Understanding synergistic ecosystem services in China’s Northeast Forest Belt: A blueprint for spatially targeted management

• Ecosystem services interactions at multiple spatiotemporal scales were integrated systematically. • Distinct variations occurred in the relationships between provisioning services and regulating services. • The location of ESs bundles varied spatially at both grid and watershed scales. • Relative stability of driving factors across scales hold significance for formulating ecosystem management suggestions. A clear understanding of the interactions at multiple scales among ecosystem services (ESs) is essential to the reasonable spatial planning of ecosystems in large-scale ecological barrier regions. This study assessed the provision of 5 typical ESs: water yield (WY), soil conservation (SC), crop production (CP), net primary productivity (NPP), and habitat quality (HQ). We explored the tradeoff/synergy relationship, mapped the bundles and analyzed their underlying socioecological influencing factors at both grid and watershed scales in the northeast forest belt (NFB). Furthermore, we provided a spatial planning and management strategy of NFB and suggested concrete practices within the range of identified ecological bundles. Our results showed that WY, SC and CP presented an obvious spatiotemporal heterogeneity while NPP and HQ only exhibited spatial heterogeneity at both gird and watershed scales. Divergences were observed in correlations between provisioning and regulating service pairs. Specifically, CP-related correlations were all negative and WY-related correlations varied depending on the combination of ES pairs, time, and scale. Notably, the absolute value of most ES pairs increased from the grid to the watershed scale, indicating a clear scale dependence. Moreover, six ES bundles (ESBs) varying spatially during the study period were further identified at both the grid and watershed scale in NFB, respectively. Geodetector analysis revealed that ESs at the grid scale shared similar determinants with those at the watershed scale, albeit with slight variations in ranking or the number of determinants. Our findings offer detailed insights for incorporating ES interactions into spatially targeted ecosystem management and future ES payment policies.