Effects of salinity on methane emission at Yangtze Estuary Phragmites australis wetland
LIU Zi-wen1,2, WEI Xue-xin1,2, XU Yun-kai1,2, GE Zhen-ming1,3, WANG Dong-qi1,2
1. Key Laboratory of GIS of Ministry of education, East China Normal University, Shanghai 200241, China;
2. School of Geographical Sciences, East China Normal University, Shanghai 200241, China;
3. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
Abstract：Salinity has a profound influence on methane(CH4) production and emission in estuarine wetlands.In order to reveal the effects of seawater intrusion on CH4 emission from estuarine wetlands,static closed chamber combined with a gas chromatograph technique was used to investigate the flux of CH4 at a Phragmites australis wetland in Chongming Dongtan from april to october in 2016.The results showed that the flux of CH4 was higher in spring and summer than in autumn and winter.The flux ranged from 0.19 to 7.68 mg/(m2·h) and the average flux was 3.41 mg/(m2·h) from april to october.High salinity level inhibits the production and emission of CH4,while low salinity promotes CH4 production within certain range.In high-salinity conditions,CH4 emission flux has a significant logarithmic negative correlation with salinity.In the early stage of growth of Phragmites australis,the flux of CH4 is positively correlated with temperature and light; however,in the later stage of growth,it is negatively correlated with temperature and light.
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