EXPERIMENTAL FELLING IN ASSISTANCE TO NATURAL FOREST REGENERATION IN KYIV REGION

Abstract

Forest management in Ukraine should be conducted considering climate change, as well as degradation and mass drying of forests. It also must follow the principles of preserving the conditions for the reproduction of biologically stable, highly productive tree stands and rational and sustainable use of forest resources. Therefore, one of the main tasks of forest management is to maximize the use of the natural seed potential of forest stands. Felling corresponds to this principle, being aimed at maximizing the use of natural seed regeneration of the forest, and as a methodological basis for creating highly productive, biologically stable forest stands. The purpose of this study is to develop a felling method that promotes natural forest regeneration and offer organizational and technical indicators for its implementation. Accounting of natural forest regeneration was performed per the A.V. Pobedynskyi’s method; the natural forest regeneration was estimated according to V.G. Nesterov’s scale; the projective cover of the forest ground vegetation was figured out on the Brown-Blanquet scale; the dryness of the climate was figured out according to the De Martonne’s aridity index; the humidification conditions at the experimental site were investigated using G.T. Selyaninov’s hydrothermal coefficient; the sum of active temperatures was figured out according to the method of the Ukrainian Hydrometeorological Centre. The regulatory framework for felling to form and sanitise forests was analysed. It was found that the current rules do not make provision for felling that would be most favourable for the natural renewal of economically valuable tree species in forests of any category, age, composition, and structure. The results of accounting and evaluation of natural forest regeneration in felled circular areas are presented. It was found that under the condition of average (3 points) and higher points of seed bearing (fruiting) and sufficient moisture on circular plots with a diameter of 1.5 of the average height of the stand (Havg), there was a very dense, healthy, evenly distributed natural forest regeneration. Dense understorey and significant sodding of the soil surface (over 50% of the area) with forest ground vegetation negatively impact the natural forest regeneration in the first year of life. Otherwise, special tillage is ineffective. In 2020, despite the decade-long droughts in March-April, as well as in August-September, favourable conditions for natural forest regeneration developed. In May and June, there was an increase in precipitation compared to the previous and subsequent months after the emergence of seedlings, which positively affected their rooting and growth. Feeling that contributes to the natural forest regeneration should be classified as felling for the formation and sanitation of forests, and the proposed organizational and technical indicators should be set up for it. The conclusions of this study will serve as a methodological framework for the introduction of a new method of felling in forest stands, which would be as favourable as possible for a sufficient amount of high-quality, viable natural regeneration of economically valuable tree species