Vegetation and climate changes around the Lama Lake, Taymyr Peninsula, Russia during the Late Pleistocene and Holocene

摘要

A continuous lacustrine sequence from the western part of Lama Lake (69°32′N, 90° 12′ E), complemented by a peat sequence from the lake catchment provides the first detailed environmental reconstruction for the Late Glacial and Holocene on the Taymyr Peninsula. Scarce steppe-like communities with Artemisia, Poaceae, and Cyperaceae dominated during the Late Glacial. Tundra-like communities with Betula nana, Dryas, and Salix grew on more mesic sites. There are distinct climatic signals, which may be correlated with the Bolling and Allerod warming and Middle and Younger Dryas cooling. The Late Glacial/Preboreal transition, at about 10,000 ~(14)C yr BP, was characterized by changes from predominantly open herb communities to shrub tundra ones. Larch forest might have been established as early as 9700-9600 ~(14)C yr BP, whilst shrub alder came to the area ca 9500-9400 ~(14)C yr BP, and spruce did not reach area before ca 9200 ~(14)C yr BP. Spruce-larch forests with shrub alder and tree birch dominated the vegetation around the Lama Lake from ca 9000 ~(14)C yr BP. Dwarf birch communities were also broadly distributed. The role of spruce in the forest gradually decreased after 4500 ~(14)C yr BP. The vegetation cover in the Lama Lake area became similar to the modern larch-spruce forest ca 2500 ~(14)C yr BP. A pollen-based biome reconstruction supports a quantitative interpretation of the pollen spectra. Climate reconstructions obtained with information-statistical and plan-functional-type methods show very similar trends in reconstructed July temperature since ca 12,300 ~(14)C yr BP, while precipitation anomalies are less coherent, especially during the Late Glacial-Holocene transition.