Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, USA.
Department of Biological Sciences, Rutgers University, Newark, NJ, USA.
Environ Monit Assess. 2018 Feb 26;190(3):176. doi: 10.1007/s10661-018-6552-3.
Biogeochemical processes in wetland soils are complex and are driven by a microbiological community that competes for resources and affects the soil chemistry. Depending on the availability of various electron acceptors, the high carbon input to wetland soils can make them important sources of methane production and emissions. There are two significant pathways for methanogenesis: acetoclastic and hydrogenotrophic methanogenesis. The hydrogenotrophic pathway is dependent on the availability of dissolved hydrogen gas (H), and there is significant competition for available H. This study presents simultaneous measurements of dissolved methane and H over a 2-year period at three tidal marshes in the New Jersey Meadowlands. Methane reservoirs show a significant correlation with dissolved organic carbon, temperature, and methane emissions, whereas the H concentrations measured with dialysis samplers do not show significant relationships with these field variables. Data presented in this study show that increased dissolved H reservoirs in wetland soils correlate with decreased methane reservoirs, which is consistent with studies that have shown that elevated levels of H inhibit methane production by inhibiting propionate fermentation, resulting in less acetate production and hence decreasing the contribution of acetoclastic methanogenesis to the overall production of methane.
湿地土壤中的生物地球化学过程复杂，由微生物群落驱动，这些微生物群落争夺资源并影响土壤化学性质。根据各种电子受体的可用性，湿地土壤中大量的碳输入可以使它们成为甲烷产生和排放的重要来源。产甲烷作用有两种重要途径：乙酸营养型产甲烷作用和氢营养型产甲烷作用。氢营养型途径依赖于溶解氢气（H）的可用性，并且存在对可用 H 的激烈竞争。本研究在新泽西 Meadowlands 的三个潮汐沼泽中进行了为期两年的溶解甲烷和 H 的同步测量。甲烷储层与溶解有机碳、温度和甲烷排放呈显著相关性，而透析采样器测量的 H 浓度与这些现场变量没有显著关系。本研究提供的数据表明，湿地土壤中溶解 H 储层的增加与甲烷储层的减少相关，这与表明升高的 H 水平通过抑制丙酸盐发酵来抑制甲烷产生的研究结果一致，从而导致乙酸盐产量减少，从而减少了乙酸营养型产甲烷作用对甲烷总产生量的贡献。
