[Priority Optimization Region Identification in Hebei Province Based on Ecosystem Service Tradeoff Synergies]

This study aims to investigate the evolution patterns of ecosystem services in Hebei Province over the past three decades, assess the trade-offs and synergies among these services, identify priority optimization areas based on these relationships, and provide a theoretical foundation for eco-environmental protection and ecological asset management in Hebei Province. Utilizing the InVEST model, we evaluate carbon storage, habitat quality, water conservation, and soil conservation within the study area from 1990 to 2020. We explore both temporal and spatial characteristics of these four services while examining trade-off synergies through spatial autocorrelation and the ecosystem service tradeoff synergy degree （ESTD） model. Bayesian networks are employed to design various optimization scenarios and spatially represent distribution patterns of optimized regions under different conditions. The findings indicate that： ① Throughout the study period, carbon storage and habitat quality experienced declines； soil conservation initially decreased before increasing again. Overall, high distributions of ecosystem services were observed in northeastern Hebei Province, while lower distributions were noted in central and southern regions. ② Based on criteria identifying above-average areas as hotspots for ecosystem services, hotspots Ⅰ, Ⅱ, and Ⅲ predominantly occurred in the central-southern plains with decreasing area over time. Conversely, hotspot Ⅳ along with non-hotspots were primarily located in northeastern Hebei near construction lands, with an increasing area trend annually. ③ Ecosystem service interactions within Hebei Province were largely characterized by synergistic relationships, albeit with notable differences, specifically during certain periods when synergy between soil conservation and habitat quality was highest, while long-term low synergy persisted among carbon storage, habitat quality, water conservation, and soil conservation across time frames. ④ Sensitivity analysis showed that the key variables affecting ecosystem services in the study area were precipitation, potential evapotranspiration, elevation, and land use type. The priority optimization areas identified by Bayesian networks were mainly distributed in the central and southern parts of Hebei Province, accounting for 5.93% of the total area of Hebei Province. The research results provide a theoretical and practical basis for ecosystem functional zoning and ecosystem service improvement in Hebei Province.