Assessment of Chinese suitable habitats of Zanthoxylum nitidum in different climatic conditions by Maxent model, HPLC, and chemometric methods

The suitable habitats of medicinal plants have changed as the result of climate change, which may affect quality of herbal medicine. However, as an important traditional herbal medicine, the Zanthoxylum nitidum (Roxb.) DC. lacks relevant research on coping with climate challenges. In this study, through field and online surveys, occurrence records and samples of Z. nitidum were gathered. The various periods' suitable habitats of Z. nitidum were predicted by using Maxent and ArcGIS software. The high performance liquid chromatography (HPLC) was used to ascertain the samples' nitidine chloride (NC) content. Chemometric methods was used to conduct hierarchical cluster analysis (HCA) and principal component analysis (PCA) on Z. nitidum samples from different suitable habitats. The results showed that the precipitation and temperature were significant factors in the distribution of Z. nitidum. The suitable habitats of current climate scenarios were predicted to be mainly distributed in south of the Yangtze River. The suitable habitats were predicted to gradually reduce southward under the four future climate scenarios. The contents of NC in suitable habitats were significantly higher than low-suitable habitats. Meanwhile, HCA and PCA showed that the Z. nitidum samples from different suitable habitats were effectively identified and evaluated based on bioactive substances. Overall, the findings of this study are useful references for the identification of suitable areas of Z. nitidum cultivation, as well as suitable habitats identification and quality evaluation of Z. nitidum resources in China.