water erosion, parent material can be broken down. The chemical and physical properties of this parent material is reflected in the qualities of the resulting soil. Climate, topography, and biological organisms all have an impact on the formation of soils in various geographic locations. Topography A steep landform is going to see an increased amount of runoff when compared to a flat landform. Increased runoff can inhibit soil formation as the upper layers continue to get stripped off because they are not developed enough to support root growth. Root growth can help prevent erosion as the roots act to keep the soil in place. This phenomenon leads to soils on slopes being thinner and less developed than soils found on plains or plateaus. Climate Varying levels of precipitation and wind have impacts on the formation of soils. Increased precipitation can lead to increased levels of runoff as previously described, but regular amounts of precipitation can encourage plant root growth which works to stop runoff. The growth of vegetation in a certain area can also work to increase the depth and nutrient quality of a topsoil, as decomposition of organic matter works to strengthen organic soil horizons. Biological processes Varying levels of microbial activity can have a range of impacts on soil formation. Most often, biological processes work to disrupt existing soil formation which leads to chemical translocation. the movement of these chemicals can make nutrients available, which can increase plant root growth. Micromorphology While soil micromorphology begins in the field with the routine and careful use of a 10x hand lens, much more can be described by careful description of thin sections made of the soil with the aid of a petrographic polarizing light microscope. The soil can be impregnated with an epoxy resin, but more commonly with a polyester resin (crystic 17449) and sliced and ground to 0.03 millimeter thickness and examined by passing light through the thin soil plasma. Porosity Porosity of topsoil is a measure of the pore space in soil which typically decreases as grain size increases. This is due to soil aggregate formation in finer textured surface soils when subject to soil biological processes. Aggregation involves particulate adhesion and higher resistance to compaction. Porosity of a soil is a function of the soil’s bulk density, which is based on the composition of the soil. Sandy soils typically have higher bulk densities and lower porosity than