Collaborative Research: Why Does the Efficiency of Methane Production Vary Dramatically Among Wetlands?

合作研究：为什么湿地的甲烷生产效率差异很大？

• 批准号: 0816743
• 负责人: Jason Keller
• 金额: $ 15万
• 依托单位: Chapman University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0816743&HistoricalAwards=false
• 关键词: Collaborative; Research; Why; Does; Efficiency

The objective of this research is to understand the factors that control the production of the greenhouse gases carbon dioxide and methane in wetland soils under anaerobic (i.e., waterlogged with oxygen depletion) conditions in current and future climates. These two gases are the end products of a complicated, interlinked set of microbial processes during the anaerobic decomposition of soil organic matter, and the goal of this project is to understand the relative ratio at which these two gases are produced within the context of the larger anaerobic carbon cycle. Both field and laboratory experiments will be used to examine the chemical, environmental, and biological factors (including microbial community structure) that control the ratio at which these important greenhouse gases are produced in six wetlands in northern Michigan. These wetlands represent a broad range of conditions in terms of hydrology, chemistry, and plant community composition. The proportion of soil carbon that ends up as carbon dioxide and methane during anaerobic decomposition varies by several orders of magnitude among different types of wetlands, and the factors that control this variation are not well understood. Because methane is a much more potent greenhouse gas than carbon dioxide, the ratio at which these two gases are produced can have a substantial impact on the Earth?s climate system. Also, methane emissions from wetlands have been sensitive to climate change in the past and may have strong feedbacks to future human-induced climate change.

本研究的目的是了解当前和未来气候条件下，沼泽土壤中温室气体二氧化碳和甲烷在厌氧(即耗氧)条件下产生的控制因素。这两种气体是土壤有机质厌氧分解过程中一系列复杂的、相互关联的微生物过程的最终产物，本项目的目标是了解在更大的厌氧碳循环背景下产生这两种气体的相对比例。在密歇根州北部的六个湿地中，化学、环境和生物因素(包括微生物群落结构)控制着这些重要的温室气体的产生比例。这些湿地在水文、化学和植物群落组成方面代表了广泛的条件。在不同类型的湿地中，在厌氧分解过程中最终形成二氧化碳和甲烷的土壤碳的比例有几个数量级的差异，控制这种差异的因素还不是很清楚。因为甲烷是一种比二氧化碳更强的温室气体，这两种气体的产生比例可能会对地球气候系统产生重大影响？S。此外，湿地的甲烷排放过去对气候变化很敏感，可能对未来人类引发的气候变化有很强的反馈作用。