Coastal surface soil carbon stocks have distinctly increased under extensive ecological restoration in northern China

Abstract

Coastal soil carbon stock is critical owing to the coexistence of terrestrial and marine carbon sinks and undergoes drastic changes under complex factors. Here we conduct surface soil organic carbon (SOC) stock mapping in northern China’s coastal areas in 2020 and 2010 based on large-scale field survey, remote sensing, and land cover data. Our results indicate that a 100 m resolution is the optimum mapping resolution for its good simulation accuracy and precise spatial details. The surface SOC stock and density in 2020 increased by 39.19% and 37.82%, respectively, compared with those in 2010 under extensive ecological restoration. The SOC densities of forests, grasslands, croplands, wetlands, and built-up areas increased by 72.58%, 74.25%, 41.39%, 4.58%, and 26.30% from 2010 to 2020, respectively. The study determines the optimum mapping resolution and denotes the positive effects of ecological restoration on coastal soil carbon.