Department of Geography, University of Toronto Mississauga Mississauga, ON, Canada ; Max-Planck-Institute for Terrestrial Microbiology Marburg, Germany.
Front Microbiol. 2013 Jul 31;4:215. doi: 10.3389/fmicb.2013.00215. eCollection 2013.
Northern peatlands are important global C reservoirs, largely because of their slow rates of microbial C mineralization. Particularly in sites that are heavily influenced by anthropogenic disturbances, there is scant information about microbial ecology and whether or not microbial community structure influences greenhouse gas production. This work characterized communities of bacteria and archaea using terminal restriction fragment length polymorphism (T-RFLP) and sequence analysis of 16S rRNA and functional genes across eight natural, mined, or restored peatlands in two locations in eastern Canada. Correlations were explored among chemical properties of peat, bacterial and archaeal community structure, and carbon dioxide (CO2) and methane (CH4) production rates under oxic and anoxic conditions. Bacteria and archaea similar to those found in other peat soil environments were detected. In contrast to other reports, methanogen diversity was low in our study, with only 2 groups of known or suspected methanogens. Although mining and restoration affected substrate availability and microbial activity, these land-uses did not consistently affect bacterial or archaeal community composition. In fact, larger differences were observed between the two locations and between oxic and anoxic peat samples than between natural, mined, and restored sites, with anoxic samples characterized by less detectable bacterial diversity and stronger dominance by members of the phylum Acidobacteria. There were also no apparent strong linkages between prokaryote community structure and CH4 or CO2 production, suggesting that different organisms exhibit functional redundancy and/or that the same taxa function at very different rates when exposed to different peat substrates. In contrast to other earlier work focusing on fungal communities across similar mined and restored peatlands, bacterial and archaeal communities appeared to be more resistant or resilient to peat substrate changes brought about by these land uses.
北方泥炭地是重要的全球碳库，这主要是因为它们的微生物碳矿化速率较慢。特别是在受到人为干扰影响较大的地方，关于微生物生态学以及微生物群落结构是否会影响温室气体产生的信息很少。本研究使用末端限制性片段长度多态性（T-RFLP）和 16S rRNA 及功能基因的序列分析，对加拿大东部两个地点的 8 个天然、开采或修复的泥炭地中的细菌和古菌群落进行了特征描述。研究了泥炭化学性质、细菌和古菌群落结构以及好氧和缺氧条件下二氧化碳（CO2）和甲烷（CH4）产生速率之间的相关性。检测到了与其他泥炭土壤环境中发现的相似的细菌和古菌。与其他报告相反，本研究中甲烷菌的多样性较低，只有 2 组已知或疑似的甲烷菌。尽管开采和修复会影响基质的可用性和微生物活性，但这些土地利用方式并不总是会影响细菌或古菌群落组成。事实上，在两个地点之间、好氧和缺氧泥炭样本之间观察到的差异大于天然、开采和修复地点之间的差异，缺氧样本的细菌多样性较低，酸杆菌门的成员更为优势。原核生物群落结构与 CH4 或 CO2 产生之间也没有明显的紧密联系，这表明不同的生物表现出功能冗余，或者当暴露于不同的泥炭基质时，相同的类群以非常不同的速率发挥功能。与其他早期关注类似开采和修复泥炭地真菌群落的工作不同，细菌和古菌群落似乎对这些土地利用方式引起的泥炭基质变化更具抵抗力或弹性。
