Evaluating the Impact of Climate Change on the Endangered Endemic Species Thuja koraiensis Nakai in Baekdudaegan, South Korea: An Ensemble Modelling Approach

Thuja koraiensis Nakai ( Cupressaceae ) is an endangered conifer species that holds significant ecological importance as an endemic plant in Korea. To facilitate the adaptive management of ecosystems on the Korean peninsula in the face of climate change, the use of species distribution models (SDMs) can be instrumental in supporting climate-adaptive forest restoration programs. In this study, we collected occurrence and bioclimatic data from remote sensing to analyze the current and projected distribution of T. koraiensis . We employed four different SDMs, namely, the general additive model, generalized boosted model, general linear model, and random forest, to predict the potential distribution of T. koraiensis under both current and future climate scenarios. To assess the risk of extinction for this species, we utilized ensemble-averaged models to estimate the extent of area loss in currently suitable habitats for T. koraiensis , with a focus on stable true skill statistic ( TSS ) results exceeding 0.9. Encouragingly, our results indicate that T. koraiensis is likely to persist into the 2070s, specifically when considering the representative concentration pathway (RCP) 4.5 scenario for climate change on the Korean peninsula. These findings provide robust predictions regarding the future habitat occupancy probabilities of T. koraiensis populations across South Korea. Moreover, they contribute to the development of climate-adaptive forest restoration programs, taking into account long-term perspectives.