Особенности строения и структуры коренного разновозрастного ельника в национальном парке «Водлозерский»

The structure of the indigenous spruce stand in the Vodlozersky National Park has been studied. It has been shown that with the long-term natural development of spruce forests in the blueberry type forest growth conditions, absolutely uneven-aged, medium-density, stable stands are formed. The distribution of trees by age classes in the studied community is characterized by the greatest representation of spruce trees 60–80 and 220–240 years old. The analysis of the wood samples has revealed that 18 % of the trees (30 % of the stock) have been affected by wood-destroying fungi. At the same time, the number of affected trees increases with age. Natural regeneration of spruce is 92 % (8.92 thousand pcs/ha) represented by viable specimens and is characterized by a relatively uniform spatial distribution. The density and condition of the undergrowth in the community contribute to maintaining the multi-age structure of the stand. The spruce tree height, its crown base height, the crown diameter and projection area, as well as its length increase with the age of the tree, with the exception of the relative length of the crown, the average values of this indicator remain almost the same for trees of all age groups. Based on the results of the analysis of spatial relationships in the stand, it has been revealed that all trees in general and spruce of different age groups, except for trees up to 80 years old, are distributed randomly. For trees up to 80 years old group placement is typical. An assessment of the competition indices for each spruce from trees within a 10 m radius has shown that with an increase in the impact force from nearby trees, the height and diameter of the stem, as well as the projection area of the crown of the “central” tree, decrease. The impact of neighbouring trees can be traced at a distance of up to 8 m for spruce trees older than 200 years and up to 12 m for spruce trees up to 80 years old.