Soil erosion disparities between karst and non-karst regions in southern China: A meta-analysis

Karst regions exhibit distinct soil erosion processes compared to non-karst areas due to their unique geological structure. However, systematic comparisons of erosion characteristics and key drivers between these regions remain limited. This study comprehensively quantifies these differences and clarifies their driving mechanisms to inform differentiated soil and water conservation strategies. Using meta-analysis, we integrated 283 relevant studies (1981-2024). Based on modeled and observed erosion data, we systematically compared the impacts of land use, topography, and climate using Principal Component Analysis. The results show: (1) Middle erosion is more prevalent in karst areas, while high-intensity erosion is slightly more frequent in non-karst areas. Grassland is the primary risk for severe erosion in karst regions, whereas cropland dominates in non-karst regions. (2) The surface erosion modulus in karst areas is significantly lower than in non-karst areas (8.1 vs. 171.7 × 10^-2 g/m²/h). This is attributed to karst's "surface-subsurface" dual structure, where substantial water and soil leakage through fissures evades conventional surface monitoring, leading to underestimated total erosion. (3) The key driving factors differ fundamentally: erosion in karst areas is primarily driven by rainfall and slope length, while in non-karst areas, it is mainly controlled by rainfall intensity. This study confirms significant erosion disparities between the regions and indirectly validates the underestimation in karst areas due to underground leakage. Future research should adopt differentiated parameter corrections for erosion models in these regions to enable accurate assessment and support ecological restoration in karst areas.