Vegetation and climate history in the Laptev Sea region (Arctic Siberia) during Late Quaternary inferred from pollen records
Vegetation and climate history in the Laptev Sea region (Arctic Siberia) during Late Quaternary inferred from pollen records
复制标题
DOI：
10.1016/j.quascirev.2010.12.026
复制
发表时间：
2011-08-01
影响因子：
4
通讯作者：
Hubberten, Hans-Wolfgang
中科院分区：
文献类型：
--
作者：
Andreev, Andrei A.;Schirrmeister, Lutz;Hubberten, Hans-Wolfgang
通过多种方法（C-14-AMS、TL、IRSL、OSL 和 Th-230/U）对拉普捷夫海地区许多永久冻土层和湖相岩芯的古环境记录进行了花粉和孢粉形态分析。这些记录揭示了过去约 200 公里的环境历史。对于间冰期花粉光谱，使用最好的现代模拟方法估计了定量温度值。稀疏的草莎植被表明北极沙漠环境条件在 200 年前就已存在。大约200-190 kyr前的间质期，茂密、潮湿的草莎苔原栖息地占主导地位，反映出夏季比以前更加温暖和湿润。稀疏的植被群落表明大约 190-130 年前的场地条件要严重得多。末次间冰期开始时，在更受保护和更潮湿的地方，有灌木林（赤杨、柳、桦）的开阔草地和蒿属群落表明气候条件与现在相似。灌木苔原（Alnus fruticosa 和 Betula nana）在峨眉纪中期气候最适宜时期占主导地位，当时夏季气温比今天高 4-5 摄氏度。早期威克塞尔期以稀疏的草莎草为主的植被表明气候条件比之前的时期更冷和干燥。中威克塞尔期间记录表明气候条件更加潮湿和温暖，例如，在 40-32 kyr BP 的时间间隔内，柳树存在于茂密的、以莎草为主的植被中。莎草-草-蒿群落表明，在距今 30 公里之后，气候变得凉爽干燥，而寒冷、干燥的条件是魏氏晚期（距今 26-16 公里）的特征，当时存在以石竹科、菊科、菊苣科、卷柏为主的草类群落。距今 16 至 12 kyr，石竹科、菊科和菊苣科的草莎草群落表明，气候比前一时期明显温暖和湿润。柳树和桦木的存在反映出阿勒罗德间隔期间的温度比大约 12-11 kyr BP 时的温度高出约 4 摄氏度，但新仙女木间隔期间没有灌木，表明气候条件恶化。赤杨、桦木、禾本科和莎草科在早期全新世光谱中占主导地位。重建的绝对温度值比现在高得多（高达 12 摄氏度）。距今7.6 kyr之后，灌木逐渐从沿海地区消失，此时植被覆盖变得与现代相似。基于代理的古环境重建与中等复杂性地球系统模型（CLIMBER-2）进行的模拟的比较表明，区域古数据和模型模拟之间具有良好的一致性，特别是在较温暖的时期。 (C) 2011 Elsevier Ltd. 保留所有权利。
Paleoenvironmental records from a number of permafrost sections and lacustrine cores from the Laptev Sea region dated by several methods (C-14-AMS, TL, IRSL, OSL and Th-230/U) were analyzed for pollen and palynomorphs. The records reveal the environmental history for the last ca 200 kyr. For interglacial pollen spectra, quantitative temperature values were estimated using the best modern analogue method. Sparse grass-sedge vegetation indicating arctic desert environmental conditions existed prior to 200 kyr ago. Dense, wet grass-sedge tundra habitats dominated during an interstadial ca 200-190 kyr ago, reflecting warmer and wetter summers than before. Sparser vegetation communities point to much more severe stadial conditions ca 190-130 kyr ago. Open grass and Artemisia communities with shrub stands (Alnus fruticosa, Salix, Betula nana) in more protected and moister places characterized the beginning of the Last Interglacial indicate climate conditions similar to present. Shrub tundra (Alnus fruticosa and Betula nana) dominated during the middle Eemian climatic optimum, when summer temperatures were 4-5 degrees C higher than today. Early-Weichselian sparse grass-sedge dominated vegetation indicates climate conditions colder and dryer than in the previous interval. Middle Weichselian Interstadial records indicate moister and warmer climate conditions, for example, in the interval 40-32 kyr BP Salix was present within dense, grass-sedge dominated vegetation. Sedge-grass-Artemisia-communities indicate that climate became cooler and drier after 30 kyr BP, and cold, dry conditions characterized the Late Weichselian, ca 26-16 kyr BP, when grass-dominated communities with Caryophyllaceae, Asteraceae, Cichoriaceae, Selaginella rupestris were present. From 16 to 12 kyr BP, grass-sedge communities with Caryophyllaceae, Asteraceae, and Cichoriaceae indicate climate was significantly warmer and moister than during the previous interval. The presence of Salix and Betula reflect temperatures about 4 degrees C higher than present at about 12-11 kyr BP, during the Allerod interval, but shrubs were absent in the Younger Dryas interval, pointing to a deterioration of climate conditions. Alnus fruticosa, Betula nana, Poaceae, and Cyperaceae dominate early Holocene spectra. Reconstructed absolute temperature values were substantially warmer than present (up to 12 degrees C). Shrubs gradually disappeared from coastal areas after 7.6 kyr BP when vegetation cover became similar to modern. A comparison of proxy-based paleoenvironmental reconstructions with the simulations performed by an Earth system model of intermediate complexity (CLIMBER-2) show good accordance between the regional paleodata and model simulations, especially for the warmer intervals. (C) 2011 Elsevier Ltd. All rights reserved.