Vegetation succession after clearcutting in oak forest stands in the conditions of the Western and Central Polissya of Ukraine

Abstract

In modern conditions, when clear-cut main felling prevails in the forestry practices in Ukraine, studies of restorative successions of vegetation at all age stages of growth and development of plantations should become the scientific basis for the development of effective measures for sustainable forest management. The studies on the renewal of common oak plantations after clear cutting in fresh and damp loams of the Western and Central Polissya of Ukraine showed that during the first three years dynamic variegated plant groups with remnants of forest species and a significant participation of light-loving ruderal and meadow species are formed on cutting areas. Taking into account the predominance of clearcutting method of final felling in Ukraine, the study of regenerative successions in subsequent growth periods should become a scientific basis for the development of measures for sustainable forestry. Summarizing the results of research on the reproduction of oak stands after clear cutting it was found that within 1-3 years on the cutting areas dynamic, variegated plant communities formed with remnants of forest species and a significant participation of light-loving ruderal and meadow species. The main limiting factor in the restoration of phytodiversity at this stage is the absence of crowns at the stand. After the closure of the crowns (approximately at the age of 10), the floristic composition and coenotic structure of phytocenoses are almost restored, and elements of the synusial structure appear in 20-year-old coenoses. Beginning from the age of 40, plant species included in the Red Book of Ukraine have been restored in the forest cultures of common oak. In particular - Lilium martagon L., and from the age of 60 – Epipactis helleborine L. and Neottia nidus-avis (L.) Rich. In the future, there is a complete restoration of both the floristic composition and the cenotic structure of phytocenoses. The similarity of the floristic composition of the herb-dwarf shrub layer of 120-year-old oak stands with 1-10-year-old plant groups is low (Sørensen-Chekanovsky index from 0.27 to 0.44). On the other hand, a high species similarity of the floristic composition of the herb-dwarf shrub layer of 40-year-old oak crops with all age categories was observed. The values of the species similarity index were: 0.72 – at the age of 10 years, 0.79 – at the age of 20, 0.73 – at the age of 60, 0.85 – at 80 years old and 0.79 – at 100 years old. In subclimax 120-year-old phytocenoses, the herb-dwarf shrub layer consisted mainly of forest species – by 88.0%, as an admixture there were meadow (8.0% of the species composition) and bog (4.0%) species. After clear felling and the creation of forest plantations in 1-year-old groupings, the share of forest species was 32.9%, light-loving meadow and ruderal species – 25.7% each, and forest species – 8.9%. In 20-year-old cenoses, there is a general tendency towards an increase in the share of forest species in the grass-dwarf shrub layer from 66.0% at 10 years of age to 77.5% at 20 years of age and a decrease in the participation of species of other ecological-cenotic groups. From the age of 40, ruderal species disappear from the floristic composition of the herb-dwarf shrub layer of forest stand, and starting from the age of 60, the participation in the floristic composition of all ecological-cenotic groups stabilizes. In particular, the share of forest species is at the level of 85-89%. The herbaceous-shrub layer of groups of all age categories is dominated by herbaceous perennials, their participation is maximum in maternal, 120-year-old, phytocenoses – 96,0%.

Keywords

• quercus robur l.; tree stand; fresh loam; wet loam; cutting areas; age stages; herb-dwarf shrub layer; floristic composition; phytodiversity; coenotic structure of phytocenosis.