Optimizing ecological security patterns in a megacity by enhancing urban-rural connectivity: Insights from Wuhan, China

Traditional approaches to urban ecological networks (ENs) often fail to address the ecological isolation between densely urbanized areas and their adjacent rural regions. To overcome this challenge, this study introduced a novel methodology for establishing urban-rural ENs, with an emphasis on landscape heterogeneity across urban-rural gradients (URGs). The approach distinguished urban and rural ecological sources (ESs) based on the “morphology-quality-scale” framework and simulated distinct urban-rural ecological corridors (ECs) using the minimum cumulative resistance model, incorporating both general and urban-rural specific resistance factors. Additionally, multi-species urban-rural ENs for biodiversity and ecological protection were optimized using graph theory and circuit theory. The results showed that: (1) The optimized urban-rural ecological network encompassed 114 ESs and 288 ECs, which were predominantly clustered in the southern and northern rural regions, whith a more dispersed pattern in suburban and urban areas. Compared to traditional strategies, the proposed network achieved α, β, and γ indices of 0.78, 2.53, and 0.85, respectively, thereby successfully enhancing ecological connectivity between urban and rural areas. (2) The optimization of the multi-species ENs improved their structure and connectivity across URGs, particularly for species with medium or long migration distances (≥10 km). (3) An ecological zoning protection and restoration strategy, comprising key protected areas, priority restoration areas, and ecological upgrading areas, was proposed based on an ecological security pattern of “two cores, six zones, and six straps.” These findings suggest that the proposed strategy can effectively strengthen urban-rural ecological linkages and provide valuable insights for ecological conservation policies in megacities.