into pieces for continued drying. T...
L. O. Tunbras
Properties and Test Methods for Energy Peat.
National Technical Information Service (NTIS)
The aim of the project SVEFIN TORV is to provide a collected picture of the properties of Swedish and Finnish industrial peat. Methods are available to test and analyze industrial peat for the variables which characterize its commercial value as fuel (cal...
G. Blomqvist D. Fredriksson R. Thun
Mineral resource of the month: peat
Peat is a natural organic material of botanical origin, harvested from deposits in bogs and fens. Commercial deposits form from the incomplete decomposition of plant matter under anaerobic conditions and gradually accumulate to form peat over about a 5,000-year period.
Jasinski, Stephen M.
Acidophilic Methanotrophic Communities from Sphagnum Peat Bogs
Highly enriched methanotrophic communities (>25 serial transfers) were obtained from acidic ombrotro- phic peat bogs from four boreal forest sites. The enrichment strategy involved using media conditions that were associated with the highest rates of methane uptake by the original peat samples, namely, the use of diluted mineral medium of low buffering capacity, moderate incubation temperature (20�C), and pH values
How old is upland catchment water?
NASA Astrophysics Data System (ADS)
Understanding the dynamics of water supply catchments is an essential part of water management. Upland catchments provide a continuous, reliable source of high quality water not only for some of the world's biggest cities, but also for agriculture and industry. Headwater streams control river flow in lowland agricultural basins as the majority of river discharge emerges from upland catchments. Many rivers are perennial and flow throughout the year, even during droughts. However, it is still unclear how reliable and continuous upland catchment water resources really are. Despite many efforts in upland catchment research, there is still little known about where the water is stored and how long it takes to travel through upper catchments. Resolving these questions is crucial to ensure that this resource is protected from changing land use and to estimate potential impacts from a changing climate. Previous research in this important area has been limited by existing measurement techniques. Knowledge to date has relied heavily on the use of variation in stable isotope signals to estimate the age and origin of water from upland catchments. The problem with relying on these measures is that as the water residence time increases, the variation in the stable isotope signal decreases. After a maximum period of four years, no variation can be detected This means that to date, the residence time in upland catchments is likely to have been vastly underestimated. Consequently, the proportion of water flow out of upland river catchments to the total river flow is also underestimated. Tritium (3H) combines directly with water molecules and enters the flow paths with the infiltrating water. Its half-life (12.32 years) makes it ideal to describe residence times in upper catchment reservoirs as it can theoretically measure water up to about 150 years old. The bomb pulse peak in the southern hemisphere was several orders of magnitude lower than in the northern hemisphere. Hence the Tritium activities in the southern hemisphere have long decayed down the natural background levels, which allows unique ages to be determined by single measurements. In this study major ion chemistry, stable isotopes and Tritium were determined at 2 locations and various stages of discharge (18 Tritium samples in between April 2013 and January 2014) in a first-order perennial stream draining a 7.3 km2 catchment in the Dandenong National Park, Melbourne, Australia. Even during major discharge event major ions and stable isotope data have little variation and Tritium activities remain low (1.4 to 1.8 TU) in comparison to local rainfall of ~ 3TU. Age estimations based on an exponential flow model are 15 to 25 years indicating that water draining from upland catchments is much older than we have previously estimated using stable isotopes.
Hofmann, Harald; Cartwright, Ian; Morgenstern, Uwe; Gilfedder, Benjamin
QTLs associated with root traits increase yield in upland rice when transferred through marker-assisted selection.
Altering root morphology of rice (Oryza sativa L.) cultivars could improve yields in drought-prone upland ecosystems. Marker-assisted backcross breeding was used to introgress four QTLs for root traits into an upland rice cultivar. The QTLs had previously been identified under experimental conditions in a different genetic background. The introgressed lines and the recurrent parent were grown for 6 years by resource-poor farmers in upland sites in Eastern India and yields recorded. In combination the QTLs significantly increased yield by 1 t ha(-1) under relatively favourable field conditions. In less favourable trials, the QTL effects were not detected due to greater heterogeneity in soil-water availability in very low yielding environments and consequent yield variability. Root studies under controlled conditions showed that lines with the introgressions had longer roots throughout tillering than the recurrent parent (14 cm longer 2 weeks after sowing). Therefore, both improved roots and increased yield can be attributed to the introgression of QTLs. This is the first demonstration that marker-assisted backcross breeding (MABC) to introgress multiple root QTLs identified under controlled conditions is an effective strategy to improve farmers' yields of upland rice. The strategy was used to breed a novel upland rice cultivar that has been released in India as Birsa Vikas Dhan 111. PMID:22968512
Steele, K A; Price, A H; Witcombe, J R; Shrestha, Roshi; Singh, B N; Gibbons, J M; Virk, D S
Use of remote sensing for the delineation of surface peat deposits south of the Venice Lagoon (Italy)
The aim of the present study is to map the regional extent of the peat soils using remote sensing. This is a first step of a wider project focused on the simulation of land subsidence due to the oxidation of organic soils in an area, the Zennare Basin, located south of the Venice Lagoon, where this process is responsible for
Vincenzo Nicoletti; Sonia Silvestri; F. Rizzetto; L. Tosi; M. Putti; P. Teatini
Methane dynamics in peat: Importance of shallow peats and a novel reduced-complexity approach for modeling ebullition
NASA Astrophysics Data System (ADS)
Northern peatlands are one of the largest natural sources of atmospheric methane (CH4), and it is important to understand the mechanisms of CH4 loss from these peatlands so that future rates of CH4 emission can be predicted. CH4 is lost to the atmosphere from peatlands by diffusion, by plant transport, and as bubbles (ebullition). We argue that ebullition has not been accounted for properly in many previous studies, both in terms of measurement and the conceptualization of the mechanisms involved. We present a new conceptual model of bubble buildup and release that emphasizes the importance of near-surface peat as a source of atmospheric CH4. We review two possible approaches to modeling bubble buildup and loss within peat soils: the recently proposed bubble threshold approach and a fully computational-fluid-dynamics approach. We suggest that neither satisfies the needs of peatland CH4 models, and we propose a new reduced-complexity approach that conceptualizes bubble buildup and release as broadly similar to an upside down sandpile. Unlike the threshold approach, our model allows bubbles to accumulate at different depths within the peat profile according to peat structure, yet it retains the simplicity of many cellular (including cellular automata) models. Comparison of the results from one prototype of our model with data from a laboratory experiment suggests that the model captures some of the key dynamics of ebullition in that it reproduces well observed frequency-magnitude relationships. We outline ways in which the model may be further developed to improve its predictive capabilities.
Coulthard, T. J.; Baird, A. J.; Ramirez, J.; Waddington, J. M.
The wettability of selected organic soils in Poland
NASA Astrophysics Data System (ADS)
The wettability was measured in the laboratory by means of two methods: Water Drop Penetration Time (WDPT) test and Thin Column Wicking (TCW) method. WDPT is fast and simple method and was used to investigate potential water repellency of analyzed samples. TCW is an indirect method and was used to determine contact angles and surface free energy components. The measurement was performed in horizontal teflon chambers for thin-layer chromatography, adapted for tubes 10 cm long. The experiment was carried out on muck soils (samples were taken from two levels of soil profile: 0-20 cm and 20-40 cm) and peat soils. There were two types of peats: low-moor peats and high moor peats. Samples of low-moor peats were taken from level 25-75 cm (alder peat) and 75-125cm (sedge peat) and 25-75 cm (peloid peat). Samples of high moor peats from level 25-175 cm (sphagnum peat) and 175-225 cm (sphagnum peat with Eriophorum). There was found no variability in persistence of potential water repellency but there were differences in values of contact angles of individual soil samples. Both muck and peat samples are extremely water repellent soils. Water droplets persisted on the surface of soils for more than 24 hours. Contact angles and surface free energy components for all samples were differentiated. Ranges of water contact angles for organic soils are from 27,54o to 96,50o. The highest values of contact angles were for sphagnum peats, and the lowest for muck soil from 20-40 cm level. It means, that there are differences in wettability between these samples. Muck soil is the best wettable and sphagnum peats is the worst wettable soil. If the content of organic compounds in the soil exceeds 40% (like in peats), the tested material displays only dispersion-type interactions. Therefore for peat soils, the technique of thin column wicking could only be used to determine the dispersive component γiLW. For muck soils it was also determined electron-acceptor (Lewis acid) γ+ and electron-donor (Lewis base) γ- surface free energy components. The authors gratefully acknowledge the Ministry of Science and Higher Education for financial support of this work (grant No. N N310 149335).
Ca?ka, A.; Hajnos, M.
Hydraulic Conductivity of Riparian Mangrove Forest Peat Adjacent to the Harney River, Everglades National Park: A Comparative Field Study of Field Saturated and Saturated Hydraulic Conductivity Methods.
NASA Astrophysics Data System (ADS)
The Shark-Harney river estuary is located in the southwest region of Everglades National Park and is the principle outflow for the freshwater everglades slough. Periodic tidal inundation, rainfall and overland freshwater flow are the forcing functions on surface soil infiltration and drainage in the adjacent estuary mangrove forest peat. Empirical soil hydraulic conductivity (K) for the mangrove peat soil is needed for hydrologic modeling efforts such as "The Tides and Inflows in the Mangroves of the Everglades" (TIME). South Florida has a bi-seasonal weather pattern of a dry and mild winters and a wet tropical summers. During the drier winter months (November-May), the mangrove peat has a 30-60 cm, unsaturated vadose zone and in the wet summer months (June-October), the peat is totally saturated. This study's purpose is to determine reliable values of soil hydraulic conductivity for mangrove peat under both the unsaturated Kfs and saturated Ksat soil conditions. Rycroft (1975) reported that field measurements are the preferred method of testing hydraulic conductivity of peat. The principle field method used to determining soil hydraulic conductivity Kfs under unsaturated conditions utilized a cylindrical permeameter (Guelph Permeameter) and the auger-hole method was used to determine soil hydraulic conductivity Ksat under saturated soil conditions. The hydraulic conductivity K samples were taken along a 300-meter transect, perpendicular to the south Harney riverbank through a mixed mangrove riparian forest and ending in a freshwater sawgrass prairie. Initial measurements were recorded in May-June 2001. A second year measurement set will be collected in March-April 2002. Hydraulic conductivity K measurements were observed in shallow peat holes (15 cm) at five equally spaced sample sites (60 m) from the river edge. Soil cores were taken at each sampling site to determine soil profile and bulk density.
Anderson, G. H.; Smith, T. J.
Assessment of the effects of land drainage upon upland flood generation using a quasi-distributed hydrological model
NASA Astrophysics Data System (ADS)
The U.K. experienced widespread drainage of upland moorland during the 1940s and 1950s. This was commonly associated with shallow drains, known as grips, which were used either to convert blanket peat bog to rough pasture or heather moorland or to prepare land for afforestation. Simultaneously, flow records suggest a major increase in the magnitude and frequency of downstream flooding coincident with this major land use change, despite only a very weak rainfall signals. Establishing a link between gripping and flooding is confounded by the fact that different experimental results have suggested that grips have different effects upon flood characteristics. Thus, the aim of this paper is to evaluate, using a quasi-distributed numerical model, the extent to which upland gripping can explain changes in the magnitude and frequency of flooding, and to assess the possible impacts upon flood characteristics arising from the grip blocking that has occurred in the last 10 years. This is based upon coupling high resolution laser altimetric data (resolution 2.0 m, point precision �0.15 m) from a gripped upland catchment to a modified form of Topmodel. In the latter, we introduce a fully-distributed travel delay treatment and a network saturation index. The time delay modification is required because of the spatial scale to which the model is being applied. The network saturation index is required to represent the dynamic behaviour of saturated areas as they connect to and disconnect from the drainage network during storm events. Results demonstrate that the effects of grips upon overland flow generation and flood magnitude and frequency are sensitively dependent upon antecedent rainfall characteristics, the relationship of grips to local topography, and the way in which the grip network changes the probability that areas that are prone to become saturated connect to the drainage network as the latter expands and contracts. This begins to reconcile the debates about the effects of grips upon flood magnitude and frequency and requires us to revisit the way in which upland drainage is addressed in simpler rainfall-runoff models. Results provide detailed spatial information required by upland managers allowing them to target and block the individual grips and grip networks that have the greatest impact on flood generation. This is of enormous benefit given that there are thousands of km of grips in the UK uplands.
Lane, S.; Brookes, C.; Holden, J.; Kirkby, M.
Ridged and gullied terrains in the Martian uplands
NASA Technical Reports Server (NTRS)
Two extensive types of geologic units in the Martian uplands are ridged plains and gullied (valley-network) terrain. The ridged plains, characterized by wrinkle ridges like those of the lunar maria, occupy depressions throughout the uplands. Gullied terrain is also widespread but is absent or rare in uplands dominated by plains or by large crater rims and basin rings. The ridged plains are rarely gullied but the gullied terrain and other upland terrain are commonly ridged. The relationship and origins of ridged plaines and gullied terrain are discussed.
Wilhelms, D. E.; Baldwin, R. J.
Redox Fluctuations Frame Microbial Community Impacts on N-cycling Rates in a Humid Tropical Forest Soil
Fluctuating soil redox regimes may facilitate the co-occurrence of microbial nitrogen transformations with significantly different sensitivities to soil oxygen availability. In an upland humid tropical forest, we explored the impact of fluctuating redox regimes on gross nitrogen cycling rates and microbial community composition. Our results suggest that the rapidly fluctuating redox conditions that characterize these upland soils allow anoxic and
Jennifer Pett-Ridge; Whendee L. Silver; Mary K. Firestone
Peat Hydrolysate Medium Optimization for Pullulan Production
Peat hydrolysate, a diluted acid-autoclaved extract of peat, was used as a substrate for the production of the extracellular polysaccharide pullulan by three strains of Aureobasidium pullulans, 140B, 142, and 2552. It was found that the addition of (NH4)2SO4 and K2HPO4 as sources of nitrogen and phosphate, respectively, is not necessary for the polysaccharide production. The economically optimized culture medium for large-scale production of pullulan contains peat hydrolysate, 0.05% NaCl, 0.02% MgSO4, and 0.01% antifoam FG-10. The initial pH of peat hydrolysate medium is adjusted to its optimum value of 6.0 with Ca(OH)2. The total ingredient cost for the production of each kilogram of pullulan with optimized medium is only 1/10 of that with the nonoptimized medium. In this study, a zero cost for peat hydrolysate was assumed, since it is an effluent of the peat and peat processing industries.
Boa, Jacques M.; LeDuy, Anh
Evaluating approaches for estimating peat depth
NASA Astrophysics Data System (ADS)
of peat depth are required to inform understanding of peatland development, functioning, and ecosystem services such as carbon storage. However, there is a considerable lack of peat depth data at local, national, and global scales. Recent studies have attempted to address this knowledge deficit by using manual probing and ground-penetrating radar (GPR) to estimate depth. Despite increasing application, little consideration has been given to the accuracy of either of these techniques. This study examines the accuracy of probing and GPR for measuring peat depth. Corresponding GPR and probing surveys were carried out at a catchment scale in a blanket peatland. GPR depth estimations, calibrated using common midpoint (CMP) surveys, were found to be on average 35% greater than probe measurements. The source of disagreement was found to be predominantly caused by depth probes becoming obstructed by artifacts within the peat body, although occasionally probing rods also penetrated sediments underlying the peat. Using the Complex Refractive Index Model, it was found that applying a single velocity of 0.036 m ns-1 across a single site may also result in -8 to +17% error in estimation of peat depth due to spatial variability in water content and porosity. It is suggested that GPR calibrated at each site using CMP surveys may provide a more accurate method for measuring peat depth.
Parry, L. E.; West, L. J.; Holden, J.; Chapman, P. J.
The Savannah River National Laboratory measured the hydraulic conductivity of peat samples using method ASTM D4511-00. Four samples of peat were packed into 73mm diameter plastic tubes and saturated from the bottom up with water. The columns were packed with Premier ProMoss III TBK peat to a dry density of approximately 0.16 gm/cc (10 lb/ft3). One column was packed using oven dried peat and the other 3 were packed using as delivered peat. The oven dried sample was the most difficult to saturate. All of the peat samples expanded during saturation resulting in a sample length (L) that was longer than when the sample was initially packed. Table 1 contains information related to the column packing. After saturation the hydraulic conductivity test was conducted using the apparatus shown in Figure 1. Three of the samples were tested at 2 different flow conductions, 1 high and 1 low. Table 2 and Figure 2 contain the results of the hydraulic conductivity testing. Each test was run for a minimum of 40 minutes to allow the test conditions to stabilize. The hydraulic conductivity at the end of each test is reported as the hydraulic conductivity for that test. The hydraulic conductivity of the 4 peat samples is 0.0052 {+-} 0.0009 cm/sec. This result compares well with the hydraulic conductivity measured in the pilot scale peat bed after approximately 2 months of operation. The similarity in results between the dry pack sample and moist pack samples shows the moisture content at the time of packing had a minimal effect on the hydraulic conductivity. Additionally, similarity between the results shows the test is reproducible. The hydraulic conductivity results are similar to those reported by other tests of peat samples reported in the literature.
Nichols, R
Peat deposits of the Carolina Bays of North Carolina
Of the approximately 500 Carolina Bays larger than 100 acres (3,000 ft. long) in the Coastal Plain of North Carolina, 96 contained at least 1 ft of peat. The 96 bays have a total of 35,000 acres of peatland containing 15 millions tons of moisture-free peat. Of these 96 bays, 43 have peat greater than 4 ft thick totaling 8,000 acres with 8 million tons of peat. The largest single deposit of peat greater than 4 ft thick contains 1.1 million tons in a 1,000 acre area. Two main types of peat are present: (1) a black, fine-grained, highly decomposed peat, and (2) a brownish, decomposed somewhat fibrous peat usually found at the base of the thicker peats. An average peat has 84% moisture, 6% ash, 0.2% sulfur, and a heating value of 10,000 Btu/lb.
Ingram, R.L.; Otte, L.J.; Witner, T.W.
Investigation of gas exchange processes in peat bog ecosystems by means of innovative Raman gas spectroscopy.
Highly sensitive Raman gas spectroscopy is introduced for simultaneous real time analysis of O(2), CO(2), CH(4), and N(2) in order to elucidate the dynamics of greenhouse gases evolving from climate-sensitive ecosystems. The concentrations and fluxes of this suite of biogenic gases were quantified in the head space of a water-saturated, raised peat bog ecotron. The intact peat bog, exhibiting various degradation stages of peat and sphagnum moss, was exposed to various light regimes in order to determine important ecosystem parameters such as the maximum photosynthesis rate of the sphagnum as well as the extent of soil and plant respiration. Miniaturized Raman gas spectroscopy was proven to be an extremely versatile analytical technique that allows for onsite multigas analysis in high temporal resolution. Therefore it is an urgently needed tool for elucidation of complex biochemical processes especially in climate-sensitive ecosystems and consequently for the estimation of climate-relevant gas budgets. PMID:23320649
Frosch, Torsten; Keiner, Robert; Michalzik, Beate; Fischer, Bernhard; Popp, J�rgen
Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska
Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50�500 years) drained lake basins (35.2 g C m?2 yr?1) and decreased exponentially with time since drainage to 9 g C m?2 yr?1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4�6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.
Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter
Halogens in porewater of peat bogs the role of peat decomposition and dissolved organic matter
NASA Astrophysics Data System (ADS)
Peatlands are one of the largest active terrestrial reservoirs of halogens. Formation of organo-halogens is a key process for the retention of halogens by organic matter and halogen enrichment in peat is strongly influenced by climatically controlled humification processes. However, little is known about release and transport of halogens in peat bogs. In this study we investigated the release of halogens from peat in three peat bogs located in the Magellanic Moorlands, southern Chile. Peat porewaters were collected using a sipping technique, which allows in situ sampling down to a depth of more than 6 m. Halogens and halogen species in porewater were determined by ion-chromatography (IC) (chlorine) and IC-ICP-MS (bromine and iodine). Results show that halogen concentrations in porewater are 15-30 times higher than in rainwater suggesting that their release from peat during diagenesis is the major source of halogens in porewater. Mean concentrations of chlorine, bromine and iodine in porewater were 7-15 mg l-1, 56-123?g l-1, and 10-20?g l-1, which correspond to mean proportions of 10-15%, 1-2.3% and 0.5-2.2% of total concentrations in peat, respectively. Organo-bromine and organoiodine were predominant in porewaters, whereas the release of organo-chlorine compounds from peat appears to be of minor importance. Results show that the release of bromine and iodine from peat depend on the degree of peat degradation, whereas this relationship is weak for chlorine. Relatively higher release of bromine and iodine was observed in less degraded peat sections, where the release of dissolved organic carbon (DOC) was also the most intensive. Here, proportions of released iodine and bromine follow proportions of released dissolved organic matter (DOM) indicating that the release of halogenated DOM is the predominant process of iodine and bromine release from peat.
Biester, H.; Selimovi?, D.; Hemmerich, S.; Petri, M.
Mass tree mortality leads to mangrove peat collapse at Bay Islands, Honduras after Hurricane Mitch
We measured sediment elevation and accretion dynamics in mangrove forests on the islands of Guanaja and Roatan, Honduras, impacted by Hurricane Mitch in 1998 to determine if collapse of underlying peat was occurring as a result of mass tree mortality. Little is known about the balance between production and decomposition of soil organic matter in the maintenance of sediment elevation of mangrove forests with biogenic soils. Sediment elevation change measured with the rod surface elevation table from 18 months to 33 months after the storm differed significantly among low, medium and high wind impact sites. Mangrove forests suffering minimal to partial mortality gained elevation at a rate (5 mm yeara??1) greater than vertical accretion (2 mm yeara??1) measured from artificial soil marker horizons, suggesting that root production contributed to sediment elevation. Basin forests that suffered mass tree mortality experienced peat collapse of about 11 mm yeara??1 as a result of decomposition of dead root material and sediment compaction. Low soil shear strength and lack of root growth accompanied elevation decreases. Model simulations using the Relative Elevation Model indicate that peat collapse in the high impact basin mangrove forest would be 37 mm yeara??1 for the 2 years immediately after the storm, as root material decomposed. In the absence of renewed root growth, the model predicts that peat collapse will continue for at least 8 more years at a rate (7 mm yeara??1) similar to that measured (11 mm yeara??1). Mass tree mortality caused rapid elevation loss. Few trees survived and recovery of the high impact forest will thus depend primarily on seedling recruitment. Because seedling establishment is controlled in large part by sediment elevation in relation to tide height, continued peat collapse could further impair recovery rates.
Cahoon, D.R.; Hensel, P.; Rybczyk, J.; McKee, K.L.; Proffitt, C.E.; Perez, B.C.
A Few Issues on the Peat Research in the Altai Mountains
NASA Astrophysics Data System (ADS)
At the present time we carry out complex research of marsh ecosystems in various areas of Gorny Altai to reveal the perspective deposits of peat in the Altai Mountains with the purpose of its use in the medical and recreational spheres. The peat deposits of the Northeastern Altai, Central Altai, and Southeastern Altai are surveyed; the selective chemical analysis of peat and marsh waters is carried out. The group structure of organic substance of various samples of peat is investigated by the method of Institutes of Peat. The toxic metals of Cd, Pb, Hg, Cu, Zn, and As were defined by the method of stripping voltammetry. The region of the Altai Mountains is characterized by the contrastive distribution of some heavy metals and arsenic in a soil cover. This is caused by a variety of petrography and granulometry of soil forming material, and also by a landscape and geochemical situation in the system of vertical zoning. The sources of natural accumulation of heavy metals in the ground might be the deposits of polymetals. In this connection the content of the specified toxic elements in the peat under research has been identified. The peat of the Turochak deposit is characterized by a significant ash content - up to 41,9%; the increased ash content is typical of the Kutyush deposit: from 6,1% up to 19, %. The peat of the Northeastern Altai is referred to non-bitumunous: the content of bitumen makes up less than 5%. In comparison with the European peat the peat under study of the transitive and lowland type is characterized by the significant content of easy hydrolysable substances in the amount of 24,8-41,1%. The amount of the non-hydrolysable rest makes up around 4,3 - 7,4 %. The total content of fulvic acids is less than the content of humic acids by 2,9 - 5,8 times. The high content of humic acids which can reach up to 58 % is characteristic of certain deposits. Humic acids extracted from the peat are characterized, as a rule, by similar IR-spectra. The distinctions are shown in an unequal intensity of characteristic absorption bands, in their spreading and some shifts. It is revealed that humic acids of peat with the increase in a degree of decomposition are exposed to transformation; therefore the increase in their structure of functional groups is observed. As a result of the research which was carried out the following elements among heavy metals in the lowland peat of the Altai Mountains are revealed: Cd (2,7 - 30)> Hg (0,67)> Zn (0,22) ~Pb (0,21)> Cu (0,13)> As (0,03). The degree of mobility of chemical elements in the peat varies within the limits of 1,3 - 36%. According to the degree of their mobility these elements form the following line: Zn (36 %)> Pb (18,1 %)> Cd (9,6 %)> Cu (1,3 %). The content and the character of distribution of the heavy metals under study and arsenic in the peat of the Altai Mountains have their unique features in comparison with the same valley analogues. The mountain peat of the Central Altai contains much less Hg than the West Siberian one: 0,078 mg/g and 0,69 mg/g accordingly. Cd represents itself as the concentrator in the lowland peat of the Northeastern and Central Altai, its content is actually the same and makes up approximately 0,3 mg/kg. The lowland Altai and West Siberian peat has the same amount of Pb: 4-5 mg/kg; they have smaller amounts of Zn and Cu in comparison with the European and West Siberian peat. The revealed features of distribution of some toxic metals are the display of specificity of peat genesis in the conditions of a mountain relief. The complex of the data received by us allows to consider the peat of the Altai Mountains as a non-polluting raw source concerning the amount of some natural toxic substances. The possible perspective directions of practical application of the mountain peat can be medicine, veterinary science, and agriculture.
Inisheva, Lydia I.; Larina, Galina; Shurova, Maya
Soil and soil organic carbon redistribution on the landscape
NASA Astrophysics Data System (ADS)
Patterns of soil organic carbon (SOC) vary widely across the landscape leading to large uncertainties in the SOC budget especially for agricultural landscapes where water, tillage and wind erosion redistributes soil and SOC across the landscape. It is often assumed that soil erosion results in a loss of SOC from the agricultural ecosystem but recent studies indicate that soil erosion and its subsequent redistribution within fields can stimulate carbon sequestration in agricultural ecosystems. This study investigates the relationship between SOC and soil redistribution patterns on agricultural landscapes. Soil redistribution (erosion and deposition) patterns were estimated in three tilled agricultural fields using the fallout 137Cesium technique. 137Cs and SOC concentrations of upland soils are significantly correlated in our study areas. Upland areas (eroding) have significantly less SOC than soils in deposition areas. SOC decreased as gradient slope increases and soils on concave slopes had higher SOC than soils on convex slopes. These data suggest that soil redistribution patterns and topographic patterns may be used to help understand SOC dynamics on the landscape. Different productivity and oxidation rates of SOC of eroded versus deposited soils also contribute to SOC spatial patterns. However, the strong significant relationships between soil redistribution and SOC concentrations in the upland soil suggest that they are moving along similar physical pathways in these systems. Our study also indicates that geomorphic position is important for understanding soil movement and redistribution patterns within a field or watershed. Such information can help develop or implement management systems to increase SOC in agricultural ecosystems.
Ritchie, Jerry C.; McCarty, Gregory W.; Venteris, Erik R.; Kaspar, T. C.
Interaction between C 4 barnyard grass and C 3 upland rice under elevated CO 2: Impact of mycorrhizae
NASA Astrophysics Data System (ADS)
Atmospheric CO 2 enrichment may impact arbuscular mycorrhizae (AM) development and function, which could have subsequent effects on host plant species interactions by differentially affecting plant nutrient acquisition. However, direct evidence illustrating this scenario is limited. We examined how elevated CO 2 affects plant growth and whether mycorrhizae mediate interactions between C 4 barnyard grass ( Echinochloa crusgalli (L.) Beauv.) and C 3 upland rice ( Oryza sativa L.) in a low nutrient soil. The monocultures and combinations with or without mycorrhizal inoculation were grown at ambient (400 � 20 ?mol mol -1) and elevated CO 2 (700 � 20 ?mol mol -1) levels. The 15N isotope tracer was introduced to quantify the mycorrhizally mediated N acquisition of plants. Elevated CO 2 stimulated the growth of C 3 upland rice but not that of C 4 barnyard grass under monoculture. Elevated CO 2 also increased mycorrhizal colonization of C 4 barnyard grass but did not affect mycorrhizal colonization of C 3 upland rice. Mycorrhizal inoculation increased the shoot biomass ratio of C 4 barnyard grass to C 3 upland rice under both CO 2 concentrations but had a greater impact under the elevated than ambient CO 2 level. Mycorrhizae decreased relative interaction index (RII) of C 3 plants under both ambient and elevated CO 2, but mycorrhizae increased RII of C 4 plants only under elevated CO 2. Elevated CO 2 and mycorrhizal inoculation enhanced 15N and total N and P uptake of C 4 barnyard grass in mixture but had no effects on N and P acquisition of C 3 upland rice, thus altering the distribution of N and P between the species in mixture. These results implied that CO 2 stimulation of mycorrhizae and their nutrient acquisition may impact competitive interaction of C 4 barnyard grass and C 3 upland rice under future CO 2 scenarios.
Tang, Jianjun; Xu, Liming; Chen, Xin; Hu, Shuijin
Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat
Palsa peats are characterized by elevated, circular frost heaves (peat soil on top of a permanently frozen ice lens) and are strong to moderate sources or even temporary sinks for the greenhouse gas nitrous oxide (N2O). Palsa peats are predicted to react sensitively to global warming. The acidic palsa peat Skalluvaara (approximate pH 4.4) is located in the discontinuous permafrost zone in northwestern Finnish Lapland. In situ N2O fluxes were spatially variable, ranging from 0.01 to ?0.02 ?mol of N2O m?2 h?1. Fertilization with nitrate stimulated in situ N2O emissions and N2O production in anoxic microcosms without apparent delay. N2O was subsequently consumed in microcosms. Maximal reaction velocities (vmax) of nitrate-dependent denitrification approximated 3 and 1 nmol of N2O per h per gram (dry weight [gDW]) in soil from 0 to 20 cm and below 20 cm of depth, respectively. vmax values of nitrite-dependent denitrification were 2- to 5-fold higher than the vmax nitrate-dependent denitrification, and vmax of N2O consumption was 1- to 6-fold higher than that of nitrite-dependent denitrification, highlighting a high N2O consumption potential. Up to 12 species-level operational taxonomic units (OTUs) of narG, nirK and nirS, and nosZ were retrieved. Detected OTUs suggested the presence of diverse uncultured soil denitrifiers and dissimilatory nitrate reducers, hitherto undetected species, as well as Actino-, Alpha-, and Betaproteobacteria. Copy numbers of nirS always outnumbered those of nirK by 2 orders of magnitude. Copy numbers of nirS tended to be higher, while copy numbers of narG and nosZ tended to be lower in 0- to 20-cm soil than in soil below 20 cm. The collective data suggest that (i) the source and sink functions of palsa peat soils for N2O are associated with denitrification, (ii) actinobacterial nitrate reducers and nirS-type and nosZ-harboring proteobacterial denitrifiers are important players, and (iii) acidic soils like palsa peats represent reservoirs of diverse acid-tolerant denitrifiers associated with N2O fluxes.
Palmer, Katharina
Actinobacterial nitrate reducers and proteobacterial denitrifiers are abundant in N2O-metabolizing palsa peat.
Palsa peats are characterized by elevated, circular frost heaves (peat soil on top of a permanently frozen ice lens) and are strong to moderate sources or even temporary sinks for the greenhouse gas nitrous oxide (N(2)O). Palsa peats are predicted to react sensitively to global warming. The acidic palsa peat Skalluvaara (approximate pH 4.4) is located in the discontinuous permafrost zone in northwestern Finnish Lapland. In situ N(2)O fluxes were spatially variable, ranging from 0.01 to -0.02 ?mol of N(2)O m(-2) h(-1). Fertilization with nitrate stimulated in situ N(2)O emissions and N(2)O production in anoxic microcosms without apparent delay. N(2)O was subsequently consumed in microcosms. Maximal reaction velocities (v(max)) of nitrate-dependent denitrification approximated 3 and 1 nmol of N(2)O per h per gram (dry weight [g(DW)]) in soil from 0 to 20 cm and below 20 cm of depth, respectively. v(max) values of nitrite-dependent denitrification were 2- to 5-fold higher than the v(max) nitrate-dependent denitrification, and v(max) of N(2)O consumption was 1- to 6-fold higher than that of nitrite-dependent denitrification, highlighting a high N(2)O consumption potential. Up to 12 species-level operational taxonomic units (OTUs) of narG, nirK and nirS, and nosZ were retrieved. Detected OTUs suggested the presence of diverse uncultured soil denitrifiers and dissimilatory nitrate reducers, hitherto undetected species, as well as Actino-, Alpha-, and Betaproteobacteria. Copy numbers of nirS always outnumbered those of nirK by 2 orders of magnitude. Copy numbers of nirS tended to be higher, while copy numbers of narG and nosZ tended to be lower in 0- to 20-cm soil than in soil below 20 cm. The collective data suggest that (i) the source and sink functions of palsa peat soils for N(2)O are associated with denitrification, (ii) actinobacterial nitrate reducers and nirS-type and nosZ-harboring proteobacterial denitrifiers are important players, and (iii) acidic soils like palsa peats represent reservoirs of diverse acid-tolerant denitrifiers associated with N(2)O fluxes. PMID:22660709
Palmer, Katharina; Horn, Marcus A
Peat?based onsite wastewater systems
The paper will present an overview of peat?based onsite wastewater systems based on the experience in the U.S.A., Canada and Ireland. Both laboratory and field studies have shown that peat?based systems for septic tank effluent treatment provide excellent performance in respect of BOD, SS and coliform removals. The paper will include a typical design with a schematic diagram of a
T. Viraraghavan
Drainage and land use impacts on changes in selected peat properties and peat degradation in West Kalimantan Province, Indonesia
NASA Astrophysics Data System (ADS)
Degradation of tropical peats is a global concern due to large Carbon emission and loss of biodiversity. The degradation of tropical peats usually starts when the government drains and clears peat forests into open peats used for food crops, oil palm and industrial timber plantations. Major properties of tropical peat forests are high in Water Contents (WC), Loss on Ignition (LOI) and Total Organic Carbon (TOC), and low in peat pH, Dry Bulk Density (DBD), and Total Nitrogen (TN). In this study, we investigated impacts of drainage and land use change on these properties. We collected peat samples from peat forests, logged over peat forest, industrial timber plantation, community agriculture, and oil palms. We used independent t-tests and oneway ANOVA to analyze mean differences of the research variables. We found that peat pH, DBD, and TN tend to increase. A significant decrease of C/N ratio in oil palm and agriculture sites importantly denotes a high rate of peat decompositions. Water contents, LOI, and TOC are relatively constants. We suggest that changes in pH, DBD, TN and atomic C/N ratio are important indicators for assessing tropical peat degradation. We infer that land use change from tropical peat forests into cleared and drained peats used for intensive timber harvesting, oil palms and industrial timber plantations in Indonesia has greatly degraded major ecological function of tropical peats as Carbon storage.
Anshari, G. Z.; Afifudin, M.; Nuriman, M.; Gusmayanti, E.; Arianie, L.; Susana, R.; Nusantara, R. W.; Sugardjito, J.; Rafiastanto, A.
National Technical Information Service (NTIS)
Humus acids are known to occur widely in soils, peats, and natural waters. Soil fertility, migration and accumulation of minerals in natural landscapes, and mineral nutrition of plants are all associated with these acids. In recent times they have been us...
D. S. Orlov
Seasonality in water, carbon, and nitrogen fluxes from an upland boreal catchment underlain by continuous permafrost
NASA Astrophysics Data System (ADS)
The balance between runoff and catchment residence time is critical to the biogeochemical processing of carbon (C) and nitrogen (N) in boreal ecosystems. Whether C is mineralized in soils or flushed from catchments depends on hydrologic fluxes and has implications for ecosystem productivity and climate change feedbacks. By measuring water fluxes and organic matter concentrations, we hope to elucidate the hydrologic and biogeochemical processes controlling C fate and transport in an upland boreal catchment underlain by permafrost. To understand the seasonal dynamics of water, C, and N fluxes, we monitored soil moisture, water chemistry, stream and subsurface flow, and conducted five conservative tracer additions in an upland catchment in the Yukon River Basin, Alaska. Tracer was added to a 2nd - order stream draining the north-facing hillslope during varying flow regimes in the summers of 2008 and 2009. Synoptic sampling and transient storage modeling results were used to explore the dynamics between hydrologic flux, and organic matter biogeochemistry in the soils and streams of this watershed. Silty hillslope soils were typically unsaturated, indicating that flow occurs predominantly through shallow, organic soils. Seasonal increases in runoff coefficients and major ion concentrations indicate greater contact with mineral soils later in the season, providing evidence that there is some flow through thawing preferential flowpaths (ie. soil pipes and/or thermokarst features) in the silt. Stream dissolved organic carbon (DOC) and nitrate concentrations were proportional to discharge at all but the lowest flows, indicating that precipitation leaches material from organic soils and transports it from the catchment. Stream DOC and nitrate concentrations were lower than expected given in-stream transport and inflows, suggesting that biogeochemical reactions were occurring. These reactions were modeled as first order decay of DOC and nitrate concentrations, and decreased seasonally, despite the fact that DOC became more labile. We believe that this indicates decreased reaction potential in the deeper subsurface flowpaths that develop later in the season, precluding water/organic soil contact. Our results highlight the importance of small surface streams and preferential flowpaths to water, C, and N export in the frozen silt uplands of interior Alaska, and identify a seasonal trend that controls stream C and N loads. Such hydrologic data is critical to our understanding of C fate and transport and provides important insight relevant to predicting boreal ecosystem changes that will likely occur as the arctic becomes warmer and wetter.
Koch, J. C.; Striegl, R. G.; Runkel, R. L.; Ewing, S. A.; McKnight, D. M.
Characterization of contamination, source and degradation of petroleum between upland and paddy fields based on geochemical characteristics and phospholipid fatty acids.
To evaluate contamination caused by petroleum, surface soil samples were collected from both upland and paddy fields along the irrigation canals in the Hunpu wastewater irrigation region in northeast China. N-alkanes, terpanes, steranes, and phospholipid fatty acids (PLFA) in the surface soil samples were analyzed. The aliphatic hydrocarbon concentration was highest in the samples obtained from the upland field near an operational oil well; it was lowest at I-3P where wastewater irrigation promoted the downward movement of hydrocarbons. The Hunpu region was found contaminated by heavy petroleum from oxic lacustrine fresh water or marine deltaic source rocks. Geochemical parameters also indicated significantly heavier contamination and degradation in the upland fields compared with the paddy fields. Principal component analysis based on PLFA showed various microbial communities between petroleum contaminated upland and paddy fields. Gram-negative bacteria indicated by 15:0, 3OH 12:0, and 16:1(9) were significantly higher in the paddy fields, whereas Gram-positive bacteria indicated by i16:0 and 18:1(9)c were significantly higher in the upland fields (p < 0.05). These PLFAs were related to petroleum contamination. Poly-unsaturated PLFA (18:2omega6, 9; indicative of hydrocarbon-degrading bacteria and fungi) was also significantly elevated in the upland fields. This paper recommends more sensitive indicators of contamination and degradation of petroleum in soil. The results also provide guidelines on soil pollution control and remediation in the Hunpu region and other similar regions. PMID:23534234
Zhang, Juan; Wang, Renqing; Du, Xiaoming; Li, Fasheng; Dai, Jiulan
Radiocarbon dating for paleoenviromental peat archive: the case study using cellulose from peat core reached to 15ka in northern Japan
NASA Astrophysics Data System (ADS)
Peat sediment is one of the most important archives to reconstruct a past climate. From previous study, we found that stable carbon isotope ratio (?13C) of peat cellulose is used as indicators of East Asian monsoon variability since the last deglaciaion including abrupt climate change (Shinozaki et al., in submission). The ?13C values recorded variability of rainfall amount related with Northern hemispheric climate change including Asian monsoon. Thus, it is crucial to establish correct age model with decadal to centennial time resolution. However, peat exists in forms of matrixes of organic matter such as intact plant and plant debris with soil mineral. In this study, we present radiocarbon dates of intact plant (Sphagnum), plant cellulose, and bulk organic matter from same horizons of peat core to investigate adequate dating candidates. Results of radiocarbon dates from plant cellulose were compared with those of bulk organic matter and intact plant (sphagnum). In addition, we tried three cellulose extraction methods to decide the most suitable one. To check their purity, results of recovery rate (%), TOC (%), TON (%), ?13C (�) and NMR measurements were discussed.
Shinozaki, T.; Uchida, M.; Kondo, M.; Minoura, K.; Shibata, Y.
ELF communications system ecological monitoring program: Upland flora studies
NASA Astrophysics Data System (ADS)
The U.S. Navy has completed a program monitoring flora, fauna, and ecological relationships for possible effects from electromagnetic (EM) fields produced by its Extremely Low Frequency (ELF) Communications System. This report documents studies of upland flora conducted near the Navy's transmitting antenna in Michigan. From 1982 through 1993 researchers from the Michigan Technological University (MTU) monitored tree, herb, and fungal species dominant in areas near (treatment) and far (control) from the ELF antenna. Above-ground parameters included the productivity, physiology, and phenology of trees, as well as the morphology and phenology of an herb. Below-ground, the important association between tree roots and fungi were monitored. Investigators also measured ambient weather conditions, soil nutrients, and EM field intensities. The MTU research team used analysis of variance and covariance to examine the data. When site-by-year interactions were significant, correlations and regressions were used to determine whether residuals were related to EM exposure. Results suggest a possible subtle EM effect to the cambial and stemwood growth of some tree species but not to any other parameter. MTU investigators conclude no short-term, adverse effects on forest health from exposure to EM fields produced by the Naval Radio Transmitting Facility-Republic, Michigan.
Mroz, Glenn D.; Cattelino, Peter J.; Gale, Margaret R.; Jones, Elizabeth A.; Jurgensen, Martin F.
Interpolations of groundwater table elevation in dissected uplands.
The variable elevation of the groundwater table in the St. Louis area was estimated using multiple linear regression (MLR), ordinary kriging, and cokriging as part of a regional program seeking to assess liquefaction potential. Surface water features were used to determine the minimum water table for MLR and supplement the principal variables for ordinary kriging and cokriging. By evaluating the known depth to the water and the minimum water table elevation, the MLR analysis approximates the groundwater elevation for a contiguous hydrologic system. Ordinary kriging and cokriging estimate values in unsampled areas by calculating the spatial relationships between the unsampled and sampled locations. In this study, ordinary kriging did not incorporate topographic variations as an independent variable, while cokriging included topography as a supporting covariable. Cross validation suggests that cokriging provides a more reliable estimate at known data points with less uncertainty than the other methods. Profiles extending through the dissected uplands terrain suggest that: (1) the groundwater table generated by MLR mimics the ground surface and elicits a exaggerated interpolation of groundwater elevation; (2) the groundwater table estimated by ordinary kriging tends to ignore local topography and exhibits oversmoothing of the actual undulations in the water table; and (3) cokriging appears to give the realistic water surface, which rises and falls in proportion to the overlying topography. The authors concluded that cokriging provided the most realistic estimate of the groundwater surface, which is the key variable in assessing soil liquefaction potential in unconsolidated sediments. PMID:22107357
Chung, Jae-won; Rogers, J David
Handling Alternatives of Weakly Decomposed Surface Peat and Compacting of It.
National Technical Information Service (NTIS)
The handling alternatives of weakly decomposed peat in different stages of peat production and peat transport is studied. The most realistic alternatives are the following: - deep ploughing of surface peat for mixing weakly decomposed and more decomposed ...
T. Lindh T. Jaervinen
Artificial Dewatering of Peat. Symposium held in Jyvaeskylae, Finland on October 15-16, 1991.
National Technical Information Service (NTIS)
Contents: Mining and Transportation--(Pumping properties of peat slurry and peat digging all-year-round); Dewatering of Peat--(Efficiency and environmental effects of peat dewatering by mechanical pressing; Some fundamental aspects of the dewatering of pe...
E. Alakangas
OPTIMITURVE Peat production based on solar enrgy. Interim report 1988-1990.
National Technical Information Service (NTIS)
The aim of the programme has been approached by developing new milled peat and sod peat production techniques. In milled peat production, the following new techniques have been introduced: the mole drainage technique, the new concept of milled peat produc...
A. Leinonen
Carbon Turnover in Organic Soils of Central Saskatchewan: Insights From a Core-Based Decomposition Study
NASA Astrophysics Data System (ADS)
Field-based decomposition studies that examine several site types tend to use one of two approaches: Either the decay of one (or more) standard litters is examined in all sites, or litters native to each site type are incubated in the environment they came from. The first of these approaches examines effects of environment on decay, whereas the latter determines rates of mass loss characteristic of each site type. Both methods are usually restricted to a limited number of litters, and neither allows for a direct estimate of ecosystem-level parameters (e.g. heterotrophic respiration). In order to examine changes in total organic matter turnover along forest - peatland gradients in central Saskatchewan, we measured mass loss of native peat samples from six different depths (surface to 50 cm) over one year. Samples were obtained by sectioning short peat cores, and cores and samples were returned to their original position after determining the initial weight of each sample. A standard litter (birch popsicle sticks) was included at each depth, and water tables and soil temperature were monitored over the growing season. After one year, average mass loss in surface peat samples was similar to published values from litter bag studies, ranging from 12 to 21 percent in the environments examined. Native peat mass loss showed few systematic differences between sites or along the forest - peatland gradient, with over 60 percent of the total variability explained by depth alone. Mass loss of standard litter samples was highly variable, with high values in areas at the transition between upland and peatland that may have experienced recent disturbance. In combination, these results suggest strong litter-based control over natural rates of organic matter turnover. Estimates of heterotrophic respiration calculated from the mass loss data are higher than values obtained by eddy covariance or static chamber techniques, probably reflecting loss of material during the handling of samples or increased mass loss from manipulated profiles. Nevertheless, the core-based method is a useful tool in examining carbon dynamics of organic soils, since it provides a good relative index of organic matter turnover, and allows for separate examination of environmental and litter-based effects.
Bauer, I. E.; Bhatti, J. S.; Hurdle, P. A.
Density and orientation of upland open drains: critical determinants of downstream flood risk?
NASA Astrophysics Data System (ADS)
Artificial, open drains, known as grips, drain over half of the UK's upland blanket peat area. Despite their hydrological importance, the influence of grips on downstream flood risk is uncertain. Grips lower the water table, thereby increasing the peat's storage capacity; but they also accelerate the delivery of rainfall to the drainage network. It has been hypothesised that the interaction of these competing processes is controlled by grip network density and grip orientation relative to the slope, and that these characteristics are critical determinants of the impact of grips on downstream flood risk. However, the variability of hydrological systems means that conclusions on the particular interactions between discharge, grip density and grip orientation cannot be drawn based purely upon observed correlations. Therefore, this research adopts an experimental numerical modelling approach using a modified version of TOPMODEL that was developed to assess the impacts of grips upon flow hydrographs. Only grip density and orientation were varied in the model, and therefore their relative effects on flow peaks could be assessed. Even with parameter uncertainty, the results indicate that all grip networks, regardless of density or orientation, significantly reduce flow peaks compared to the ungripped case. In general, they also delay the flow peaks. The greatest reductions in flow peaks are seen with increasing grip density and with increasing orientation to the slope. Grip density appears to have a greater influence on discharge than orientation. Increases in both grip density and orientation cause catchment storage capacity to increase, which outweighs the reduced flow travel times. The results have important implications for the current land management practice of grip blocking, which is carried out for ecological benefits.
Coles, A. E.; Milledge, D.; Lane, S. N.
Comparison on the performance of five different electromagnetic sensors in sphagnum peat
NASA Astrophysics Data System (ADS)
Electromagnetic (EM) soil moisture sensors are widely used to measure water contents in porous media, particularly in field studies. The accurate determination of saturation states in soils is vital for many environmentally related research questions. Electromagnetic water content measurements are based on the determination of the dielectric permittivity of a medium. As the dielectric permittivity is high in water compared to other soil constituents it can be related to soil water content. However, this method is affected by the properties of the medium investigated and until now there is little knowledge about its applicability to peat soils. The aim of our study was to investigate the performance of electromagnetic sensors to measure water content in sphagnum peat and to identify problems of the EM method associated with this special substrate. For this purpose, a comparison under laboratory conditions was conducted. Five different commercially available types of soil moisture sensor were selected with a range of geometries and various measurement principles. These included a time domain reflectometry probe, IMKO Trime Pico 64, and four frequency domain technique devices, namely the Stevens Hydra Probe, Delta-T Wet-2, Decagon 5TM and Decagon GS3. For this a sphagnum sample (40 cm by 60 cm by 30 cm), taken from a soli-ombrotrophic peat bog, was instrumented with the five sensor types at two different depths. Water content was altered by continuous evaporation at the top. To check the water content readings for plausibility, matrix potentials in four depths and the weight of the sample were monitored during the evaporation experiment. The dielectric permittivity readings from the soil moisture sensors were converted to volumetric water content either by calibration equations for organic substrates supplied by the manufacturer or from calibration equations for sphagnum found in scientific publications. In both parameters, dielectric permittivity and volumetric water content, large systematic differences between the sensor types were observed, especially in the wet range. With four sensor types giving plausible results in both measurement depths, one sensor type gave unplausible readings during most of the experiment. While the earlier suggests that a sphagnum- and possibly peat type specific calibration equation for each sensor might be necessary, the latter indicates that some sensor geometries could be inappropriate for peat soils.
Daniela, Reineke; Weber, Tobias K. D.; Durner, Wolfgang
Carbon dioxide and methane fluxes in drained tropical peat before and after hydrological restoration.
Present tropical peat deposits are the outcome of net carbon removal from the atmosphere and form one of the largest terrestrial organic carbon stores on the Earth. Reclamation of pristine tropical peatland areas in Southeast Asia increased strikingly during the last half of the 20th century. Drainage due to land-use change is one of the main driving factors accelerating carbon loss from the ecosystem. Dams were built in drainage-affected peatland area canals in Central Kalimantan, Indonesia, in order to evaluate major patterns in gaseous carbon dioxide and methane fluxes and in peat hydrology immediately before and after hydrologic restoration. The sites included peat swamp forest and deforested burned area, both affected by drainage for nearly 10 years. Higher annual minimum soil water table levels prevailed on both sites after restoration; the deforested site water table level prevailed considerably longer near the peat surface, and the forest water table level remained for a longer period in the topmost 30 cm peat profile after restoration. Forest soil gas fluxes were clearly higher in comparison to the deforested area. Cumulative forest floor CO2 emissions (7305-7444 g x m(-2) x yr(-1); 166.0-169.2 mol CO2 x m(-2) x yr(-1)) and the deforested site CO2 emissions (2781-2608 g x m(-2) x yr(-1); 63.2-59.3 mol CO2 x m(-2) x yr(-1)) did not markedly reflect the notably differing hydrological conditions the year before and after restoration. The forest floor was a weak CH4 sink (-0.208 to -0.368 g x m(-2) x yr(-1); -13.0 to -22.9 mmol CH4 x m(-2) x yr(-1)) and the deforested site a comparable CH4 source (0.197-0.275 g x m(-2) x yr(-1); 12.3-17.1 mmol CH4 x m(-2) x yr(-1)) in the study period. In general, higher soil water table levels had a relatively small effect on the annual CH4 emission budgets. In the two site types the gas flux response into hydrological conditions in degraded tropical peat can be attributed to differing CO2 and CH4 dynamics, peat physical characteristics, and vegetation. PMID:19137955
Jauhiainen, Jyrki; Limin, Suwido; Silvennoinen, Hanna; Vasander, Harri
Microbial ecology in tea soils
We determined the protease activity to analyze the mechanism of organic nitrogen decomposition (protein degradation) in tea soils. The hydrolyzing activities of N-benzoyl l-arginine amide (BAA), N-benzyloxycarbonyl l-phenylalanyl l-Ieucine (ZPL), and N-benzyloxycarbonyl glycyl l-phenylalanine (ZGP) were investigated at two depths in five acid tea soils, in upland crop Boils and in uncultivated soils (soils with near neutral pH) as controls.
Kanokpan Pansombat; Shinjiro Kanazawa; Tsuyoshi Horiguchi
Changuinola peat deposit of northwest Panama
We studied the economics of generating electricity in a 30-MW power plant using peat as a fuel. We calculated the breakeven point; that is, the point at which the cost of producing electricity from a coal- or an oil-fueled facility was equal to the cost of producing electricity from a peat-fueled facility, both a fluidized-bed and a conventional suspension boiler and for wet-mined and milled peat production. In the base case, the price range for oil was assumed to be $0.09 to $0.108 per liter, and the price range for coal was assumed to be $35 to $42 per metric ton. Parametric studies were done varying the capacity factor, real cost of money, and the mining costs. The parametric studies indicate that a peat-fueled plant can remain competitive with an oil-fueled plant when each of the parameters, considered separately, have the following values: (1) capacity factor greater than 65%; (2) real cost of money less than 9%; and (3) actual peat mining cost, not exceeding the estimated cost by more than 25%. 9 refs., 15 figs., 8 tabs.
Thayer, G.R.; Williamson, K.D. Jr.; Ramirez, A.
Impact of prescribed and repeated vegetation burning on blanket peat hydrology
NASA Astrophysics Data System (ADS)
In some peatlands there has been a tradition over the past century of burning vegetation to manage the landscape for a range of purposes. These include producing an environment suitable for game birds used in the gun sports industry and reducing the biomass fuel load to reduce possible wildfire damage to the peat. However, there have been few studies that have interrogated the impacts of this activity on peatland hydrological processes both at the plot scale and at the catchment scale. The EMBER project measured water tables, overland flow, hydraulic conductivity, stream discharge, and a myriad of aquatic invertebrate and peat physical and water chemistry indicators (at plot and stream scale) in ten upland blanket peat catchments in the UK. Five catchments were subject to a history of prescribed rotational patch burning with burning taking place each year over a proportion of the catchment (typically 5-10 %) but where for an individual patch the interval was typically 10-20 years. The other five catchments acted as controls which were not subject to burning, nor confounded by other detrimental activities such as drainage or forestry. Stream flows were flashier in response to rainfall in the catchments with prescribed burning patches and had greater rainfall to runoff efficiencies. Water tables were found to be significantly shallower with a smaller interquartile range for unburnt catchments. In the burnt catchments, more recently burnt plots had significantly greater mean water table depths and water table residence times were much less frequent within the upper 10 cm of the peat profile compared to plots that been burned more than a decade before. The water table residence curves will be explored in the presentation. The occurrence of overland flow was significantly impacted by both burning and time since burn with significantly less overland flow recorded for more recently burnt sites. This ties in well with our water table data since blanket peat systems are dominated by saturation processes rather than infiltration-excess overland flow. In this presentation we focus on the hydrological findings from the EMBER project but where relevant we relate these to other supporting environmental data we collected in order to interrogate process explanations for the differences we observed. For example, surface and near-surface peat temperatures were significantly more variable (both warmer and cooler depending on season and time of day) for burnt sites (and for patches burnt < 5 yrs prior to monitoring within burnt sites) but with warmer peat associated with burning overall. The results provide clear evidence that prescribed vegetation burning on blanket peat significantly impacts peatland hydrology at both the plot and stream scale and therefore raises issues for government bodies who have legal responsibility to protect many peatland landscapes, their integrity, their biogeochemical functions and the ecosystem services that peatlands provide.
Holden, Joseph; Brown, Lee; Palmer, Sheila; Johnston, Kerrylyn; Wearing, Catherine; Irvine, Brian
Production, oxidation, emission and consumption of methane by soils: A review
Methane emission by soils results from antagonistic but correlated microbial activities. Methane is produced in the anaerobic zones of submerged soils by methanogens and is oxidised into CO2 by methanotrophs in the aerobic zones of wetland soils and in upland soils. Methanogens and methanotrophs are ubiquitous in soils where they remain viable under unfavourable conditions. Methane transfer from the soil
Jean Le Mer; Pierre Roger
Changes in upland wildlife habitat on farmland in Illinois 1920-1987
An index of upland wildlife habitat was developed to investigate patterns and changes in habitat over time, using four years (1920, 1940, 1964, 1987) and the state of Illinois as an example. The index was composed of two subdivisions that described, at the county level, the quantity of wildlife habitat and a third subdivision that described farming disturbances that impacted the quality of the habitat. Data came from the US Census of Agriculture. The first subdivision that reflected quantity of habitat was called the wildlife habitat subdivision and was the sum of percentage woodland on farms, percentage farmland in nonrow crops, and percentage farmland in set-aside programs. The second subdivision that reflected the quantity of habitat was termed the soil-related features subdivision and was the sum of the percentage of farmland that was not highly erodible, the percentage of farmland in soil-protecting crops, and the percentage of farmland in conservation tillage. The third subdivision, reflecting the quality of the habitat, was the farming disturbance subdivision and was the sum of the percentage of grazing and the percentage of land on which fertilizers, pesticides, and herbicides were applied. Overall, major decreases occurred between 1920 and 1987 in the subdivisions reflecting the quantity of wildlife habitat and a major increase occurred in the subdivision associated with farming disturbance, reflecting the intensification of agriculture in the state. However, there was variability throughout the state, with some counties being more favorable to wildlife (as measured by the subdivisions) than others. Most of the changes within the state for the subdivisions reflecting quantity of upland wildlife habitat occurred during 1940 while changes in the farming disturbance subdivision (reflecting habitat quality) occurred in 1964. By 1987, the western and southern parts of Illinois were the most favorable for wildlife as reflected in all three subdivisions. Upland wildlife harvest indices were related to the subdivisions in 1964 and 1987, when harvest indices were available. Cottontail and northern bobwhite harvests were higher in counties with higher amounts of the wildlife habitat subdivision in both years. Cottontail harvest was also higher in counties with lower levels of the farming disturbance subdivision in 1964 and higher levels of soil-related features subdivision in 1987. Indices at the county level have the potential to be used in a multiscale analysis to investigate the impact of policy changes on large- scale areas of the Midwest and to develop regional perspectives of the impacts of agriculture on upland wildlife and their habitats.
Ribic, C. A.; Warner, R. E.; Mankin, P. C.
The variability in fallout content of soils and plants and the design of optimum field samplings strategies
Sampling was carried out at an upland peat site in Ireland to assess the variability in {sup 137}Cs deposition to soils and activity concentration in individual vegetation species. A 3,600 m{sup 2} quadrat was laid out, and a soil core was extracted within each of sixteen 20 x 20 cm soil monoliths. The coefficient of variation values for {sup 137}Cs deposition and activity in individual soil horizons were in all cases greater than 30%, and the relative variability between corresponding horizons tended to increase with depth. Samples of Calluna vulgaris and Juncus squarrosus were taken at each soil sampling location and coefficients of variation for {sup 137}Cs activity in these species were 12 and 20%, respectively. The data was used to examine the relationship between the number of samples analyzed in a survey, the variability within those samples, and the way those two factors affect our ability to detect between-site differences in {sup 137}Cs contamination levels. A methodology is developed for detection of between-site differences in {sup 137}Cs contamination under different experimental criteria. The data show that, of the sample types examined, between-site differences could he detected most efficiently with C vulgarism Because of the variability associated with the {sup 137}Cs content of each sample type, between-site differences could be detected with fewer plant samples than soil samples. Plant-soil concentration ratios, transfer factors, and plant-plant ratios were calculated from the data, and the variability associated with each parameter was assessed. The variation among values for plant-plant ratios was less than among concentration ratios, and the greatest spread of values was associated with plant-soil transfer factors. 32 refs., 3 figs., 3 tabs.
McGee, E.J.; Synnott, H.J.; Colgan, P.A. [Radiological Institute of Ireland, Dublin (Ireland)] [and others

subset: commoncrawl