Seasonal dynamics of changes in the morphological parameters of silver birch (Betula pendula roth) leaves in the conditions of industrial impact (Ufa, Republic of Bashkortostan)

The paper presents the results of the study of seasonal changes in the morphological parameters of leaves of the silver birch (Betula pendula Roth). The investigation was carried out in the plantations within the Ufa industrial center. Permanent sample plots were selected taking into account the level of pollution and were laid in the zone of the direct impact of industrial production (the northern part of Ufa) and in the zone of relative control (the western part of the city, the recreation zone). To characterize the features of birch leaves growth, a correlation analysis was performed, and the depth of correlation between the area and the mass of leaves was estimated. The tightness of correlation in the contaminated area and the correlation in May is categorized as “weak”, in June - as "strong", in July and September - as "moderate". According to the quantitative characteristics of the correlation tightness, in the zone of relative control the correlation refers to the category of “strong”. The values of mass and area of a birch leaf indicate that in the conditions of industrial pollution the uniform development of leaves was observed during the growing season of 2016. However, the correlation analysis allowed us to establish that there was an ambiguous relationship between the mass and the area of the leaf. It can be explained by the adaptive reactions of birch that occur during the seasonal development of leaves.