Наукові праці Лісівничої академії наук України (Nov 2023)
The dynamics of mensurational indicators of spruce stands on the north-eastern macroslope of the Ukrainian Carpathians
Abstract
The dynamics of stand mensurational indicators in the two spruce-predominant forest types ‒ beech-silver fir-spruce forests on moist fairly fertile site type and pure spruce forests on moist fairly fertile site type was studied on 41 sample plots with a total area of 7.225 ha in Ivano-Frankivsk, Lviv and Chernivtsi regions. The sample plots were laid out in forests of both natural and artificial origin of varying stand densities. They were located in forests of different categories, on slopes of different exposure and inclination. The age of the investigated spruce stands ranged from 31 to 157 years. The growing stock in the researched spruce stands varies from 237 to 1,044 m3∙hа-1, depending on age, site class, altitude above sea level and stand density. According to the developed growth forecast model for spruce stands of site class I in the conditions of the pure spruce forests on moist fairly fertile site type, at the age of 100 years, they will have the following mensurational characteristics: average height ‒ 29.6 m, average diameter ‒ 31.8 cm, stand basal area ‒ 40.4 m2, stand density ‒ 510 trees/ha, growing stock ‒ 563 m3∙hа-1. Spruce stands of site class Ia in the conditions of the beech-silver fir-spruce forests on moist fairly fertile site type will have the following mensurational characteristics at the age of 100 years: average height ‒ 33.4 m, average diameter ‒ 39.8 cm, stand basal area ‒ 41.2 m2, stand density ‒ 331 trees/ha, growing stock ‒ 652 m3∙hа-1. It was found that the average growing stock change (excluding tree mortality) at the age of 100 years by the prevailing stand relative density of 0.7 in the pure spruce forests on moist fairly fertile site type is 5.7 m3∙hа-1 per year, and in the beech-silver fir-spruce forests on moist fairly fertile site type ‒ 6.6 m3∙hа-1 in a year. For normal stands with a stand density of 1.0, it can reach 8.1 m3∙hа-1 per year in the pure spruce forests on moist fairly fertile site type and 9.4 m3∙hа-1 per year in the beech-silver fir-spruce forests on moist fairly fertile site type, respectively. The results of the comparison of our model of the dynamics of mensurational indicators of spruce stands with the existing yield tables of E.I. Tsuryk and G.A. Khodot show minor deviations. The maximum discrepancy exists in the spruce stands density in the conditions of the beech-silver fir-spruce forests on moist fairly fertile site type and amounts to 29.7%.
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