Group Variability of Morphological Features in the Leaves of Betula pendula Roth (Betulaceae, Magnoliópsida) in the Gradient of Weather Conditions and Technogenic Soil Transformation

The group variability of morphological features of the leaves of Betula pendula Roth was studied in the gradients of adverse weather conditions and technogenic soil transformation. The studies were carried out on the territory of the Tagil zone of the Middle Urals in the years 2016–2019. It has been shown that the majority of the leaf features studied have an average level of variation, while a high one is typical for the shape index, and a low one is typical for the leaf blade index and the angles between the main and lateral vein of the first order, located in the middle and upper parts of the leaf. The variability of the features increases in the gradient of deterioration of weather conditions and decreases in the gradient of technogenic soil transformation. The morphological features making the greatest contribution to the variability of the size and shape of the leaf were identified by principal component analysis. Leaf variability is mainly determined by dimensional features. Allometric features are more stable. To assess the resistance of an organism to adverse factors, it is proposed to use the stability coefficient, which reflects the number of feature transitions from one level of variability to another one. This indicator increases both in the gradient of technogenic soil transformation and in the gradient of unfavorable weather.