A comprehensive assessment of climate and topographic changes to identify conservation gaps for the critically endangered species Coptis teeta Wall in southwest China.

INTRODUCTION: Coptis teeta Wall, a nationally protected Grade II plant species endemic to China, is mainly distributed in the Yunnan and Sichuan provinces. Predicting its potential suitable habitats is essential for understanding its ecological responses to climate change and for supporting effective conservation planning. METHODS: Based on 20 occurrence records of Coptis teeta Wall, this study employed bioclimatic and topographic variables derived from WorldClim to simulate habitat suitability under past, present, and future climate conditions using the MaxEnt model. Four future climate scenarios across two time periods were considered to assess potential distribution dynamics. RESULTS: The results indicate that precipitation of the warmest quarter (Bio18) is the primary climatic factor governing the species' distribution, while topographic variables such as elevation and slope contribute to habitat stability. Spatiotemporal analysis reveals that the suitable habitat area of Coptis teeta Wall exhibited a "decrease-increase" trend from the Last Glacial Maximum to the present, reaching its maximum extent under current climatic conditions. However, future projections under Shared Socioeconomic Pathway (SSP) scenarios suggest a general contraction of suitable habitats. Notably, the species is projected to shift not only toward higher elevations but also toward southeastern coastal regions of China. Under high-emission scenarios such as SSP370, intensified climate variability and winter warming (Bio6) are expected to exacerbate habitat fragmentation, substantially increasing extinction risk. CONCLUSION: Accordingly, Conservation priorities should include the existing core range in the Sichuan-Guizhou-Yunnan region, as well as potential future climate refuges identified along the Guizhou-Hunan border.