Evaluating the Vulnerability of Tetracentron sinense Habitats to Climate-Induced Altitudinal Shifts

Objective: Exploring the evolving geographical distribution pattern of Tetracentron sinense and its main influencing factors since the last interglacial can provide a scientific foundation for the efficient conservation and administration of the species. Methods: : The MaxEnt model was used to construct the potential distribution areas of T. sinense in different periods such as the last interglacial, the last glacial maximum, the Mid-Holocene, the current and future. On the premise of discussing the influence of dominant environmental factors on its distribution model, the suitable area changes of T. sinense under different ecological climate situations were quantitatively analyzed. Results: : The AUC value predicted by the optimized model was 0.959, indicating a good predictive effect by the MaxEnt model; the potential suitable areas for T. sinense in the current are mainly located in southwest China, which are wider compared to the actual habitats. Jackknife testing showed that the lowest temperature in the coldest month, elevation, seasonal variation coefficient of temperature and surface calcium carbonate content are the dominant environmental factors affecting the distribution of T. sinense . From the last interglacial to the current, the total suitable area of T. sinense showed a decreasing trend; the distribution points of T. sinense populations in Mid-Holocene may be the origin of the postglacial population, and Southwest China may be its glacial biological refuge. Compared with the current, the total suitable area ranges of T. sinense in China in the future decreased, and the centroid location of its total fitness area all migrated to the northwest, with the largest migration distance in 2070s under the SSPs 7.0 climate scenario. Conclusion: Temperature was the most important factor affecting the distribution of T. sinense . With the global warming, its suitable area ranges will show a shrinking trend. Ex-situ conservation measures could be taken to preserve its germplasm resources.