The process of forest death covers the entire boreal zone of the Northern Hemisphere. Due to the deterioration of the sanitary condition of forest areas, harmful organisms are becoming more active, where the most dangerous pest is Ips typographus. The aim of the work was to study the chemical structure of spruce wood in samples of various living conditions in the zones of active reproduction of bark beetles.The research studies the biochemical composition of Píceao bovata wood within the places of Ips typographus development (bythe example of the Udmurt Republic). The research was carried out within the European part of the Russian Federation, the Udmurt Republic region. The republic area is 42 thousand km2. A total of 15 sample plots were laid out and more than 8,000 trees were analyzed. It was revealed that in the subtaiga zone, the processes of death of spruce stands are observed.

The process of forest destruction is very dynamic and covers the entire boreal zone of the Northern hemisphere. Against the background of deterioration of the sanitary condition of plantings, pathogenic organisms become more active. The article presents materials on the study of the chemical composition of wood of individuals of various life conditions of Siberian spruce (Pícea obovata Ledeb.) in the conditions of distribution of bark beetle (Ips typographus L.). Plants of various life States were studied for the content of water-soluble and resin-like extractives, tannins, lignin, and polysaccharides. The obtained data were subjected to statistical processing. Under the influence of the bark beetle-typographer, no significant differences were found between individuals of different life States in the polymer structural components of spruce wood (lignin and polysaccharides). In the course of the study, it was noted that during the colonization of bark beetles in plants, the content of extractive substances increases. With deterioration, the proportion of phenolic compounds begins to increase from 25.8% in plants of good condition to 37.5% in plants of unsatisfactory condition, with a decrease in the proportion of resinous substances. An increase in phenolic compounds is associated with an increase in tannins. The highest content of all groups of metabolites (including tannins) was observed in individuals of a satisfactory life state and is 7.15% of the a.s.s.

The article presents materials on the prospects of processing wood waste into high-strength structural cellulose material using alkaline processing of raw materials followed by hot pressing. Materials on the study of the cellulose-lignin complex and non-structural components of wood on the example of coniferous plants of various life conditions, including dead wood, are presented. Differences in the content of extractive substances (non-structural components) in individuals of different living conditions, which have a significant impact on the chemical treatment of wood, were revealed. The possibility of using white rotting wood-destroying fungi for partial delignification of wood is considered. The study was carried out with the financial support of the RFBR grant No. 19-04-00353 A.

Background. A significant deterioration in the state of dark coniferous forests, which in some cases is accompanied by their drying, has manifested itself throughout the Northern Hemisphere. This process is very dynamic and covers the entire boreal zone from Europe to the North American continent, covering all forest-forming species Research in the field of the ecological biochemistry of wood opens up wide possibilities for studying the stability of spruce stands. Coniferous wood, including spruce, consists of polymer structural components (cellulose, hemicellulose and lignin) and non-structural components (including extractives, ash and other minor substances). Extractives with high biological activity, which are produced as protective compounds during the life of plants from external environmental stresses, play an important protective function in coniferous wood. The structure of wood and its biochemical composition can change under various influences. The content of extractives varies greatly not only in different areas, but also from specimen to specimen, depending on their condition. In this regard, the aim of our research was to study the content of extractives in spruce wood in specimens of different life states.Methods. This work presents the results of studies on the characteristics of the biochemical composition of Siberian spruce (Pícea obovata L.) in mass drying conditions in the territory of the Udmurt Republic (Russia). The enumeration method was used to create a plot taxation. A study of the biochemical composition of wood was carried out based on the content of extractives from specimens in various life states. Results. Trial plot stands are characterized by low tree density in the main canopy. According to biochemical analysis, the highest content of extractives was observed in specimens with good and satisfactory vitality. In trees with an unsatisfactory life state, biochemical parameters were low, which is associated with the lack of self-regulation in dead wood. Conclusions. Obviously, the substances under study play a large role in the adaptive reactions of Pícea obovata, and the increase in their production is a response to negative environmental factors.