Peculiarities of natural regeneration in beech stands of the Ukrainian Carpathians

Abstract

The peculiarities of natural regeneration have been studied in beech stands in which management activities are carried out or are absent. Investigated was the dependence of the amount of self-seeding and young growth of beech upon the age of the trees, stand density, and the size of gaps ("openings") in the stand canopy. The objects of the study were beech forests over 61 years old at the state enterprises "Volovets Forestry" and "Svalyava Forestry", as well as beech virgin forests in Uzhansky National Nature Park of Transcarpathian region. The success of natural regeneration of beech stands in the mountain forests of the Ukrainian Carpathians depends on the forestry and inventory indicators of the stand: age, stand density and light intensity under the canopy of the stand. In commercial beech stands, the amount of self-seeding and young growth of beech increases with their age. The largest amount of beech young growth under the canopy of forest stands averages 6.2 thousand pcs/ha at an age of 101-140 years. The amount of beech young growth in commercial forests reaches its highest value in low-density stands and averages 12 thousand pcs / ha. The areas of 65-95-year-old beech stands in which young growth is absent prevail. The share of stands without young growth of beech of these age groups varies between 54 and 72%, and the share of stands with the presence of young growth of beech up to 5 thousand pcs/ha varies between 15 and 33%. There is a significant correlation between the amount of young growth and the age of beech stands at density of 0.7 and 0.8, and the correlation is weak at density of 0.6. The low level of correlation is apparently due to intensive management activities, when a significant amount of young growth dies in stands during felling. In virgin beech forests good natural regeneration of trees is formed in the gaps of the stand canopy. The amount of self-seeding and young growth of the tree species increases with an increase in the size of the openings in the canopy and in the largest gaps reaches 72.3 thousand pcs/ha. The share of beech in the young growth in individual gaps ranges from 6.2 to 98.7 %. Beech young growth predominates in 44 % of the studied gaps, in 39 % of gaps sycamore maple prevails, and in 9 % of gaps ‒ Norway maple, and 4 % of gaps is dominated by beech and sycamore maple. In the young growth composition of virgin beech forests, the fraction of small-size plants (less than 50 cm in height) predominates, the share of which in individual gaps ranges from 13.5 to 94.0 % of the total amount of young growth. In the composition of small young growth, sycamore maple prevails in almost half of the trial plots, the amount of which in individual canopy gaps reaching 50 thousand pcs/ha. The greatest loss of young growth is observed in the fraction of small-size plants, which leads to the predominance of beech in the young growth of greater height. In the stands of a moist fertile beech forest type with the presence of sycamore maple, young growth of beech, sycamore and Norway maple prevails. In the stands of a moist fertile beech forest type involving fir, the amount of beech and sycamore young growth is the same, and there is also a sufficient amount of fir young growth. The available amount of young growth of the main tree species in the pure and fir fertile beech forest type is sufficient to form primary stands in these types of forests.

Keywords

• virgin beech forests
• self-seeding
• young growth
• forest type
• young growth composition
• forestry