Morphological and anatomical parameters of Forsythia suspensa (Thunb.) Vahl leaves in the urban environment

The anatomical and morphological parameters of the leaf blade of Forsythia suspensa were investigated to determine the species’ stability in the Kyiv metropolis (Ukraine) conditions and monitor environmental pollution. The leaves of F. suspensa were selected at four monitoring sites in Kyiv, which differed in their distance to highways and the intensity of traffic. The histological structure of F. suspensa leaves changed toward xeromorphism in the variants where plants were exposed to increased vehicles’ emissions. In particular, the thickness of the cuticle and adaxial epidermis increased, the stomatal size decreased, the degree of stomata opening decreased and their density increased, and the stomatal index and xeromorphism index increased. In general, such changes in the structure of F. suspensa leaves increased the plants’ resistance to pollution. This indicates the plasticity of F. suspensa plants and a sufficient level of their adaptation to the urban environment. Hence, the parameters of the stomatal apparatus of F. suspensa leaves can be applied as test indicators for biomonitoring of urban pollution. This species can be recommended for creating stable culturphytocoenoses in conditions of a high level of technogenic influence.