湿地微生物介导的甲烷排放机制

Microbial driven methane emission mechanisms in wetland ecosystems

摘要:

湿地生态系统是陆地上巨大的有机碳库，同时也是大气中甲烷（CH₄）的主要排放源。由于CH₄对全球的增温潜能是CO₂的34倍，因此关于湿地CH₄排放在全球气候变化中有关碳汇、碳源的研究具有极其重要的意义。全球80%-90%的CH₄排放离不开微生物活动，湿地生态系统中产CH₄菌和CH₄氧化菌的种类组成、数量及功能与CH₄通量密切相关，但基于湿地生态系统中介导CH₄循环的功能微生物对甲烷排放通量的影响及作用机制研究相对比较分散。为更好地认识微生物介导的CH₄排放过程的微生物调控机制，本文综述了湿地生态系统中参与CH₄循环的功能微生物，对介导CH₄循环相关微生物活性的影响因子进行了回顾，重点总结了湿地生态系统微生物介导的CH₄排放机制，并对未来的相关研究方向进行了展望。由于湿地微生物介导的碳循环过程也可能决定了湿地生态系统对全球气候变暖的反馈，因此本文也能为全球气候变化研究提供微生物方面的参考。

Abstract:

Wetland is one of the largest carbon sink among all terrestrial ecosystems, and regarded as the main emission source of methane (CH₄) in the atmosphere. As CH₄ has 34 times warming potential of carbon dioxide (CO₂)per mole, it is of great importance to study the contribution of wetland as carbon sink or carbon source to global climate change. Totally, 80% to 90% of CH₄ emissions come from microbial activity, and CH₄ flux in wetland is closely related to microbial composition, abundance and function of methanogens and methanotrophs. However, the studies on the effects and mechanisms of the functional microorganisms that control CH₄ cycling in wetland ecosystem is relatively decentralized. To better understand the microbial regulation mechanism of CH₄ emission process, we provide an overview of microbial community associated to CH₄ cycling, the factors influencing the microbial methane emission activity, and the microbial methane emission mechanisms in wetland ecosystem. Besides, we indicate further research needs on microbial-driven CH₄ emission and their potential response to climate change.