ISSN 1067-4136, Russian Journal of Ecology, 2019, Vol. 50, No. 4, pp. 311–322. © Pleiades Publishing, Ltd., 2019. Russian Text © The Author(s), 2019, published in Ekologiya, 2019, No. 4, pp. 243–254. Structure and Dynamics of Tree Stands at the Upper Timberline in the Western Part of the Putorana Plateau A. A. Grigor’eva, *, N. M. Devia, V. V. Kukarskikha, S. O. V’yukhina, b, A. A. Galimovaa, P. A. Moiseeva, and V. V. Fomina, b aInstitute of Plant and Animal Ecology, Ural Branch, Russian Academy of Sciences, Yekaterinburg, 620144 Russia bUral State Forestry Engineering University, Yekaterinburg, 620100 Russia *e-mail:
[email protected] Received October 10, 2018; revised November 12, 2018; accepted November 30, 2018 Abstract—Analysis of the age structure of Dahurian larch (Larix gmelinii Rupr.) forests in the western part of the Putorana Plateau (Sukhie Gory Range) and comparison of diachronous topographic maps and satellite images have revealed changes in the altitudinal position of the upper boundary of tree vegetation. The most significant changes occurred on south- and southwest-facing slopes. Correlations of trunk diameters with the phytomass of trees and its fractions have been found. The course of changes in the structure and phytomass of tree stands in the upper timberline over the past centuries has been reconstructed. Forest expansion has been facilitated by the general change in climate conditions (warming) in the study area. Keywords: Dahurian larch, upper timberline ecotone, phytomass of trees and stands, climate changes, Puto- rana, Subarctic DOI: 10.1134/S1067413619040076 The determination and quantitative assessment of thaws earlier, which results in an increased duration of the transformation and biological productivity of the growing season [8, 9].