Exploring the spatial heterogeneity of trade-offs and synergies across ecosystem service bundles based on supply and demand relationships in the Wuhan Metropolitan Area.

Understanding the trade-offs and synergies among ecosystem services (ESs) is crucial for multi-objective management and ecosystem sustainability. However, limited research has focused on identifying ecosystem service bundles (ESBs) through ES supply-demand relationships and analyzing the internal trade-offs and synergies within each bundle. To address this gap, this study used the Wuhan Metropolitan Area (WMA) in 2021 as a case study to evaluate the supply and demand of six ESs at both the raster and county scales, using the InVEST model and multisource data including geospatial and statistical datasets. The spatial distribution of ESB was identified at different scales through agglomerative hierarchical clustering. Furthermore, the trade-offs and synergies among ES supply across ESBs were analyzed using the Spearman correlation coefficient. The conclusions indicated that, first, ES deficits were predominantly concentrated in urban core areas, whereas surplus areas were distributed variably. Provisioning service surplus areas were primarily located in the central and western parts of the WMA, regulating and maintenance service surplus areas were mainly distributed in the eastern forested mountainous regions, and cultural service surplus areas were typically distributed on the outskirts of urban built-up areas. Second, at both scales, ESB types were relatively similar, categorized as agricultural production bundles, urbanization control bundles, and forest protection bundles. The differences lie in that, due to cumulative effects, ES distribution differences at smaller scales were often spatially averaged, leading to diminished distinctions among ESBs. This underscores the significance of implementing ecosystem management at multiple scales. Third, trade-offs and synergies among ES supply across ESBs exhibited distinct spatial heterogeneity. In conclusion, this work provides an important reference for taking ESBs as the basic management unit in multi-objective ecosystem management.