Identification of key areas for soil conservation service and driving factors under ecological restoration projects in South China Karst

It is urgent and challenging to evaluate the effects of soil conservation (SC) under ecological restoration projects (ERPs) in karst regions. In this study, the surrogate biophysical method was adopted to investigate the spatiotemporal evolution of SC under ERPs in Guizhou Province from 2000 to 2023. We found that SC showed an increasing trend, and SC hotspots were mainly spatially aggregated in southern Guizhou Province (Qianxinan and Qiannan), while its cold spots were concentrated primarily in the western and northern regions. Returning farmland to forest (RFTF) exhibited the strongest SC effectiveness. However, returning farmland to water bodies (RFTW) became increasingly effective in enhancing SC over the study period (0.01–0.04). This indicates that RFTW showed potential for further enhancing SC in karst regions. The dominant factors of SC demonstrated temporal variability, and precipitation, slope, and soil types were the dominant factors of SC in Guizhou Province during the study period.