A research team led by Prof. WANG Wei from the Institute of Botany of the Chinese Academy of Sciences revealed the evolutionary history of the world's largest evergreen broadleaved forest (EBLF), East Asian EBLF, through a multi-taxon analysis. The study was published in National Science Review.

The East Asian EBLF, spanning southern China, southern Japan and southernmost Korea, houses high levels of biodiversity and endemism, and plays important roles in regional carbon storage and cycling. However, its evolutionary history remains an open question.

In this study, researchers sampled 21 angiosperm clades with 2,028 species that include evergreen and deciduous species, and used evergreen lineages within as the proxy to unravel the evolutionary history of East Asian EBLF at a global scale.

They found that the transition from deciduous to evergreen lineages, and in situ diversification and immigration of evergreen lineages in subtropical East Asia all experienced a dynamic process. Transition and immigration reached their first peaks and in situ diversification sharply increased at the Oligocene–Miocene boundary (OMB), and all of them reached their highest peaks in the late Miocene.

Multiple regression and breakpoint regression analyses support that Asian monsoon climate changes have a profound impact on the assembly of East Asian EBLF. Some ancient elements of East Asian EBLF can traced back to the Cretaceous along with the Cretaceous Terrestrial Revolution. However, the modernization of East Asian EBLF does not take place until the OMB, driven by the formation of modern-like Asian monsoon climate system. The EBLF flourished continuously in East Asia throughout the Miocene and markedly deteriorated since the Pliocene.