Ecological security pattern construction based on ecosystem services revealed conservation gaps in the Yellow River Delta

Construction of the ecological security pattern (ESP) is an important prerequisite for maintaining ecosystem stability and promoting regional sustainable development, but the processes of ESP construction always lack comprehensive optimization of ecological source extraction and ignore the importance of ecological nodes. To address this research gap, we developed a comprehensive technical framework for constructing an ESP grounded in ecosystem services (ESs), the non-dominated sorting genetic algorithm II (NSGA-II), and the minimum cumulative resistance (MCR) model, and applied it to the Yellow River Delta (YRD) as a case study to optimize regional ecosystem conservation strategies. The results show that the YRD contains 28 key ecological sources, accounting for 27.84% of the study area, these sources are mainly distributed in the eastern and northern regions, provide higher-quality ESs, and exhibit better internal connectivity; 12 ecological corridors and 6 ecological nodes ensure effective connectivity among sources, pinpointing critical locations for safeguarding ecological security; the ESP composed of ecological sources, corridors, and nodes reveals that the YRD still suffers from insufficient delineation of nature reserve boundaries and suboptimal effectiveness in the implementation of protection policies; subsequent efforts should combine scientific, policy, and market tools to sustain regional ecological security and stability, and to align ecological protection with economic development processes and goals. This study offers data and practical support for advancing ecological conservation and enhancing ecological well-being in the YRD, and also provides methodological and technical references for future research in related fields.