Against the background of man-made impact on the environment, the role of landscape architecture increases. Green plantings reduce the impact of adverse factors. A special role is given to coniferous plants that perform environmental-improving functions all year round. The collection of the VNIISPK arboretum includes more than 310 species, forms and varieties of woody plants representing 31 families. The most numerous family of Pinaceae includes 5 genera, one of which is the genus Abies Mill. The purpose of the study is a comprehensive assessment of ecological and biological features of the genus Abies of different origin to justify the success of the introduction in conditions of the Central Chernozem region of Russia. All the studied species have high winter hardiness in the conditions of the central part of Russia.A. balsamea, A. concolor, A. fraseri, A. lasiocarpa, and A. sibirica were resistant to infectious diseases. A. alba, A. concolor, A. fraseri, A. nephrolepis, A. sachalinensis and A. veitchii showed resistance to pests. According to the results of comprehensive assessment of the ecological and biological features of 9 introduced species of the genus Abies, three highly decorative genotypes of North American origin, resistant to a complex of adverse environmental factors, were identified: A. balsamea, A. concolor, and A. fraseri.

Plantings’ ornamentality is an important aspect of the aesthetic appearance formation of urbanized landscapes. In urban ecosystems, trees and shrubs are often exposed to high stress levels that shortens their lifespan and reduces ornamentality. Plant introduction is one of the methods of enriching the assortment with resistant species. The aim of the research was to comprehensively assess the ornamentality degree of North American introduction tree groups from the genetic collection of the All-Russian scientific research Institute of Fruit Crop Breeding (VNIISPK) arboretum and to give recommendations on improving their composition. Research was carried out in 2013-2019, taking into account the dynamics of changes in decorative qualities during the year. Throughout the year, landscape compositions showed peaks of ornamentality in the same seasons of the year (May, September). To give dynamism to groups in the summer period, it is recommended to plant Spiraea douglasii in the 1st group; in composition 2 — Hydrangea arborescens and two varieties of Physocarpus opulifolius: ‘Darts Gold’ and ‘Summer Wine’. Graphics of ornamentality degree changes of landscape groups are recommended to be used when drawing up landscape groups for various purposes to ensure their ornamentality during either an entire year or a certain period.

High interest in ornamental plants as an element of landscaping has been actively going on in recent years. In urban green construction, it is increasingly possible to meet not native local species, but introduced plants, which in urbanized environments are in many cases more stable and durable. For several years, we have been studying the selection of root formation stimulants, as well as their necessary concentration for treating cuttings of Thuja occidentalis forms. As a result of the calculation of economic efficiency, an increase in profitability was revealed when using phytohormones compared with the control. As an effective growth stimulator, the IBA (indole-buteric acid) drug (100 mg/l) was chosen. The use of IBA auxin (100 mg / l) allows to increase the profitability of production and provides a high yield of planting material with minimal costs.