Authors: Junji Yuan Weixin Ding Deyan Liu Jian Xiang Yongxin Lin
Publish Date: 2013/08/02
Volume: 98, Issue: 4, Pages: 1817-1829
Abstract
Invasion by the exotic species Spartina alterniflora which has high net primary productivity and superior reproductive capacity compared with native plants has led to rapid organic carbon accumulation and increased methane CH4 emission in the coastal salt marsh of China To elucidate the mechanisms underlying this effect the methanogen community structure and CH4 production potential as well as soil organic carbon SOC dissolved organic carbon dissolved organic acids methylated amines aboveground biomass and litter mass were measured during the invasion chronosequence 0–16 years The CH4 production potential in the S alterniflora marsh range 294–395 μg kg−1 day−1 was significantly higher than that in the bare tidal mudflat CH4 production potential correlated significantly with SOC acetate and trimethylamine concentrations in the 0–20 cm soil layer The abundance of methanogenic archaea also correlated significantly with SOC and the dominant species clearly varied with S alternifloradriven SOC accumulation The acetotrophic Methanosaetaceae family members comprised a substantial proportion of the methanogenic archaea in the bare tidal mudflat while Methanosarcinaceae family members utilized methylated amines as substrates in the S alterniflora marsh Ordination analysis indicated that trimethylamine concentration was the primary factor inducing the shift in the methanogenic archaea composition and regressive analysis indicated that the facultative family Methanosarcinaceae increased linearly with trimethylamine concentration in the increasingly sulfaterich salt marsh Our results indicate that increased CH4 production during the S alterniflora invasion chronosequence was due to increased levels of the noncompetitive substrate trimethylamine and a shift in the methanogenic archaea communityThis work was supported by the strategic priority research program—Climate Change Carbon Budget and Relevant Issues of the Chinese Academy of Sciences XDA05020501 the National Basic Research Program of China 2012CB417102 and the Natural Science Foundation of China 41171190 41001045 and 41001173
Keywords: