A new record of Holocene climate change from the bottom sediments of Lake Baikal
A new record of Holocene climate change from the bottom sediments of Lake Baikal
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DOI：
10.1016/s0031-0182(99)00141-8
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发表时间：
2000-03
期刊：
影响因子：
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通讯作者：
E. Karabanov;A. Prokopenko;D. Williams;G. Khursevich
中科院分区：
文献类型：
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作者：
E. Karabanov;A. Prokopenko;D. Williams;G. Khursevich
从贝加尔湖沉积物中获得了BDP-93-2钻孔中分辨率约为30- 120年的硅质微体化石记录（硅藻和金藻孢囊），以测试贝加尔湖系统对全新世期间微小气候变化的敏感性。我们的新结果表明，亚寒带时期的特点是最高的积累硅藻硅藻壳和金藻孢囊在贝加尔湖沉积物。硅质微体化石记录表明，亚洲内陆地区全新世气候最佳期对应于亚寒带期2.5-4.5ka，而不是大西洋期4.6- 6 ka。虽然与欧亚大陆欧洲部分的全新世重建有很大不同，但贝加尔湖的全新世沉积记录与西伯利亚东南部和蒙古的孢粉学和土壤气候记录具有良好的相关性，这些记录也记录了陆地生物圈的类似反应。一个独特的针杆藻属硅藻物种，符合最大的金藻孢囊积累在亚寒带时期，认为贝加尔湖的营养状态可能短期的变化，从贫营养，冷水硅藻组合，富营养化与嗜热的单种硅藻植物群。硅藻和孢囊响应的比较提供了一个关键，区分湿度和温度响应在未来的研究中的高分辨率记录贝加尔湖。
Detailed siliceous microfossil records (diatoms and chrysophyte cysts) from the BDP-93-2 borehole with resolution of ca 30–120years were obtained from Lake Baikal sediments to test the sensitivity of the Lake Baikal system to minor climate changes during the Holocene. Our new results demonstrate that the Subboreal period is characterized by the highest accumulations of diatom frustules and chrysophyte cysts in Lake Baikal sediments. The siliceous microfossil record suggests that the Holocene climatic optimum in this interior part of Asia corresponds to the Subboreal period 2.5–4.5ka and not to the Atlantic period 4.6–6ka. Although quite different from Holocene reconstructions for the European part of Eurasia, the Holocene sedimentary record from Lake Baikal shows good correlation with palynological and soil climatic records from southeast Siberia and Mongolia where similar responses of the terrestrial biosphere are also documented. A distinctive monospecific lamina of Synedra acus diatom species, coincident with the maximum of chrysophyte cyst accumulation during the Subboreal period, argues for the possible short-term changes of the trophic state of Lake Baikal from oligotrophic, with a cold-water diatom assemblage, to eutrophic with a thermophilic monospecific diatom flora. Comparison of diatom and cyst responses provides a key to distinguishing the humidity from temperature response in future studies of high-resolution records of Lake Baikal.