Research Progress of Blue Carbon Sink in Chinese Salt Marshes

Abstract:

Coastal blue carbon mainly refers to the carbon sequestrated by the blue carbon ecosystems, such as mangroves, salt marshes, and seagrass meadows, which plays a vital role in mitigating climate warming. Salt marshes, the largest coastal wetlands in China, have been greatly affected by anthropogenic activities in the past several decades. However, there is still a lack of data synthesis of existing estimations and observations on carbon storage and sink of the salt marshes in China. Here, we systematically reviewed the distribution of salt marshes, carbon storage, carbon burial, carbon sources, and greenhouse gas fluxes in China. The distribution of salt marshes in China was (1.27-3.43)×10⁵hm², the soil organic carbon storage of salt marshes in China was (7.5±0.6) Tg, the carbon burial rate was 7-955 g C/(m²·a), and the greenhouse gas fluxes were 23.6-986 μg CH₄/(m²·h) and 1.58-110 μg N₂O/(m²·h), respectively. The research on the carbon cycle of Chinese salt marshes still needs to deepen the understanding of carbon sequestration mechanism and key regulators, so that salt marshes can make a greater contribution to the strategies of carbon neutrality in China.