Identification of green patches prioritized for urban expansion as a supplementary approach to mitigating landscape connectivity loss

The promotion of landscape connectivity is an important way to address habitat fragmentation, and the limited land resources in high-density urban areas pose greater challenges to protecting or increasing ecological patches and corridors. This study identifies green patches that can be prioritized as land for urbanization, in addition to the supplementation of patches or corridors, and explores a supplementary method to reduce landscape connectivity loss. Beijing, a typical urbanized area, is selected as the research area. A land simulation model (PLUS) is combined with an ecological network model based on graph theory (Graphab) to evaluate the environmental impact of urbanization. The ecological network is optimized via optimization algorithms, and the potential of target patches for land supply and connectivity protection is analyzed. Under the 2035 urbanization scenario, habitat area is projected to decline by 62.51 km², with a 36.69 % reduction in landscape connectivity (PC). The optimization framework successfully mitigates this loss, improving PC by 10.48 %. It is shown that even with reductions in patch area, landscape connectivity and ecological functional integrity can be preserved through targeted optimization, revealing the relationship between connectivity loss and patch shrinkage. This approach provides a practical tool for managing green patches in rapidly urbanizing regions, offering strategic support for balancing land development with ecological sustainability.