Multi-Temporal Raster-Based Accounting of Gross Ecosystem Product for Sustainable Territorial Governance in the Changsha–Zhuzhou–Xiangtan Urban Agglomeration Green Heart

Monitoring whether metropolitan ecological spaces can sustain ecosystem functions while accommodating urbanization and economic activity is central to sustainability. Gross Ecosystem Product (GEP) accounting supports this by translating ecosystem contributions into spatially explicit indicators for assessment and territorial governance. This study developed a multi-temporal, raster-based GEP framework on a common 30 m accounting grid for the Changsha–Zhuzhou–Xiangtan Urban Agglomeration Green Heart across six observation years from 2000 to 2023. It integrated six regulating services and a tourism-related cultural contribution with Sen’s slope, a supplementary Mann–Kendall test, spatial-consistency and sensitivity analyses, and Geodetector. Total accounted GEP declined by 9.14%. Climate regulation and water conservation remained dominant, while the tourism-related cultural contribution ranked third by 2023. Farmland and forest were the principal land-cover contributors. Positive Sen’s slopes predominated spatially but were mostly weak and non-significant, despite the aggregate decline. Land-cover change and vegetation productivity showed the highest explanatory power. Spatial consistency improved at 500 m, and sensitivity to the 2023 land-cover proxy was limited. Overall, the framework provides a spatial sustainability assessment tool for identifying ecological decline and supporting cross-jurisdictional conservation, ecological compensation, and sustainable territorial governance.