The uplift and outward growth of Asia’s three great plateaus is a major driver of changes in the Asian landscape and biodiversity, according to a new study led by Prof. Wang Wei from the Institute of Botany of the Chinese Academy of Sciences (IBCAS).

The study is published in Trends in Ecology & Evolution.

The three great Asian plateaus—the Qinghai–Tibet Plateau (QTP), the Iran Plateau (IP), and the Mongolia Plateau (MP)—together with their adjacent regions form the world’s largest contiguous highland system and cradle the richest temperate alpine biotas on Earth.

This mountain belt houses five global biodiversity hotspots of great conservation value and is highly sensitive to global warming. Yet the original timing and evolutionary drivers of this biodiversity remain poorly resolved.

To address this, the researchers analyzed 123 diversification events and 28 vicariance events from 45 organismal groups (covering pteridophytes, gymnosperms, angiosperms, amphibians, reptiles, invertebrates, and fishes) to explore how ecosystems and biodiversity have evolved across the three plateaus and adjacent areas.

Integrating these data with geological, ecological, and paleontological evidence, the researchers found that the plateaus underwent multiple-stage uplift throughout the Cenozoic. These geological events have greatly reshaped Asia’s topography and altered regional and even global climate, thereby driving evolutionary radiations across the plateaus and their neighboring areas.

The results indicate that biodiversity of the three plateau regions was not a product of the Pleistocene ice age, but has experienced a long and complex evolutionary process, with the Neogene serving as a critical interval for biotic modernization.

Among the three plateaus, the QTP harbors the most ancient evolutionary history and therefore the oldest biotic components. Comparative analyses of vascular plant diversity reveal markedly different present-day richness across the three plateaus: the QTP hosts the greatest species richness, followed by the IP and then the MP.

However, current protected areas do not fully cover the species diversity hotspots of the three plateaus. Only the QTP’s Plateau Platform meets the Kunming-Montreal Global Biodiversity Framework target of protecting more than 30% of key habitats.

The researchers proposed four research priorities for the future: exploring abiotic and/or biotic drivers of biodiversity; evaluating the relative roles of colonization and in-situ speciation to this biodiversity; expanding molecular-phylogenetic and paleontological work focus on species-rich but under-sampled areas and/or taxa; and pursuing integrative analyses that treat the three plateaus as a single biogeographic unit to explore inter-plateau biodiversity relationships.

By systematically reviewing the geological development of the three great Asian plateaus and the evolutionary dynamics of their biodiversity, the study provides new insights into Asia’s geological and biological history.

Meanwhile, it highlights substantial conservation gaps that must be addressed to safeguard this irreplaceable biodiversity.