Late Quaternary vegetation and lake system dynamics in north-eastern Siberia: Implications for seasonal climate variability
Late Quaternary vegetation and lake system dynamics in north-eastern Siberia: Implications for seasonal climate variability
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DOI：
10.1016/j.quascirev.2015.08.014
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发表时间：
2016-09-01
影响因子：
4
通讯作者：
Diekmann, B.
中科院分区：
文献类型：
--
作者：
Biskaborn, B. K.;Subetto, D. A.;Diekmann, B.
虽然北方半球全新世的气候发展是众所周知的，但古湖泊气候重建揭示了北方欧亚大陆的时空变化。在这里，我们提出了一个多代理研究东北西伯利亚相结合的沉积物地球化学，硅藻和花粉的数据，从湖泊沉积物岩心覆盖了过去的38,000 cal.年。我们的研究结果表明，黄铁矿含量和fragilarioid硅藻物种分布的重大变化，表明延长的季节性湖泊冰盖之间的相似13,500和相似8900 cal.年BP和可能在8200 cal.年BP冷事件。一个基于花粉的气候重建产生的平均7月温度为17.8摄氏度在全新世热最高（HTM）之间类似于8900和类似于4500卡尔。舟形硅藻出现在全新世晚期，表明季节性冰盖的缩短一直持续到今天。我们的研究结果揭示了一个很强的相关性之间的应用陆地和水生指标和自然的季节性气候动态在全新世。浮游硅藻表现出强烈的响应湖泊生态系统的变化，由于最近的气候变暖在Anthropocene.We评估其他古湖沼学的研究，推断时空格局的HTM和确认，其发病的时间，从北到南的差异高达3000年，可以很好地解释气候遥相关。西风带将冷空气带到西伯利亚的这一地区，直到7000年前劳伦泰德冰盖消失。在西伯利亚中部记录的HTM的明显延迟结束可以归因于生态阈值落后于冬季温度的增加和减少对比度的季节之间的日照在全新世中期至晚期，以及缺乏夏季和冬季之间的分化趋势在古湖泊重建。(C)2015爱思唯尔有限公司版权所有。
Although the climate development over the Holocene in the Northern Hemisphere is well known, palaeolimnological climate reconstructions reveal spatiotemporal variability in northern Eurasia. Here we present a multi-proxy study from north-eastern Siberia combining sediment geochemistry, and diatom and pollen data from lake-sediment cores covering the last 38,000 cal. years. Our results show major changes in pyrite content and fragilarioid diatom species distributions, indicating prolonged seasonal lake-ice cover between similar to 13,500 and similar to 8900 cal. years BP and possibly during the 8200 cal. years BP cold event. A pollen-based climate reconstruction generated a mean July temperature of 17.8 degrees C during the Holocene Thermal Maximum (HTM) between similar to 8900 and similar to 4500 cal. years BP. Naviculoid diatoms appear in the late Holocene indicating a shortening of the seasonal ice cover that continues today. Our results reveal a strong correlation between the applied terrestrial and aquatic indicators and natural seasonal climate dynamics in the Holocene. Planktonic diatoms show a strong response to changes in the lake ecosystem due to recent climate warming in the Anthropocene.We assess other palaeolimnological studies to infer the spatiotemporal pattern of the HTM and affirm that the timing of its onset, a difference of up to 3000 years from north to south, can be well explained by climatic teleconnections. The westerlies brought cold air to this part of Siberia until the Laurentide ice sheet vanished 7000 years ago. The apparent delayed ending of the HTM in the central Siberian record can be ascribed to the exceedance of ecological thresholds trailing behind increases in winter temperatures and decreases in contrast in insolation between seasons during the mid to late Holocene as well as lacking differentiation between summer and winter trends in paleolimnological reconstructions. (C) 2015 Elsevier Ltd. All rights reserved.