Using of morphometric and phenological parameters of Tilia cordata Mill. for bioindication

The paper contains the results of long-term bioindication studies of assessing the state of Tilia cordata Mill. in the conditions of Yoshkar-Ola city, which differ in the degree of environmental pollution by industrial transport emissions. The work analyzes a variability of Tilia cordata individuals of various ontogenetic states of the generative period according to a complex of morphological and phenological characters using statistical methods of principal components and an analysis of variance. The heterogeneity of ontogenetic groups of trees according to morphological and phenological characteristics is established. The individuals of the mesobiontic species T. cordata under the conditions of an average degree of pollution of the urban environment are considered to be small-leaved. With an increase in anthropogenic load the area of the leaf blade decreases, but the area of its damage increases. The index of fluctuating asymmetry of the leaf blade does not differ concerning the trees growing in various environmental conditions. A method of principal components helped to identify T. cordata’s most variable signs of shoots and rhythms of seasonal development, which can be used for bioindication: sizes and number of structural elements of buds and shoots, terms and duration of phenophases. The most sensitive to habitat pollution are middle-aged generative trees of T. cordata.