Role of microstructure and silicon of leaf in adaptation of Quercus robur trees to different light intensity

The microstructure, localization, and content of silicon inclusions in the leaf epidermis of Quercus robur trees grown in forest-steppe zones of southern Ukraine with different sunlight intensities were studied with the electron microscopic method and laser confocal microscopy. We established the influence of sun intensity on silicon content in oak leaf epidermis. It was found that silicon is most accumulated in trichomes, stomata, and ordinary epidermal cells of oak leaves. The observed phenotypic plasticity of leaves is manifested in an increase in the trichome number and stomatal density, as well as in a decrease in leaf size and area in trees growing in direct sunlight. Common oaks from the southern region of Ukraine are able to grow normally and adapt to high levels of solar radiation due to their increased ability to absorb and reflect light by leaf surface. The various characteristics of these leaves can be used for practical applications.