A recent study published in Science Advances on December 19, 2025, has revealed significant insights into how mountain formation and climate change have influenced alpine biodiversity over the past 30 million years. Researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences, collaborating with international partners, investigated five major mountain systems in the Northern Hemisphere and found that these geological processes are pivotal in fostering the rich plant diversity found in the world’s alpine regions.
Mountain ecosystems are known to host a disproportionate number of plant species, but the mechanisms behind this diversity have remained elusive. The study addressed this gap by employing phylogenetic analyses alongside geological context and paleoclimate reconstructions. This approach enabled researchers to discern the roles of mountain uplift and changing climates in shaping alpine flora.
Researchers focused on the evolutionary trajectories of 34 groups of flowering plants, encompassing 8,456 species. They meticulously reconstructed the timing and locations of these plants’ diversification across various mountain ranges. The results indicated that as climates cooled over millions of years, cold habitats expanded, allowing previously isolated high-altitude regions to connect.
Key Findings on Plant Evolution
According to Xing Yaowu, co-corresponding author of the study, “Our work links plant evolution with Earth’s geological and climate history, showing how ancient mountains and climate changes have shaped alpine life in clear, predictable ways.” The research highlighted that the diversification of alpine plant groups was contingent on both mountain uplift and cooler global temperatures, irrespective of their points of origin.
The study illustrated that rising mountain ranges created new habitats conducive to plant evolution, while cooler climates facilitated the dispersal and mixing of plant species across mountain systems. Notably, the researchers observed distinct evolutionary mechanisms across various mountain systems. The Tibeto-Himalayan-Hengduan (THH) region served as a “cradle” for biodiversity, where over half of new species originated from in-situ diversification. In contrast, European and Irano-Turanian alpine floras primarily developed from local mid- to low-elevation lineages that adapted to alpine conditions. The Tianshan Mountains, on the other hand, largely imported species from the THH region.
Overall, the findings underscored a consistent pattern: active mountain uplift accelerates the emergence of new plant species within specific areas, emphasizing the significance of geological processes in biodiversity formation.
Implications for Global Biodiversity
The research also sheds light on why alpine plant communities vary significantly from one region to another. Ding Wenna, the study’s first author, stated, “These asynchronous yet predictable assembly dynamics help explain why alpine plant communities differ so much from one region to another today.” The last five million years saw intensified global cooling, enhancing connections between cold Arctic and alpine habitats, which transformed the boreal-arctic region into a “biogeographic crossroads” for the exchange of flora between Eurasia and North America.
The implications of this research are profound. It offers a coherent explanation for the exceptional biodiversity found in mountainous regions worldwide, highlighting the intricate interplay between geological and climatic forces. The study not only enhances our understanding of plant evolution but also serves as a vital reference for future biodiversity conservation efforts in the face of ongoing climate change.
For more detailed insights, refer to the study by Wen-Na Ding et al, titled “The asynchronous rise of Northern Hemisphere alpine floras reveals general responses of biotic assembly to orogeny and climate change,” published in Science Advances (2025). DOI: 10.1126/sciadv.adz1888.
