Generative capacity of species from the genus Quercus L. as a method to enhance the oak plantations productivity

The article highlights the urgent issue of losses of economically valuable tree species due to pests and diseases spread caused by climate changes. Examples of mass dieback of common ash (Fraxinus excelsior L.) due to chalar necrosis and infection of Ulmus L. trees with Dutch elm disease are provided. The lack of effective control measures against such fungal diseases poses a significant threat to forests biodiversity. A strategy for preserving valuable species, particularly common oak (Quercus robur L.), through the introduction of Quercus L. species from other floristic regions is proposed. Special attention is given to the generative capacity of oaks, which determines their ability to flower and bear fruit. Additionally, an analysis of seed morphometric characteristics, germination energy, and other parameters in the Right-Bank Forest-Steppe of Ukraine was conducted. The adaptation values of various studied species to environmental stressors (drought, frost, soil pollution) were considered and it was established that the introduced species (Quercus rubra L., 354 Агробіологія, 2025, № 1 agrobiologiya.btsau.edu.ua Quercus castaneifolia C.A.M.) have high resistance to pests and diseases, which contributes to plantation productivity. The conclusions emphasize the necessity of detailed research into the bioecological features of introduced species and development of high-quality planting material. Oaks introduction is a promising approach to adapting forest ecosystems to climate changes and increasing their productivity. Generative capacity of Quercus L. species, their adaptation to the conditions of the ForestSteppe of Ukraine, and the prospects of their use in forestry have been examined. The results showed that the native Q. robur and North American species (Q. coccinea, Q. palustris, Q. rubra) produce highquality seeds, Q. rubra demonstrates abundant natural renewal. The introduction of these species is recommended to enhance productivity and preserve forest ecosystems. Key words: introduction, floristic regions, fruiting, germination, high quality, germination energy, natural regeneration.