Emission of Greenhouse Gases (CH4 and CO2) into the Atmosphere from Restored Mangrove Soil in South China

Abstract

Xu, Y.; Liao, B.; Jiang, Z.; Xin, K.; Xiong, Y., and Guan, W., 2021. Emission of greenhouse gases (CH4 and CO2) into the atmosphere from restored mangrove soil in South China. Journal of Coastal Research, 37(1), 52–58. Coconut Creek (Florida), ISSN 0749-0208.Mangroves are a special ecosystem in tropical and subtropical coastal areas. Currently, it is not adequately understood whether soils in restored mangroves are a substantial source of greenhouse gases. The objectives of this study were to determine whether restored mangrove soils are a substantial source of carbon dioxide (CO2) and methane (CH4) and to identify environmental factors affecting soil CO2 and CH4 fluxes in mangrove sites. From August 2019 to January 2020, CO2 and CH4 flux surveys were conducted in soils at four planted mangrove sites, dominated by Excoecaria agallocha, Kandelia obovata, Bruguiera gymnorrhiza, and Hymenocallis littoralis, respectively, in a mangrove reserve in southern China. The results showed that the CO2 and CH4 flux ranges of the four mangrove sites were 0.9432–1.7892 mmol m–2 h–1 and –0.104 to 0.845 µmol m–2 h–1, respectively. Soil CO2 flux was strongly positively (p < 0.01) correlated with soil organic carbon content and positively correlated (p < 0.05) with soil total N content, temperature, and redox potential. CH4 flux was positively correlated with soil temperature. The results confirm that these restored mangrove soils are only a small greenhouse gases source to the atmosphere.