Microbiological and biogeochemical investigations of the microbial driven methane dynamic in the Siberian Arctic during glacial-interglacial climate changes

目前观测到的全球变暖引起的气候变化预计将产生强烈影响，特别是对北极永久冻土环境的影响。永久冻土的融化被认为与温室气体的大量释放有关，特别是甲烷。因此，北极永久冻土区在全球碳循环和地球气候的未来发展中发挥着重要作用。为了了解该系统将如何应对气候变化，不仅要调查碳周转的现状，而且要调查该系统过去如何应对气候变化。因此，在拟议的项目中，微生物驱动的甲烷动力学在西伯利亚东北部的北极湿地在冰川-间冰期气候变化将进行调查。为此，将微生物脂质标志物和核糖体RNA的组合地层分析应用于晚更新世至全新世的冻土和湖泊沉积物。2008年11月至2009年5月，在综合社区发展项目“El'gygytgyn火山口湖科学钻探”的范围内，从El' gygytgyn湖地区采集了永久冻土和湖泊沉积物。El'gygytgyn湖是一个理想的案例研究，因为该地区自陨石撞击以来一直没有冰川。因此，在该地区的沉积物存档几个气候阶段，在其发展过程中，它是预期的气候引起的化学和物理变化的沉积序列的结果在变化的微生物群落伴随着影响甲烷气体通量在过去。所获得的数据将加深我们对气候变化期间微生物群落变化以及这些变化对微生物驱动的甲烷循环的影响的了解。

The currently observed climate change due to global warming is expected to have a strong impact especially on the Arctic permafrost environments. The thawing of permafrost is suggested to be associated with a massive release of greenhouse gases, in particular methane. Thus, Arctic permafrost regions play a fundamental role within the global carbon cycle and the future development of the Earth’s climate. For the understanding how the system will respond to climate changes it is not only important to investigate the current status of carbon turnover but also how the system reacted to climate changes in the past. Therefore, in the proposed project the microbial driven methane dynamic in Arctic wetlands of Northeast Siberia during glacial-interglacial climate changes will be investigated. For this purpose a combined stratigraphic analyses of microbial lipid markers and ribosomal RNA will be applied on permafrost and lake sediments of Late Pleistocene to Holocene age. The permafrost and lake sediments were recovered from the El’gygytgyn Lake region in the scope of the ICDP project “Scientific Drilling at El’gygytgyn Crater Lake” from November 2008 to May 2009. The El’gygytgyn Lake represents an ideal case study because the region was unglaciated since the time of the meteorite impact. Thus, the sediments in this region archive several climatic stages during its development and it is expected that climatically induced chemical and physical changes in the sedimentary sequences results in variations of the microbial communities concomitantly affecting the methane gas fluxes in the past. The acquired data will deepen our knowledge on the variations within the microbial communities during climate changes and the effect of these changes on the microbial driven methane cycling.