A medicinal plant highly stable for survival under climate change due to UV buffering–Chrysanthemum indicum L. future adaptation analysis

Clarifying the appropriate distribution range of species is a fundamental task in addressing the effects of climate change. Herbal medicine is an important part of China's traditional Chinese medicine (TCM) system, and among them, Chrysanthemum indicum L. (C. indicum) is a vital medicinal plant facing growing demand driven by climate change and economic influences. Consequently, it is crucial to properly assess how C. indicum responds to the continuously changing climate and explore its survival stability. In this study, the MaxEnt model was employed to simulate the shifts in suitable habitats for the species of C. indicum in China from the present to the 2100s under two scenarios, a low forcing scenario (SSP1–2.6) as well as a high forcing scenario (SSP5–8.5), on the basis of environmental factors including climate, soil, and topography, and quantified the potential changes in the suitable areas. The results demonstrated that under current climate conditions, the suitable areas for C. indicum are concentrated in the Yangtze River Basin and areas south of the Yangtze River in China, the most suitable habitat was identified in Hubei Province, and this distribution is projected to remain largely stable over an extended period in the future. Seasonal ultraviolet-B radiation (UVB2) was identified as the most influential environmental factor. In addition, the “UV-B buffer hypothesis” was proposed, suggesting that when UV-B radiation serves as a key limiting factor, species distribution can remain stable despite climate warming. Taken together, the findings offer insights into the production and future conservation planning of C. indicum, and provide a roadmap for the preservation of other UV-B-dependent species in a changing world.