Zonal patterns and driving factors of soil organic carbon density in Zhejiang Province, China

The complex topography and intensive land use and land cover change (LUCC) might shift the spatial pattern of soil organic carbon (SOC) density. However, the effects of LUCC caused by development on the distribution and driving factors of SOC density remain unclear. As one of the most developed regions in China, Zhejiang Province has experienced intensive land use change and has various vegetation types, making it an ideal location to analyse the zonal pattern and driving factors of SOC density in terrestrial ecosystems. To do that, a dataset was built with data collected from existing literature. The average SOC density in Zhejiang Province was 69.75 Mg ha−1, ranging widely from 6.44 to 301.90 Mg ha−1 depending on land and vegetation types. We found that forests had the highest mean SOC density (78.30 Mg ha−1), while cropland had the lowest (45.69 Mg ha−1). Meanwhile, the SOC density of unmanaged land was significantly higher than that of managed land (P < 0.001). Additionally, SOC density varied greatly with longitude and altitude, showing a decreasing zonal pattern from west to east and from high to low altitude. The RF model indicated that vegetation type, stand age, mean annual temperature (MAT), soil pH, and mean annual precipitation (MAP) were the five most important factors affecting SOC density in this area, but the effects differed between managed and unmanaged lands. These results aid with understanding the dynamics of SOC pools in terrestrial ecosystems and inform policy-making to mitigate global climate change. These findings provide valuable insights into the dynamics of SOC pools in terrestrial ecosystems, enabling more effective policymaking to mitigate the impact of global climate change.