Structural, functional, and resilience dynamics of ecological networks in the Guangdong-Hong Kong-Macao Greater Bay Area: Impacts of climate and urbanization

Ecological networks (ENs) safeguard regional ecological security from an overall perspective. However, under the multiple pressures of urbanization and climate change, their structural and functional integrity faces systemic threats. Existing studies lack a systematic exploration into the dynamic evolutionary mechanisms of ENs' structural, functional, and resilience characteristics under urban expansion and climate change scenarios. As a highly urbanized and ecologically sensitive region, the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) provides a representative case for exploring the evolution and resilience of ENs under multiple stressors. This study focuses on the GBA and constructs a structure-function-resilience framework to systematically analyze the spatiotemporal evolution of ENs from 1990 to 2060. It also develops four disturbance strategies-random, climate-stress, source-degradation, and corridor-fragmentation-to quantitatively assess the impacts of different disturbance strategies on both structural and functional resilience. Furthermore, a random forest regression model was employed to explore the driving effects of land use and cover change (LUCC) on the evolution of ENs' structure and function, thereby revealing the coupling mechanisms linking structural, functional, and resilience within ENs. The results indicate that: The results indicate that: (1) Urban expansion has been a key driver forces of ecological source degradation in the GBA. For future scenarios, SSP126 maintains stable ecological sources, while SSP585 projects continued source decline. (2) Historical EN landscape patterns were highly aggregated with large, connected patches, but future scenarios exhibit increasing fragmentation: SSP126 shows high diversity but severe fragmentation, and SSP585 displays low diversity and poor connectivity. (3) Historical resilience was highest initially but declined later, with source degradation causing the most severe disruption. Future resilience is projected to decrease overall, particularly under SSP585, which exhibits heightened sensitivity to combined LUCC and climate stress, while SSP126 maintains relatively higher resilience (4) Beneficial conversions (e.g., cropland to forest). enhance connectivity and node importance, improving structural integrity; urban expansion-dominated destructive conversions fragment landscapes, disrupt corridors, isolate key nodes, and trigger a chain reaction of "structural damage → functional decline → resilience loss". The findings offer actionable insights for future land use planning, emphasizing strategies to enhance ENs resilience, safeguard ecosystem services, and strengthen regional ecological security in rapidly urbanizing regions.