Construction and optimization of composite functional urban ecological network: Integrating "ecological-recreational"...

Urban ecological networks are essential for improving the connectivity of urban ecological space (UES) and promoting both ecological and social functions. This study presents a paradigm for integrating ecological and recreational functions to construct a composite functional urban ecological network. Using the "Element-Structure-Function" framework, ecological sources are identified based on ecological functions pertinent to urban areas, including habitat quality, the cool island effect, carbon sequestration, and stormwater retention. Accessibility analysis determines recreational sources, while a resistance surface is constructed using multiple factors, and corridors are extracted using the MCR model, forming single-function networks for ecological functions and recreational services. These are integrated into a composite network, which then optimizes the configuration of corridors and nodes. Results show: (1) Greenspace is crucial for the ecological network, while large greenspaces and water bodies are significant for the recreational network. (2) The composite network contains 63 sources and 138 corridors, with the α, β, and γ indices increasing by 16.10 %, 11.21 %, and 7.89 %, respectively, compared to the ecological network, enhancing network structure and connectivity. (3) Optimal corridor widths are 500 m for ecological corridors and 12 m for composite and recreational corridors, with a significant proportion of built-up land within each corridor width. Additionally, 73 pinch points and 44 barrier points are identified for optimizing the composite network. The composite network can enhance UES efficiency, facilitating the alignment of ecological protection and urban development while providing critical insights into the optimal arrangement of UESs.