呼伦湖、乌伦古湖全新世植物群发展与气候环境变化

THE VEGETATIONAL AND CLIMATIC-ENVIRONMENTAL CHANGES IN HULUN LAKE AND WULUNGU LAKE DURING HOLOCENE

于1990－1993年分别对呼伦湖及乌伦古猢进行了调查，并对其剖面及钻孔进行了孢粉分析，结合14C测年、介形类、硅藻分析资料，对两区孢粉植物群演替、气候与湖泊环境变迁进行了比较。结果表明，10．0kaB．P．前，西北地区湖水位变化与冰川融水有关，东北湖区温凉湿润气候受季风环境影响所致；10．0－7．0kaB．P．及5．0－3．0kaB．P．间，气候干旱，两者受西风带控制；7．0－5．0kaB．P，气候温暖湿润，东亚季风边界推移至我国西北湖区，约2．5-1．0kaB．P．间，季风曾两次在西北湖区作短暂停留，降水略有增多。

In order to reconstruct environmental changes during Holocene fromlake sediment in arid and semiarid areas in Northeast and Northwest China, HulunLake and Wulungu Lake sporopollen profiles were analysed from 1990 to 1993.The changes of climate and environment in the two regions are discussed andcompared in detail based on sporopollen assemblage analysis, diatom andostrycods data, and 14C dating. About 10.0kaB.P., the water level was related tomelting of glacial ice in the Northwest China and the temperate-wet condition wasinfluenced by monsoon change in Northeast China. About 10.0-7.0kaB.P. and5. 0 - 3.0kaB. P., westerlies prevailed in these areas during the arid period.About 7.0 - 5.0 kaB.P., the boundary of the eastern monsoon winds reached to thenorthwest region. During 2. 5 - 1.0kaB. P., monsoon winds prevailed in thenorthwest region two times, during which precipitation increased slightly.