[Habitat suitability and quality division of Mentha haplocalyx]

In this study, ecological factors, occurrence records, the essential oil components content were used to predict the potential geographical distribution and quality division of Mentha haplocalyx in China based on the MaxEnt modeling and geographic information system(GIS). The AUC of ROC curve was above 0.950,indicating that the predictive results with the maximum model were highly precise. The results showed that the main environmental factors determining the potential distribution were annual average precipitation (the contribution rate, 45.87%), mean temperature of wettest quarter (11.92%), mean temperature of warmest quarter (7.84%), average monthly precipitation of May (6.80%), standard deviation of seasonal temperature variation (4.42%), mean temperature of the coldest quarter (3.47%) and altitude (2.92%). The environmental variables in the highly potential areas were determined as annual average precipitation around [530,1 465] mm, mean temperature of wettest quarter around [24.5,29] ℃, mean temperature of the warmest quarter around [25.5,29] ℃, average monthly precipitation of May around [67,133] mm, standard deviation of temperature seasonal change around [8 333,9 643], mean temperature of the coldest quarter around [1.7,8.3] ℃ and the altitude around [0,165] mm. The best quality distribution of M. haplocalyx was mainly located in Jiangsu, Anhui, Shandong, Zhejiang and Heilongjiang. The zoning results basically coincide with the actual situation. The quality division of M. haplocalyx can be used for providing a scientific basis for selection of artificial planting base and guidance of its production.