Paleolimnological reconstructions of Holocene Environments and Climate from Lake Lyadhej-To, Ural Mountains, Northern Russia

• Main Authors: Cremer, H., Andreev, Andrei, Hubberten, Hans-Wolfgang, Wischer, Frank
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2004
• Subjects: Antarctic and Alpine Research; Arctic; ural mountains
• Online Access: https://epic.awi.de/id/eprint/5993/; https://epic.awi.de/id/eprint/5993/1/Cre2002a.pdf; https://hdl.handle.net/10013/epic.16547; https://hdl.handle.net/10013/epic.16547.d001

A sediment core recovered in Lake Lyadhej-To at the northwestern edge of the Ural Mountains reflects the complete Holocene environmental history from ~11,000 cal. yrs BP. Five limnological episodes are identified in the diatom and geochemical records. The initial lake stage, Episode I (~11,000-10,850 cal. yrs BP), was characterized by the absence of biogenic production and a high influx of clastic sediments. Episode II (~10,850-8650 cal. yrs BP) is characterized by ice-free conditions during summer, highest bioproductivity, strong growth of planktic diatoms and anoxic bottom waters. This period represents the Holocene climatic optimum. Deterioration of climatic conditions commenced in Episode III (~8650-7000 cal. yrs BP) as indicated by distinctly lower bioproductivity and longer persistence of winter ice on the lake. During Episode IV (~7000-2500 cal. yrs BP) the diatom and pollen records indicate that temperatures were cool and the growing season was short. Finally, in Episode V (~2500 cal. yrs BP to present) limnological conditions, indicated by increased organic carbon and diatom deposition, initially suggest improved conditions followed by a return to modern conditions beginning ~500 cal. yrs BP. The pollen stratigraphy from Lake Lyadhej-To is consistent with other paleoclimatic records from northern Eurasia, confirming rapid postglacial warming, the presence of dense tree forests during the climatic optimum and finally a gradual southward retreat of the treeline towards its modern location.