Integrating ecosystem service trade-offs and bundles for ecological zoning and management optimization: A case study of the Danjiangkou reservoir area, China

Reservoir ecosystems are under increasing pressure from ecological degradation and land-use conflict. This study proposes an integrated framework combining ecosystem service (ES) evaluation, trade-off analysis, and service bundling to support ecological functional zoning in the Danjiangkou Reservoir Area, a key water source in China. Six ESs were assessed from 2010 to 2023, revealing spatial heterogeneity and rising trends in water- and climate-related services. Over time, ES interactions shifted from trade-off dominance to synergy, indicating improved ecological coordination. Cluster analysis identified two ES bundles in 2010 and four stable bundles after 2015. Based on bundle composition and inter-service dynamics, four functional zones were delineated: regulation protection, restoration priority, agricultural production core, and water yield-conservation core. These zones reflect dominant ES structures and offer a practical basis for differentiated, adaptive ecosystem management in reservoir regions. The proposed method provides a transferable tool for ecological zoning in data-rich reservoir watersheds, offering new insights for adaptive ecosystem governance.