Cultivation of Tree Species in the Arboretum of the Siberian Forest Experimental Station in the City of Tyumen

The article presents the results of a study on the state of coniferous and deciduous trees growing in the arboretum of the Siberian Forest Experimental Station in Tyumen to provide a possible justification for the use of promising species in order to improve the species composition of forest stands in the Tyumen Region and increase their sustainability. It has been established that according to the average indicators of sanitary and vital state, as well as the average relative height, the majority of the examined introduced coniferous tree species are characterized as healthy and stable, while deciduous tree species are weakened. The proportion of severely weakened specimens among coniferous and deciduous species does not exceed, on average, 20 and 30 %, respectively. Among coniferous tree species, Picea pungens Engelm., Larix sibirica L. and Pinus sibirica Du Tour are distinguished by high vital state indicators and decorative properties. Among deciduous tree species, these are Betula pendula Roth., B. pubescens Ehrh., Populus balsamifera L., Tilia cordata Mill. and Júglans mandshurica Maxim. According to the main inventory indicators, such coniferous species as Larix sibirica Ledeb and Pinus sibirica Du Tour, by the age of 40–60 years old, grow according to Iа–I quality classes and form highly productive stands. These species can be recommended for plantation cultivation. Picea obovata Ledeb, P. pungens Engelm., Thuja occidentalis L., Phellodéndron amurénse Rupr. and Quercus robur L. successfully adapt to the conditions of the temperate continental climate of the forest-steppe zone of the Tyumen Region. This confirms the possibility of their use for landscaping the city of Tyumen. The adaption of individual representatives of woody vegetation of the broad-leaved forest subzone and their introduction into forest stands with the aim of creating forest stands that are complex in structure and composition and, as a result, more stable in the conditions of a changing climate and ecological environment should be among the priority tasks of forestry in the protective forests of the Tyumen Region.