Comparative evaluation of multiple models for predicting the potential distribution areas of Astragalus membranaceus var. mongholicus

Based on 123 distribution points of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao and 19 ecological variables, four ecological niche models (i.e., BIOCLIM, DOMAIN, GARP, and MAXENT) were used to predict the potential distribution areas of Astragalus membranaceus, with the different models then judged and compared using areas under the receiver operating characteristic curves (AUC) and Kappa values. Results showed that the four models had good prediction accuracy and consistency, with AUC values above 0.8 and Kappa values above 0.6. The DOMAIN model demonstrated the highest AUC and Kappa values, indicating that the prediction accuracy and results of this model were optimal and stable. The predicted suitable area range of the GARP model was the widest, with the MAXENT and BIOCLIM models showing similar prediction ranges and DOMAIN demonstrating relatively dispersed prediction regions. The four models showed that the northwest regions could be used as major production areas for A. membranaceus var. mongholicus cultivation. The prediction results indicated that the potential distribution areas for A. membranaceus var. mongholicus were mainly located in north of 33°N, and included Mongolia, Shaanxi, Shanxi, Gansu, Ningxia, Hebei, and the border area of northeastern provinces and Inner Mongolia. In addition, small potentially suitable areas were also located in Xinjiang, Tibet, Qinghai, and Sichuan. However, the most suitable areas were distributed in Gansu, Ningxia, Shaanxi, Shanxi, Hebei and Inner Mongolia Autonomous Region.