Late glacial and Holocene vegetation and regional climate variability evidenced in high-resolution pollen records from Lake Baikal
Late glacial and Holocene vegetation and regional climate variability evidenced in high-resolution pollen records from Lake Baikal
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DOI：
10.1016/j.gloplacha.2004.09.020
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发表时间：
2005-04-01
影响因子：
3.9
通讯作者：
Oberhänsli, H
中科院分区：
文献类型：
--
作者：
Demske, D;Heumann, G;Oberhänsli, H
高分辨率的花粉记录从贝加尔湖揭示了相当大的区域差异的植被发展和显着的气候变率在末次冰期-间冰期过渡和全新世。岩芯之间的相关性成功地建立在AMS C-14测年花粉浓缩物的年代学基础上。与贝加尔湖地区的其他放射性碳年代测定的花粉序列相比，所提供的年代学是非常可靠的，因此可以很容易地与其他年代测定的事件进行相关。花粉指数反映了主要植被类型的相对变化以及水分供应和温度对生长条件的限制，表明植被变化几乎是同步的，这表明整个贝加尔湖地区的大规模气候变化是同步的。由于贝加尔湖地区人类活动的影响有限，花粉数据表明，在欧亚大陆东北部全新世的大陆内部，气候变率非常明显。在最初的变暖和相对湿度的强烈增加（约。16 cal ka BP），Bolling-Allerod类事件被三个凉爽干燥的事件打断。这些事件，日期之间CA。15和13 cal ka BP，可以与格陵兰冰芯GISP 2氧同位素记录中记录的冷却进行比较。白桦组的扩展。纳纳尔Fruticosae，蒿和藜科标志着新仙女木（YD）一样的冷却事件（约。全新世早期的高温和有利的水分条件有利于暗针叶针叶林针叶林的最佳发育时期，南部为11- 7.5calkaBP，东北部为10-8 calkaBP。在南方山区的冷杉和云杉下降（约。9.5-8.5 cal ka BP）可能与8.2 cal ka BP冷却事件有关。中全新世的显著冷却事件和向干燥条件的过渡（约。8-7苏格兰松森林的最大分布标志着全新世的最佳温度（约ka BP）。6.5-5.7 cal ka BP），随后是两次随后的冷却事件（约。5.5-4.5 cal ka BP）。随后贝加尔湖东南部地区的温度最佳值在亚寒带-亚大西洋过渡期间（约100摄氏度）以明显的冷却结束。3-2.5 cal ka BP）。灌木桤木的晚期蔓延可能是小冰河期开始的证据。(C)2004 Elsevier B. V.保留所有权利。
High-resolution pollen records from Lake Baikal revealed considerable regional differences in the vegetation development and pronounced climate variability during the last glacial-interglacial transition and Holocene. Correlation between cores was successfully based on a chronology constructed from AMS C-14 dating of pollen concentrates. Comparison to other radiocarbon-dated pollen sequences from the Baikal region suggests that the chronology presented is very reliable, and thus correlation to other dated events can easily be performed. Pollen indices, which reflect relative changes in major vegetation types and limitations of growing conditions by moisture availability and temperature, demonstrate near-synchronous vegetation changes, which suggest synchronous large-scale climate variation across the Baikal region. Due to the limited influence of human impact in the Lake Baikal region, the pollen data illustrate that, in the continental interior of NE Eurasia Holocene, climate variability was very pronounced. After initial warming and a strong increase in relative moisture (ca. 16 cal ka BP), the Bolling-Allerod-like event was punctuated by three cool and dry events. These events, dated between ca. 15 and 13 cal ka BP, can be compared to coolings as recorded in GISP 2 oxygen isotope records from Greenland ice cores. An expansion of Betula sect. Nanael Fruticosae, Artemisia and Chenopodiaceae marks the Younger-Dryas (YD)-like cooling event (ca. 12.5-12 cal ka BP).High temperatures and favourable moisture conditions during the first part of Holocene favoured the optimum development of dark coniferous taiga between 11-7.5 cal ka BP in the south and 10-8 cal ka BP in the northeast. A fir and spruce decline in the southern mountains (ca. 9.5-8.5 cal ka BP) can be related to the 8.2 cal ka BP cooling event. The pronounced mid-Holocene cooling event and a transition towards dry conditions (ca. 8-7 cal ka BP) preceded the nearly synchronous regional expansion of pine taiga.Maximum distribution of Scots pine forests marks the Holocene thermal optimum (ca. 6.5-5.7 cal ka BP), which was followed by two subsequent cooling events (ca. 5.5-4.5 cal ka BP) at the Atlantic-Subboreal transition. A subsequent temperature optimum in the southeastern Baikal region ended with pronounced cooling during the Subboreal-Subatlantic transition (ca. 3-2.5 cal ka BP). A late spread of shrub alders may evidence the beginning of the Little Ice Age. (C) 2004 Elsevier B.V. All rights reserved.