北京西山末次冰期中期植被演化序列研究

Study on the Sequence of Vegetation Change during the Middle Stage of the Last Glacial in Xishan Mountain of Beijing Area

对北京西山马兰黄土中的古土壤部分进行了孢粉分析,恢复了末次冰期中期这一地区的植被演化序列,研究结果显示末次冰期中期北京西山地区的植被演化分为三个阶段,这一特征与我国北方其它地区的环境演化序列具有较好的一致性.北京西山地区MIS3阶段早、晚发育草甸草原或森林草原,中期发育荒漠草原;中期中存在较多的次一级波动,说明当时气候不稳定.从植被的状况来看MIS3阶段早期的植被状况要好于晚期,可能接近但还没有达到现代水平,说明当时青藏高原“高温大降水事件”对北京西山地区影响极其微弱或没有影响.

The spore-pollen analysis of palaeosol section of Malan Loess of Xishan Mountain of Beijing revealed the sequence of vegetation change during the Middle Sage of the Last Glacial of this area, and the sequence could be divided into three stages, which corresponded well with those sequences of environmental change of other areas of North China. There appeared meadow or sparse forest steppe during the early stage and late stage of MIS 3, and desert vegetation during the middle stage of MIS 3 with several sub-fluctuations, which showed the climate unsteady. The vegetation condition during the early stage of MIS 3 was better than that of the late stage of MIS 3, but not as good as that of today, which demonstrated that the Episode of Strengthened Summer Monsoon had weak or no influence on Xishan Mountain of Beijing.