Climate and Landscape Drivers of Endangered Bird Distributions and Richness in South Korea: Random Forest Projections Across Municipalities and National Parks Under SSP Scenarios

Climate change poses an unprecedented threat to global biodiversity, with birds serving as critical indicators of ecosystem responses. This study assessed the impacts of climate change on 29 endangered bird species in South Korea, a critical stopover region within the East Asian-Australasian Flyway (EAAF). Using Random Forest models, we predicted current (2010 baseline) and future species distributions under two climate scenarios (SSP2-4.5 and SSP5-8.5) for four time periods (2030s, 2050s, 2070s, and 2090s). Model performance was robust, with a mean AUC of 0.844 ± 0.122 across all species and 72.4% of species achieving AUC ≥ 0.80. Elevation emerged as the most influential predictor for 44.8% of species, followed by precipitation of the driest month (17.2%) and distance to water bodies (10.3%). Current species richness patterns showed spatial heterogeneity, with higher concentrations along coastal wetlands, particularly in the western and southern coasts and Jeju Island. Under SSP2-4.5, species richness patterns remained relatively stable through 2090, while SSP5-8.5 projected more dramatic shifts, particularly after 2070. Coastal regions and national parks exhibited differential responses, with some areas showing increases and others experiencing declines in species richness. High-elevation national parks, including Mt. Hallasan, Mt. Seoraksan, and Mt. Odaesan, demonstrated potential to serve as climate refugia, maintaining relatively stable species richness under both scenarios. Our spatial analysis at municipality and national park levels identified priority conservation areas and emphasized the need for climate refugium identification, habitat connectivity along elevational gradients, and adaptive management strategies. The findings provide actionable guidance for science-based conservation planning and contribute to international efforts to protect migratory birds along the EAAF. Urgent conservation measures are needed to safeguard coastal wetlands and establish ecological corridors to facilitate species range shifts under changing climatic conditions.