Abstract: Land use optimization strategies for maintaining and improving ecosystem services are crucial for improving landscape sustainability. As current research primarily focuses on case studies, a universal land use optimization framework based on ecosystem services is lacking. To fill this knowledge gap, we proposed a land-use optimization framework for the maintenance and improvement of ecosystem services within different ecosystem services bundles. This framework involves first identifying priority protected areas, then determining key improvement types and the influencing factors, and finally integrating local land use/ecological protection policies. We tested the feasibility of the framework with the Yangtze River Delta Ecological Greening Development Demonstration Area as a study area. The results showed that: (1) From 1980 to 2020, food production, water production, and recreational opportunities in the study area increased by 60.35%, 30.59%, and 17.56%, respectively. In contrast, air purification, carbon sequestration, and habitat quality showed decreased by 10.75%, 5.10%, and 32.25%, respectively. (2) This framework can effectively protect the high-value ecosystem service areas within each bundle and improve the degraded ecosystem services. The priority protection areas for ecosystem services were mainly concentrated in the central part of the study area, accounting for 53.10% of the total area. The ecological multi-functional service bundle should focus on improving habitat quality services, while the food supply-oriented service bundle and the urban built environment-oriented service bundle need to improve the services of air purification, carbon sequestration, and habitat quality. (3) Among the three bundles, NDVI and patch density were positively correlated with air purification, whereas population density was negatively correlated with habitat quality. However, there were certain differences in the influencing factors among different bundles. (4) Compared with the situation before optimization, the comprehensive ecosystem services of the three bundles increased by 0.47%, 15.59%, and 12.62%, respectively. This study provides a scientific basis for land spatial planning in the Yangtze River Delta and offers a conceptual framework and methodological reference for land use optimization in other regions around the world.

Key words: land use optimization framework, ecosystem services bundle, spatiotemporal pattern, influencing factor, Yangtze River Delta Ecological Greening Development Demonstration Area