Ecological Network Construction in the Central Urban Area of Fuzhou: A Perspective of Green Infrastructure Supply and Demand

In the rapid urbanization process, ecological spaces are continuously encroached upon, leading to an increase in landscape fragmentation. This, in turn, results in a series of issues, such as weakened ecological connectivity and an imbalance in the supply and demand of ecosystem services. Green infrastructure serves a variety of ecosystem functions, and constructing and optimizing ecological networks based on green infrastructure is a key approach to enhancing landscape connectivity and mitigating the negative effects of urbanization. This study takes the central urban area of Fuzhou as a case study, innovatively combining the ecological network construction with supply–demand assessments of green infrastructure. It identifies ecological nodes and priority optimization zones. Results indicate that green infrastructure supply exhibits a pattern of “low in the central-eastern areas and high in the northern–southern areas,” while demand shows the opposite trend, revealing significant spatial mismatch between the two. The study identifies 7 key optimization areas, 29 ecological sources, 35 ecological corridors, and 61 ecological nodes. These are classified into core, important, and general levels based on centrality indices, and the ecological elements are finally overlapped to form an ecological network. This research provides practical insights for optimizing green infrastructure.