RESERVES OF ABOVEGROUND PHYTOMASS AND DEPOSITED CARBON IN SPRUCE TREE STANDS IN THE HIGHLANDS OF THE SOUTHERN URALS
Z. Ya. Nagimov1, A. A. Grigor’ev1,2, D. S. Balakin1,2, A. A. Bartysh1, P. A. Moiseev2, I. V. Shevelina1
1Ural State Forest Engineering University, Yekaterinburg, Russian Federation
2Institute of Plant and Animal Ecology, Russian Academy of Sciences, Ural Branch, Yekaterinburg, Russian Federation
Keywords: climate change, mountain massif Iremel, spruce tree stands, ecotone, tree growth form, aboveground phytomass, carbon reserves
Abstract
It has been established that in the highlands of the Southern Urals, spruce trees are represented by single- and multi-stemmed forms of growth. Over the past two decades, the total number of spruce ( Picea A. Dietr.) trees in the upper tree-line ecotone has increased significantly, which indicates the continued colonization of relatively open spaces of the ecotone with woody vegetation. The nature of the dependence of the mass of the crowns as a whole and the mass of the needles on the diameter of the trunks is determined by the form of tree growth. Therefore, when evaluating these fractions of aboveground phytomass, the corresponding equations should be developed separately for single- and multi-stemmed trees. The form of the growth does not affect the dependence of the mass of trunks on their diameter. The total aboveground phytomass of spruce stands, and, consequently, the reserves of carbon deposited in them, increase significantly as the altitude above sea level decreases. During the period from 2002 to 2024, the aboveground phytomass of sparse tree stands and open forests increased at a higher rate than in the lower closed forest. In particular, it increased 2.2 times in sparse tree stands, 1.9 times in open forests, and only 1.2 times in closed forests. This situation is explained by the continued expansion of arboreal vegetation in the upper tree-line ecotone and the lower age of the stands formed there. The data we have obtained on the reserves of aboveground phytomass of spruce stands and carbon deposited in them can be used to assess and forecast the biosphere role (in particular, the carbon budget) of forests formed in previously treeless territories of highlands as a result of modern climate change.
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