Predicting plant extinction risk in a biodiversity hotspot: Environmental and anthropogenic drivers in the Western Cape, South Africa

Biodiversity loss is accelerating due to climate change, habitat modification, and biological invasions, disproportionately affecting plant species in biodiversity hotspots. The Western Cape, part of the Cape Floristic Region, harbours exceptional plant diversity but faces escalating extinction risks. This study assessed the environmental and anthropogenic determinants of extinction risk among 2,794 plant species using species distribution data and a Random Forest model. Key predictors of extinction risk include precipitation during the warmest and coldest quarters, invasive species density, human modification index, and fire frequency. The model achieved an accuracy of 87.56%, highlighting the significance of habitat transformation and climatic variability in shaping species vulnerability. Spatial projections indicate that species classified as Critically Endangered (CR) and Endangered (EN) will experience severe habitat contraction by 2061–2080, with habitat loss projected to exceed 78.5% for CR species. Meanwhile, Near Threatened and Rare species may experience range expansions under changing climatic conditions. These findings highlight the urgent need for regionally tailored conservation strategies that integrate climate adaptation, habitat restoration, and invasive species management. Strengthening protected areas and implementing proactive management interventions will be critical to safeguarding South Africa’s unique plant biodiversity under future climate scenarios.