Priority management measures based on analyses of conservation effectiveness and threat factors for medicinal plants used by three ethnic groups in China

Ethnic minority medicinal plants (EMMPs), an important valuable resource of traditional medicine, are experiencing an unprecedented risk of extinction due to various threat factors, and there is a profound lack of systematic and comprehensive research regarding their geographical distribution and conservation effectiveness. In this study, we investigated the distribution pattern for 1893 EMMPs used by the Miao, Zhuang, and Dai ethnic groups in southwest China based on >400,000 occurrence records and identified four classes of hotspots based on thresholds of top 5 %, top 10 %, top 17 %, and top 30 %, and then assessed the conservation effectiveness of the current protection networks for the hotspots and analyzed the threat factors experienced by endangered EMMPs. Although there were apparent differences in distribution patterns among the EMMPs, the hotspots of all EMMPs were mostly confined to southwest China, particularly the provincial boundary regions, which contained >98.78 % of EMMPs. The combined conservation effectiveness indicated that >68.16 % of hotspots and 98.47 % of EMMPs were protected, and provincial nature reserves played a more important role in hotspot conservation. But >18.18 % of all hotspots were unprotected. Moreover, plants where roots or the complete herbs were used for medicine were at higher risk of extinction. Over-harvesting associated with an increasing population was the key driver causing EMMPs to become endangered. We suggest that optimization of conservation networks, changes in the medical usages of plants or their parts, and promotion of artificial cultivation to ensure extensive resources.