Richard Ree, Associate Curator of Flowering Plants
Field Museum

Topic: Tempo and mode of biodiversity hotspot assembly in China's Hengduan Mountains

Abstract:
The disproportionately rich biodiversity of mountains is often attributed to uplift-driven diversification, the idea that orogeny creates conditions favoring rapid in situ speciation of resident lineages. Of the mountains surrounding the Qinghai-Tibetan Plateau (QTP), the Hengduan Mountains region is the richest in plant species; it is also the wettest, and was uplifted most recently, since the late Miocene. Analyses of the tempo and mode of species accumulation across time, space, and clades shows that the Hengduan Mountains flora was assembled disproportionately by recent in situ diversification, temporally congruent with its orogeny. This supports the uplift-driven diversification hypothesis. However, dispersal has also played an outsize role, reflecting the connectedness of the Hengduan Mountains relative to other mountain hotspots. In some clades, pulses of diversification detected prior to Hengduan uplift may reflect uplift of the Himalayas, suggesting ancestral diversification outside of the current center of endemism.

Host Lab: Davis