Ecosystem carbon stocks of mangrove forest in Yingluo Bay, Guangdong Province of South China

Mangrove ecosystems could play important ecological, social and economic roles in addressing the mitigation of climate change through reduced deforestation. The present study aimed to estimate ecosystem carbon stocks (carbon accumulated in both biomass and soil) across the tidal gradient of mangroves in Yingluo Bay, Guangdong Province of South China. The ecosystem carbon storage, as well as vegetation biomass and soil organic carbon (SOC) storage, increased along with the tidal gradient of mangrove forests from the low intertidal zone to the high intertidal zone. The ecosystem carbon storage of the Avicennia marina, Sonneratia apetala, Aegiceras corniculatum + Kandelia obovata, Rhizophora stylosa and Bruguiera gymnorrhiza stands were 212.88 t/ha, 262.03 t/ha, 323.57 t/ha, 443.13 t/ha and 376.80 t/ha, respectively and their vegetation carbon pools accounted for 11.65%, 29.79%, 19.19%, 37.76% and 25.94% of ecosystem carbon storage, respectively. Compared to the mangrove ecosystem, there was a much lower ecosystem carbon stock (97.32 t/ha) at the bare mud flat. The relatively high vegetation biomass, which coupled with carbon-rich soils, resulted in the presence of larger ecosystem carbon stocks compared to other subtropical forests in the same latitude zone. A significant positive correlation was found between vegetation biomass and soil organic carbon concentration of the upper 0-50 cm layers. This may indicate that the increase of vegetation biomass will raise the mangrove-derived SOC in the soil (especially the 0-50 cm soil layers). Reforestation by using mangrove forests is an important way to increase ecosystem carbon sequestration in coastal areas.