Spatiotemporal Differentiation and Coupling Coordination Relationship of the Production–Living–Ecological Function at County Scale: A Case Study of Jiangsu Province

Land is multifunctional and includes production, living, and ecological functions (PLEF). Each aspect of PLEF is critical to the stability of human and natural ecosystems, and the balanced coordination of the three is an important guarantee of sustainable development. The study of the coupling and coordinated relationship of the three functions is of great significance to comprehensively optimizing the allocation of territorial space and promoting the coordinated and sustainable development of the national territory. Taking Jiangsu as a case study, based on the perspective of PLEF, this research constructed a PLEF evaluation index system adapted to rapidly urbanizing areas at the county scale and adopted the modified coupling coordination degree model (CCDM) for in-depth analyses of their coupling and coordinated relationships. The results of this study showed that the spatial distribution of PLEF had obvious heterogeneity, with living function (L) and ecological function (E) presenting as high in the south and low in the north, and production function (P) presenting as high in the middle and low in the north and south of Jiangsu; from 2010 to 2020, the production function steadily increased, the living function showed obvious signs of improvement, while the ecological function remained basically stable. The coupling degree and coupling coordination degree formed a spatial pattern with the intersection belt of North and Central Jiangsu and Central and South Jiangsu as the high-value area; from 2010 to 2020, both the coupling degree and the coupling coordination degree showed an upward trend. In the future, differentiated development strategies should be implemented according to the law of coupling and coordinated evolution and different regional characteristics. This study will provide a more appropriate reference for promoting the coordinated development of PLEF in rapidly urbanizing areas and formulating county policy planning.