Hotspot and conservation gap analysis of endemic vascular plants in the Altai Mountain Country based on a new global conservation assessment

The Altai Mountains of Central and North Asia are biologically rich and comprise a wide range of ecosystems and phytogeographical regions. According to the latest checklist, a total of 321 endemic vascular plant species, including 217 endemic and 104 subendemic taxa, have been recognized in the Altai Mountain Country (AMC). In this study, we conducted species risk assessment, distribution evaluation and conservation gap analysis for the endemic vascular flora of the AMC. The conservation status of 217 endemic species was assessed at the global level using the ConR package. As a result, 197 species were evaluated as potentially threatened, of which 101 are critically endangered (CR), 72 species are endangered (EN), and 24 species are vulnerable (VU). The remaining 20 species were evaluated as not threatened. Furthermore, the AMC was divided into 350 grid cells, with a grid cell size of 50 x 50 km2, for the spatial assessments of the endemic vascular plants. A total of 2657 unique georeferenced occurrences of endemic species were found and analyzed with three endemism indices, species richness (SR), weighted endemism (WE), and corrected weighted endemism (CWE), to quantify geographic patterns and centers of endemism across the whole AMC. The results showed that the endemic species are spread across 186 grid cells and distributed unevenly within the AMC. According to the conservation gap analysis, the main hotspots of endemism (i.e., SR and WE indices) were found at high elevations in the Russian Altai, while the CWE points to the Kazakh Altai as a hotspot, and many such hotspots are currently afforded no formal protections.