Bark Beetle Outbreaks as a Factor of Dark Coniferous Forests Degradation

Causes and process of spruce forests weakening and dieback are provided. According to state forest pathological monitoring, indicators of bark beetle (Ips typographus L.) focispread in 18 regions of European Russia for 2002–2023 are calculated. The most large-scale old spruce forests drying is analyzed on the North Dvina and Pinega rivers watershed in the early 21st century. A long-term (1970–2023) dynamics of the precipitation amount and air temperature were assessed, hydrothermal indicators change and bark beetle foci areas in the Arkhangelsk region in 2002–2011 were analyzed. The quantitative indicators’ values are obtained that distinguish the conditions for bark beetle population turning to outbreak state and forming chronic foci in vast territory.