9520743 VIRGINIA Aridland productivity is closely linked to the organic carbon cycle. Few studies address changes in soil carbon resulting from desertification. Previous studies suggest that desertification results primarily from modifications in soil carbon source / sink relationships and long-term ecosystem stability. These impacts may reduce the economic potential of aridland regions. The proposed study tests these hypotheses using organic carbon abundance techniques and radiocarbon dating to quantify changes in modern carbon cycles. The study will provide initial quantification of long-term accumulation / decomposition process in a changing aridland environment, characterize changes in total soil carbon due to desertification, and compare modern desertification rates with past community changes and climatic history.
