DISSERTATION RESEARCH: Altered Rainfall Impacts on Carbon and Nitrogen Cycling in California Grassland

论文研究：降雨变化对加州草原碳和氮循环的影响

• 批准号: 0608484
• 负责人: Whendee Silver
• 金额: $ 1.18万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0608484&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Altered; Rainfall; Impacts

The soil carbon reservoir outweighs the carbon in living plants, the atmosphere, or fossil fuel emissions. This study tests the effects of a future climate change, increased rainfall, on soil carbon quality in a California annual grassland. One possible outcome of increased rainfall in this ecosystem is increased soil microbial respiration (conversion of soil carbon to carbon dioxide by soil microorganisms), leaving behind carbon more resistant to degradation. Two techniques, applied in the laboratory and the field, will track this process. First, soil carbon will be fractionated: separated into light or heavy fractions based on density. Second, radiocarbon analysis will be used to determine a turnover rate (how fast soil carbon is converted to carbon dioxide) for each fraction. These techniques may detect changes in soil carbon quality even if no changes are seen in total soil carbon quantity. This study will enhance our understanding of rainfall effects on carbon cycling and budgets.

土壤碳储量超过了活植物、大气或化石燃料排放中的碳。 这项研究测试了未来气候变化、降雨量增加对加州一年生草地土壤碳质量的影响。 该生态系统中降雨量增加的一个可能结果是土壤微生物呼吸增加（土壤微生物将土壤碳转化为二氧化碳），从而留下更难降解的碳。 在实验室和现场应用的两种技术将跟踪这一过程。 首先，土壤碳将被分馏：根据密度分为轻质部分或重质部分。 其次，放射性碳分析将用于确定每个部分的周转率（土壤碳转化为二氧化碳的速度）。 即使土壤总碳量没有变化，这些技术也可以检测土壤碳质量的变化。 这项研究将加深我们对降雨对碳循环和预算影响的理解。