Research on ecological security pattern based on the paradigm of "portray-assessment-construction-validation" --Minjiang River Basin as an example.

While rapid urbanization drives socio-economic development, it also leads to a decline in regional ecosystem security. Ecological Security Patterns (ESPs) serves as a crucial research pathway for revealing the interactions between humans and nature and their spatial patterns. However, in the face of evolving regional spatial planning functions and shifting development visions, there is an urgent need to adopt a dynamic and holistic approach to design a dynamic ESP assessment framework, enabling the capture of its spatiotemporal changes and revealing future optimization directions. The Minjiang River Basin, serving as a multifunctional area in the upper reaches of the Yangtze River, faces an imbalance between ecological and economic development, necessitating urgent comprehensive optimization. Taking the Minjiang River Basin as a case study, this research characterizes the regional ecological security pattern based on conventional ESP construction methods. Furthermore, innovatively selected evaluation indicators were extracted from pattern elements and integrated into the "Pressure-State-Response" model to evaluate the ESP for the years 2000, 2010, and 2020. The PLUS model is applied to simulate land use changes in 2030, and the ESP for 2030 is constructed using this simulation combined with other data conditions. Finally, the 2030 ESP is re-evaluated using the same indicator system to validate the optimization effect. The results show that, from 2000 to 2020, the ecological source area experienced both expansion and contraction, with low-resistance areas concentrated in the upstream and downstream sections, while ecological corridors and ecological barrier points increase and decrease simultaneously. The overall ecological security level in 2010 was higher than in 2000, but it declined significantly by 2020. In the optimized ESP for 2030, the length of ecological corridors increased by 590.28 km compared to 2020, while the number of ecological barrier points decreased to 13. The final evaluation showed an improvement in the overall ecological security value compared to 2020, indicating that the ESP was successfully optimized and enhanced. This study expands the existing ESP research paradigm by fully considering the temporal evolution and spatial variation of pattern characteristics. By incorporating pattern elements into the evaluation system, this study strengthens the deep integration of ESP and ESA, enabling a more precise assessment of ecological security status. The simulation and optimization of the ESP help provide scientific guidance for achieving more coordinated regional ecological security protection.