Earth`s Cryosphere, 2019, Vol. XXIII, № 2, p. 53-60
LANDSCAPE AND CLIMATIC FACTORS IMPACTING THE THAW DEPTH IN SOILS OF PERMAFROST PEAT PLATEAUS (ON THE EXAMPLE OF CALM R52 SITE)
D.A. Kaverin1, A.V. Pastukhov1, A.B. Novakovsky1, K. Biasi2, M. Marushchak2, V.V. Elsakov1
1Institute of Biology, Komi Science Center UB RAS,
28, Kommunisticheskaya str., Syktyvkar, 167982, Russia; dkav@mail.ru
2University of Eastern Finland, P/O box 1627, FI-70211, Kuopio, Finland
The data obtained during the five-year (2013–2017) active layer monitoring in soils of permafrost peat plateau at the Circumpolar Active Layer Monitoring site R52 (Seida) in the European Northeast of Russia (the Usa River basin) are presented. Analysis of the impact of landscape and climatic factors allowed to estimate spatial-temporal differentiation of the active layer thickness. The spatial heterogeneity of seasonal thaw depth is governed by the topography of the peatland site dominated by drained peat mounds covered with shrubby moss vegetation and bare peat circles, with fens occupying a small area only. Relative elevation and surface soil moisture are found to be major factors affecting the active layer thickness within peat mounds covered with shrubby moss vegetation. In the bare peat circles, snow depth and microtopography exert a primary control on thaw depth. The active layer thickness dynamics during the research period was characterized by a positive trend. The air-freezing index (frost number) is interpreted as the most effective climatic parameter for estimation of inter annual dynamics of the active layer depth in peat soils.
Peat plateaus, peat soils, active layer, permafrost, landscape and climatic factors