leaves. This theory is still applied when the boundary layer to the atmosphere is closed, e.g. when plant stomata are closed or in senesced plants. The pressure gradient is developed between soil layers with different water potentials causing water to move by the roots from wetter to drier soil layers in a similar manner as when a plant is transpiring. Fungal associations It has been understood that hydraulic lift aids the host plant and its neighboring plants in the transportation of water and other vital nutrients. At that time, the hydraulic lift described as the movement of water and soil nutrients from a vascularized host into the soil during at night mostly. Then after studies in the 2000s, a more comprehensive word was taken into consideration where it described a bi-directional and passive movement exhibited by the plant roots and further assisted by mycorrhizal networks. A 2015 study then described a "direct transfer of hydraulically redistributed water" between the host and fungi into the surrounding root system. As mentioned, hydraulic redistribution not only transports water but nutrients as well. The fungi most likely to form water and nutrient networks are Ectomycorrhizae and Arbuscular mycorrhizae. Significance The ecological importance of hydraulically redistributed water is becoming better understood as this phenomenon is more carefully examined. Water redistribution by plant roots has been found influencing crop irrigation, where watering schemes leave a harsh heterogeneity in soil moisture. This influencing process also assist in seedling success. The plant roots have been shown to smooth or homogenize the soil moisture. This sort of smoothing out of soil moisture is important in maintaining plant root health. The redistribution of water from deep moist layers to shallow drier layers by large trees has shown to increase the moisture available in the daytime to meet the transpiration demand. The implications of hydraulic redistribution seem to have an important influence on plant ecosystems. Whether or not plants redistribute water through the soil layers can affect plant population dynamics, such as the facilitation of neighboring species. The increase in available daytime soil moisture can also offset low transpiration rates due to drought (see also drought rhizogenesis) or alleviate competition for water between competing plant species. Water redistributed to the near surface layers may also influence plant nutrient availability. Observations and modeling Due to the ecological significance of hydraulically redistributed water, there is an ongoing effort to continue the categorization of