Dissertation Research: Anaerobic Methane Oxidation in Freshwater Wetlands

论文研究：淡水湿地中的厌氧甲烷氧化

• 批准号: 0104954
• 负责人: Joseph Yavitt
• 金额: --
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0104954&HistoricalAwards=false
• 关键词: Dissertation; Research; Anaerobic; Methane; Oxidation

Methane is a natural component of the earth's atmosphere. However, the increase in the concentration of atmospheric methane since the turn of the century is a likely contributor to the enhancement of the greenhouse effect. A significant portion of atmospheric methane comes from freshwater wetlands where microorganisms produce methane in oxygen depleted soil. It is known that microorganisms living in the oxygenated part of the soil can consume some of the methane produced, so that the amount of methane leaking to the atmosphere is the difference between production and consumption. It is also possible that this methane consumption can occur in the oxygen depleted zone of the soil, yet this process is poorly understood. Most evidence for this process comes from sediments beneath the ocean, yet I have found strong evidence that large amounts of methane also can be consumed by microorganisms in the oxygen poor soil of a freshwater wetland in central New York State. The process is elusive and linked to seasonal climate patterns, which may be why the process was not seen by earlier investigators. This proposal requests funds to examine the extent of the process in peatlands in central New York State, Maryland, West Virginia, and Sweden. These are all well studied sites where the process would be expected to occur. Primary objectives are to assess the role of microorganisms that use iron instead of oxygen to consume methane, and how iron availability might limit the process. Results of this study should provide valuable insight into the relationship between atmospheric methane and wetland methane emissions. Moreover, a mechanistic understanding of methane emissions is essential in order to predict how methane emissions from wetlands will respond to future environmental changes.

甲烷是地球大气中的自然组成部分。但是，自世纪之交以来大气甲烷浓度的增加可能是增强温室效应的原因。大气中的很大一部分来自淡水湿地，在淡水湿地中，微生物在氧气耗尽的土壤中产生甲烷。众所周知，生活在土壤中的含氧部分中的微生物可以消耗一些产生的甲烷，因此泄漏到大气的甲烷量是生产和消费之间的差异。这种甲烷消耗也可能发生在土壤的氧气耗尽区域中，但该过程却鲜为人知。这一过程的大多数证据来自海洋下方的沉积物，但我发现有力的证据表明，在纽约州中部淡水湿地的氧气贫穷土壤中，微生物也可以消耗大量甲烷。该过程难以捉摸，并且与季节性气候模式有关，这可能就是为什么早期研究人员看不到该过程的原因。该提案要求资金审查纽约州中部，马里兰州，西弗吉尼亚州和瑞典的泥炭地的过程程度。这些都是经过良好研究的地点，期望发生该过程。主要目标是评估使用铁代替氧气消耗甲烷的微生物的作用，以及铁的可用性如何限制过程。这项研究的结果应为大气甲烷与湿地甲烷排放之间的关系提供宝贵的见解。此外，对甲烷排放的理解对于预测湿地中的甲烷排放将如何应对未来的环境变化至关重要。