Koval I. Dendrochronological principles of evaluation of pine and oak stands of Ukraine

Theoretical generalizations and analysis of data on the peculiarities of the response of tree rings of Scots pine, English oak, Crimean pine to ecological changes in forest ecosystems under the influence of climatic and anthropogenic factors in different natural zones of Ukraine are presented in the dissertation. The common in forestry and forestry assessment methods, methods of comparative ecology and dendrochronological methods are used. Dendrochronology studies the tree ring width, early and late wood as complex indicators that reflect the state of stands. New regional tree-ring chronologies lasting 143 years for Scots pine were developed on the basis of samples from living trees and 143 years for English oak in Polissya stands; lasting 97 years for Scots pine and 114 years for English oak in the stands of the Left Bank Forest-Steppe. Two local tree-ring chronologies for the Crimean pine with a duration of 149 years and one with a duration of 42 years for the stands of the southern slope of the Crimean mountains were developed. For pine stands under the influence of emissions from the Zmiiv Thermal Power Plant, it was found that in 1969–1978 the pine radial growth was limited by precipitation and temperatures during the year and the growing season. In the following 1979–1988, the increment in damaged stands was limited by March temperatures and precipitation during the growing season. In 1989–1998, further increases in temperatures during the winter and March periods led to improved growth at all research plots. In 1999–2008, further intensive warming in winter and early spring exceeded the optimum threshold for tree growth, which led to a reduction in radial pine growth against the background of chronic pollution of forest ecosystems, despite decrease emissions. The effectiveness of a combination of the dendrochronological, silvicultural, taxonomic, and comparative ecology methods is theoretically and practically proved. The correlation coefficient between tree-ring chronologies of trees, sensitivity coefficient, first-order autoregression, coefficient of variation, results of correlation analysis between tree-ring chronologies, and climatic factors should be used as indicators of oak and pine stands condition under the influence of climate and anthropogenic load in Polissya, Forest-steppe and mountainous Crimea.