杨属是北半球温带森林生态系统中一个重要的乔木属。文中概述了青藏高原古近纪和新近纪的杨属化石记录，并根据最新的地层学和年代学数据，对化石的时代进行厘定。化石记录显示杨属在青藏高原最早出现于始新世最晚期。在渐新世和中新世杨属在青藏高原的南部和北部都有较多的化石，但在高原中部尚未见记录。青藏高原具有杨属的化石植物群大多数都是温带落叶阔叶的河岸植被，进一步证实杨属在其演化历史早期就偏好温带近河岸的环境。青藏高原北部的早渐新世植物群中杨属多样性较高，并占据显著优势，表明这一地区在杨属早期分化中具有重要作用。

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.

中国科学院战略性先导专项（B类）（XDB26000000）和国家自然科学基金（41772014）联合资助。