A brief review of Populus fossils from the Tibetan Plateau.

Populus L. is an ecologically important tree genus in the Northern Hemisphere temperate forest. In this paper we summarize the Populus fossil records from the Paleogene and Neogene of the Tibetan Plateau with updated stratigraphic and chronological data. Fossil evidence shows that Populus first occurred in the plateau in the latest Eocene. The genus is well-documented in the southern and northern Tibetan Plateau in the Oligocene and Miocene, but lacking in the central plateau. Most of the fossil floras in the Tibetan Plateau containing Populus are temperate, deciduous and broadleaved, riparian vegetation, further confirming that the genus had favored a temperate and riparian environment in their early evolutionary history. Besides, the high diversity and prominent dominance of Populus in early Oligocene flora in the northern Tibetan Plateau suggests this region had played an important role in the early diversification stage of Populus.

杨属（Populus L.）是北半球温带森林中具有重要生态意义的一个乔木属。本文结合最新的地层和年代数据，对青藏高原古近纪和新近纪的杨属化石记录进行了总结。化石证据表明，杨属最早于始新世晚期出现在高原地区。在渐新世和中新世，该属在青藏高原南部和北部均有大量记录，但在高原中部缺失。青藏高原大多数含杨属的化石植物群为温带落叶阔叶河岸植被，这进一步证实，在早期演化历程中，杨属偏好温带河岸环境。此外，杨属在青藏高原北部渐新世早期植物群中具有高度多样性且占显著优势，这表明该地区在杨属早期多样化阶段发挥了重要作用。