Predictions of potential geographical distribution and quality of <i>Schisandra sphenanthera</i> under climate change

Climate change will significantly affect plant distribution as well as the quality of medicinal plants. Although numerous studies have analyzed the effect of climate change on future habitats of plants through species distribution models (SDMs), few of them have incorporated the change of effective content of medicinal plants. <i>Schisandra sphenanthera</i> Rehd. et Wils. is an endangered traditional Chinese medical plant which is mainly located in the Qinling Mountains. Combining fuzzy theory and a maximum entropy model, we obtained current spatial distribution of quality assessment for <i>S. spenanthera</i>. Moreover, the future quality and distribution of <i>S. spenanthera</i> were also projected for the periods 2020s, 2050s and 2080s under three different climate change scenarios (SRES-A1B, SRES-A2 and SRES-B1 emission scenarios) described in the Special Report on Emissions Scenarios (SRES) of IPCC (Intergovernmental Panel on Climate Change). The results showed that the moderately suitable habitat of <i>S. sphenanthera</i> under all climate change scenarios remained relatively stable in the study area. The highly suitable habitat of <i>S. sphenanthera</i> would gradually decrease in the future and a higher decline rate of the highly suitable habitat area would occur under climate change scenarios SRES-A1B and SRES-A2. The result suggested that in the study area, there would be no more highly suitable habitat areas for <i>S. sphenanthera</i> when the annual mean temperature exceeds 20 °C or its annual precipitation exceeds 1,200 mm. Our results will be influential in the future ecological conservation and management of <i>S. sphenanthera</i> and can be taken as a reference for habitat suitability assessment research for other medicinal plants.