Abstract
Krascheninnikovia ceratoides (L.) Gueldenst., the primary food source for the western population of Pantholops hodgsonii (Tibetan antelope) during their breeding period in the Western Kunlun Mountains, plays a crucial role in maintaining alpine ecosystems. Herein, we focused on this species and used optimized MaxEnt and biomod2 models to predict its potential distribution ranges during the Mid-Holocene, current period, and future climate scenarios (RCP2.6, RCP4.5, RCP6.0, RCP8.5), incorporating both climatic and soil factors and performing cross-validation with the XGBoost-SHAP model. Additionally, we analyzed the centroid migration characteristics of suitable habitats under different scenarios and identified conservation gaps for Tibetan antelopes using the InVEST Habitat Quality module. The results showed that both biomod2 and XGBoost-SHAP models exhibited high accuracy: biomod2 had AUC values > 0.98, TSS values > 0.85, and Kappa values > 0.6; the XGBoost-SHAP model had small RMSE and MAE for both training and test sets, with R (2) > 0.98. Analysis of environmental factor contributions revealed that mean diurnal range (bio2) had the highest contribution to the distribution of K. ceratoides, followed by annual mean temperature (bio1), annual precipitation (bio12), and topsoil clay fraction (t_clay). Currently, the total potential suitable habitat area of this species is 0.5745 × 10(4) km(2), accounting for 35.6855% of the study area, and is mainly concentrated in the western and central regions. Among different climate scenarios, the Mid-Holocene had the largest suitable habitat area (0.7436 × 10(4) km(2), 46.1838% of the study area), followed by the RCP4.5 scenario. Warming to some extent promoted the expansion of suitable habitats, but the newly added areas were mostly low suitable habitats, which may face resource competition pressure. With rising temperatures, the centroid of suitable habitats generally migrated from the southeast to high altitude areas in the northwest, then shifted back to the southeast over time. Furthermore, the average habitat quality index of the study area was only 0.277, indicating a relatively harsh ecological environment, and conservation gaps for Tibetan antelopes were concentrated in the southern areas adjacent to existing protected zones. This study provides a scientific basis for the targeted conservation of K. ceratoides and the improvement of conservation gaps for Tibetan antelopes.