Species of conifers in collection of the Botanical garden of the Institute of biology of the Komi science centre and the prospects of their usage in city tree planting

Results of introduction of coniferous plant species in the Botanical Garden of the Institute of biology are given in view of new collection adjunctions. At the beginning of the 1990s, 17 species and forms including seven species of the native flora were listed in the collection of coniferous plants. By the moment, the number of such species has increased more than five times. Seedlings of many decorative forms were brought as rooted cuttings from the Botanical Gardens of Yoshkar-Ola, Samara, Voronezh, Cheboksary, Ufa, Barnaul, Magadan, Novosibirsk, Yekaterinburg and Minsk (Belarus). The collection includes 96 taxa (38 species and58 decorative forms and varieties) from 11 genera and three families: genera Chamaecyparis Spach, Juniperus L., Microbiota Kom., Thuja L., Thujopsis Siebold et Zucc. from Cupressaceae Rich. ex Bartl., genera Abies Hill, Larix Hill, Picea A. Dietr., Pinus L., Pseudotsuga Carr. from family Pinaceae Lindl. and genus Taxus L. from family Taxsaceae Lindl. Brief description of 48 species, varieties and forms of conifers from the old and new collections that are the most prospective for the culture in the Komi Republic is given. Biology of their growth and development is characterized; winter hardiness of the species and forms was also assessed. Attention was also paid to the decorative properties of plants. The data on the rate of growth and size of plants at certain age are given. Some information on the vegetative propagation of decorative forms of conifers by summer cuttings in the open field is provided. The experiments showed that the highest rate of rooting was found for genera Juniperus, Chamaecyparis and Thuja (65-85%). Decorative forms of Picea and Microbiota decussata and Taxus baccata rooted harder (30-45 %). Compact multicaulis bushes ready for permanent landing formed in two years after the rooting. Within a relatively short period of observation of the new collection of conifers (10-15 years), about 40 taxa were revealed and recommended for the limited use in landscaping.