Наукові праці Лісівничої академії наук України (Jun 2021)
State and structure of the natural spruce forests in the Pokuttia Carpathians
Abstract
The Pokuttia Carpathians are located in the south-eastern part of the north-ern mega-slope of the Ukrainian Carpathians, covering an area of 659.7 square km, which is about 3% of the Ukrainian Carpathians area. The forest area of the Pokuttia Carpathians is 39.1 thousand hectares, including 8.2 thousand hectares of the natural spruce forests or 21% of the forests of study region. The forests of the Pokuttia Carpathians where studied in the framework of the WWF-Ukraine project «The identification of the virgin forest of the Ukrainian Carpathians» to identify their belonging to virgin, quasi-virgin and natural spruce groups of protected forests. The main assessment characteristics and the successions dynamics in the spruce forests are analyzed based on the example of a permanent research plot in the spruce forest. Its characteristics are very close to the virgin forest in the con-ditions of moist pure highland spruce forests. The studied natural forest сorre-sponds to almost all the features of spruce virgin forests, except the area (less than 20 hectares). The field studies were conducted since 2010 with five-year intervals in ac-cordance with the method of second level environmental monitoring under the program "ISR-Forest". The assessment results on the condition and structure of natural spruce communities of the Pokuttia Carpathians are presented in the pa-per. An interactive map of the virgin and quasi-virgin forests distribution at the study area has been developed. The dynamics of the quantitative characteristics of natural spruce stands over the past 10 years indicates a little rate of the total number of trees decreas-ing. During 2015-2020 there was a significant increase of the spruce-trees number in the second layer, while the number of trees in the third layer is consistently low. The number of live trees of the first tier during the 10-year observation peri-od decreased significantly (by almost 24%). The trees are located in the stand as a biogroups. The crowns in the bi-ogroups ranges from 0.8 to 1. Forest herbaceous species (34 species) form a fair-ly dense cover. Their projective cover is 85% in the presence of more than 30 species. At the same time, the processes of vegetation transformation in natural spruce ecosystems are observed. The recent monitoring shows some decreasing of the indices at the category of condition, vitality, marketability and crown length of spruce trees and increas-ing of the indices at the category deadwood volume and variety of damages (compared to 2010). The reason is, first of all, in climate change. Spruce forests very sensitive to such changes. The study of the state and structure of natural spruce forests in the Pokuttia Carpathians in the dynamics provides an opportunity to foresee the future devel-opments of spruce virgin and quasi-virgin forests in the Ukrainian Carpathians.
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