Modeling for Predicting the Potential Geographical Distribution of Three Ephedra Herbs in China

Abstract

<i>Ephedra</i> species are beneficial for environmental protection in desert and grassland ecosystems. They have high ecological, medicinal, and economic value. To strengthen the protection of the sustainable development of <i>Ephedra</i>, we used occurrence records of <i>Ephedra sinica</i> Stapf., <i>Ephedra intermedia</i> Schrenk et C.A. Mey., and <i>Ephedra equisetina</i> Bge., combined with climate, soil, and topographic factors to simulate the suitable habitat of three <i>Ephedra</i> based on ensemble models on the Biomod2 platform. The results of the models were tested using AUC, TSS, and kappa coefficients. The results demonstrated that the ensemble model was able to accurately predict the potential distributions of <i>E. sinica</i>, <i>E. intermedia</i>, and <i>E. equisetina</i>. Eastern and central Inner Mongolia, middle and eastern Gansu, and northeastern Xinjiang were the optimum regions for the growth of <i>E. sinica</i>, <i>E. intermedia</i>, and <i>E. equisetina</i>, respectively. Additionally, several key environmental factors had a significant influence on the suitable habitats of the three <i>Ephedra</i>. The key factors affecting the distribution of <i>E. sinica</i>, <i>E. intermedia</i>, and <i>E. equisetina</i> were annual average precipitation, altitude, and vapor pressure, respectively. In conclusion, the results showed that the suitable ranges of the three <i>Ephedra</i> were mainly in Northwest China and that topography and climate were the primary influencing factors.