Determination of Damage to Forest Ecosystems DISTURBED by Siberian Silk Moth

It is accepted that the amount of damage is equal to the difference in the value of the stands before and after the external impact. Hence, the task of determining damage comes down to identifying the cost of the stands. It is shown that the cost can be represented as the sum of the ecosystem (ecological and resource) functions of the stands. The calculation is performed relative to a specific function, the cost of which is known. As such a function, a wood resource was used, which, in the form of a tax rate of payment, is balanced by location, tree species, marketability classes and is widely used as a standard indicator in setting fees for forest use. The sequence of damage calculations is demonstrated using the example of the southern taiga forests of the Yenisei, Nizhne-Yenisei, and North Yenisei forest districts of Krasnoyarsk Krai. There was an outbreak of Siberian silkworm ( Dendrolimus sibiricus Tschetverikov) here between 2016 and 2018. The area with varying degrees of damage to stands amounted to 803,983 hectares. The total area of forest inventory units where tree stand death was recorded is 2,034,665 hectares. To calculate the damage, mass forest survey materials were used as initial data. Descriptions of forest inventory units were analyzed separately for protective, operational and reserve forests. Calculations were made based on the predominant tree species. The cost of protective forests turned out to be more than operational ones, and the cost of ecosystem functions of the stands turned out to be an order of magnitude higher than the tax value of the wood resource. The total cost of stands before the Siberian silkworm outbreak was determined to be 70,275.2 million rubles, after the outbreak - 52,249.8 million rubles. The total damage to forests amounted to 18,025.5 million rubles - 25.7 % of the cost of stands before the Siberian silkworm outbreak.