Assessing Climate-Driven Range Dynamics of Hippophae tibetana Schltdl. Using an Ensemble Modeling Approach

Hippophae tibetana Schltdl. is a cold-tolerant deciduous shrub endemic to the Tibetan Plateau, playing a vital ecological role in high-altitude environments. This study utilized the Biomod2 platform to model its current and future potential distribution under climate change, integrating 34 environmental variables across bioclimatic, topographic, edaphic, anthropogenic, and ultraviolet (UV) dimensions. Among ten candidate species distribution models (SDMs), the random forest (RF) algorithm exhibited the highest predictive accuracy and stability. An ensemble model (EM) combining RF, GBM, MARS, and FDA further improved predictive performance (ROC = 0.992, TSS = 0.923, and Kappa = 0.886). Key determinants of habitat suitability included altitude, temperature, UV radiation, and biodiversity, with RF response curves revealing distinct nonlinear thresholds. Optimal suitability occurred at around a 4000 m elevation, decreasing beyond this range, while temperature and UV exhibited similar unimodal responses. Under the SSP2-4.5 climate scenario, the suitable habitat is projected to expand from the 2050s to the 2090s, particularly in eastern Qinghai, southwestern Gansu, northwestern Sichuan, and central–southern Tibet. The species’ distribution centroid is anticipated to shift southwestward toward Qinghai Province, with more rapid migration projected after the 2050s. These findings underscore the complex interplay of environmental factors shaping H. tibetana distribution and offer valuable insights for conservation planning in the ecologically fragile Tibetan Plateau.