Environmental determinants impacting the spatial heterogeneity of karst ecosystem services in Southwest China

Abstract Severe rocky desertification and considerable terrain relief in karst areas increase the difficulty of identifying determinants of ecosystem services (ESs), leading to relatively insufficient research on the quantitative attribution of karst ESs. This study investigates environmental determinants and their interactions affecting karst ESs in Southwest China and spatially variable correlations between environmental determinants and karst ESs in geomorphological regions using the geographical detector and geographical weighted regression methodologies. Results show that land use and vegetation coverage are the determinants of water yield and soil loss at the basin scale, with explanatory power of 67.2% and 32.3%, respectively; and the combination of elevation and vegetation coverage determines the spatial distribution of carbon sequestration. The determinants of ESs differed substantially among diverse geomorphological types due to differences in the inner characteristics of each. In addition to the dominant role of land use in each geomorphological type, the effects of vegetation coverage and precipitation on the water yield are significant in mountainous regions. The explanatory power of land use for soil loss decreases with increased terrain relief, while that of the vegetation coverage shows the opposite trend. For carbon sequestration, terrain factors play a more important role than land use at the basin scale, while land use is more influential in each geomorphological type. Furthermore, precipitation and vegetation coverage have the largest impact area on water yield and soil loss in each geomorphological type, respectively, and the impact area of each determinant of carbon sequestration shows obvious regional differences.