Construction and Optimization of Ecological Security Pattern Along Beijing–Shanghai High-Speed Railway Based on Self-Organizing Map and Complex Network

As one of the most important transportation corridors in China, the long-term operation of the Beijing–Shanghai High-Speed Railway may lead to the fragmentation and fragility of the ecological pattern and an imbalance between the supply and demand of ecosystem services in the provinces along the line, thereby affecting ecological security. How to construct and optimize the ecological security pattern to address these issues is a challenging problem in the territorial spatial planning of the provinces along the Beijing–Shanghai High-Speed Railway. Complex networks serve as the primary approach for constructing ecological security frameworks, and the SOM model can objectively extract ecological source areas from the perspective of ecosystem service functional dimension. Therefore, this study combines the SOM model with complex network analysis methods to construct and optimize the ecological security pattern across seven provinces along the Beijing–Shanghai High-Speed Railway. The results show that, except for carbon sequestration, the other five types of ecosystem services (habitat quality, soil conservation, water purification, water production, and NPP) in the study area exhibit significant spatial heterogeneity. The ecological network constructed in this study identified 335 source areas and extracted 334 ecological corridors. A comparative study of three edge addition schemes shows that the edge addition strategy based on betweenness centrality has the best optimization effect, adding 93 new corridors to the original ecological network. The ecological security pattern constructed in this study provides an important reference for territorial spatial planning and for constructing forestry and grassland ecological restoration projects in the seven provinces along the Beijing–Shanghai High-Speed Railway, thereby contributing to the region’s ecological sustainable development.