Spartina alterniflora invasion drastically increases methane production potential by shifting methanogenesis from hydrogenotrophic to methylotrophic pathway in a coastal marsh

作者：Junji Yuan, Deyan Liu, Yang Ji, Jian Xiang, Yongxin Lin, Ming Wu, Weixin Ding · 发表于：Journal of Ecology · 年份：2019 · DOI：10.1111/1365-2745.13164 · 被引用次数：85 · 研究领域：Coastal wetland ecosystem dynamics、Methane Hydrates and Related Phenomena、Microbial Community Ecology and Physiology

Abstract Plant invasion can strongly influence carbon (C) cycling processes, thus it may affect climate change by altering C sequestration and greenhouse gas emissions in the invaded ecosystem. Since 1979, the exotic Spartina alterniflora has rapidly expanded in China’s coastal areas, where significant increase in methane (CH 4 ) emissions has been documented from post‐invaded sites. However, a mechanistic understanding of the structural and functional changes of associated methanogens accompanying this invasion remains elusive. Here we conducted integrated biogeochemical investigations on methanogenic substrates, activity, and diversity to identify implications of S. alterniflora invasion for methanogenesis in coastal wetlands. To do this, we collected and analysed 0–50 cm soil profiles from an uncolonised tidal flat (TF) and salt marshes that S. alterniflora has invaded for 1 year (SA‐1) and 12 years (SA‐12) in Jiangsu, China. Methanogenic community composition was characterised by massive parallel sequencing. The rates and pathways of methanogenesis were determined by adding trace concentrations of 13 C‐labelled substrates to anaerobic incubated samples. Our results revealed that 12‐year invasion of S. alterniflora drastically increased CH 4 production potential by one order of magnitude over that of TF. This substantial increase was primarily attributed to methanogenesis from trimethylamine; its rates increased by two orders of magnitude over TF whereas those from acetate...