4.6 Article

Effects of constant and fluctuating saltwater addition on CH4 fluxes and methanogens of a tidal freshwater wetland: A mesocosm study

期刊

ESTUARINE COASTAL AND SHELF SCIENCE
卷 277, 期 -, 页码 -

出版社

ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.ecss.2022.108076

关键词

Sea-level rise; Storm surge; Tidal freshwater marsh and floodplain; Methane (CH4) emission; Methanogens

资金

  1. Key Natural Science Foundation of Fujian Province, China [2019J02008]
  2. National Sci- ence Foundation of China [41877335]
  3. Technology Projects of Forest Bureau of Fujian, China

向作者/读者索取更多资源

This study examined the effects of constant and fluctuating salinity increases on CH4 emissions and methanogens in tidal freshwater marsh and floodplains. The results showed that salinity fluctuations significantly reduced methanogen abundance and diversity, and altered the community structure. Porewater sulfate and chloride concentrations, as well as pH, were important factors affecting methanogen abundance and diversity. Both constant and fluctuating salinity treatments reduced CH4 flux, and methanogen abundance and diversity were positively correlated with CH4 flux.
The importance of salinity in regulating CH4 emissions from coastal tidal wetlands has been widely recognized. However, the different effects of constant versus fluctuating salinity increases on CH4 emission and methanogens in both tidal freshwater marsh and floodplains are not yet well understood. We constructed mesocosm experiments on both a Cyperus malaccensis marsh and an adjacent non-vegetation-covered tidal floodplain over one year. We examined the effects of constant freshwater (CF), constant salinity (CS), and fluctuating salinity (FS) on porewater geochemistry, CH4 flux, methanogen abundance, diversity, and community structure in the tidal marsh and floodplain. Compared with CF treatment, methanogen abundance and Chao1 index were significantly lower in the marsh mesocosms under FS and CS treatment, but only in the floodplain mesocosms under CS treatment. CS treatment significantly reduced the proportion of Methanosarcinales but significantly increased the proportion of Methanobacteriales. Porewater SO42- and Cl- concentrations and pH were important factors affecting methanogen abundance and diversity. Both the CS and FS treatments considerably reduced CH4 fluxes in marsh and floodplain mesocosms; the main factor impacting CH4 flux was porewater dissolved CH4 concentration, and both methanogen abundance and Chao1 index were positively correlated with CH4 flux. Our results suggest that both continuous saltwater intrusion caused by sea-level rise and pulse saltwater intrusion perhaps caused by typhoons could reduce CH4 flux from subtropical estuarine tidal freshwater wetlands.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.6
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据