As members of the Xishuangbanna Tropical Botanical Garden (XTBG) report in the journal Science , the alpine flora of the Hengduan Mountains has existed continuously for much longer than any other flora on Earth .
Threatened by global warming, the world’s richest temperate alpine biota is found in the Qinghai-Tibet Plateau (QTP), Himalayas and the Hengduan Mountains (THH).
In the research , time-calibrated phylogenies of 18 groups of flowering plants were analyzed using a joint model of biome occupation, geographic range evolution, and lineage diversification.
The Hengduan Mountains are not only the cradle of alpine plants, but they are also the main source of alpine lineages that colonize the Himalayas and the QTP. As Ding Wenna , first author of the study, explains:
Our results, derived from time-scale molecular phylogeny analysis and non-in situ fossil evidence of Alpine ancestry, are, however, temporally consistent with the more recent geological evidence that active orogeny associated with generalized shortening and thickening of the crust established highlands from eastern Tibet to the Hengduan Mountains in the late Eocene.