Abstrakt: |
As a prominent carbon (C) emitter, China's decarbonisation will contribute to global climate action. An understanding of topsoil carbon distribution and its influencing factors is urgently needed to explore how soils can help China reach carbon neutrality. Here, we analyze soil organic carbon (SOC) distribution in forestland, grassland, and farmland in seven districts of China. The correlations and contribution rates of external (elevation-E, temperature-T, and rainfall-R) and internal factors (fractal dimension-D, soil total nitrogen-STN, soil total phosphorus-STP, pH, and C/N ratio) were explored. We found that SOC in China gradually increased from the west to east, with a mean value of 11.20 g kg−1. The SOC content in northeast China was higher than elsewhere in the country. Forestland had greater SOC content than farmland and also grassland (P < 0.05). All the factors influencing SOC, except for R, had distinctly different in spatial patterns and land use types. STN was the most important internal factor, followed by STP. The most important external factor was T, followed by R. Overall, STN was most important for determining SOC. We found a close correspondence between the SOC distribution and the Hu Huanyong Line, the 6.5–10.5 °C T contour line in south China. Our results provide theoretical support for soil C cycle and storage research, enabling China to address issues surrounding climate change. [ABSTRACT FROM AUTHOR] |