A Climate–Habitat–Network Robustness (CHNR) framework reveals climate-driven habitat shifts and corridor resilience for Milu in China

Habitat fragmentation and climate change threaten species persistence, yet few approaches integrate species-specific constraints, climate-driven dynamics, and network robustness in a unified framework. We propose a transferable Climate–Habitat–Network Robustness (CHNR) framework combining multi-scenario ensemble modelling, habitat transformation analysis, and graph-theoretic connectivity metrics. Milu (Elaphurus davidianus) habitats were projected under SSP2-4.5 and SSP5-8.5 for four periods (2021–2100), followed by cumulative resistant kernel and factorial least-cost path analyses. Structural resilience, functional redundancy, and climate consistency indicators were quantified. SSP2-4.5 retained 82.8% of baseline habitats, avoiding a 2040–2060 fragmentation window; SSP5-8.5 lost up to 33.9% and increased migration cost. Both scenarios showed scarce (