Provenance tests of Pinus sylvestris L.: Estimation at the age of the half-rotation period

The study of geographical crops is relevant because they are one of the reliable tools for identifying possible scenarios for the response of forest woody plant species to climate change. The purpose of the study of geographical crops of Scots pine established in 1981 in the Kyiv Oblast was to compare the growth and productivity of provenances in different age periods, determine the optimal time for early and final diagnosis of their ranking, and model the relationship between the growth and survivability indicators of provenances with climatic and other environmental variables at the age of 21, 32, and 37 years. The ANOVA method established a statistically significant influence of the geographical origin of seeds on the growth of geographical crops. At the age of 37, the capacity for survival varies from 25% (Lviv provenance) to 36.2% (Chernihiv provenance). At this age, populations from Lviv, Kyiv, and Cherkasy oblasts are characterised by the highest height. According to the intensity of radial growth, these same provenances are distinguished, as well as variants from Volyn and Luhansk. In terms of the stock of stem wood, the best is provenance from the Chernihiv Oblast. Stabilisation of the ranks of provenances in terms of survivability, growth, and productivity is observed only after 21 years. It is assumed that the most accurate assessment of the growth and condition of Scots pine provenances can be obtained at an age that corresponds to a third or a half of the age of the main felling. The trend of clinal variability in the survival of provenances and the average diameter of their trunks along the geographical (latitudinal) and ecological (temperature) gradients is revealed. The study results can be used to update the current forest-seed zoning of Ukraine