The Current and Future Distribution Areas of the Rare and Endangered Fern Cibotium barometz (Cibotiaceae) in Guizhou, China, Based on the MaxEnt Model and ArcGIS.

Climate change poses an increasing threat to rare medicinal plants, yet the response mechanisms of many endangered species remain poorly understood. Cibotium barometz (L.) J. Sm., listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), is a typical example of this conservation challenge due to its overexploitation for traditional medicinal use in China. In this study, the MaxEnt model and ArcGIS software were used to predict the potential suitable habitats for C. barometz in China under current and future climate scenarios (from SSP1-2.6 to SSP5-8.5). The results showed that precipitation of the driest quarter (bio17) contributed the most to model construction, with an optimal precipitation range of 50-150 mm. The species distribution model indicated that under current climatic conditions, the national high-suitability zone encompasses 24,410 km2, predominantly located in Guangdong, Guangxi, and southwestern Guizhou. Under future climate scenarios, the suitable habitat area of C. barometz shows an increasing trend under the low-emission pathway (SSP1-2.6), but faces a continuous decline risk under medium-emission pathways (SSP2-4.5 and SSP3-7.0). Under the high-emission scenario (SSP5-8.5), the area of high-suitability habitat expands to 279,800 km2, with its centroid shifting significantly southward by 148.95 km. Consequently, this study identifies priority areas for in situ conservation (southwestern Guizhou and southern Guangdong) and key regions for ex situ conservation (central Guizhou), providing a crucial reference for the sustainable utilization of this endangered medicinal fern.