Regional difference in Holocene vegetational change and the possible migration of major trees in NE China

摘要: Regional difference in forest changes over Northeast China is investigated using the previously completed pollen isochrone maps and the data from a few representative profiles. During the Holocene, Quercus and Pinus seem to have appeared in the Xiao Hinggan Ling Range and the Sanjiang Pingyuan 1 000-to-2 000 years later than in the Changbai Shan. Little difference in the appearance times of Ulmus is found at the representative sites between north and south. It is therefore plausible that Quercus and Pinus may have experienced south-to-north migration after climate became warmer and more suitable for their growth.