The Condition of Siberian Stone Pine Forests on the Southern Border of Western Siberia Range

Destructive processes are taking place in boreal forests all over the planet, driven and catalyzed by climate change and the subsequent impact of forest pests. In Siberia, this pattern is most pronounced in Siberian stone pine forests on the southern border of the taiga zone. Taking into account the social significance of the village Siberian stone pine forests, the aim of the study has been to assess the condition of the forest cover of the Luchanovo-Ipatovsky Siberian stone pine forest in the Tomsk Region. In 2016–2017, there were 2 foci of the Siberian moth on its territory, and subsequently, stem pests have actively multiplied. A complete ground survey has been carried out on the lands of the forest area and a visual assessment of the sanitary condition of Siberian Stone pine (Pinus sibirica Du Tour) trees has been given. 21 sample plots have been laid, 45 samples of wood cores have been taken proportionally from living, shrinking and dead trees. Also, the interpretation of satellite images of the Luchanovo-Ipatovsky Siberian stone pine forest for the period from 2015 to 2023 has been carried out. It has been established that 75 % of the forest area under study is occupied by Siberian stone pine stands. The provision of undergrowth for preliminary generations is unsatisfactory. Statistical analysis has shown that stem pests have damaged trees of different generations and different diameters (p = 0.09 > 0.05 and p = 0.30 > 0.05, respectively). The course of growth with the age trend removed in groups of trees of different conditions has revealed the absence of a reliable difference in radial increment before the mass reproduction of the Siberian moth (p = 0.06 > 0.05), but it has appeared after the population outbreak (p = 0.04 < 0.05). It was the trees weakened by the Siberian moths that have been attacked by stem pests. According to our data, the total area of 2 isolated foci of the Siberian moth reproduction has been 34 ha (10 % of the total area of Siberian stone pine stands). It was in these foci that the mass reproduction of stem pests has occurred. An assessment of the disturbed areas has shown that their size is approximately 235 ha, or 70 % of the territory of Siberian stone stands. Ground-based studies have confirmed the results of space imagery interpretation, and in the medium term, a decrease in the forest-forming role of Siberian stone pine in this forest area is expected, up to the complete destruction of pure-composition stands and the ones with significant participation of Siberian stone pine in 1/2 of the current area of these stands.