Integrating habitat suitability, phytochemical quality, and landscape stability to identify conservation priorities for Arnebia guttata Bunge under climate change in East Asia.

Arnebia guttata Bunge is a threatened medicinal plant predominantly distributed in arid and semi-arid regions of China and Mongolia. Increasing medicinal demand and ongoing climate change highlight the need for an integrated evaluation of its habitat dynamics, medicinal quality, and ecological stability. In this study, we combined species distribution modeling, niche analysis, phytochemical evaluation, and landscape fragmentation analysis to assess habitat suitability, medicinal quality, and habitat stability within a unified framework. Results showed that the suitable habitats of A. guttata are projected to remain relatively stable while moderately expanding toward the Altai, Qilian, Helan, and Tianshan Mountains by the end of the 21st century. Hydrological variables exerted dominant control over habitat suitability, whereas medicinal quality showed comparatively weaker and more spatially heterogeneous relationships with environmental conditions. Areas with relatively high phytochemical quality were more spatially restricted and environmentally differentiated than climatically suitable habitats. In addition, suitable habitats and phytochemical quality zones differed markedly in spatial distribution and environmental characteristics, suggesting that ecological suitability does not necessarily correspond to medicinal quality. Landscape analysis further revealed clear differences in fragmentation and connectivity among habitat types.