title: Response of gaseous carbon emissions to low-level salinity increase in tidal marsh ecosystem of the Min River estuary, southeastern China.
abstract: Although estuarine tidal marshes are important contributors to the emission of greenhouse gases into the atmosphere, the relationship between carbon dioxide (CO2), methane (CH4) emission, and environmental factors, with respect to estuarine marshes, has not been clarified thoroughly. This study investigated the crucial factors controlling the emission of CO2and CH4from a freshwater marsh and a brackish marsh located in a subtropical estuary in southeastern China, as well as their magnitude. The duration of the study period was November 2013 to October 2014. Relevant to both the field and incubation experiments, the CO2and CH4emissions from the two marshes showed pronounced seasonal variations. The CO2and CH4emissions from both marshes demonstrated significant positive correlations with the air/soil temperature (p<0.01), but negative correlations with the soil electrical conductivity and the pore water/tide water Cl-and SO42-(p<0.01). The results indicate no significant difference in the CO2emissions between the freshwater and brackish marshes in the subtropical estuary, whereas there was a difference in the CH4emissions between the two sites (p<0.01). Although future sea-level rise and saltwater intrusion could reduce the CH4emissions from the estuarine freshwater marshes, these factors had little effect on the CO2emissions with respect to an increase in salinity of less than 5‰. The findings of this study could have important implications for estimating the global warming contributions of estuarine marshes along differing salinity gradients.
authors.affiliation: School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Sub-tropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou 350007, China; Research Centre of Wetlands in Subtropical Region, Fujian Normal University, Fuzhou 350007, China. Electronic address: mjhu0014@163.com.
authors.forename: Minjie
authors.initials: M
authors.lastname: Hu
authors.affiliation: School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Sub-tropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou 350007, China; Research Centre of Wetlands in Subtropical Region, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Hongchang
authors.initials: H
authors.lastname: Ren
authors.affiliation: School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Sub-tropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou 350007, China; Research Centre of Wetlands in Subtropical Region, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Ren
authors.affiliation: School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China; School of Environmental Sciences, Fujian Normal University, Fuzhou 350007, China.
authors.forename: Jiabing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Biological Sciences, Florida International University, Miami, FL 33199, USA. Electronic address: bwils034@fiu.edu.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Wilson
authors.affiliation: School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Sub-tropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou 350007, China; Research Centre of Wetlands in Subtropical Region, Fujian Normal University, Fuzhou 350007, China. Electronic address: tongch@fjnu.edu.cn.
authors.forename: Chuan
authors.initials: C
authors.lastname: Tong
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere; D002244:Carbon / Q000032:analysis*; D002245:Carbon Dioxide / Q000032:analysis; D002681:China; D004784:Environmental Monitoring; D063366:Estuaries; D008697:Methane / Q000032:analysis; D054712:Salinity; D053833:Wetlands
chemical_list: D000393:Air Pollutants; D002245:Carbon Dioxide; D002244:Carbon; D008697:Methane
keywords: Global warming; Greenhouse gases; Min River estuary; Salinity gradient; Tidal marsh