There exists a relationship between soils on one part of the landscape and soils nearby. The Catena concept provides an excellent way of illustrating this geographic relationship using slope dynamics. The main components of a contena are (1) fluxes of water and matter, and (2) the location of the water table (Schaetzl, 2005). On a sloped surface, water infiltration rates depend upon the permeability of the soils and the gradient of the slope. If the slope gradient is high enough, sediments will be transported, and deposited in the form of alluvium and slopewash. The location of the water table determines how well these sediments are deposited, thus contributing to the development of the soils.
According to the Runge Energy Model, the two most important variables for soil development are climate, and relief. The relief of the landscape determines how the catena concept applies, and the water introduced into the system is dependant upon the climate. In artillery craters of Verdun, France both the Runge Model and the Catena Concept are used to explain soil formation in a way that promotes and/or inhibits the recovery of healthy vegetation.
Much of the Verdun landscape is littered with craters caused by artillery fire during World War I. As a result, soil development changed in process following this initial disturbance. Soil profiles within cratered landscapes can be explained using the Runge model and the catena concept of soil development.
Similar to the Jenny model, Runge's energy model explains soil development as a
function of relief, climate, organic constituents, and time (Schaetzl,
2005). Climate and relief, being the
most important factors, determine the amount of water accessible to the system
and the potential energy of that water moving through the soil profile.
Locations where water accumulates and permeates through the soil profile, will
have better developed soils (Schaetzl, 2005). The use of Runge's energy model
to explain soil development is limited by the permeability of the soil and the
location of the water table. Locations with a low water table and soil textures
that encourage leaching will have the most developed soil. Alongside water
available for leaching is the important variable of relief. This concept is
best explained using the Catena concept.
Microtopography, often overlooked, is a significant factor influencing soil development. Small changes in relief create pit-and-mound topography that affects variables contributing to soil development such as soil temperature, organic litter accumulation, and water infiltration/movement Schaetzl, 2005). A horizons within crater bottoms are expected to thicken as a result of the decomposition and weathering of organic materials. However, tree litter may impede the growth of vegetation as will erosive activity on crater sides.
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