Supplementary file 1_Systematic protection of threatened vertebrates—a solution balancing ecological benefits and socio-economic costs.docx

It is critical for global conservation to expand protected area networks in biodiversity hotspots with dense human populations, but this faces substantial socioeconomic constraints. Relying solely on area expansion can trigger resistance to implementation, which undermines conservation outcomes. To address this issue, we developed a dual-cost framework that integrates land-use opportunity costs and environmental conflict risks in order to evaluate the feasibility of conserving threatened vertebrates. Stacked Maximum Entropy (MaxEnt) habitat suitability predictions (33 species) and known distribution ranges (20 species), we mapped critical habitats for 53 species, then used Marxan to compare spatial efficiencies under varying cost scenarios. The final priority conservation network under the integrated optimization scenario (S3-b) covers an area of 134,938 km2, which constitutes 20.02% of the total study area. This area includes 660 existing national protected areas (NPAs), with a total overlap of 53,329 km2, representing 32.54% of the priority conservation areas. The network is mainly distributed across the northern parts of Region III, the southern regions of Region I, and the central parts of Region IV, reflecting critical biodiversity hotspots with high ecological value. Our findings suggest that the integrated optimization scenario (S3) most effectively balances ecological gains with social costs. In contrast, the status quo augmentation strategy (S3-b) revealed that over 52% of priority units, including 462 existing national protected areas, fall within high-conflict “low-feasibility zones”. While this scenario requires lower annual funding (6.44–12.18 billion CNY) than complete restructuring, the high conflict risk highlights the limitations of strict uniform protection in areas with frequent human–land interaction. We therefore argue that transitioning to differentiated management based on feasibility grading would provide a more effective way of balancing ecological security with community livelihoods.