Variability of Pedunculate Oak (Quercus robur L.) Provenances in Central Ukraine

A total of 65 pedunculate oak (Quercus robur L.) provenances from the southern, central, northern, and eastern parts of the oak distribution range in Vinnytsia region (Central Ukraine) were assessed in a common garden experiment. Analysis of the population’s survival dynamics indicates an increase with age in the adaptive capacity of the provenances to the environmental conditions. In the initial stage, up to 10 years, the survival rate of the local populations was about 75%, by 40 years the survival decreased to 15%. At the same time, the number of trees of other provenances, which were characterised by higher survival rate, increased. The best adaptive capacity was obtained for the Rivne (Ostrozke), Kirovohrad (Svitlovodske), Chuvash (Kanaske), and Ulyanovsk (Melekske) provenances. The indicators of average height of the trees and geographic longitude (r=-0.513) and latitude of the natural growth of the populations (r=-0.474) are characterised by a significant and moderately close relationship. Oak populations differ by average diameter and remoteness from the natural location ratio (r=-0.431), and by the geographic latitude of their growing place (r=-0.478) in a moderate correlation. According to the comprehensive assessment of the non-local populations, which included survival rate, mean diameter and height, and tree breeding category, we can conclude that in general, the central populations have optimal values. Populations of Bryansk, Khmelnytskyi, Zaporizhzhya, and Cherkassy origin, as well as the local ones, have the highest values. The lowest indicators were observed manly for the northern oak populations.