Spatial Heterogeneity, Trade-offs, and Bundle Identification of Ecosystem Services in Karst Watersheds: A Comprehensive Assessment of the Lijiang River Basin

The Lijiang River Basin is under pressure from rapid urbanization and tourism. To support sustainable management, the present study assessed 10 ecosystem services (ESs) from 2000 to 2020 using the InVEST model and spatial statistics. Correlation analysis and a Self-Organizing Map neural network were combined to analyze ES interactions and identify service bundles, whereas Geodetector revealed driving factors. There was significant spatial differentiation of the services, with high-value areas for carbon sequestration, habitat quality, food production, and soil conservation in high-altitude forest regions, whereas low-altitude regions showed high water yield, recreational services, and nutrient retention due to human activity. There were notable interactions among the services, with most regulating services exhibiting spatial synergies, particularly in mountainous regions, while water purification faced trade-offs with other services. Five typical service bundles were identified, reflecting the interplay of natural resilience and human impact. Land use was the primary driver of service differentiation, with an increasing influence of socioeconomic factors. Based on the results, the study recommends differentiated governance strategies: strict protection of ecological supply zones and optimization of pressure response zones, which provide a scientific basis for ecological security and land planning in karst regions.