Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2005
Publication Date: 4/1/2006
Citation: Monger, H.C., Bestelmeyer, B.T. 2006. The soil-geomorphic template and biotic change in arid and semi-arid ecosystems. Journal of Arid Environments. 65:207-218. Interpretive Summary: The concept of the soil-geomorphic template is described. The concept provides a foundation for interpreting the coupled changes in biotic attributes (e.g., plant and animal populations) and soils/topography. This coupled view is an essential starting point for describing change in aridlands systems.
Technical Abstract: Desertification, characterized as biotic change toward a degraded state, is a common phenomenon in many arid and semiarid regions of the world. Such biotic change is often accompanied by and linked to geomorphic change. Important geomorphic factors that determine the vulnerability of a system to coupled biotic and abiotic change includes soil, topography, and soil parent material—which together form the soil-geomorphic template. Soil exerts control because it is the substrate that provides water, nutrients, anchorage for roots, and habitat for burrowing animals. Topography exerts control by its influence on microclimate via water redistribution, aspect, and elevation. Soil parent material exerts control by its contribution to the nutrient supply and formation of soil. Numerous linkages and feedback-loops occur between the soil-geomorphic template, micro-climate, 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 processes provides a good example of how biological and geological systems are coupled and co-evolve.