Abstract:
Hillslope hydrological process is the basic unit of watershed hydrological process. The runoff and sediment are generated and transported on the hillslope, thereby impacting on the dynamics of soil organic carbon (SOC) pool. Studying the migration of SOC driven by hillslope hydrological process will be helpful to get in-depth understanding of carbon cycling at the watershed or broader scale. This review collected data from four typical regions (i.e., Northeastern Black Soil region, Southern Hilly Red Soil region, Northern Loess Plateau region, and Southwestern Karst region) in China, and then the relationships between hydrological process and SOC migration were discussed on the slope. Meanwhile, the effects of soil types, rainfall intensity, slope, tillage practices, fertilization, and land use on SOC migration were also analyzed. The results showed that hydrological processes leaded to distinct migration paths and forms of SOC in different regions. Furthermore, soil types, rainfall intensity, and slope changed the migration of SOC and which of accumulation in sediments by influencing the runoff path and sediment generation. Tillage practices, fertilization, and land use not only affected the amount of SOC migration through changing the SOC content and exogenous input, but also affected the migration paths and forms of SOC. Finally, it should be strengthened in the future that the synchronous monitoring of different SOC migration paths in hilly red soil regions and karst regions, coupled relationship between the SOC migration and transformation processes and microbial community during the water erosion process, and the modeling simulation of SOC dynamics from the perspectives of multi-dimensional and multi-interface hydrological processes.