Vulnerability of Soil Organic Matter to Temperature Changes: Exploring Constraints Due to Substrate Decomposability and Microbial Community Structure

土壤有机质对温度变化的脆弱性：探索底物分解性和微生物群落结构的限制

• 批准号: 0444880
• 负责人: Richard Conant
• 金额: --
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0444880&HistoricalAwards=false
• 关键词: Vulnerability; Soil; Organic; Matter; Temperature

Recent research suggests that even modest temperature increases could cause large releases of CO2 from soils. A one-degree temperature increase could prompt soil carbon losses (as CO2) equivalent to five times the annual CO2 release from all fossil fuel burning. However, such forecasts are based on results from short-term studies that implicitly assume all of the carbon in the soil is uniformly temperature-sensitive. The bulk of applicable research suggests that older, more resistant carbon fractions may be less temperature-sensitive than younger, less resistant carbon fractions. This project will evaluate the extent to which the physical, chemical, and biochemical mechanisms that protect soil carbon from decomposition act to reduce the temperature sensitivity of soil carbon. An important corollary is that soil carbon stocks are less vulnerable to changes in temperature than previously supposed. As a part of this project, we will evaluate temperature sensitivities of soil carbon fractions in soils that differ with regard to their relative abundances of labile versus relatively stable carbon. Results from this work will reduce uncertainty about the vulnerability of soil carbon stocks to changes in temperature, thus improving information available to aid decision makers. This research will also advance our understanding of basic ecosystem dynamics, present a number of unique opportunities for undergraduate and graduate training, and build international collaboration.

最近的研究表明，即使温度升高也可能导致土壤中的大量二氧化碳释放。 一级温度的升高可能会促使土壤碳损失（CO2），相当于所有化石燃料燃烧的年度二氧化碳释放的五倍。但是，这种预测是基于短期研究的结果，这些研究隐含地假设土壤中的所有碳对温度均匀敏感。大部分适用的研究表明，较老，更耐碳的碳部分可能比年轻，耐药少的碳馏分较低。该项目将评估保护土壤碳免于分解的物理，化学和生化机制，以降低土壤碳的温度敏感性。一个重要的推论是，土壤碳储备的温度不那么容易变化。作为该项目的一部分，我们将评估土壤碳分数的温度敏感性在不稳定和相对稳定的碳相对丰度方面不同。这项工作的结果将减少有关土壤碳储备与温度变化的脆弱性的不确定性，从而改善可用的信息以帮助决策者。这项研究还将提高我们对基本生态系统动态的理解，为本科和研究生培训提供许多独特的机会，并建立国际合作。