Dissertation Research: Effects of Oxic-Anoxic Dynamics on Methanogenesis and Methane Oxidation in Humid Tropical Forests-Evidence from Stable Isotope Distributions

论文研究：含氧缺氧动力学对潮湿热带森林产甲烷和甲烷氧化的影响——来自稳定同位素分布的证据

• 批准号: 0206547
• 负责人: Whendee Silver
• 金额: $ 1万
• 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: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0206547&HistoricalAwards=false
• 关键词: Dissertation; Research; Effects; Oxic; Anoxic

The dynamics and the stable isotope geochemistry of methane in wet, tropical forest soils are poorly understood, compromising our ability to predict rates of methane flux and 13 C exchange with the atmosphere. Quantifying the source/sink strength and * 13 C signature of methane flux is crucial if we hope to evaluate the role of the tropics in the global methane budget. In systems where redox fluctuates, such as wet tropical forest soils, variations in oxygen influence methane emissions by altering the balance between methanogenesis and methane oxidation. This study explores the effects of oxygen variations on methanogenesis, methane oxidation and 13 C exchange with the atmosphere. Patterns of methane flux and 13 C exchange will be documented across natural gradients of oxygen in the field. Sources and sinks of methane will be identified, both in soil and across the landscape, through gas concentrations and stable isotope analysis. A series of mechanistic laboratory experiments will be performed to explore the effects of oxygen variation on gross methanogenesis, methane oxidation and stable isotope fractionation. This study will advance our knowledge of the factors that regulate methane and 13 C flux from wet tropical forests to the atmosphere.

在湿，热带森林土壤中甲烷的动力学和稳定的同位素地球化学知识较少，从而损害了我们预测甲烷通量速率和与大气交换的13 C交换的能力。如果我们希望评估热带地区在全球甲烷预算中的作用，那么量化源/下沉强度和 * 13 c的标志至关重要。在氧化还原波动（例如湿热带森林土壤）的系统中，氧的变化通过改变甲烷发生和甲烷氧化之间的平衡来影响甲烷的排放。这项研究探讨了氧变化对甲烷发生，甲烷氧化和与大气交换13 C的影响。甲烷通量和13 C交换的模式将记录在田间自然氧梯度上。通过气体浓度和稳定的同位素分析，将在土壤和整个景观中确定甲烷的来源和水槽。将进行一系列机械实验室实验，以探索氧变化对甲烷发生，甲烷氧化和稳定同位素分馏的影响。这项研究将使我们对调节甲烷和13 C通量的因素从湿的热带森林到大气的了解。