Species diversity and vital state of trees and bushes in the plantings of Kazan city

The dendroflora of Kazan city centre includes 99 species and forms belonging to 48 genera and 26 families. The proportion of native species is 24%, and the rest are introduced ones. The most abundant families are Rosaseae, Pinaceae, Aceraceae, Salicacea, and the most numerous genera are Acer, Spiraea, Picea, Salix, Populus and Ulmus. Seven species are the most abundant in plantations (occurrence 75-100%), among which Larix sibirica, Thuja occidentalis, Pinus sylvestris, Tilia cordata, and Picea x fennica have high quantitate contribution to the vegetation of Kazan city centre parks (650-940 pc/ha). In urban environments, Populus balsamifera and Larix sibirica grow in the conditions of bonitet I, which indicates their resistance to the complex of anthropogenic factors. The other species bonitet is 1-2 units lower compared to the growth in the zonal vegetation. The vital state degree of the urban populations of trees and bushes varies from 15 to 100%. Healthy plantations were noticed for 54,5% species and forms, mostly introduced ones: Acer platanoides "Drummondii", Robinia pseudoacacia, Quersus rubra, Picea pungens, Fraxinus pennsylvanica, Juglans mandshurica, Acer negundo, etc. Weakened plantations were found for 39,4% species of different origin: Acer platanoides, Aesculus hippocastanum, Juniperus virginiana, J. chinensis, Pinus sylvestris, Amelanchier canadensis, Taxus baccata, Sorbus aucuparia, etc. Severely damaged plantations were noticed for 6,1% species, including Acer platanoides "Crimson king", Tilia cordata, Ulmus glabra, Ul. pumila et al. The most common disease is powdery mildew, and the most damaged species are Sorbus aucuparia, Crataegus sp., and Berberis vulgaris.