Testing the consequences of the carbon-quality temperature hypothesis for soil organic matter decomposition

这项研究将调查土壤中二氧化碳损失对温度升高的敏感程度，以及为什么不同土壤之间存在差异。 将在受控的实验室条件下收集和分析来自美国各种生态系统的土壤，以确定微生物在不同温度下呼吸土壤碳的速度以及生物有效氮的增加如何影响这种温度敏感性。这项研究将测试预测是否柠檬酸土壤碳损失将更敏感的温度上升比少柠檬酸土壤碳。此外，该研究还将测试氮可用性的增加是否会降低温度敏感性。在全球范围内，土壤碳是最大的碳储存库之一，但如果不对控制土壤微生物如何利用碳的机制有所了解，就不可能预测它在变暖世界中的命运。这项研究将检验一套关于土壤功能的关键假设，并将提供对改进生态系统如何应对气候变化和生物沉积的模型至关重要的数据。有效氮研究的核心是确定变暖的土壤是否可能对全球温度提供积极的反馈，同时确定那些最容易因变暖而导致碳损失的土壤和土壤成分。

This research will investigate how sensitively carbon dioxide loss from soil responds to increasing temperature and why this varies among different soils. Soils from a variety of ecosystems across the United States will be collected and assayed under controlled laboratory conditions in order to determine how fast soil carbon is respired by microbes at different temperatures and how increases in biologically available nitrogen affect this temperature sensitivity. The research will be testing predictions as to whether recalcitrant soil carbon loss will be more sensitive to increases in temperature than less recalcitrant soil carbon. In addition, the research will test whether increases in nitrogen availability decrease temperature sensitivity. Globally, soil carbon is one of the largest repositories of carbon, yet its fate in a warmer world will be impossible to predict without mechanistic understanding of what controls how soil microbes utilize it. For global change biologists, this research will test a critical set of hypotheses about soil functioning and will provide data that are essential to improving models of how ecosystems respond to climate change and deposition of biologically available nitrogen. At the heart of the research is determining whether warming soils are likely to provide a positive feedback to global temperatures while also identifying those soils and components of soils that are most susceptible to carbon loss due to warming.