Pollen assemblages of modern soil samples and results of the pollen analysis of the PG1755 core from Lake Billyakh, Yakutia, Russia

• Main Authors: Müller, Stefanie, Tarasov, Pavel E, Andreev, Andrei A, Tütken, Thomas, Gartz, Steffi, Diekmann, Bernhard
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2015
• Subjects: AWI_PerDyn; Permafrost Research (Periglacial Dynamics) @ AWI; permafrost; taiga; Tundra; Yakutia
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.849667; https://doi.org/10.1594/PANGAEA.849667

Here we present a detailed radiocarbon-dated 936 cm long pollen record from Lake Billyakh (65°17' N, 126°47' E; 340 m a.s.l.) situated in the western part of the Verkhoyansk Mountains, about 140 km south of the Arctic Circle. A set of 53 surface pollen samples representing tundra, cold deciduous forest and taiga was collected in northern and central Yakutia communities to verify the accuracy of the quantitative biome reconstruction method and to obtain a more precise attribution of the identified pollen taxa to the main regional biomes. The adjusted method is then applied to the pollen record from Lake Billyakh to gain a reconstruction of vegetation and environments since about 50.7 kyr BP. The results of the pollen analysis and pollen-based biome reconstruction suggest that herbaceous tundra and steppe communities dominated the area from 50.7 to 13.5 kyr BP. Relatively low pollen concentrations and high percentages of herbaceous pollen taxa (mainly Cyperaceae, Poaceae and Artemisia) likely indicate a reduced vegetation cover and/or lower pollen production. On the other hand, extremely low percentages of drought-tolerant taxa, such as Chenopodiaceae and Ephedra, and the constant presence of various mesophyllous herbaceous (Thalictrum, Rosaceae, Asteraceae) and shrubby taxa (Betula sect. Nanae/Fruticosae, Duschekia fruticosa, Salix) in the pollen assemblages prevent an interpretation of the last glacial environments around Lake Billyakh as extremely arid. The lowest pollen percentages of woody taxa and the highest values of Artemisia pollen attest that the 31-15 kyr BP period as the driest and coldest interval of the entire record. A relative high content of taxa representing shrub tundra communities and the presence of larch pollen recorded prior to 31 kyr and after 13.5 kyr BP likely indicate interstadial climate amelioration associated with the middle and latest parts of the last glacial. An increase in pollen percentages of herbaceous taxa around 12 kyr BP suggests broader distribution of drier communities in ...