SEASONAL RHYTHMS OF THE DEVELOPMENT OF WOOD INTRODUCED SPECIES USED IN THE GREENING OF THE CITY BRATSK
The paper discusses the use of introduced species in landscaping northern cities on the example of the city of Bratsk. The climatic characteristics of the study area are given. Observations of the seasonal rhythms of plant development were carried out in 2016-2018 at the territory of the university arboretum, as well as in urban plantings. As the objects of research, woody plants divided into four floristic groups are considered: European, Far Eastern, North American and Siberian. Total 120 trees and shrubs of 24 species were surveyed. The plants recorded seasonal rhythms of development were fixed: the opening of vegetative buds, the appearance of green leaf cone, the beginning and the end of flowering, the beginning of autumn leaf coloring, and mass leaf fall. The dependence of the passage of various phenological phases, as well as the vegetation period on the temperature factor, the year of study, is traced. The correlation coefficient between the sum of effective temperatures and the onset of phenophases is calculated. Depending on the dates of the beginning and the end of the growing season, the species of woody plants are divided into groups: I – species that early start and early end the growing season; II – species that early start and late end the growing season; III – species that late start and early end the growing season; IV – species that late start and late end the growing season. Plants belonging to groups I and II are considered winter-hardy. Most of the plants in study, 62 % of the total number of species, belong to the first and second groups. The first group includes mainly Far Eastern species. In conclusion, recommendations on the use of a range of introduced plants for landscaping urban areas are proposed.