Mountain Riparian Zones as Refugia for Rare and Endangered Plants Under Climate Change.

Climate and land use changes pose a severe threat to plant biodiversity, particularly to rare and endangered species that are highly sensitive to environmental changes. Nevertheless, very little is understood about the spatiotemporal dynamics and current conservation status of these taxa in fragile dryland ecosystems. This study projected the potential distribution of 32 rare and endangered plant species in the Irtysh River Basin under both contemporary and projected future (2050) climate scenarios and identified biodiversity hotspots and conservation gaps based on an ensemble model that integrated Species Distribution Models (SDMs) with the InVEST habitat quality model. The results showed that water availability and topography were the primary determinants of the spatial distribution of these species, which were concentrated in riparian zones, particularly in mountainous river segments. Projections indicated that future climatic shifts would precipitate range contractions of approximately 60% of the studied species, leading to an overall decline in biodiversity across the basin. Conversely, biodiversity in mountainous areas was projected to increase, underscoring that mountainous areas acted as important climate refugia. It is worth noting that approximately 80% of the studied species were classified as gap species, highlighting severe conservation gaps in current protected area networks. These results reveal the responses of rare and endangered plants to climatic alterations and offer a sound basis for developing biodiversity conservation and management strategies in dryland ecosystems.