Unveiling the Spatial Variation in Ecosystem Services Interactions and Their Drivers Within the National Key Ecological Function Zones, China

Understanding the spatial differentiation of ecosystem service (ES) interactions and their underlying driving mechanisms is crucial for effective ecosystem management and enhancing regional landscape sustainability. However, comprehensive analyses of the effects of key influencing factors on ES interactions remains limited, especially regarding the nonlinear driving mechanisms of factors and their regional heterogeneity. We assessed and validated five key ES in the National Key Ecological Function Zones (NKEFZs) of China—net primary productivity (NPP), soil conservation (SC), sandstorm prevention (SP), water retention (WR), and biodiversity maintenance (BM). By integrating the optimal parameter geographical detector with constraint line methods, we further explored the complex responses of ES interactions to driving factors across different functional zones. The results showed that most ES exhibited significant spatial synergistic clustering. In contrast, widespread spatial trade-off clustering was detected in ES pairs related to WR, mainly distributed in the Tibetan Plateau, northeast China, and the Southern Hills region. Due to the improvement in ES, the overall synergies of ES enhanced from 2000 to 2020. The dominant factors in different functional zones influenced ES interactions in a non-stationary manner, with the same factors potentially showing diverse effect types in different sub-regions. Additionally, we detected the dominant role of landscape configuration factors in sub-regions for specific interaction types (e.g., WR-NPP interaction in the SP zones), suggesting the potential for achieving multi-ES synergies through landscape planning without altering landscape composition. This research provides valuable insights into understanding ES interactions and offers a scientific foundation for the implementation of ecological protection and restoration plans.