The response of the species diversity pattern of Populus to climate change in China

Increasing evidence shows that climate has already triggered species' range and species diversity patterns shifting on the large scale, while the underlying mechanisms about it yet no consensus has been researched, due to various species focused and different scales researches performed. Based on the findings that the species diversity pattern supported niche conservatism between the sections (subgenus) of genus Populus, by exhaustively searching the herbarium specimen records, we investigated the species diversity patterns of genus Populus and projected their potential range and diversity pattern in the future scenarios of climate in China, using a geographic information system (GIS) and Gaussian model. Our analyses showed that (1) under the condition of contemporary climate, the species diversity center of Populus was distributed in a transitional region of arid-semiarid areas, near the "Heihe-Tengchong Line", within which species diversity increased from northeast to southwest China along the line; (2) in the future scenarios of climate, the species distribution range of Populus will expand to the eastern and northern directions; and (3) the species diversity center of Populus tends to enlarge to northeast and northwest in the future scenarios of climate.