Landscape reconstruction and the relationship between human and environment in Yaowuyao area, Northeastern Tibetan Plateau since 15000 yr BP

Understanding the paleoenvironment (such as climate and landscape) in the area where the early ancient human appears on the Tibetan Plateau is an interesting topic. Based on the results of pollen data on the Yaowuyao loess section of the Qinghai Lake Basin, we used landscape reconstruction algorithms to reconstruct the changes in vegetation cover for 15,000 years. It is shown that the vegetation in the Yaowuyao area changed from temperate steppe (15-7.5 ka) to forest-steppe (7.5-4 ka). Compared with previous studies on the sediment in Qinghai Lake, our study can better reflect the local environment of the Qinghai Lake basin. Furthermore, based on the paleoclimate change data and archeological data from the surrounding areas, it is noticed that while precipitation increases and trees increase, human activities decrease. This may be caused by the substance and strategies of the ancient human beings that have adapted to the steppe. In addition, our results also show that the intensity of ancient human activity has a negative correlation with plant biodiversity, which may be related to human disturbance to the environment. Our paleoecological and environmental study not only shows the paleoenvironment of the early human activities on the Qinghai-Tibet Plateau but also revealed possible early human activity signals.