Construction and evaluation of ecological network in the Yellow River Delta High-efficiency Ecological Economic Zone

The fragmentation of habitat patches is rising due to economic development and urban expansion. The systematic design of an ecological network can link fragmented habitat patches, improve landscape connectivity, augment ecosystem service capabilities, and foster the robust development of the ecosystem. We employed the methods of morphological spatial pattern analysis and landscape connectivity analysis to identify ecological source areas, and utilized the minimal cost resistance model through the superimposition of multiple factors to construct the ecological resistance surface. Combining circuit theory to extract ecological corridors, grips, and obstacle points, we constructed the ecological network of the Yellow River Delta Efficient Ecological Economic Zone by using the "source-corridor-node" paradigm and analyzed the structure and resilience of this network. We identified 41 ecolo-gical sources regions, with a total area of 2994.45 km². We extracted 21 first-level ecological corridors, 26 second-level ecological corridors, and 18 third-level ecological corridors, with a total length of 1655.42 km and an average length of 25.46 km. We identified 127 ecological pinch points with a total of 32.92 km² and 20 ecological obstacles, corresponding to regions that required key ecological conservation and restoration work. The ecological network closure index was 0.74, the connectivity index was 2.32, and the connectivity index was 0.83, indicating a relatively comprehensive ecological network structure. The initial values of the connectivity robustness and vulnerability robustness of the ecological network were 0.98 and 0.42, respectively. The critical values for the stability of the ecological network function were an edge failure ratio of 45% and a node failure ratio of 20%. Generally, our findings have significant reference and guiding value for the landscape fragmentation management, biological habitat protection, development of ecological security, and ecdogical network evaluation in the Yellow River Delta Efficient Ecological Economic Zone.