Effect of origin conditions on the anatomical structure of the annual ring of Pinus sylvestris L. in the taiga zone

The studies were conducted in South Karelia (middle taiga subzone) in 2006. Objects of study were the following kinds of pine forest: bilberry, cowberry and wild rosemary-bog moss ones. The investigation has shown that with the advancement of the tree in the forest canopy the annual growth ring of the trunk increases significantly. Thus, in the bilberry pine forest in the trees of the growth class I this index is higher than in the trees of the growth classes II-III and IV-V by 4 and 97 %, respectively. In the bilberry pine forest the percentage of the participation of late wood in the formation of growth ring in the dominant trees is by 6-9% less than that of the rest of the stand. The width of the early tracheid shells in the trees of the growth class I-III is by 22% more than in the overtopped ones in the bilberry pine forest. Annual ring width and latewood percentage in the pine forest of Hylocomium group is higher than in the wild rosemary – bog moss one by 41-50 and 7-35%, respectively. The maximal thickness of the late tracheid shells was observed in the cowberry pine forest (6.8-7.4 microns).