Eolian Vs. Biogeochemical Influences On Pedogenesis in An Aridic Calciustoll.

Estimating the rate of soil formation is one of the greatest challenges in soil science. It is also of great importance to many science fields that use soil data (hydrological modeling, climate change research, landscape stability, and earthquake risk being a few examples). While it is known that plants affect soil development, information on soil formation is especially lacking in arid ecosystems under the influence of long-lived plant species such as curlleaf mountain mahogany (CMM)(Cercocarpus ledifolius, Rosaceae). Because CMM may attain ages in excess of 1000 years, and may reestablish in the same positions on the landscape, the potential for quantifying soil devlopment and deriving rates of several soil formation processes is great. Our research focuses on CMM woodlands in southern Nevada. Results suggest that soils developed under CMM have significantly greater soil development and biogeochemical cylcing associated with tree morphology enhance soil development, but that eolian deposition still is the dominat factor affecting pedogenesis. Since many models predict the expansion of arid ecosystems with global climate, CMM will likely play an even greater role in soil development in the future. In addition, curlleaf mountain mahogany is an extremely valuable wildlife forage, provides a unique habitat enhancing local biodiversity, and controls erosion and increases water infiltration on steep slopes.