Ecosystem service dominance of natural forest vegetation in karst landscapes: evidence from Southwest China

Clarifying how ecosystem services (ESs) differ among vegetation types under contrasting lithological settings and elevation gradients is essential for guiding ecological restoration in karst regions. Taking Guizhou Province in Southwest China as a representative karst landscape, this study distinguished karst from nonkarst areas and classified vegetation into natural forest, planted forest, shrubland, and grassland. For 2005, 2010, 2015, and 2020, four ES indicators, namely water conservation, soil conservation, habitat quality, and carbon storage, were quantified using the InVEST model and further integrated into a composite index of ecosystem services. Based on 5,000 stratified random samples, ANOVA was applied to examine differences in ES supply among vegetation types across lithological settings and elevation zones. The results indicated that natural forests generally had the highest CIES, particularly for WC, HQ, and CS, whereas grasslands performed best in SC. Vegetation related ES patterns differed between karst and nonkarst areas and also changed along elevation gradients. These differences were interpreted through a process based framework in which vegetation functional attributes interact with karst critical zone conditions, including shallow and spatially heterogeneous soils, rock exposure, surface and subsurface hydrological partitioning, and elevation driven climatic and topographic gradients. The findings provide evidence for differentiated vegetation management and ecological restoration across lithological and elevation settings in karst regions.