On the issue of developmental stability of urban tree populations

Fluctuating asymmetry as an indirect deviation in the difference between the right and the left bilaterally symmetrical traits is considered an indicative symptom of stress. The results of urban populations studying Betula pendula, Tilia cordata, Quercus robur and Acer platanoides using the conventional normalizing method and the geometric morphometrics are presented. The relationship between the environmental stress of an urbanized area and asymmetry values was analyzed. 8-10% of the samples | R – L | / (R + L) had a normal distribution (K-S test, p <0.01). Only one trait in birch and one in linden significantly (p <10⁻⁴) reflected the stress effect in a direct relationship. Q. robur and A. platanoides had a wider range of FA, and the traits reflecting stress were different. No correlation was found between the FA and GMFA integral indices. High heterogeneity of values (R – L) was accompanied by the significance of directional asymmetry. The GM method extinguished the kurtosis in trait and showed a significant value of GMFA at kurtosis values γ < 2.5. The high heterogeneity (γ >2.5) accompanied by insignificant fluctuating asymmetry in Procrustes ANOVA. The authors emphasize that the toxic effect of pollutants can be associated with the relief and protection from winds in urbanized areas. The heterogeneity of the genotype of plantings from different nurseries increases the factor diversity, which makes the results of the analysis of developmental stability much more critical.