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作 者:李月丛[1] 许清海[2] 阳小兰 肖举乐[1] 梁文栋[1] 彭彦嘉[1]
机构地区:[1]中国科学院地质与地球物理研究所,北京100029 [2]河北师范大学资源与环境学院,石家庄050016 [3]河北省地理科学研究所,石家庄050011
出 处:《古地理学报》2004年第3期316-328,共13页Journal of Palaeogeography:Chinese Edition
基 金:国家杰出青年科学基金 (4 992 5 2 0 5 );国家科技部重大基础研究前期研究专项(2 0 0 3CCA0 180 0 );国家自然科学基金(4 0 1710 95 );河北省自然科学基金(4 0 2 615)资助
摘 要:岱海位于半干旱区东部边缘及东亚夏季风的尾闾区 ,生态环境体系脆弱 ,气候和环境变化敏感 ,是研究环境变化的理想地区。 6 5个湖泊表层及入湖河流冲积物样品的孢粉分析揭示了岱海表层孢粉沉积特征及孢粉来源。岱海表层孢粉主要来源于区域性植被的孢粉 ,其总体特征反映了区域植被的组成 ,但不同部位孢粉组合的差异反映了湖滨当地植被的变化。受沉积环境的影响 ,岱海湖区孢粉浓度总体上要低于入湖河流孢粉浓度 ,湖区中部孢粉浓度最高。岱海孢粉以河流携带的为主 ,同时受风力传播的影响。蒿、藜科、桦、虎榛子等花粉和蕨类孢子以河流搬运的为主 ,松、禾本科及莎草科花粉可能还受风力传播的影响。一些仅在个别样品中出现且百分比很低的花粉类型如豆科、十字花科等还有可能是昆虫。The Daihai Lake is located in the east margin of semiarid region and the north margin of the East Asia summer monsoon This region is sensitive to the changes of climate and environment, thus being very suitable for the study of environmental changes The pollen analysis of 65 surface sediment samples from the Daihai Lake and alluvia from its inflow rivers showed the characteristics of modern pollen distribution in the Daihai Lake and different transport vectors for different pollen types Most of the pollen grains in the Daihai Lake came from regional pollen types,and the pollen assemblages coincided with the regional vegetation However the variance of pollen assemblages in different parts of the lake reflected the changes of local vegetation to some extent Affected by the deposition environment,pollen concentration in the lake surface sediment was lower than that in fresh alluvia of its inflow rivers,and the highest pollen concentration appeared in the central part of the lake Most of the pollen grains and spores in the Daihai Lake came from their inflow rivers,while the influence of wind cannot be ignored Insect,bird and human activities also played a role Most pollen grains of Artemisia ,Chenopodiaceae, Betula,Ostryopsis and spores came from their inflow rivers,while Pinus ,Graminaceae and Cyperaceae pollen grains came from both their inflow rivers and the transport of wind Some other herbs,such as Leguminosae,Crucifereae and so on,may be carried into the lake by insect,bird or human activities DCA analysis supported the conclusions
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