Dendrochronological assessment of climate risks for the restoration of oak forests in the Ukrainian Polissya

The deterioration of climatic conditions caused by global warming poses a threat to the sustainable development of forest ecosystems, particularly oak stands, which are an important component of Ukraine’s forestry sector. The purpose of the study was to determine the growth responses of Quercus robur L. trees to long-term climatic changes leading to increased aridity in the conditions of the Ukrainian Polissya. The gradients of the temperate climate in the locations where Quercus robur L. trees grow in Ukraine were analyzed, namely the climatic factors (extreme temperatures, precipitation) that affect the growth and development of trees on a monthly and seasonal time scale. The results provide important information on the regional prospects for growing oak plantations in Ukraine. Random climatic factors, which act synergistically with systemic factors, negatively affect tree growth, regardless of the characteristics of the forest management system. The influence of climatic conditions on the radial growth of Quercus robur L. trees within their natural range was studied. Particular attention was paid to situations where the analyzed trees formed rings whose width exceeded the interval – the mean plus or minus the standard deviation (R ̅±SD). Chronologies of climatic signals covering the new reference period 1991-2020 were developed for the studied locations. Simple indices of extreme monthly average air temperatures and monthly precipitation indices were calculated. A climatic analysis was conducted for the years in which anomalies in the growth of Quercus robur L. trees were observed, identified by the tree ring width index (TRWI). It has been established that annual precipitation totals and maximum air temperatures in the spring-summer season have a statistically significant impact on radial growth. The constructed polynomial models allow predicting changes in the growth dynamics of Quercus robur L. trees for the studied region