天然湿地土壤产甲烷菌及其影响因子研究进展

Progress on Spatial Variation of Methanogens and Their Influencing Factors in Natural Wetlands

综合评述了天然湿地产甲烷菌种类、主要产甲烷途径的空间变异及其影响因子。温度不仅可以改变产甲烷菌群落结构和功能,也可影响产甲烷菌功能发挥,目前有关温度对湿地土壤甲烷产生的影响机制有待揭示。以乙酸为底物的产甲烷菌大多生存于维管束植物生长的湿地,H2/CO2还原则为苔藓泥炭沼泽甲烷产生的主要途径;在pH<4.7的偏酸性湿地中,自由态乙酸可以降低乙酸发酵型产甲烷菌活性,而氢营养型产甲烷菌和部分其他微生物可能具有自身的弥补机制。还提出今后中国沼泽湿地产甲烷菌和甲烷排放有待加强研究的主要内容。

The spatial variability of predominant methanogenic archaea,main pathways of methane production and their influencing factors in natural wetlands are reviewed.Temperature could not only directly alter the community structure and function of methanogenic archaea,but also might affect the supply of substrates for methanogens,which in turn indirectly regulate the function of methanogenic archaea.The underlying mechanism of temperature on methane production in natural wetlands is not to be understood clearly.Acetoclastic methanogens generally live in wetlands vegetated with vascular plants,while reduction of H2/CO2 or hydrogenotrophic methanogensis is the main pathway for methane production in peatland where few vascular plants is present.The presence of free acetic acid in wetlands might reduce the activities of acetoclastic methanogens when pH is 4.7,but hydrogenotrophic methanogens and other microorganisms might have a special mechanism to compensate for decoupling by acetic acid.Meanwhile,we also give hints on future studies from natural wetlands in China.