Ancient orogenic and monsoon-driven assembly of the world's richest temperate alpine flora

Understanding how alpine biotas formed in response to historical
environmental change may improve our ability to predict and mitigate the
threats to alpine species posed by global warming. In the world's
richest temperate alpine flora, that of the
Tibet-Himalaya-Hengduan region, phylogenetic reconstructions of
biome and geographic range evolution show that extant lineages emerged by
the early Oligocene and diversified first in the Hengduan
Mountains. By the early to middle Miocene, accelerated diversification and
colonization of adjacent regions were likely driven jointly by
mountain building and intensification of the Asian monsoon. The alpine
flora of the Hengduan Mountains has continuously existed far longer than
any other alpine flora on Earth and illustrates how modern biotas have
been shaped by past geological and climatic events.