The Collection Fund of Tree and Shrub Plants of the Kryvyi Rih Botanical Garden of the National Academy of Ukraine as a Source of Enrichment of the Assortment for Greening Urban Areas

Abstract

Topicality. Green areas of cities are an integral and functionally important part of the human environment. The greatest importance is gained by woody vegetation, which becomes a human shield between humans and health-harmful emissions from industry, cars, etc. Accordingly, optimizing and improving the functional quality of urban green areas due to the introduction of new promising species and cultivars is one of the key parameters of the state of the city itself. Analysis of recent research and publications. A number of works by researchers from Kryvyi Rih Area are devoted to the study of urban plantations in the steppe zone of Ukraine. The taxonomic composition, life status, botanical and geographical analysis of the dendroflora of Kryvyi Rih, problems of further optimization of the city's tree plantations are highlighted in many works by scientists of the Kryvyi Rih Botanical Garden of National Academy of Sciences of Ukraine and the Kryvyi Rih Pedagogical University (V. M. Savosko et al., 2013, 2017; V. D. Fedorovskyi .D. et al., 2013, Terlyha N.S. et al., 2014, 2015). In the collective work edited by E. O. Yevtushenko and V. M. Savosko “Structure and development of cultural phytocenoses of Kryvyi Rih Area” (2017) considered the structure and state of tree-shrub cultural phytocenoses of the region, ways and directions of their preservation and optimization. The purpose of the research is to determine the potential of the collection fund of woody plants of Kryvyi Rih Botanical Garden of NAS of Ukraine as a source of enrichment of the assortment for landscaping urban areas in the steppe zone of Ukraine. Research materials and methods. Identification of taxa was carried out according to the international classification. Vital status was determined according to the methods of L. S. Savelyeva (1975), V. D. Fedorovskyi (2007), V. T. Yarmishko (2002). The geographical analysis was carried out on the basis of the floristic zoning of the Earth by A. L. Takhtadjian (1978). Decorativeness of plants was studied according to the modified scale of Z. A. Vardanyan (2017). Research results and their discussion. The structure of greenery in Kryvyi Rih with all its shortcomings and imperfections is typical for other cities of Ukraine (Cherevchenko T.M., Kuznetsov S.I., 2003). Currently, the taxonomic composition of tree and shrub vegetation of parks and squares of Kryvyi Rih is represented by 202 taxa (162 species and 40 cultivars) from 89 genera and 41 families (Terlyha, 2014). The unsatisfactory condition of 40% of the examined woody plants and the uniformity of the taxonomic composition indicate the need for the reconstruction of plantations with the involvement of new representatives of tree and shrub vegetation and the use of modern measures of landscape design. A collection fund of tree and shrub plants, located in the arboretum of Kryvyi Rih Botanical Garden of National Academy of Sciences of Ukraine on the territory of 22 hectares, has a powerful potential for diversifying the city's plantations. Currently, the collection fund of woody plants of Kryvyi Rih Botanical Garden of National Academy of Sciences of Ukraine includes 720 species, 31 subspecies, 24 varieties, 421 cultivars, 1 intergeneric hybrid – a total of 1197 taxa belonging to 56 families and 155 genera. Gymnosperms are represented as follows: 6 families, 17 genera, 185 taxa, 48 species, 136 cultivars, 1 variety. The most numerous are the families Cupressaceae Bartl. – 109 and Pinaceae – 49 taxa. The greatest taxonomic diversity is characteristic of such genera as Juniperus L. – 56 taxa, Thuja L. – 31, Pinus L. – 21, Picea A. Dietr. - 15. Angiosperms have the following composition: 961 taxa from 57 families and 142 families, of which 679 species, 11 varieties, 225 cultivars, 46 hybrids. The family Rosaceae Juss. is represented by the greatest species and form diversity. – 237 species, 7 varieties, 56 forms, 20 hybrids, a total of 320 taxa, or 30% of the taxonomic composition of the collection. The most numerous genera from this family are: Crataegus L. – 63 taxa, Cotoneaster Medik. – 49, Spiraea L. – 45, Sorbus L. – 20, Malus L. – 19. The families Сaprifoliaceae and Berberidaceae are also diversely represented – 45 taxa in each, Fabaceae – 33, Oleaceae – 30, Salicaceae – 19, Aceraceae – 21, Betulaceae – 19, Hydrangeaceae – 18, Rhamnaceae – 15, Cornaceae – 16, Fagaceae – 14 species. In terms of life forms, gymnosperms in the collection are dominated by trees – 65% of the total number of taxa. In angiosperms, shrubs account for 55.5% of the total number of taxa, and trees – 38%, the remaining 6.5% – semi-shrubs and vines. Species from the East Asian region predominate in the collection of woody and shrubby plants – 30.1%, species with a wide range account for 22.8%, Circumboreal – 16.1%, Atlantic-North American – 15.5%. The number of species from the Irano-Turanian and Mediterranean regions, the ecological and biological features of which correspond as little as possible to the steppe conditions of Kryvyi Rih, is the smallest – 11.0% and 2%, respectively. The highest level of life status was determined in 35% of trees and bushes, slightly reduced in 25%, average in 32%, reduced in 8%. Very high decorativeness is characteristic of 55% of taxa, high – 25%, medium – 15%, low – 5%. At this time, 671 (90%) types of deciduous and coniferous species have reached the generative phase of development. On the basis of many years of research into the ecological and biological features of the functioning of woody plants both in the botanical garden and in the plantations of the city, an assortment of coniferous and deciduous plants promising for the conditions of the steppe climate was developed, which includes 510 species and 350 cultivars from 110 genera. A computer database of the collection fund of tree and shrub plants has been created, which contains information about their taxonomic composition and characteristics (source of acquisition, number of specimens, life state, generative capacity, etc.) and will be used to forecast its enrichment and preservation in the conditions permanent climatic changes. Conclusions and perspectives. The collection fund of Kryvyi Rih Botanical Garden of National Academy of Sciences of Ukraine is a center for the representation of woody vegetation of non-regional flora in the steppe industrial region of Ukraine and serves as a source of enrichment of green plantations with new species and cultivars. An introductory examination of woody plants from different botanical and geographical areas in the collections is a scientific basis for the development of phytooptimization solutions and the creation of new cultural phytocenoses in the region of the steppe zone.