CO2 is the main form of greenhouse gas exchanged between local soils and the atmosphere with its annual average flux several magnitudes higher than that of CH4 and N2O, which is in well accordance with the results by Tong et al. (2012, 2014) in Cyperus and Spart in acodominated marshes in Min River Estuary and by Chen et al. (2010, 2011, 2012)in Kandelia-dominated mangrove forests in Hong Kong