Ecological security pattern construction and network robustness optimization in the transboundary Gaoligong Mountain region

Introduction Gaoligong Mountain’s transboundary region is characterized by a critical contradiction between its essential ecological barrier function and the growing threat of habitat fragmentation. This study seeks to address this challenge by constructing and optimizing a resilient ecological network to facilitate cross-border collaborative conservation. Methods To overcome the challenges of integrating heterogeneous data in a transboundary context, we introduced a methodological innovation: applying Spatial Principal Component Analysis (SPCA) to objectively assign weights to a multidimensional set of "natural-spatial-social" resistance factors, thereby generating a robust composite resistance surface. Ecological sources were first identified using InVEST-MSPA. Building on this, ecological corridors and key nodes were extracted by integrating the Minimum Cumulative Resistance (MCR) model with circuit theory. Finally, the structure of the constructed network was evaluated and optimized based on principles from complex network theory. Results Our findings are as follows: (1) The constructed ecological network comprises 869 source areas and 1,187 corridors, exhibiting a high level of landscape connectivity (Probability of Connectivity, PC = 0.68). (2) The analysis identified 127 key barrier points and 43 pinch points, the spatial distribution of which aligns well with recognized species migration hotspots. (3) While the network shows vulnerability to deliberate attacks, its redundancy and overall resilience can be significantly enhanced through a targeted corridor supplementation strategy informed by network topology. Discussion This study demonstrates that the proposed integrated framework effectively tackles the difficulties inherent in transboundary ecological assessment, particularly in synthesizing disparate datasets. The optimized ecological network and the methodological approach provide a practical, quantitative foundation to inform ecological restoration and collaborative spatial planning in Gaoligong Mountain and other similar transboundary regions.