CHANGE IN ECOSYSTEM CARBON STORAGE OF THE MANGROVE FOREST ALONG THE CHINESE COAST BETWEEN 1990 AND 2010

Mangrove forests provide important ecological services, and play a critical role in global carbon cycling. Although temporal changes in ecosystem carbon storage have been assessed in upland forests, there has been a lack of scientific evaluation of such change in mangrove forests. In this study, in order to overcome the shortage of soil organic carbon (SOC) data for estimating SOC storage, a simple linear regression equation between vegetation biomass and SOC density (R = 0.697, P < 0.01, N = 39) was derived to quantify the change of ecosystem carbon storage by combining field measurements with data from the published literature. Significant correlation was found between vegetation biomass and SOC concentration of the surface soil layer in the mangrove forests. Ecosystem carbon storage increased from 1037.55 Gg in 1990 to 1449.96 Gg in 2010, with an average carbon accumulation of 111.53 Gg/year in the mangrove forests along the Chinese coast. Ecosystem carbon density increased from 280.56 t/ha in 1990 to 299.14 t/ha in 2010, with an average carbon uptake of 0.93 t/(ha.year). Average carbon accumulation rate in the soil accounted for more than 80% of the total carbon accumulation rate. Mangrove forests accumulate more ecosystem carbon in comparison with other types of forests located at the same latitudes. Our results suggest that afforestation and reforestation will increase carbon sequestration in the mangrove forests along the Chinese coast, as both vegetation carbon and SOC storage increased in association with biomass growth.