Identifying conservation priority areas for gymnosperm species under climate changes in China

China has a rich flora of gymnosperms. Gymnosperm species dominate and co-dominate more than half of China's forest area, but many of them are threatened and vulnerable to climate changes. This study mapped the geographical distributions of 209 gymnosperm species in China, modeled the niches of 124 gymnosperm species with adequate records of field occurrences using MaxEnt, and predicted their range changes under two dispersal scenarios (no dispersal and unlimited dispersal) and three emission scenarios (Representative concentration pathway [RCP] 2.6, RCP 6.0, RCP 8.5). To inform gymnosperm conservation facing climate change, we proposed a multi-criteria framework to identify conservation priority areas by integrating information on species diversity patterns and potential climate refugia, and detected gymnosperm conservation gaps with reference to the existing conservation networks. Our results indicated that the centers of species richness, threatened species, and endemism of gymnosperms in China were highly consistent in space and were concentrated in the subtropical mountains. By the 2070s, 64 (RCP 2.6)-88 (RCP 8.5) species would lose more than 10% of their currently suitable climatic niche, and 19 (RCP 2.6)-45 (RCP 8.5) species would lose more than 30%. Cathaya argyrophylla (endangered, EN), Pinus bungeana (EN), Pinus koraiensis (vulnerable, VU) and Torreya fargesii (VU) would be most vulnerable to the projected climate changes. Seven high conservation priority regions were identified, and a substantial proportion of the regions were found lack of adequate protection. The primary recommended measures included increasing the size of protected areas to cover more high priority regions and establishing populations in new sites as required ex-situ conservation efforts.