Large-scale vegetation history in China and its response to climate change since the Last Glacial Maximum

摘要

Large-scale palaeovegetation reconstruction plays a critical role in improving our understanding of the response of vegetation to climate change and in reducing the uncertainty in predictions of vegetation change under global warming scenarios. Here, we present quantitative vegetation reconstructions for China since the Last Glacial Maximum (LGM), using 286 selected fossil pollen records analyzed using the biomization method. The results show that from 23 to 19 ka (1 ka = 1000 cal yr BP), steppe and desert expanded southeastwards, dominating northern China, whereas forest in eastern China shrank southwards to near the middle and lower reaches of the Yangtze River; the percentage of forested sites at this time was the lowest during the studied interval. Forest then developed gradually during 18-12 ka. During the early and middle Holocene, tropical seasonal forest, broad-leaved evergreen/warm mixed forest, and temperate deciduous forest shifted northwards by 2 degrees, 4 degrees and 5 degrees in latitude, respectively, relative to today, and then declined in the late Holocene. In detail, forest flourished in the middle Holocene (9-4 ka) in semi-arid and semi-humid northern China, whereas it reached a maximum in the early and middle Holocene (11.5-6 ka) in humid southern China. Our results suggest that although forest throughout China exhibited the expected response to the evolution of the East Asian summer monsoon, precipitation exerted a more significant effect on vegetation change in northern China, whereas temperature and precipitation played a more important role in southern China. Our results are a potentially useful reference for assessing future vegetation dynamics under global warming scenarios.