Managing the supply-demand mismatches and potential flows of ecosystem services from the perspective of regional integration: A case study of Hangzhou, China.

Regional integration is a development strategy that synergizes various components as a whole to maximize overall benefits. The natural heterogeneity and fluidity of ecosystem service (ES) make it a promising target for regional integration. However, the current focus on regional integration was more on the socio-economic factors rather than ecological resources, and the understanding of the supply-demand relationship and potential flow of ecosystem services was still limited. Therefore, we attempted to interpret ecological integration management by linking ES budgets, bundles, and flows in this study. The results showed that the spatial mismatches of ESs supply-demand were observed in all six selected ES types. Most of the ESs deficit regions were concentrated in urban centers, while ES surplus regions were scattered in surrounding rural areas. Multiple heterogeneous ES resources could ideally benefit an additional 0.13-4.84 million people in 9-70 townships through potential ES flows under ecological integration management. Therefore, we connected the service provisioning areas (SPAs) and service beneficiary areas (SBAs) with three types of ES flows and drew the potential provider-beneficiary relationship networks at the townships/bundles scale, demonstrating the interactive relationship of ecological integration within the region. On this basis, we also proposed the applicability matrix of governance tools for the first time according to the type of ES flows, and then put forward the corresponding governance opinions around the two aspects of "improving ES budges within clusters" and "strengthening ES flow among clusters". This study provided an ecological perspective for understanding regional integration, and relevant conclusions can inform environmental policy priorities for sustainable decision-making in urbanized areas.