Variability of morphometric leaf traits in small-leaved linden (Tilia cordata Mili.) under the influence of air pollution

The study concerns the ecological responses of Tilia cordata Mill. to pollution and describes the advantages of estimating of the degree of environmental pollution. The aim was, to find out whether the degree of pollution conforms to the contents of the investigated elements in leaves, the assessment of variability of morphometric leaf traits and the cationic equilibrium values. The study has shown a statistically significant differentiation between the analysed sites in respect of dust fall, concentrations of elements in soils and leaves, morphometric traits of leaves and the cationic equilibrium. The hierarchical tree plot of cluster analysis qualified the sites as polluted and non-polluted. In polluted sites the contents of metals in leaves were significantly higher and the cationic equilibrium in leaves was disturbed. The surface, width and asymmetry of leaves, and also the variability of these measures were higher in polluted sites. In sites, which are not directly affected by pollution the cationic equilibrium is close to the const. value, whereas leaf traits have shown the lowest values and a considerably lower variability. The investigations show that leaf traits and cationic equilibrium correspond to the level of pollution and can be used as a tool for evaluation of the environment status.