The impact of dissolved organic carbon on the spatial variability of methanogenic archaea communities in natural wetland ecosystems across China
The impact of dissolved organic carbon on the spatial variability of methanogenic archaea communities in natural wetland ecosystems across China
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溶解有机碳对中国自然湿地生态系统产甲烷古菌群落空间变异的影响
DOI：
10.1007/s00253-011-3842-x
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发表时间：
2012-10-01
影响因子：
5
通讯作者：
Cai, Zucong
中科院分区：
文献类型：
--
作者：
Liu, Deyan;Ding, Weixin;Cai, Zucong
CH4 排放量的显着空间变化是自然湿地生态系统的一个公认特征。为了了解影响 CH4 产生的关键因素，利用变性梯度凝胶电泳，在中国选定的湿地中研究了与底物和外部环境影响相关的产甲烷古菌群落结构的变化。案例研究区为亚热带鄱阳湿地、暖温带洪泽湿地、寒温带三江沼泽、青藏高原高山若尔盖泥炭地。洪泽湿地表土层产甲烷菌数量最多；最低的是鄱阳湿地。 CH4 产量最大出现在三江苔草沼泽表土层，最小出现在若尔盖泥炭地。 CH4 生产潜力与溶解有机碳 (DOC) 浓度显着相关，但与产甲烷古菌的丰度或多样性指数无关。系统发育分析和DOC浓度表明，优势产甲烷菌从富含DOC的湿地中的氢营养型甲烷杆菌目转变为在DOC相对较高的湿地中具有低亲和力的甲烷八叠球菌科，然后转变为在低DOC或高DOC但富含硫酸盐还原菌的湿地中具有高亲和力的醋营养产甲烷菌Methanosaetaceae。因此，有人提出湿地中主要产甲烷菌类型主要受有效DOC浓度的影响。反过来，中国东部湿地CH4生产潜力的变化归因于DOC含量和存在的主要产甲烷菌类型的差异。
Significant spatial variation in CH4 emissions is a well-established feature of natural wetland ecosystems. To understand the key factors affecting CH4 production, the variation in community structure of methanogenic archaea, in relation to substrate and external environmental influences, was investigated in selected wetlands across China, using denaturing gradient gel electrophoresis. Case study areas were the subtropical Poyang wetland, the warm-temperate Hongze wetland, the cold-temperate Sanjiang marshes, and the alpine Ruoergai peatland on the Qinghai-Tibetan Plateau. The topsoil layer in the Hongze wetland exhibited the highest population of methanogens; the lowest was found in the Poyang wetland. Maximum CH4 production occurred in the topsoil layer of the Sanjiang Carex lasiocarpa marsh, the minimum was observed in the Ruoergai peatland. CH4 production potential was significantly correlated with the dissolved organic carbon (DOC) concentration but not with the abundance or diversity indices of methanogenic archaea. Phylogenetic analysis and DOC concentration indicated a shift in the dominant methanogen from the hydrogenotrophic Methanobacteriales in DOC-rich wetlands to Methanosarcinaceae with a low affinity in wetlands with relatively high DOC and then to the acetotrophic methanogen Methanosaetaceae with a high affinity in wetlands with low DOC, or with high DOC but rich sulfate-reducing bacteria. Therefore, it is proposed that the dominant methanogen type in wetlands is primarily influenced by available DOC concentration. In turn, the variation in CH4 production potential in the wetlands of eastern China is attributable to differences in the DOC content and the dominant type of methanogen present.