YIELD TABLE OF WILLOW STANDS’ PHYTOMASS OF ARKHANGELSK OBLAST

In Russia, the intensive growth of areas naturally overgrown with such species as willow ( Salix L.), alder ( Alnus Mill.), pine ( Pinus L.), etc., increases the biodiversity of entire regions, but the contribution of these areas to the carbon balance and climate stabilization is mostly unknown. Especially critical in this regard is the situation with willow plantations, which was not included in the system of State accounting of the forest fund. Since the energy generated from willow plantations is CO₂ neutral, the use of this renewable and sustainable energy source has the potential to reduce global CO₂ emissions from fossil fuels. Willow phytomass can be used for the production of fuel in the form of chips, briquettes and pellets, and in some cases - for the production of bioethanol or wood gas. In addition to economic aspects, willow cultivation has a number of environmental advantages, such as the ability to accumulate toxins from polluted areas, improve landscaping and serve as hedges. To plan and manage forestry in willow plantations in the conditions of the North taiga subzone of Arkhangelsk Oblast and assess its contribution to the carbon balance, data on the biological productivity of willow trees and standards for assessing their phytomass are needed. The purpose of the study is to develop models and tables for assessing the structure and dynamics of the aboveground phytomass of the willow stands in the conditions of Arkhangelsk Oblast. To achieve it, the following tasks have been implemented: 52 sample plots have been established to assess aboveground phytomass of willows; regression models of the dependence of willow phytomass on the volume-forming inventory indicators of trees are constructed; the models obtained are combined with the yield table of willow stands and the table of age dynamics of willow phytomass is constructed according to site indices for the conditions of Arkhangelsk Oblast. A comparative analysis of the results obtained with data on the productivity of willows in Sweden showed that at the same age of stands, the stocks of aboveground phytomass of Swedish willow correspond to the stocks of phytomass of willows of Arkhangelsk Oblast at an average level between the I and II site productivity classes.