Figure 2 (IMAGE) Science China Press Caption Pollen percentages of Quercus in lake sediments since 24,000 cal yr BP based on 46 pollen records from northern and central China. Yellow circles indicate sites with Quercus pollen records, and the circle sizes are proportional to the pollen percentages. The red dots indicate archaeological sites (Hosner et al., 2016), which represent the spatial pattern of human disturbances. Credit ©Science China Press Usage Restrictions Use with credit. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.