Crossing the Boundary: A New Perspective Unmasking the Differential Evolution and Divergent Drivers of Ecosystem Service Trade-Offs

Nature reserves (NRs) sustain biodiversity and multiple ecosystem services (ESs), yet assessments commonly stop at administrative boundaries and seldom examine how service relationships and associated factors vary across surrounding landscape gradients. We assessed carbon storage (CS), habitat quality (HQ), soil retention (SR), and water yield (WY) in 54 NRs in Jiangxi Province, China, and nested 5 and 10 km surrounding zones for 2000, 2010, and 2020. The InVEST model, a comprehensive ecosystem service index (CESI), correlation analysis, RMSE, and GeoDetector were used to characterize service dynamics, trade-offs/synergies, and spatial associations. CS and HQ increased slightly, whereas SR and WY rose until 2010 and subsequently declined. Mean CESI decreased outward from NR interiors (0.53) to the 5 km (0.50) and 10 km zones (0.49), although WY was higher outside NRs in 2020. CS–HQ and SR–WY were predominantly synergistic, while HQ–SR showed the strongest trade-off. Dominant associated factors and their interactions varied among services and spatial zones. These findings reveal context-dependent cross-boundary differentiation in ecosystem-service patterns, supporting coordinated management of NRs and their surrounding landscapes and service-specific conservation priorities.