Projected Impacts of Climate Change on the Habitat of Handeliodendron bodinieri: An Ensemble Species Distribution Modeling Approach

Handeliodendron bodinieri is a rare tree species endemic to the karst mountains of southwestern China and is listed as a national Class II key protected wild plant. Due to its highly specialized habitat requirements and limited reproductive dispersal ability, the species is exceptionally vulnerable to environmental changes. To predict the impacts of future climate change on its habitat suitability while minimizing predictive uncertainties, this study compiled multi-source occurrence data alongside bioclimatic, topographic, and edaphic variables. We deployed an ensemble species distribution modeling framework to project the current and future (2100) distribution patterns and dynamic shifts in suitable habitat for H. bodinieri under three Shared Socioeconomic Pathways (SSP126, SSP370, and SSP585). Three independent evaluation metrics (AUCprg, TSS, and the Boyce index) consistently demonstrated that the ensemble model significantly outperformed individual algorithmic models (GLM, MARS, MAXENT, and RFd). Under current conditions, the weighted-average ensemble model estimated the suitable habitat area for H. bodinieri to be 70,582 km2. By 2100, the suitable habitat area is projected to contract under all three SSP scenarios, with reduction rates ranging from 27.38% to 80.43%. Concurrently, the centroid of the suitable habitat is expected to shift southeastward or southward by 13–40 km, accompanied by varying degrees of shifts in mean elevation. Furthermore, we identified climate-insensitive regions across the scenarios, which are primarily clustered along the border between Guangxi and Guizhou provinces. Our study provides a robust scientific foundation for formulating effective conservation and management strategies for H. bodinieri amidst ongoing climate change, ultimately maintaining the sustainable survival of the species.