东北全新世乔木种类演化的区域差异及其迁移问题

根据花粉等时线图和代表性剖面花焰资料，总结了东北全新世主要乔木在再现和发展的地区差异。三江平原和小兴安岭地区的栎属与松属的出现和发展分别比长白山地区推迟１－－２千多上时间上的差别说明它们可能有从南向北的迁移过程。不同乔木种类迁移的速率也不一样。初步估计的几种乔木迁移速率为，栎２５０～５９０ｍ／ａ，松属１５０－５８０ｍ／ａ，胡桃属２００－８１０ｍ／ａ。这种差异可能主要与种子大小、河流和地形等因素有联

REGIONAL DIFFERENCE IN HOLOCENE VEGETATIONAL CHANGE AND THE POSSIBLE MIGRATION OF MAJOR TREES IN NE CHINA

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. Estimated migration rates are 250-590 m/a for Quercus, 150-580 m/a for Pinus, and 200-810 m/a for Juglans . The difference of the migration rates between the taxa may depend on such factors as the size and weight of seeds, distance of the profile sites from major rivers and specific topographical feature.