Soil Geomorphic Change During Desertification

Title	Soil Geomorphic Change During Desertification
Publication Type	Conference Paper
Year of Publication	2005
Authors	Monger CH, Bestelmeyer BT
Conference Name	Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meetings
Date Published	November 6-10, 2
Conference Location	Salt Lake City, UT
ARIS Log Number	193054
Keywords	desertification, geomorphic, soil
Abstract	The objective of this paper is to illustrate the concept of the soil-geomorphic template and its relationship to biotic change. Desertification, as an example of biotic change toward a degraded state, is a common phenomenon in many arid and semiarid regions of the world. Such biotic change is typically accompanied by and linked to geomorphic change. Geomorphic factors that are involved in biotic change are soil, topography, and soil parent material, which together form the soil-geomorphic template. Soil is involved because it is the substrate that provides water, nutrients, anchorage for roots, and habitat for burrowing animals. Topography is involved by its influence on microclimate via elevation, lateral redistribution of water, and slope aspect. Soil parent material is involved by its contribution to the nutrient supply. Numerous linkages and feedback-loops occur between the soil-geomorphic template, microclimate, vegetation, and animals. A perturbation in any of these factors can steer an ecosystem from one state to another. Some soil-geomorphic templates are more prone to change than others. For example, landscapes with sandy soils are more vulnerable to desertification than landscapes with fine-textured soils that receive run-in water and, therefore, require distinct management practices. Desertification involving simultaneous changes in biotic and geomorphic states provides a good example of how biological and geological systems are coupled and co-evolve.