Science of The Total Environment | June 10, 2023
Protecting and restoring vegetated coastal ecosystems present valuable opportunities for mitigating climate change. Coastal shelter forests, as one of these ecosystems, play a vital role in protecting sandy coasts. However, their potential for soil organic carbon (OC) sequestration has received less attention. A study conducted by the Chinese Academy of Sciences provides the first national-scale assessment of soil OC stocks, fractions, sources, and accumulation rates in shelter forests and sandy beaches along a 22° latitude span in China.
Comparing shelter forests to sandy beaches, the study reveals that shelter forest plantations achieve significant soil desalination rates of 92.0% and reduce soil pH by 1.3 units, enhancing soil quality. This improved soil quality facilitates OC sequestration, resulting in an average increase of 11.8 MgC ha−1 in soil OC stock in shelter forests. Particulate OC (POC) is the dominant fraction in both sandy beaches and shelter forests, with shelter forests having POC proportions exceeding 80%. The study suggests a substantial contribution of plant-derived OC, as indicated by low δ13C values, higher C:N ratios, and the dominance of POC. The analysis estimates soil OC stocks in Chinese shelter forests to be 20.5 MgC ha−1 in the top meter, with an accumulation rate of 45.0 gC m−2 year−1. According to afforestation plans, additional soil carbon sequestration of 1.72 TgC is expected in the future. These findings highlight the effectiveness of coastal shelter forests in sequestering soil carbon and emphasize their importance in coastal ecosystem management.
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