Dynamics of radial growth of siberian pine <i>Pinus sibirica </i>Du Tuor in focus of invasion of four-eyed fir bark beetle <i>Polygraphus proximus </i>Blandf
In the 21st century cases of invasions of dendrophilous insects in boreal forests increased sharply. A example of these processes is invasion of four-eyed fir bark beetle Polygraphus proximus Blandf. in forests with siberian fir Abies sibirica Ledeb. in territory of Siberia. The aim of the research was to study dynamics of radial growth of siberian pine trees in damaged stands. The Larinsky landscape reserve was chosen as model territory. A series of permanent trial plots (PTP) for monitoring the transformation of forest ecosystems was laid on its territory. As a result of invader impact, stands dominated by fir were most affected. They significantly reduced completeness and dominance passed to siberian pine. In stands with a predominance of siberian pine and spruce, changes also occurred in structure. However, species changes did not occur. For entire life period of siberian pine trees, radial growth was at PTP 1 - 2,3±0,1 mm, for PTP 2 - 2,1±0,1 mm, for PTP 3 - 2,5±0,1 mm, for PTP 4 - 1,6±0,1 mm. There were no significant differences ( p = 0,9357 > 0,05). Immediately before the invasion, a slight decrease in tree growth in thickness was noted, in particular, for PTP 1, it was 2,2±0,1 mm, for PTP 2 - 1,1±0,1 mm, for PTP 3 - 2,1±0,1 mm, for PTP 4 - 0,9±0,1 mm. Thus, radial growth increased, but a significant difference was established only for PTP 1 ( p = 0,0292 < 0,05), which is characterized by a completely degraded state.