Holocene vegetation and hydroclimate changes in the Kansk forest steppe, Yenisei River Basin, East Siberia
Holocene vegetation and hydroclimate changes in the Kansk forest steppe, Yenisei River Basin, East Siberia
复制标题
DOI：
10.1111/bor.12542
复制
发表时间：
2021-08
期刊：
影响因子：
2.2
通讯作者：
A. B. Mikhailova;A. Grenaderova;I. Kurina;L. Shumilovskikh;T. G. Stojko
中科院分区：
文献类型：
--
作者：
A. B. Mikhailova;A. Grenaderova;I. Kurina;L. Shumilovskikh;T. G. Stojko
我们的研究重点是东西伯利亚南部全新世水文气候的长期趋势，并将其置于北部西伯利亚针叶林和南部干旱的中亚相邻地区的背景下。我们提出了一个新的记录，从富营养化的沼泽，在森林草原地区，涵盖了过去9000年。我们的多指标方法包括理化指标（灰分含量、粒度、微木炭、泥炭分解）和生物指标（花粉、非花粉孢粉、植物宏体化石、有壳变形虫、软体动物）。记录表明，在全新世热最大值期间，8150-7400 cal. aBP的湿度增加，以及7400-5100 cal. aBP的火灾证据的干燥条件。其次，根据河流影响的证据，在5100-1400 cal. a BP取芯地点出现了较潮湿的条件，这与更广泛地区的其他记录一致。在1400-1300 cal. a BP发生了短期干旱事件，随后是潮湿的中世纪温暖期（1300-650 cal. a BP）和小冰期（450-300 cal. a BP），以及从300 cal. a BP到现在的适度潮湿环境。这些结果与先前发表的东西伯利亚和西西伯利亚南部草原和森林草原地区的古环境重建结果一致，并共同揭示了一个共同的趋势，即最大湿度在4500至3000 cal. aBP之间。这与更北的针叶林地区和更南的阿尔泰山和哈萨克斯坦山不同，后者显示了全新世从干燥到潮湿然后再到干燥条件的趋势，以及与全新世趋势是干燥条件的跨贝加尔湖地区不同。这项研究支持了全新世北大西洋对东西伯利亚森林草原地区区域古气候变化的主要影响。
Our study focuses on the Holocene hydroclimate long‐term trends in southern East Siberia and places them in the context of the adjacent areas of the Siberian taiga in the north and the arid central Asia in the south. We present a new record from the eutrophic mire, in the forest‐steppe region, covering the last 9000 years. Our multi‐proxy approach includes physiochemical (ash content, grain size, micro‐charcoal, peat decomposition) and biological indicators (pollen, non‐pollen palynomorphs, plant macrofossils, testate amoebae, molluscs). The record indicates increased humidity during the Holocene Thermal Maximum at 8150–7400 cal. a BP, and drier conditions with evidence for fires at 7400–5100 cal. a BP. Next, wetter conditions occurred at the coring site at 5100–1400 cal. a BP based on evidence of fluvial influence, which is consistent with other records in the wider region. A short‐term dry episode occurred at 1400–1300 cal. a BP, followed by a wet Medieval Warm Period (1300–650 cal. a BP) and Little Ice Age (450–300 cal. a BP) and a moderately wet environment from 300 cal. a BP to the present day. These results are consistent with the previously published palaeoenvironmental reconstructions from the steppe and forest‐steppe regions in the south of East and West Siberia and taken together reveal a common trend towards wetter conditions with a maximum wetness between 4500 and 3000 cal. a BP. This differs from the taiga region further north and from the Altai‐Sayan Mountains and Kazakhstan Hills further south, which show the trend from dry to wet and then to drier conditions in the Holocene, and from the Trans‐Baikal region where the Holocene trend is to drier conditions. This study supports the predominant influence of the North Atlantic on the regional palaeoclimate changes in the forest‐steppe region of East Siberia during the Holocene.