Climate-driven habitat suitability dynamics and species-specific conservation implications for three montane Osmanthus Lour. (Lamiales, Oleaceae) species in Southwest China

Osmanthus (Oleaceae) is an economically and culturally important genus. The three montane Osmanthus species examined here are Chinese endemics centered in Southwest China and provide a system to examine climate-change responses and species-specific conservation. Using 136 environmentally matched occurrence records (49 O. delavayi , 46 O. yunnanensis , and 41 O. serrulatus ), we applied an optimized MaxEnt framework integrating climatic, edaphic, and topographic predictors to model habitat suitability across paleoclimatic, current, and future periods. Temperature-related predictors dominated all three models, but their relative importance and model-inferred suitable ranges differed among species. Temperature seasonality (bio4) and minimum temperature of the coldest month (bio6) were repeatedly influential, while isothermality (bio3) was especially important for O. delavayi and precipitation seasonality (bio15) for O. serrulatus . Soil variables contributed less overall but further differentiated suitability near climatic range margins. Paleoclimatic projections also differed, with O. serrulatus following a trajectory that contrasts with those of O. delavayi and O. yunnanensis . Under the selected BCC-CSM2-MR global climate model (GCM) and three shared socioeconomic pathway (SSP) scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5), modeled suitable area declined by up to 90% for O. delavayi by the 2090s under SSP5-8.5 and by up to 34% for O. yunnanensis by the 2090s under SSP2-4.5, whereas O. serrulatus showed pathway-dependent contraction and expansion. Suitability centroids for O. delavayi and O. yunnanensis shifted mainly northward or northwestward, whereas that of O. serrulatus shifted mainly westward. Only 3.86–7.08% of current modeled suitable area fell within protected areas. These contrasts support species-specific priorities: protecting persistent high-elevation cores of O. delavayi , monitoring spatial discontinuity across the broader modeled suitable range of O. yunnanensis , and strengthening in situ protection of the restricted humid montane habitats of O. serrulatus .