大气甲烷的微生物产生与消耗

Microbial Production and Consumption of Atmospheric Methane

通过对土壤甲烷产生的微生物过程的分析,揭示了土壤中甲烷的产生主要是土壤有机质厌氧分解的末端产物,在有氧时,则易被甲烷氧化菌氧化成二氧化碳。阐述了土壤的甲烷主要来自于湿地、稻田和垃圾填埋场等,据估算其排放量占每年全球甲烷产生量的一半左右。在通气良好的土壤中,大气甲烷的氧化占全球甲烷吸收总量的10%左右。提出了土壤是大气甲烷的源还是汇,主要取决于土壤甲烷产生与甲烷氧化的活动的相对速率。

Methane i s considered to be a significant greenhouse gas. Methane is produced in soils as the end product of the anaerobic decomposition of organic matter. In the absence of oxygen, methane is very stable, but under aerobic condition it is mineralized to carbon dioxide by methanotrophic bacteria. Soil methane emissions, primarily from natural wetlands, landfills and rice paddies, are estimate to represent about half of the global methane production. Oxidation of atmospheric methane by well-drained soils accounts for about 10% of the global methane sink. Whether a soil is a net source or a sink for methane depends on the relative rates of methanogenic and methanotrophic activity.