The impact of connectivity in natural protected areas on the resilience of urban ecological networks: A research framework based on hierarchical disturbance scenario simulation

In the context of accelerating ecological fragmentation, it is urgent to enhance the interconnectivity of urban ecological patches to form a resilient ecological network (EN). The construction of a Natural Protected Area (NPA) system proposed in 2019 is the latest strategy implemented by China in protecting ecological spaces. However, the effectiveness of this strategy has not been adequately demonstrated. This study specifically analyzes the concrete impacts of the natural protected area system on the resilience of ecological networks (ENs). The economically developed Urban Agglomeration around Hangzhou Bay (UAHB) was chosen as an example for the argumentation. Firstly, we utilized circuit theory to construct an EN consisting of 173 ecological sources and 401 ecological corridors. Secondly, the ecological sources were categorized into three levels based on their connectivity values. Finally, a dynamic disturbance scenario simulation framework was constructed to evaluate the impact of NPA on the resilience of EN. The results indicated that: (1) The preceding 47% of ecological sources are crucial for maintaining the resilience of the EN; (2) Compared with other ecological spaces, NPAs have a 38% and 1100% greater effect on the resilience of the EN in first and second-level ecological sources, respectively, while its impact in third-level is 118% lower. This study innovatively investigates the differential impacts of hierarchical natural protected areas and natural unprotected areas on the ecological environment.