Ecological Functional Zoning in Urban Fringe Areas Based on the Trade-Offs Between Ecological–Social Values in Ecosystem Services: A Case Study of Jiangning District, Nanjing

Amid the rapid socio-economic development of urban fringe areas, promoting the multi-functional supply of ecosystems and sustainable development is essential. Taking Jiangning District in Nanjing as a case study, this study explores the relationships and spatial clustering characteristics among various ecosystem service values in urban fringe areas, focusing on the trade-offs between ecological and social values. Ecological functional zones were delineated based on the ecosystem service clustering results and regional conjugation principles, followed by an analysis of the trade-offs and synergies among the values within each zone. The findings reveal the following: (1) trade-offs between ecological and social ecosystem service values are prevalent across the entire region, as well as within sub-regions in urban fringe areas; (2) Jiangning District can be divided into five key ecological functional zones—the Vibrant Industry-Urbanization Integration Zone, Important Habitat Conservation Zone, Livable Organic Renewal Zone, Characteristic Rural Landscape Development Zone, and Riparian Recreation and Ecological Conservation Zone. Each zone exhibits significant differences in the types and features of the services provided; and (3) understanding the relationships among ecological and social values within each zone may help to resolve trade-offs between them. This progressive trade-off analysis, from the regional to sub-regional level, enables more precise identification of ecosystem functions, providing reference for decision-making to enhance the overall regional value and guide sustainable planning and management practices in urban fringe areas.