Variability of leaves of Betula pendula Roth during the growing season in the recreation area in the industrial center

Research was carried out at the Ufa Industrial Center on the territory of recreational zone. Morphological changes in birch leaves (Betula pendula Roth) during the growing season of 2019 are shown. Model birch trees grow on a permanent trial plot. On the trees, 10 leaves were numbered. During the growing season (June - September) photographs of each leaf were taken. The integral indicator of the stability of leaf development is calculated on five grounds. Statistical processing of the data obtained. It has been established that there are deviations in the morphological development of birch leaves. It is shown that an individual trajectory of morphological development is characteristic of leaves. The phenomenon of adaptive polymorphism of birch leaves is noted. Moreover, the morphological and functional features of the leaf are inextricably linked.