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冻土是陆地生态系统中最容易受到全球气候变化影响的碳库,既发挥着碳源又起着碳汇的作用。人们非常关注贮存于冻土中有机碳的最终归宿,是因为全球气候变暖会加快冻土的解冻,释放更多的温室气体(二氧化碳和甲烷)到大气中,从而进一步加剧温室效应。据估计每年从北半球冻原陆地生态系统释放进入大气的甲烷约占全球自然界释放甲烷总量的25%。研究证实冻土生物源甲烷的产生和消耗分别由耐(嗜)低温的产甲烷菌(methanogens)和甲烷氧化菌(methanotrophs)介导。鉴于冻土甲烷循环对全球甲烷平衡的显著作用以及在冻土生物地球化学循环中的重要功能,对介导冻土甲烷循环的产甲烷菌和甲烷氧化菌的研究将有助于更好地评估冻土生态系统对全球气候变化的响应和影响,就冻土甲烷循环过程、产甲烷菌、甲烷氧化菌的群落结构、活动、生态功能及其对气候和环境变化的响应机制的最新研究进行综述,以期为我国开展冻土甲烷循环机理研究提供支持。
Permafrost is the most vulnerable carbon sink in terrestrial ecosystems affected by global climate change, playing both a carbon source and a carbon sink. People are very concerned about the final destination of organic carbon stored in the frozen soil because global warming further exacerbates the greenhouse effect by accelerating the thawing of frozen soils and releasing more greenhouse gases (carbon dioxide and methane) into the atmosphere. It is estimated that methane released into the atmosphere from the tundra terrestrial ecosystems in the northern hemisphere each year accounts for about 25% of the total methane released by the world’s nature. Studies have demonstrated that generation and depletion of biogenic methane from permafrost are mediated by methanogens and methanotrophs that are resistant to (addicted to) low temperatures, respectively. In view of the significant role of the permafrost methane cycle in global methane balance and its important function in the biogeochemical cycles of the frozen soils, the study of methanogenic and methanotrophs that mediate permafrost methane circulation will help to better assess The review of the response and impact of permafrost ecosystems to global climate change is reviewed in the recent work on the methane cycle in permafrost, the community structure of methanogenic bacteria and methanotrophs, their activities, ecological functions, and their response mechanisms to climate and environmental changes , In order to provide support for the research on the mechanism of permafrost methane circulation in our country.