A quantitative analysis of dendrometric data on Sorbus domestica L. phenotypes for urban greenery

The quantitative parameters characterizing the esthetic and spatial characteristics of the tree species Sorbus domestica L., including the architecture and the crown size, were evaluated in order to assess the qualified sources of planting material for the urban environment. Five types of crown shape (spherical, hemispherical, umbrella-shaped, ovate, and conical) were identified during field assessment of trees growing in the open landscape. Conformity of the classification under specific phenotypes within field studies and classification of trees based on quantitative parameters were evaluated using discriminant analysis. The variables included in the discriminant analysis model (crown diameter, crown length, and stem girth) were obtained from direct measurement in the field. A statistically significant relationship was found between crown volume and diameter at breast height. Under the specific environmental conditions of an open landscape, high values of crown volume were recorded not only for the thickest trees but also for trees with diameters oscillating around the mean values of this parameter. Our results indicate that the environment has a greater effect on the stem diameter increment of trees, than on the crown size and crown architecture of S. domestica.