Predicting global distribution of Caryopteris under climate change using an optimized MaxEnt model: insights into ecological adaptation and conservation

Climate change is reshaping plant species distributions, posing challenges for drought-adapted taxa with restricted native ranges. This study employed an optimized MaxEnt ecological niche model, using GBIF occurrence records and a suite of bioclimatic and UV-B radiation variables, to project the current and future potential distribution of Caryopteris Bunge under four climate scenarios (SSP126, SSP245, SSP370, and SSP585). The model exhibited relatively high predictive performance, forecasting a consistent expansion of highly suitable habitats across all future pathways, with the SSP585 scenario projecting a 24.41% increase by 2090. A northeastward shift of the habitat centroid suggests potential expansion into temperate and high-altitude ecosystems. UV-B radiation (28.4%), diurnal temperature range (23.0%), and precipitation seasonality (10.2%) were the most influential environmental predictors.However, increased fragmentation-especially in Central Asia and inland Australia-may reduce population viability.Conservation gap analysis revealed that, although the spatial extent of protected areas remains relatively stable under future climate scenarios, a large portion of highly suitable habitats, especially in East Asia and the Middle East, remains outside protected zones, indicating insufficient protection coverage in projected future hotspots. These findings provide critical insights for adaptive conservation planning and ecological restoration in arid and semi-arid regions.