The Effects of Cold Tolerance on the Distribution of Two Extreme Altitude Lizard Species in the Qinghai–Tibetan Plateau

Species distribution models (SDMs) have been widely used to predict potentially suitable habitats for species. However, traditional SDMs have been criticized for ignoring the physiological processes by which species respond to their environment. Integrating physiological tolerance into the model is essential to improve the prediction accuracy of SDMs. Currently, this approach has not been applied in the study of <i>Phrynocephalus erythrurus</i> and <i>Phrynocephalus theobaldi</i>, which are part of the world's highest reptiles and endemic to Qinghai-Tibetan Plateau. In this study, based on experiments, we found that the critical thermal minimum (CT_min) of the <i>Phrynocephalus theobaldi</i> was 0.85 °C. Further, we studied the effect of cold tolerance on the prediction of potential areas for these two reptile species. The high suitability area predicted by the SDMs incorporating cold tolerance data were 37.13% smaller than that predicted by the traditional SDMs. The difference between the two SDMs is primarily concentrated at the edges of the high suitability areas. The incorporation of cold tolerance data influenced the model's predictions by effectively reducing the extent of edges of the high suitability areas. Our findings have theoretical significance for optimizing SDM predictions and provide a robust scientific basis for biodiversity conservation in the extreme-altitude ecosystems of the Qinghai-Tibetan Plateau.