Dissertation Research: Origin and Flux of Soil Carbon Following Shrub Invasion: Isotopic Analyses of Community Change

[9520743]弗吉尼亚干旱地区的生产力与有机碳循环密切相关。很少有研究涉及沙漠化导致的土壤碳变化。以往的研究表明，沙漠化主要是由土壤碳源/碳汇关系的改变和生态系统的长期稳定性引起的。这些影响可能会降低干旱地区的经济潜力。拟议的研究使用有机碳丰度技术和放射性碳定年法来量化现代碳循环的变化，以检验这些假设。该研究将初步量化在不断变化的干旱环境下的长期积累/分解过程，描述荒漠化导致的土壤总碳的变化特征，并将现代荒漠化率与过去的群落变化和气候历史进行比较。

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.