Оптимізація структури мішаних лісів басейну Бистриці Тисменицької (Українські Карпати) на засадах наближеного до природного лісівництва в умовах можливої зміни клімату

Abstract

У статті обґрунтована система заходів, спрямованих на реконструкцію похідних лісів у басейні Бистриці Тисменицької. У межах висотних лісових поясів і висотних ландшафтних місцевостей запропоновано параметри цільових деревостанів, заходи з наближеного до природного лісівництва та рекомендовані способи рубань.

The article substantiates a system of measures aimed at the reconstruction of mixed forests in the Bystrytsia Tysmenytska basin in the Ukrainian Carpathians for the sake of mitigating the effects of possible climate change. The theoretical basis for such research should be a system of close-to-nature forestry. The total area of the Bystrytsia Tysmenytska basin, excluding the area of its largest right tributary, Tysmenytsia, makes some about 510 km2. In terms of relief, the basin territory is clearly divided into the Subcarpathian (Upper Dniester Plain) and Carpathian (Drohobych Upland) parts. The climatic conditions of the basin territory are quite favourable for the cultivation of highly productive mixed fir and beech forests. More detailed differences in the nature of the tree stands are determined by edaphic (soil) factors. Analysis of the main ecological factors makes it possible to trace the correspondence between the natural conditions of the territory and the main types afforests that are most common nowadays in the territory of the studied basin. In the territory of the Bystrytsia Tysmenytska basin, as part of the northern macroslope of the Ukrainian Carpathians within the heights of 250-850 m above sea level. S. Stoyko (2004) identified three altitudinal forest belts: a belt of oak forests made of common oak, a belt of fir and oak forests made of common oak, and a belt of beech forests. Within these altitudinal forest zones, based on the materials of the latest forest inventory and our own forestry and natural-geographical research, we have identified areas of natural forests that are associated with various natural-territorial complexes. The natural forests of the basin include 19 most common forest types. Within each altitudinal forest belt and corresponding altitudinal landscape areas, the current parameters of tree stands (origin, tree stand formula depending on forest type, age composition, horizontal and vertical structures) were analysed for the most common types of oak, fir and oak, and beech forests. For the most common forest types within oak, fir and oak, and beech forests, target tree stand parameters have been proposed, based on a close-to-nature forestry system, with the aim of mitigating possible climate change. A well-founded system of close-to-nature forestry measures and recommended felling methods has been developed. The main goal of close-to-nature forestry within the oak forest belt is to maximise the stimulation of seed renewal of common oak and measures to promote its growth and development, the transformation of oak forests of vegetative origin into seed forests, the creation of mixed and complex plantations of natural and artificial origin, and the selection and breeding of oak forms and populations that are most resistant to changing climatic conditions and the spread of diseases. In the fir and oak as well as oak and fir forests, the main goal of close-to-nature forestry is to stimulate the emergence of seedling growth, promote its development and growth, and create mixed-composition and complex-structure fir and oak as well as oak and fir forests of natural and artificial origin. The goal of the close-to-nature forestry system in the beech forest belt is to form highly productive and complex plantations, maintain their high natural regeneration potential, and transform low-stemmed, thinned tree stands into high-stemmed and high-density ones through forestry measures. The forestry system based on natural forests, suggested for the high-altitude forest belts of the Bystrytsia Tysmenytska basin, presupposes regulation of various measures for natural regeneration, main felling, maintenance and restructuring logging, preservation of biotic diversity, forest protection, reconstruction of transformed plantations, and optimisation of forest cultivation. Such reconstruction of secondary forests can mitigate the effects of possible future climate change in the region under study.