Morphological Changes of Leaves of Birch (Betula pendula Roth) During the Growing Season in the Conditions of Petrochemical Pollution of the Environment

Abstract

Abstract The authors analyze their data on birch leaves (Betula pendula Roth) during the growing season of 2019. Studies were conducted on the territory of the Ufa industrial center near oil refineries. Model birch trees grow on permanent plots. Ten leaves are numbered on the trees. Photographs of each plate were taken during the growing season (June-July-August-September). The integral indicator of the stability of leaf development was calculated according to five criteria: (1) the wide of the left and right halves of the leaf; (2) the length of the second vein from the base of the plate; (3) the distance between the grounds of the bottom of the first and second veins of the second-order of the leaf; (4) the distance between the ends of the first and second veins of the second-order of the plate; (5) the angle between the central vein and the second vein of the second order from the base of the leaf. The research shows that under conditions of the hydrocarbon type of environmental pollution, there are deviations in the morphological development of birch leaves. The authors show 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 plate are inextricably linked. Leaf asymmetry indicators can be used to characterize the state of birch trees in urban conditions.