[Optimization of Ecological Network in the Guangdong-Hong Kong-Macao Greater Bay Area Based on Ecosystem Service Trade-offs and Complex Network Theory].

Constructing an ecological network that promotes the synergistic delivery of ecosystem services and ensures stability and effectiveness is a crucial spatial approach for the sustainable development of urban agglomerations， possessing significant theoretical and practical implications. Existing research has seldom considered the impact of trade-offs in urban agglomeration ecosystem services on the selection of ecological sources， and in-depth exploration is needed for methods optimizing ecological network topology based on complex network theory. This study takes the Guangdong-Hong Kong-Macao Greater Bay Area （GBA）， an ultra-large urban agglomeration， as a case study. It employs the ordered weighted averaging （OWA） model， considering ecosystem service trade-offs， to select ecological sources that best achieve synergistic delivery. The ecological network is constructed using the least-cost path and circuit theory and then optimized based on complex network theory， informed by topological and robustness analyses. The results indicate that： ① Incorporating ecosystem service trade-offs into the ecological source selection process effectively identified ecological patches that promote the synergistic delivery of key ecosystem services. Among multiple trade-off scenarios evaluated using the OWA model， the optimal scenario （Scenario 3） demonstrated the highest average protection efficiency for ecosystem services （1.942） and a relatively low decision-making risk （0.2）， significantly enhancing the overall benefits of ecological source selection. ② A total of 278 ecological sources were identified， predominantly distributed in the northern continuous mountainous forest ecological barrier zone. Together with 700 ecological corridors （totaling 6 680.627 km）， 132 ecological pinch points， and 283 ecological obstacle areas， they constituted an integrated ecological network. ③ Optimization strategies derived from complex network theory， involving the spatial supplementation of network nodes and edges， markedly improved the overall connectivity and stability of the ecological network. The 32 new ecological sources and 91 new ecological corridors were primarily concentrated in regions of the eastern and northern GBA with favorable ecological conditions and in areas where existing corridor connectivity was relatively weak. By integrating ecosystem service trade-offs with complex network theory， this study offers a novel perspective for establishing ecological networks that are both functionally synergistic and robustly stable in ultra-large urban agglomerations. It provides theoretical and practical references for addressing spatial conflicts between urban development and ecological conservation under intense human activity， particularly for mega-urban agglomerations exemplified by the GBA.