Earth’s Cryosphere, 2017, Vol. XXI, No. 5, p. 3-13
ARCTIC PEATLANDS OF THE YAMAL-GYDAN PROVINCE OF WESTERN SIBERIA
S.M. Fotiev
Earth Cryosphere Institute, Tyumen Scientific Centre SB RAS, P/O box 1230, Tyumen, 625000, Russia; kriozem@gmail.com
Based on the foregoing seminal research works, this paper focuses on peat formation processes proceeded under extreme climatic and permafrost conditions of the northern West Siberia. It has been shown that because of the extreme climatic and permafrost conditions, rather than despite of them, peatlands up to 7.5 m thick reinforced with large ice wedges currently occupy extensive areas in the tundra zone. Vertical growth of peatlands is found to be most intense (at a rate 1.5–4.4 mm/year) in a limited time period from 9 to 6 kyr BP, which suggests that lower horizons of peatlands up to 3.0–4.5 m thick accumulated in just 1500 years’ time. The three reasons that determined the active vertical growth of peatlands have been identified and thoroughly discussed in this research: huge ice content, abundance of wood remains in peatlands, and intense frost heaving during the freezing of a newly formed peat layer. It has been shown that birch stands of high bonitet class grew in the tundra only locally, in the areas underlain by insulation-radiogenic taliks, which proves that in the Holocene, there was no northward shift to 400–500 km of the northern boundary of the forest tundra.
Peat, ice wedges, Arctic peatland, rate of vertical growth of peatlands, insulation-radiogenic talik