Biosystems
Diversity
ISSN 2519-8513 (Print) ISSN 2520-2529 (Online) Biosyst. Divers., 2019, 27(3), 276-290 doi: 10.15421/011937
The non-native woody species of the flora of Ukraine: Introduction, naturalization and invasion
R. I. Burda, S. N. Koniakin
Institute for Evolutionary Ecology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
Article info
Received 16.07.2019 Received in revised form
14.08.2019 Accepted 15.08.2019
Institute for Evolutionary Ecology, National Academy of Sciences ofUkraine, Lebedeva st., 37, Kyiv, 03143, Ukraine. Tel.: +38-097-245-99-18. E-mail: riburda@ukr.net, ser681@ukr.net
Burda, R I., & Koniakin, S. N. (2019). The non-native woody species of the flora of Ukraine: Introduction, naturalization and invasion. BiosystemsDiversity, 27(3), 276-290. doi:10.15421/011937
The process of invasion, naturalization, dispersion and invasive activity of non-native woody species in 5 regional floras, 5 urban floras and over 30 floras of the protected areas is discussed. It has been established that 182 non-native species out of 95 genera and 45 families are currently at different naturalization stages in the spontaneous flora of Ukraine. In terms of life-forms, they may be divided as follows: trees - 41%, shrubs - 35%, trees/shrubs - 15%, lianas - 9%. Most species spread both via seed dispersal and the vegetative way - 56%, using only seed dispersal - 42%, only the vegetative way - 2%. According to the preliminary rating of species-wise invasive activity, 71 species (40%) have naturalized completely, among them 20 invasive species, including 12 transformer species, 29 potentially invasive species, and 22 naturalized species which demonstrate no invasive tendencies. The initial stages of invasion of 111 species are as follows: introduction - 9%, survival - 36%, adaptation of the reproductive sphere - 28%, establishment, formative of local populations - 27%. In terms of dispersion, non-naturalized species are divided as follows: rare - 45%, local - 16%, sporadic - 6%, unique - 12%, spreading under control beyond collections and expositions in botanical gardens and arboretums - 21%. Twelve transformer species, the greatest threat to local diversity, are Acer negundo, Ailanthus altissima, Amorpha fruticosa, Bupleurum futicosum, Elaeagnus angustifolia, E. rhamnoides, Fraxinus ornus, Parthenocissus quinquefolia, P. vitacea, Robinia pseudoacacia, Rhamnus alaternus, Salix x blanda and 8 invasive proper species: Berberis aquifolia, Colutea orientalis, Daphne laureola, Prunus cerasifera, P. serotina, Quercus ilex, Viburnum tinus, Vitis vinifera. The list of alien species, most widespread in 50 regions of Europe, includes Robinia pseudoacacia (42 regions), Ailanthus altissima (40), Acer negundo (38), Prunus cerasus (34), Quercus rubra (34), Rosa rugosa (34), Prunus domestica (31). The mitigation of the impacts of these species on local biodiversity is possible via the restoration of local native plant communities, land use organization, strict selection of introduced species prior to the introduction, culture of planting management, preventive measures and extending awareness and sharing of information about plant invasions. Therefore, Ukraine's spontaneous flora is notable for the active process of naturalization of non-native woody species with considerable involvement of invasive alien species. This is the first and preliminary evaluation of the invasive activity of woody species in Ukraine's flora. The manifestations of the global tendency of increased involvement and invasive activity of alien woody species in domestic flora have been confirmed. These conclusions are also relevant for elaborating the system of preventive, containing and mitigating measures regarding plant invasions in Ukraine.
Keywords: invasive alien species; tree; shrub; liana; species invasive activity.
Introduction
It is hard to overestimate the role of woody plants in creating plant cover and nutrient cycling, transfer of energy and information in the biosphere. They are dominants of plant community complexes and nuclei of consortia in ecosystems. While improving the environment, humans have long tried to draw woody plants nearer, to use all their diversity in order to satisfy intellectual, aesthetic, recreational and utilitarian needs. Since the end of the 18th century, Ukraine has had the oldest introduction centers -arboretums "Alexandria" and "Sofiivka", and somewhat younger collections of world flora treasures - the Nikitsky Botanical Garden, the arboretum of the biosphere reserve "Askania Nova", academic and university botanical gardens. In addition to their decorative, educational, aesthetic value and favourable impact on the environment, the establishment of the reserves of alien woody species (so called exotic plants) is relevant for greenery building, forestries and protective forestation, etc. However, the accumulation of exotic plants in cultivation is a remote risk of further invasions, naturalization, some of them penetrate to natural plant communities, which causes changes in the composition, structure and functions of the latter and poses a threat to the local gene fund.
Information on the distribution of alien plant species in the world is dramatic. The Global Naturalized Alien Flora (GloNAF) database contains 13,168 species or 3.9% of the extant global flora of vascular
plants. These alien species have secondary regions (van Kleunen et al., 2015; Pysek et al., 2017a, b). At least 75% and 93% of the world's naturalized alien flora is grown in home and botanical gardens, respectively (van Kleunen et al., 2018). The role of evolutionary changes during biological invasions must be understood (Blackburn et al., 2014; Zenni et al., 2017). This is important for mitigating the impacts and threats of penetration of woody plants into the natural flora (Pollegioni et al., 2013; Hirsch et al., 2017; Gaskin et al., 2017).
The article starts the analysis of diversity of the woody species, introduced to Ukraine, in order to find those which have invaded native or native-related plant communities, formed stable self-restoring local populations in them, become naturalized, revealed the ability to invade, formed secondary ranges and their own ecological niches, become invasive; it aims to determine the level of invasive activity of alien woody species and cryptic (hidden) threats of non-native woody species at the initial stages of migration.
Materials and methods
Let us define the main terms used in this article. Non-native (adventive, non-indigenous, exotic) species are the species whose occurrence in a specific territory is not related to the processes of natural florogenesis. These have overcome the geographical barrier due to human activity. Among them, we
distinguish alien species - completely naturalized, which created secondary ranges, and non-naturalized species, which are undergoing the first stages of migration. Spontaneous species are those, the occurrence and distribution of which in a specific territory does not depend on humans.
There is no separate accessible database in Ukraine, related to a relevant group of vascular plants in human life - woody species, intentionally introduced into the culture. In order to form the total list and the volume of cultivated woody species, we have had to review current "Catalogues" of collection funds of the botanical gardens (Kondratyuk, 1988; Kokhno, 1997; Grevtsova, 2000; Solomakha, 2007; Kolisny-chenko et al., 2011) and arboretums (Kosenko, 2000). We also used some articles about live botanical collections and spontaneous dispersion of woody exotic species from collections and expositions within introduction centers. The invasive activity of alien species in Ukraine's spontaneous flora was studied beyond introduction centers in native and approximately native community complexes within protected areas (Ba-ranovski et al., 2016; Lykholat et al., 2017, 2018a, 2018b). Special attention was paid to studying urban floras. We also noted the results of evaluating the invasive activity in regional floras, floras of agrolandsca-pes and floras of the nature reserve fund of different zones (Burda, 2003, 2007, 2018). Only non-native and spontaneously spreading species of Ukraine's flora have been considered. Sometimes native species, specified in the mentioned articles, have not been included in the analyzed lists (Acerplatanoides L., A. tataricum L., Sambucus nigra L. and Staphylea pinnata L.).
Non-native woody species, found in Ukraine's flora, have been characterized by 6 categories, traditional for invasive botany. The degree of their invasive activity has been described in accordance to the categories, implemented by the European Botanical Gardens Consortium (Mayorov et al., 2013). These are three categories of alien species: transformer species - a group of species, changing the conditions and nature of ecosystems in their larger area, they pose a threat to environmental safety of the region; invasive species - naturalized species, capable of having great amounts of progeny, due to which they spread rapidly across large distances from their paternal plants, are capable of invading and persisting in large areas, have invaded local community complexes, they affect local species, their communities and ecosystems; potentially invasive species - also naturalized species, which may become invasive upon future increase in their number, they do not have any visible impacts on local diversity; species, which have become naturalized, but have not demonstrated invasive activity. Additional consideration has been given to non-naturalized species in the process of naturalization, which are sometimes restored via seed dispersal or in a vegetative way near the area of native species, but are not capable of further invasion yet (a small number of diaspores, no functional connections). These plants do not demonstrate expressed tendencies of naturalization, their presence depends on constant stable input of diaspores from cultivated plants, though they do reproduce in some cases.
The species of the abovementioned groups are characterized in accordance to traditional classifications, used by Ukrainian authors in the abovementioned articles, which requires some elaboration (Didukh et al., 2000). The category "degree of naturalization" has 6 descriptors: аgrio-phyte - naturalized species which invaded native and native-related habitats; hemiagriophyte - species naturalized mostly in habitats which are close to native or degraded ones; epoecophyte - species naturalized only in anthropogenically transformed habitats; ergasiophyte - species intentionally introduced by humans which sometimes escape the cultivation limits, but are usually in the immediate proximity to the place of cultivation; colonophyte, non-naturalized species, unstable element of flora, related to cultivation, somewhat adjusted to new conditions of survival, capable of periodic formation of seeds or reproduction in the vegetative way; ephemerophyte - also non-naturalized species, unstable element of flora, which periodically occur in the places of cultivation of introduced woody species or among secondary habitats and vanish with time, as they are accidental migrants. The following species categories are distinguished in terms of occurrence: common species, widely and abundantly spread in the whole territory; local species, known in the whole territory, but abundant only in some locations; sporadic species, which occur frequently, but with low abundance, rare species, which are
present in 3-5 (7) locations, unique species, found in 1-2 locations, and controlled species, spread via seed dispersal or in the vegetative way beyond collections and expositions within the botanical gardens and arboretums. Three categories have been distinguished in terms of life-forms: a tree - a perennial woody plant with one well-formed stem and a crown, formed by side branches; a shrub - a perennial woody plant with multiple stems coming out of one source, the habitus does not have one well-formed main stem, and a liana - a perennial woody plant with a long stem, not capable of maintaining the vertical position without any additional support.
The names of the species are presented according to "The Plant List" database. The authors of all the names of the species, mentioned in the text, are given in Tables 5 and 6. The volumes of families of Mag-noliophyta (Angiosperms) and the sequence of their location in Tables 2, 5 and 6 are in accordance to "Synopsis of Families and Orders of Angiosperms of the Flora of Ukraine" (Mosyakin, 2013).
The non-native woody species of the flora of Ukraine, escaping from cultivation in botanical gardens and arboretums
Over 50 centers ofplant introduction are officially registered in Ukraine (Cherevchenko, 2011), and 10 of them are over 130 years old (Table 1). In addition, there are private commercial centers which import decorative plants, including trees, shrubs, and lianas, for sale. The attempts at finding and summarizing the diversity of live collections of the botanical gardens and arboretums have failed due to the absence of any unified database in free access mode. Our centers of plant introduction are mainly located in the temperate zone. They have been working for many years within creative cooperation of the Council of Botanical Gardens and Arboretums of Ukraine, exchanging their methods and seeds.
Taking into consideration these two circumstances, it becomes clear that the collections of woody plants in the introduction centers are somewhat duplicated. It would be reasonable to consider the richest collections of woody plants, collected in the arboretum "Sofivka", the M M Hryshko National Botanical Garden, the O. V. Fomin Botanical Garden, and the arboretum of the Nititsky Botanical Garden, which is located in conditions, approximated to those of the eastern Mediterranean (Table 1).
However, it is common knowledge that "every garden is famous for its own collections". For instance, the National Arboretum "Sofiiv-ka" is known for its rich collections of the genera Corylus - 28 species, Fagus - 21, Picea - 41, 100 species of lianas and over 320 varieties of roses (Kosenko, 2000). The O. V. Fomin Botanical Garden collected the most abundant generic complexes of Juniperus, Pinus, Cotoneaster, Forsythia, Lonicera, Magnolia, Rhododendron, Spiraea (Solomakha, 2007) and the Nikitsky Botanical Garden owns luxurient collections of genera Cupressus, Berberis, Cotoneaster, Lonicera, Philadelphus, Quer-cus, Spiraea, Thuja and Viburnum (Plugatar et al., 2015). As this statement reflects reality, it is noteworthy that the volume of the collections has neither changed much nor decreased for many years. For instance, the statistics for the arboretum of the Nikitsky Botanical Garden as of 1970 stated the presence of 1,704 species, including 689 trees, 879 shrubs, 136 lianas (Kormilitsin & Golubeva, 1970). In 1971 the collection of the National Botanical Garden contained 2,054 species, including Angiospermae - 1,884 species and Gymnopsermae - 170 species (Rubtsov & Gordienko, 1971). The collections, exceeding 1,000 woody species, have been collected in each of 8 introduction centers. It was recorded that in 1994 there were 1,655 species, 32 varieties, 547 forms of introduced trees, shrubs, and lianas (Kokhno, 1994). It should be also noted that the ratio between trees and shrubs (different life-forms) is not significant. It may be balanced (arboretum "Alexandria", the Botanical Garden of the National University of Dnipro, the Donetsk Botanical Gardens), or the number of species whose life-form is a shrub may exceed the number of species belonging to the tree life-form (arboretum "Sofiivka", the Kryvyi Rih Botanical Garden), or the ratio between the species with these life-forms is reverse (the Botanical Garden of Odesa University). Thus, the volumes of the richest modern collections and their age permit the assumption that these collections may be a source of dispersing non-native woody species into the domestic flora, completely established quite a long time ago.
Table 1
The collection funds of woody plants in the leading Ukrainian centers of plant introduction
Center of plant introduction Year of Source Number of species
foundation total tree* shrub* liana*
The arboretum "Alexandria", NAS of Ukraine 1793 Galkin et al., 2017 1282 538 680 64
The National Arboretum "Sofiivka", NAS of Ukraine 1796 Kosenko, 2000 2400 800 1600
Botanical Garden of V. N. Karazin Kharkiv National University 1804 Alokhin et al., 2019 781 - - -
The Nikitsky Botanical Garden 1812 Plugatar et al., 2015 1690 - - -
The arboretum "Trostyanets", NAS of Ukraine 1834 Medvedyev & Ilyenko, 2018 623 - - -
O. V. Fomin Botanical Garden of Taras Shevchenko National Universi- 1839 Solomakha, 2007 1828 923
ty of Kyiv - -
Botanical Garden of Ivan Franko L'viv National University 1852 Prokopiv, 2004 787 - - -
Botanical Garden of Odesa of I. I. Mechnikov National University 1867 Filatova et al., 2014; Slyusarenko et al., 2017 1025 611 341 73
Botanical Garden of Yuriy Fedkovych Chernivtsi National University 1877 Cherevchenko, 2011 1150 - - -
The arboretum of F. J. E. Falz-Fein "Askania Nova" Nature Biosphere 1887 Rubtsov et al., 2012 1114
Reserve, NAAS of Ukraine
Botanical Garden of National University of Life and Environmental Sciences of Ukraine, Kyiv 1928 Kolisnychenko et al., 2011 604 - - -
Botanical Garden of Oles Honchar Dnipro National University 1933 Kvasha et al., 2010 389 159 147 83
M. M. Hryshko National Botanical Garden, NAS of Ukraine 1935 Kokhno, 1997 1025 - - -
The Donetsk Botanical Garden, NAS of Ukraine 1964 Kondratyuk, 1988 868 457 411 -
The Kryvyi Rih Botanical Garden, NAS of Ukraine 1980 Grevtsova, 2000 661 245 393 23
Note: "-" - marks: data is absent in source.
Only two published "Catalogues" of collection funds present systematized information about spontaneous dispersion ofwoody species from collections and expositions (Kondratyuk, 1988; Solomakha, 2007) (Table 2). Some fragments of the data are stated in special publications. After twenty years of introductory testing, 15 woody species, including 8 non-native cultivated ones, had natural regrowth in the Donetsk Botanical Garden of NAS of Ukraine (Kondratyuk, 1988). After 10 years, 54 species, including 13 aboriginal species, were found to be spontaneously distributing; 48 species had stable natural regrowth (Burda et al., 1998). It was noted
Table 2
The list of non-native species, spontaneously distributing in the centers of plant introduction
that the species of genus Clematis, in particular, C. vitalba, spread far from the place of initial introduction, while remaining in the garden. Later it was additionally reported that 19 non-native species had spontaneously spread within the boundaries of the garden (Eremenko & Ostapko, 2011, 2014). The total number amounted to 67 species. The location of C. vitalba was found 4 km from the garden and was interpreted as "escaping" from its collections (Ostapko et al., 2013). We place this assumption in question as C. vitalba was found on the roadside between the cities of Donetsk and Makiivka, which bordered summer cottages.
Family Taxon* Life-form Spread Center of introduction
Pinophyta
Pinaceae *Larix decidua MU tree seed Donetsk Botanical Garden
Cupressaceae *Thuja occidentalis L. 1ree/shrub seed Botanical Garden of Ivan Franko National University of L'viv
Magnoliophyta
Berberidaceae Berberidaceae Berberidaceae Berberis aquifolium Pursh. *B. thunbergii DC. B. vulgaris L. shrub shrub shrub seed, vegetative way seed, vegetative way seed, vegetative way Donetsk Botanical Garden Arboretum "Alexandria" Donetsk Botanical Garden
Ranunculaceae Ranunculaceae Ranunculaceae "Clematis gouriana Roxb. ex DC. *C. jackmanii T. Moore. *C. ligusticifolia Nutt liana liana liana seed, vegetative way seed, vegetative way seed, vegetative way Donetsk Botanical Garden Donetsk Botanical Garden Donetsk Botanical Garden
Ranunculaceae Ranunculaceae *C. tangutica (Maxim.) Korsh. C. vitalba L. liana liana seed, vegetative way seed, vegetative way Donetsk Botanical Garden Arboretum "Alexandria", Donetsk Botanical Garden
Ranunculaceae *C. viticella L. liana seed, vegetative way Arboretum "Alexandria"
Hamamelidaceae *Parrotia subaequalis (Hung T. Chang) R M. Hao & H. T. Wei tree/shrub seed M. M. Hryshko National Botanical Garden
Grossulariaceae *Ribes americanum Mill. shrub seed Donetsk Botanical Garden
Grossulariaceae R. aureum Pursh shrub seed Donetsk Botanical Garden
Grossulariaceae R europaea (L.) Mill. shrub seed Donetsk Botanical Garden
Grossulariaceae R. rubrum L. shrub seed Donetsk Botanical Garden
Grossulariaceae R. spicatum Robson shrub seed Donetsk Botanical Garden
Vitaceae Vitaceae "Ampelopsis aconitifolia Bunge *A. delavayana var. glabra (Diels & Gilg) C. L. Li liana liana seed, vegetative way seed, vegetative way Donetsk Botanical Garden Donetsk Botanical Garden
Vitaceae Vitaceae Vitaceae *A. bodinieri (H. Lev. & Vaniot) Rehder *A. glandulosa var. brevipedunculata (Maxim.) Momiy Parthenocissus quinquefolia (L.) Planch. liana liana liana seed, vegetative way seed, vegetative way seed, vegetative way Donetsk Botanical Garden Donetsk Botanical Garden Botanical Garden of Oles Honchar National University of Dnipro, Donetsk Botanical Garden, O. V. Fomin Botanical Garden
Vitaceae Vitaceae Vitaceae P. vitacea (Knerr) Hitchc. *Vitis coignetiae Bull. ex Planch V. vinifera L. liana liana liana seed, vegetative way seed, vegetative way seed, vegetative way Donetsk Botanical Garden Donetsk Botanical Garden Donetsk Botanical Garden, O. V. Fomin Botanical Garden
Fabaceae Fabaceae Amorpha fruticosa L. Caragana arborescens Lam. shrub shrub seed, vegetative way seed, vegetative way Arboretum "Alexandria", Botanical Garden of Oles Honchar National University of Dnipro, Donetsk Botanical Garden Arboretum "Alexandria", Donetsk Botanical Garden
Fabaceae Gleditsia triacanthos L. tree seed Botanical Garden of Oles Honchar National University of Dnipro, Donetsk Botanical Garden
Fabaceae Gymnocladus dioica (L.) K. Koch tree seed Arboretum "Alexandria", Donetsk Botanical Garden
Family Taxon* Life-form Spread Center of introduction
Fabaceae Halimodendron halodendron (Pall.) Voss shrub seed Donetsk Botanical Garden Arboretum "Alexandria", Donetsk Botanical Garden,
Fabaceae Robinia pseudoacacia L. tree seed, vegetative way O. V. Fomin Botanical Garden, Botanical Garden of Ivan Franko National University of L'viv
Fabaceae R viscosa Vent. tree seed, vegetative way Arboretum "Alexandria"
Rosaceae Cerasus tomentosa (Thunb.) Wall. ex T. T. Yu & C. L. Li shrub seed Donetsk Botanical Garden
Rosaceae Crataegus submollis Sarg. shrub seed Arboretum "Alexandria"
Rosaceae Crataegus sp. shrub seed Donetsk Botanical Garden
Rosaceae Malus domestica Borkh. tree seed, vegetative way Donetsk Botanical Garden
Rosaceae Mespilus germanica L. shrub seed, vegetative way Donetsk Botanical Garden
Rosaceae Physocarpus opulifolius (L.) Maxim. shrub seed, vegetative way Arboretum "Alexandria"
Rosaceae Prunus armeniaca L. tree seed, vegetative way Donetsk Botanical Garden
Rosaceae P. cerasus L. tree seed, vegetative way Donetsk Botanical Garden
Rosaceae P. cerasifera Ehrh. tree/shrub seed, vegetative way Arboretum "Alexandria"
Rosaceae P. mahaleb L. shrub seed Donetsk Botanical Garden
Rosaceae P. serotina Ehrh. tree/shrub seed, vegetative way Donetsk Botanical Garden
Rosaceae Rosa sp. shrub seed, vegetative way Donetsk Botanical Garden
Rosaceae *Rubus odoratus L. shrub seed, vegetative way Arboretum "Alexandria"
Rosaceae Sorbaria sorbifolia (L.) A. Braun shrub seed, vegetative way Arboretum "Alexandria", Donetsk Botanical Garden, O. V. Fomin Botanical Garden
Rosaceae Spiraea x billardii Hérin shrub seed, vegetative way Donetsk Botanical Garden
Rosaceae S. chamaedryfolia L. shrub seed, vegetative way Arboretum "Alexandria"
Rosaceae S. salicifolia L. shrub seed, vegetative way Arboretum "Alexandria"
Elaeagnaceae Elaeagnus angustifolia L. tree/shrub seed, vegetative way Donetsk Botanical Garden
Elaeagnaceae E. rhamnoides (L.) A. Nelson shrub seed, vegetative way Donetsk Botanical Garden
Elaeagnaceae E. umbellata Thunb. tree seed, vegetative way Arboretum "Alexandria"
Ulmaceae Celtis australis L. tree seed M. M. Hryshko National Botanical Garden
Ulmaceae C. occidentalis L. tree seed Donetsk Botanical Garden
Ulmaceae Ulmus pumila L. tree seed, vegetative way Donetsk Botanical Garden, O. V. Fomin Botanical Garden
Moraceae Morus alba L. tree seed Donetsk Botanical Garden
Fagaceae Quercus rubra L. tree seed Arboretum "Alexandria", Donetsk Botanical Garden, O. V. Fomin Botanical Garden
Fagaceae *Q. macranthera Fisch. & C.A Mey. ex Hohen. tree seed M. M. Hryshko National Botanical Garden
Juglandaceae Juglans mandshurica Maxim. tree seed Donetsk Botanical Garden
Juglandaceae J. nigra L. tree seed Arboretum "Alexandria"
Juglandaceae J. regia L. tree seed Arboretum "Alexandria", Donetsk Botanical Garden, O. V. Fomin Botanical Garden
Celastraceae Celastrus angulata Maxim. liana seed, vegetative way Donetsk Botanical Garden
Celastraceae C. flagellaris Rupr. liana seed Donetsk Botanical Garden
Celastraceae C. orbiculatus Thunb. liana seed Arboretum "Alexandria", Donetsk Botanical Garden
Salicaceae Populus balsamifera L. tree seed, vegetative way Donetsk Botanical Garden
Salicaceae P. x canadensis Moench tree seed, vegetative way Donetsk Botanical Garden
Salicaceae P. trichocarpa Torr. & A. Gray ex Hook. tree seed, vegetative way Donetsk Botanical Garden
Anacardiaceae Rhus glabra L. tree/shrub seed, vegetative way Botanical Garden of Ivan Franko National University of L'viv
Anacardiaceae *R typhina L. tree vegetative way Arboretum "Alexandria", Donetsk Botanical Garden, Botanical Garden of Ivan Franko National University of L'viv
Anacardiaceae *R. typhina 'Laciniata' tree vegetative way Arboretum "Alexandria"
Anacardiaceae Toxicodendron pubescens Mill. shrub seed, vegetative way Arboretum "Alexandria"
Anacardiaceae T. radicans (L.) O. Kuntze shrub seed, vegetative way Donetsk Botanical Garden Arboretum "Alexandria", Botanical Garden of Oles Hon-
Aceraceae Acer negundo L. tree seed char National University of Dnipro, Donetsk Botanical Garden, O. V. Fomin Botanical Garden, Botanical Garden of Ivan Franko National University of L'viv
Aceraceae *A. platanoides L. f. atropurpurea 'Krimson King A. saccharinum L. tree seed Donetsk Botanical Garden
Aceraceae tree seed Donetsk Botanical Garden
Hippocasta naceae Aesculus hippocastanum L. tree seed Arboretum "Alexandria", Donetsk Botanical Garden, O. V. Fomin Botanical Garden
Simaroubaceae Ailanthus altissima (Mill.) Swingle tree seed, vegetative way Arboretum "Alexandria", Botanical Garden of Ivan Franko National University of L'viv, Donetsk Botanical Garden
Cornaceae Cornus alba L. shrub seed, vegetative way Donetsk Botanical Garden
Hydrangeaceae Philadelphus coronarius L. shrub seed, vegetative way Donetsk Botanical Garden
Solanaceae Lycium barbarum L. shrub seed, vegetative way Arboretum "Alexandria"
Oleaceae Fraxinus ornus L. tree seed Nikitsky Botanical Garden
Oleaceae F. pennsylvanica Marshall tree seed Donetsk Botanical Garden
Oleaceae Syringa vulgaris L. shrub seed, vegetative way Arboretum "Alexandria", Donetsk Botanical Garden, O. V. Fomin Botanical Garden
Bignoniaceae *Campsis grandiflora (Thunb.) K. Schum. liana vegetative way Arboretum "Alexandria"
Bignoniaceae *C. radicans (L.) Seem. liana vegetative way Arboretum "Alexandria"
Caprifoliaceae Lonicera caerulea L. shrub seed Donetsk Botanical Garden
Caprifoliaceae L. caprifolium L. shrub seed Arboretum "Alexandria"
Caprifoliaceae L. tatarica L. shrub seed Arboretum "Alexandria", Donetsk Botanical Garden
Caprifoliaceae Symphoricarpos albus (L.) S.F. Blake shrub seed, vegetative way Donetsk Botanical Garden
Apiaceae Bupleurum fruticosum L. shrub seed, egetative way Nikitsky Botanical Garden
Aracaceae *Aralia elata (Miq.) Seem. shrub seed, vegetative way Botanical Garden of Ivan Franko National University of L'viv
Note: * - the species whose dispersion is known only beyond the framework of collections and expositions in botanical gardens and arboretums.
The inspection of spontaneous spreading of intentionally introduced species from O. V. Fomin Botanical Garden of Taras Shevchenko National University of Kyiv resulted in issuing "The preliminary list of the species of the O. V. Fomin Botanical Garden, spreading beyond their place of cultivation" (Solomakha, 2007). This list contains 245 species, including 6 species - trees (Acer negundo, Aesculus hippocastanum, Juglans regia, Quercus rubra, Robinia pseudoacacia and Ulmus pumila), 2 species - shrubs (Sorbaria sorbifolia and Syringa vulgaris), 2 species -lianas (Parthenocissus quinquefolia and Vitis vinifera).
45 woody species, including 13 aboriginal ones, are spontaneously spreading using seed dispersal and vegetative reproduction within the arboretum "Alexandria". Some non-native species do not reproduce via seed dispersal, but reproduce actively via vegetative reproduction: Camp-sis grcmdifom, C. radicans, Rhus typhina, R typhina 'Laciniata', Rubus odoratus, Syringa vulgaris, Toxicodendronpubescens (Doyko et al., 2014).
Woody plants, capable of reproducing spontaneously via either seed dispersal or vegetative reproduction, were found among intentionally introduced plants in the Botanical Garden of the Ivan Franko L'viv National University. These were four species of trees (Acer negundo, Ailanthus altissima, Robinia pseudoacacia and Thuja occidentalis) and three species of shrubs (Aralia elata, Rhus glabra, R. typhina) (Borsu-kevych & Prokopiv, 2014). Among spontaneous species of the flora at the Botanical Garden of Oles Honchar National University of Dnipro, there are four known woody species (Acer negundo, Amorpha frutico-sa, Gleditsia triacanthos and Parthenocissus quinquefolia). While analyzing the results of long-term observations, the authors noted the tendency towards the increase in their number and degree of naturalization within the garden (Tarasov et al., 1998). The "Catalogue" of plants of the M. M. Hryshko National Botanical Garden (Kokhno, 1997) does not have any data about seed dispersal. Occasionally there were some publications about seed dispersal of woody plants from its collections and expositions. Shinder (2013) considers the botanic-geographical area "Caucasus" to be the source of distribution of Caucasian species into anthropogenically altered locations within the garden. Celtis australis escaped the boundaries of the "Caucasus" area. Some Caucasian species have established stable spontaneous cenopopulations in the created simulated communities of this exposition. For instance, a rare species Quercus macranthera dominates in the growing stock of the planted dry oakery, constantly forming abundant natural self-sown plants. Periodic formation of abundant natural self-seeding of Parrotia subaequalis was recorded (Doroshenko et al., 2013).
The naturalization of plants in the oldest arboretums of the Nikitsky Botanical Garden must have occurred at the beginning of the 20th century. Without highlighting the collections ofthe garden, Stankov (19241925) noted the remarkable presence of the cultural element of the Mediterranean flora in the plant cover of the South Coast of Crimea. He mentioned 55 non-native species, which added unique Mediterranean charm to the landscape. S. S. Stankov observed the naturalization of the following 22 species in the Crimea personally: Ailanthus altissi-ma, Berberis aquifolium, Bupleurum fruticosum, Cercis siliquastrum, Clematis flammula, Cydonia oblonga, Elaeagnus angustifolia, E. rhamnoides, Ficus carica, Fraxinus ornus, Ilex aquifolium, Laburnum anagyroides, Madura pomifera, Morus alba, Olea europaea, Prunus armeniaca, P. cerasifera, P. cerasus, P. domestica, P. domestica subsp. insititia, Rhamnus alaternus and Spartium junceum. This list was later supplemented with Laurus nobilis, Lonicera caprifolium, Viburnum ti-nus, and S. S. Stankov doubted their going out of cultivation (Bagriko-va, 2013). Obviously, we do not have any evidential materials to prove that all of these species have spread within the South Coast of Crimea after escaping the Nikitsky Botanical Garden. On the one hand, this institution had supplied many exotic trees, shrubs, and lianas to the market, being the only center of plant introduction in the Crimea, on the other hand, in different times, even with active dendrological collections of the Garden, amateurs of the garden art brought decorative woody plants to the Crimea, which could have spread beyond the locations of cultivation in different corners of the South Coast of Crimea. There is only one direct statement about two species (Bupleurum fruticosum, Fraxinus ornus), spreading within the nature reserve "Mys Martian" from the adjacent plant communities ofthe Nikitsky Botanical Garden (Bagrikova et al., 2014).
Therefore, 92 non-native woody species out of 49 genera and 28 families are spreading in collection areas and expositions or beyond them, but not escaping the boundaries of introduction centers in 6 abo-vementioned botanical gardens and arboretums. Table 2 presents 6 families, covering 5 or more species: Rosaceae - 17, Vitaceae - 8, Fabaceae - 7, Ranunculaceae - 6, Anacardiaceae - 5 and Grossulaceae - 5. Spontaneous distribution of most species has been noted only in one garden (73), in 5 gardens there is a noted distribution of only Acer ne-gundo, and in 4 - Robinia pseudoacacia. Half of these species have long been naturalized and become common elements of spontaneous flora. However, spontaneous distribution of 23 species is known only in controlled conditions of the botanical gardens and arboretums. For instance, these are Aralia elata, Parrotia subaequalis, Vitis coignetiae, Rhus typhina, R. typhina 'Laciniata', Rubus odoratus. Thus, the assumption, expressed by us regarding the centers of initial introduction of plants in Ukraine as the sources of distributing non-native woody species, has not been confirmed.
The non-native woody species in the urban flora of Ukraine
The degree of invasive activity of alien woody species in the framework of urban flora plays an important role in determining their part in the spontaneous flora of Ukraine. The main centers of naturalization of non-native species are cities with their suburbs, which unite parks, public gardens, green zone plantings, botanical gardens and arboretums. We have analyzed the lists of four recently thoroughly studied urban floras of such cities as Kyiv (Mosyakin & Yavorska, 2002), Kryvyi Rih (Kuchrevskyi & Shol, 2009), Uzhhorod (Protopopova & Shevera, 2002), Kharkiv (Zvyagintseva, 2015), and combined floras of Slo-viansk, Donetsk, Luhansk, and Mariupol, which have formed within industrial Donbas (Burda, 1997). These cities are in different regions of Ukraine and differ in the degree of environmental urbanization. Concluding the consideration of urban floras, we would like to highlight that the lists of alien species coincide in the main part (Table 3). This fact allowed us to combine woody species into a unified list to determine the degree of their naturalization. The authors of urban floras often added aboriginal species to them. They are absent in the combined list: Betula pendula Roth, B. pubescens Ehrh., Lonicera xylosteum L., Rubus idaeus L., Sambucus racemosa L., Sorbus aucuparia L., Tilia platy-phyllos Scop., Viburnum lantana L., etc. Consideration was also given to the list of flora in Chernihiv, where the degree of naturalization was not indicated (Zavyalova, 2010). This urban flora contains about 50 non-native woody species, and the combined list of urban floras of Ukraine was added Phellodendron amurense and Spiraea x vanhouttei therefrom. The total list of alien woody species of 6 urban floras of Ukraine contains 80 species, 1 subspecies, and 1 hybrid (Table 3, 4). The picture of naturalization of non-native species in urban floras is very rich. They differ in terms of structure, degree of naturalization, species composition, and all of these are mutually related. The richest floras are noted for Kyiv, Kharkiv, Chernihiv, and the urban flora of Kryvyi Rih is not far behind them.
The degree of naturalization is also different. The only species, evaluated in all the floras as agriophyte, is Salix x blanda, and the one close to it is Acer negundo. The following species occur in one urban flora only: Ficus carica, Rubus macrophyllus, Toxicodendron radicans, Vitis labrusca. Agriophytes are concentrated in Kharkiv, hemiagriophytes and colonophytes - in Kyiv, ergasiophytes - in Kharkiv and Kryvyi Rih. Thus, urban floras have a high degree of naturalization of non-native woody species.
The course of invasion of non-native woody species in the regional floras and in the floras of protected areas
The regional studies, conducted by the specialists, headed by V. V. Protopopova, defined the following transformer species in the flora of 5 regions: Polissia - Robinia pseudoacacia (Protopopova et al., 2015); Bukovyna Cis-Carpathian region - Acer negundo, Robinia pseudoacacia (Protopopova et al., 2010); Middle Dnipro region - Acer negundo, Amorpha fruticosa, Robinia pseudoacacia (Protopopova et al.,
2014); North Black Sea region - Amorpha fruticosa, Elaeagnus angus-tifolia and Salix x blanda (Protopopova et al., 2009); South Coast of Crimea - Ailanthus altissima, Bupleurum fruticosum, Fraxinus ornus and Rhamnus alaternus (Protopopova et al., 2012). The authors distinguished 39 invasive species, including 13 woody species, in the flora of the Crimea. Robinia pseudoacacia is mentioned in four regions, Acer negundo, Amorpha fruticosa - in three, Elaeagnus angustifolia - in two and Salix x blanda - in only one region. According to our observations, the features of transformer species in the floras of 14 territories, which are subject to special protection in the Forest Steppe, are remarkable for 7 species: Acer negundo, Elaeagnus angustifolia, E. rhamnoides, Par-thenocissus quinquefolia, P. vitacea, Robinia pseudoacacia and Salix x blanda. They occurred in at least 9 out of 14 floras, except for E. rham-noides, noted in 3 floras only (Burda et al., 2015b). The study of alien flora species in 30 territories of the nature reserve fund in different natu-
ral zones revealed the same 7 species of transformers.These are three trees: Acer negundo, Robinia pseudoacacia and Salix x blanda; 2 shrubs: Elaeagnus angustifolia and E. rhamnoides and 2 lianas: Parthenocissus quinquefolia and P. vitacea (Burda et al., 2015a). While determining the "transformer species" status, the main feature is stated as the ability to change the ecosystem completely. Five invasive species proper have been distinguished in the same place: Amorpha fruticosa, Morus alba, Prunus cerasus, P. semtina and P. virginiana. The floras of the nature reserve fund contain 16 woody species, which have naturalized (according to the scheme, accepted in this article, this notion is close to the term, further used by us, - "potentially invasive species"). In addition to the mentioned species, let us mention 31 more species, related to the ones which reproduce spontaneously, sporadically or in a single way in the reserve areas.
Table 3
The degree of naturalization and the occurrence of non-native woody species in some urban floras of Ukraine
Species Kyiv Kryvyi Rih Kharkiv Uzhhorod Donbas Flora Degree of naturalization
Salix x blanda agriophyte agriophyte agriophyte agriophyte agriophyte 5 5 agriophytes
Acer negundo agriophyte hemiagriophyte agriophyte hemiagriophyte agriophyte 5 3 agriophytes: 2 hemiagriophytes
Berberis aquifolia agriophyte ergasiophyte agriophyte ergasiophyte 0 4 2 agriophytes: 2 ergasiophytes
Prunus cerasifera 0 ergasiophyte agriophyte agriophyte 0 3 2 agriophytes: 1 ergasiophyte
Amorpha fruticosa agriophyte hemiagriophyte ergasiophyte ergasiophyte ergasiophyte 5 1 agriophyte: 1 hemiagriophyte: 3 ergasiophytes
Elaeagnus angustifolia 0 hemiagriophyte agriophyte ergasiophyte epoecophyte 4 1 agriophyte: 1 hemiagriophyte: 1 epoecophyte: 1 ergasiophyte
Prunus serotina agriophyte ergasiophyte 0 0 0 2 1 agriophyte: 1 ergasiophyte
Parthenocissus vitacea hemiagriophyte 0 agriophyte 0 0 2 1 agriophyte: 1 hemiagriophyte
Cydonia oblonga 0 0 agriophyte 0 0 1 1 agriophyte
Prunus domestica subsp. insititia 0 0 0 agriophyte 0 1 1 agriophyte
Robinia pseudoacacia hemiagriophyte hemiagriophyte ergasiophyte ergasiophyte ergasiophyte 5 2 hemiagriophytes: 3 ergasiophytes
Lycium barbarum hemiagriophyte hemiagriophyte epoecophyte epoecophyte epoecophyte 5 2 hemiagriophytes: 3 epoecophytes
Ulmus pumila hemiagriophyte hemiagriophyte ergasiophyte 0 0 3 2 hemiagriophytes: 1 ergasiophyte
Caragana arborescens hemiagriophyte ergasiophyte ergasiophyte 0 ergasiophyte 4 1 hemiagriophyte: 3 ergasiophytes
Acer saccharinum hemiagriophyte ergasiophyte ergasiophyte 0 0 3 1 hemiagriophyte: 2 ergasiophytes
Quercus rubra hemiagriophyte ergasiophyte ergasiophyte 0 0 3 1 hemiagriophyte: 2 ergasiophytes
Ptelea trifoliata hemiagriophyte ergasiophyte 0 0 0 2 1 hemiagriophyte: 1 ergasiophyte
Elaeagnus commutata 0 hemiagriophyte 0 0 0 1 1 hemiagriophyte
Morus alba epoecophyte ergasiophyte colonophyte 0 epoecophyte 4 2 epoecophytes: 1 ergasiophyte: 1 colonophyte
Gleditsia triacanthos colonophyte ergasiophyte epoecophyte ergasiophyte 0 4 1 epoecophyte: 2 ergasiophytes: 1 colonophyte
Fraxinus pennsylvanica epoecophyte epoecophyte ergasiophyte 0 0 3 2 epoecophytes: 1 ergasiophyte
Elaeagnus rhamnoides 0 epoecophyte epoecophyte ergasiophyte 0 3 2 epoecophytes: 1 ergasiophyte
Lonicera tatarica colonophyte epoecophyte epoecophyte 0 0 3 2 epoecophytes: 1 colonophyte
Populus deltoides colonophyte epoecophyte epoecophyte 0 0 3 2 epoecophytes: 1 colonophyte
Parthenocissus quinquefolia colonophyte epoecophyte 0 ergasiophyte 0 3 1 epoecophyte: 1 ergasiophyte: 1 colonophyte
Ailanthus altissima epoecophyte colonophyte ergasiophyte 0 0 3 1 epoecophyte: 1 ergasiophyte: 1 colonophyte
Spiraea salicifolia epoecophyte 0 ergasiophyte 0 0 2 1 epoecophyte: 1 ergasiophyte
Symphoricarpos albus colonophyte 0 epoecophyte 0 0 2 1 epoecophyte: 1 colonophyte
Parthenocissus tricuspidata 0 0 epoecophyte 0 0 1 1 epoecophyte
Cornus sericea 0 0 epoecophyte 0 0 1 1 epoecophyte
Juglans regia ephemerophyte ergasiophyte ergasiophyte ergasiophyte 0 4 3 ergasiophytes: 1 ephemerophyte
Prunus armeniaca colonophyte ergasiophyte ergasiophyte 0 ergasiophyte 4 3 ergasiophytes: 1 colonophyte
P. cerasus colonophyte ergasiophyte ergasiophyte 0 ergasiophyte 4 3 ergasiophytes: 1 colonophyte
Syringa vulgaris colonophyte colonophyte ergasiophyte ergasiophyte 0 4 2 ergasiophytes: 2 colonophyte
Vitis vinifera ephemerophyte ergasiophyte ergasiophyte 0 ergasiophyte 4 3 ergasiophytes: 1 ephemerophyte
Aesculus hippocastanum 0 ergasiophyte ergasiophyte ergasiophyte 0 3 3 ergasiophytes
Ribes uva-crispa 0 ergasiophyte ergasiophyte 0 ergasiophyte 3 3 ergasiophytes
Malus domestica colonophyte ergasiophyte ergasiophyte 0 0 3 2 ergasiophytes: 1 colonophyte
Prunus mahaleb colonophyte ergasiophyte 0 0 ergasiophyte 3 2 ergasiophytes: 1 colonophyte
Catalpa bignonioides 0 0 ergasiophyte ergasiophyte 0 2 2 ergasiophytes
Juglans nigra 0 ergasiophyte ergasiophyte 0 0 2 2 ergasiophytes
Populus bolleana 0 ergasiophyte ergasiophyte 0 0 2 2 ergasiophytes
P. nigra var. italica 0 ergasiophyte ergasiophyte 0 0 2 2 ergasiophytes
Aronia melanocarpa colonophyte 0 ergasiophyte 0 0 2 1 ergasiophyte: 1 colonophyte
Malus baccata colonophyte 0 ergasiophyte 0 0 2 1 ergasiophyte: 1 colonophyte
Celtis occidentalis colonophyte ergasiophyte 0 0 0 2 1 ergasiophyte: 1 colonophyte
Lonicera caprifolium colonophyte 0 0 ergasiophyte 0 2 1 ergasiophyte: 1 colonophyte
Rhus typhina 0 colonophyte ergasiophyte 0 0 2 1 ergasiophyte: 1 colonophyte
Aesculus flava 0 0 ergasiophyte 0 0 1 1 ergasiophyte
Castanea sativa 0 0 0 ergasiophyte 0 1 1 ergasiophyte
Crataegus sanguinea 0 0 ergasiophyte 0 0 1 1 ergasiophyte
Juglans cinerea 0 ergasiophyte 0 0 0 1 1 ergasiophyte
Populus suaveolens 0 0 ergasiophyte 0 0 1 1 ergasiophyte
Persica vulgaris 0 ergasiophyte 0 0 0 1 1 ergasiophyte
Prunus virginiana 0 0 ergasiophyte 0 0 1 1 ergasiophyte
Species_Kyiv_Kryvyi Rih_Kharkiv_Uzhhorod_Donbas Flora_Degree of naturalization
P. domestica 0 ergasiophyte 0
Tilia americana 0 0 ergasiophyte
Colutea arborescens 0 ergasiophyte 0
Cornus alba 0 ergasiophyte 0
Philadelphus coronarius 0 0 ergasiophyte
Salix babylonica 0 0 ergasiophyte
Ribes aureum 0 ergasiophyte 0
R. rubrum 0 0 0
Rosa rugosa colonophyte 0 ergasiophyte
Robinia neomexicana 0 0 ergasiophyte
Robinia viscosa 0 ergasiophyte 0
Juglans mandshurica colonophyte 0 0
Amelanchier ovalis colonophyte 0 0
Berberis thunbergii colonophyte 0 0
B. vulgaris colonophyte 0 0 Populus balsamifera colonophyte 0 0 Quercus palustris colonophyte 0 0 Sorbaria sorbifolia colonophyte 0 0 Spiraea douglasii colonophyte 0 0 Physocarpus opulifolius colonophyte 0 0 Cotoneaster melanocarpus colonophyte 0 0 Clematis jackmanii colonophyte 0 0
C. viticella colonophyte 0 0 Ficus carica ephemerophyte 0 0 Rubus macrophyllus 0 0 0 Toxicodendron radicans ephemerophyte 0 0 Vitis labrusca_ephemerophyte_0_0
Tbtaí 49 44 49
Note: here and in Tables 4 and 7 "0" - the species is absent.
Table 4
The degree of naturalization of woody exotic species in some urban floras of Ukraine
Degree of naturalization Kyiv Kryvyi Rih Kharkiv Uzhhorod Donbas Total*
Agriophyte 5 1 7 3 2 10
Hemiagriophyte 8 7 0 1 0 8
Epoecophyte 4 5 8 1 3 12
Ergasiophyte 0 28 33 13 9 36
Colonophyte 27 3 1 0 0 12
Ephemerophyte 5 0 0 0 1 4
Total 49 44 49 18 15 82
Note: * - this column presents the data about the number of species in specific
categories of the total list.
68 exotic species have spontaneously spiead within the South Coast of Crimea. These aie 27 agiiophytes: Acer negundo, Ailanthus altissima, Berberis aquifolia, Bupleurum fruticosum, Buxus sempervirens, Cercis si-liquastrum, Clematis flammula, Colutea orientalis, Cydonia oblonga, Daphne laureola, Elaeagnus angustifola, Ficus carica, Fraxinus ornus, Laburnum anagyroides, Lonicera etrusca, Lycium barbarum, Malus domestica, Platycladus orientalis, Prunus cerasifera, P. dulcis, Ptelea trifo-liata, Pueraria montana var. lobata, Pyrus communis, Quercus ilex, Rhamnus alatemus, Viburnum tinus and Vitis vinifera, 40 colonophytes: Abies pinsapo, Amorpha fruticosa, Buddleja davidii, Caragana arbores-cens, Castenea sativa, Catalpa bignonioides, Cedrus atlantica, C. deoda-ra, Celtis australis, C. caucasica, Cladrastis kentukea, Colutea arbores-cens, Cotoneaster glaucophyllus, Cupressus sempervirens, Dyospyros lotus, Gleditsia triacanthos, Koelreuteria paniculata, Prunus laurocerasus, Laurus nobilis, Lonicera caprifolium, L. standishii, L. tatarica, Maclura pomífera, Morus alba, M. nigra, M. rubra, Olea europaea, Parthenocis-sus quinquefolia, Prunus armeniaca, P. domestica, P. vulgaris, Pyracan-tha rogersiana, Ribes aureum, R. rubrum, R. spicatum, Robinia pseudoacacia, Sophora japonica, Spartium junceum, Syringa vulgaris and Zel-kova carpinifolia and ephemerophyte Prunus cerasus.
18 exotic woody species penetrated the flora of the Yalta Mountain-Forest Natural Reserve. All of them are agiiophytes - 13 species, and colonophytes - 5 species (Bagrikova & Bondarenko, 2015). A number of alien woody species form local populations of normal type in the native communities of "Mys Martian" nature reserve: Bupleurum fiuticosum, Buxus sempervirens, Fraxinus ornus, Laburnum anagyroides
0 0 1 1 ergasiophyte
0 0 1 1 ergasiophyte
0 0 1 1 ergasiophyte
0 0 1 1 ergasiophyte
0 0 1 1 ergasiophyte
0 0 1 1 ergasiophyte
0 0 1 1 ergasiophyte
0 ergasiophyte 1 1 ergasiophyte
0 0 2 1 colonophyte
0 0 1 1 ergasiophyte
0 0 1 1 ergasiophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 colonophyte
0 0 1 1 ephemerophyte
0 ephemerophyte 1 1 ephemerophyte
0 0 1 1 ephemerophyte
0_0_1_1 ephemerophyte
18 15 - -
and Prunus cerasifera (Bagrikova et al., 2014). In addition to the data about naturalization of plants in the botanical gardens, cities and nature reserve fund, we have considered articles about their separate records (Tyshchenko et al., 2013; Burda, 2014). It has also been noted that Acer negundo and Robinia pseudoacacia are viewed as diagnostic species of the synanthropic Robinietea class, stable components of Salicetea pur-pureae class, capable of intruding into the phytocenoces of Querco-Fagetea class causing structural disruption. Elaeagnus angustifolia and E. commutata are transformer species in Steppe and Circum-Pontic regions, conditioning the colonization of river basins, changing the grass cover of salinized coastal depressions (Abduloyeva & Karpenko, 2009). Ailanthus altissima, Celtis occidentals, Juglans cinerea, J. mandshurica, J. regia, Prunus serotina, P. virginiana, Ribes uva-crispa, spread spontaneously from forest culture in the nature reserve territories of the Forest-Steppe, also in the habitats of G type (forests and shrubs), Acer negundo and Amorpha fruticosa are involved in the cenoses of Rham-no-Prunetea class (Pashkevych & Burda, 2017).
The invasion of alien woody species into spontaneous flora in Ukraine
Therefore, 182 non-native woody species (172 species, 1 subspecies, 4 varieties and 5 hybrids) have been distinguished in the spontaneous flora of Ukraine (Tables 5, 6). This list is obviously incomplete. Only the articles in general access have been considered. The archive data on thorough studies of the course of initial introduction are unaccessible. Herbarium labels do not always highlight the origin of herborized samples, collected in the botanical gardens and arboretums. On the one hand, the compilation of a more precise list of woody exotic species is hindered by the absence of a unified inventory of collection funds and database of the course of naturalization of these species, and, on the other hand, the naturalization process is not over. On the contrary, it is getting stronger. Plant invasion is an extremely dynamic process. However, the presented list gives a general idea about the composition and character of non-native woody trees in the domestic flora.
71 alien completely naturalized plants have been differentiated (66 species, 1 subspecies, 1 variety and 3 hybrids). They belong to 47 genera and 28 families of two divisions - Pinophyta and Magnoliophyta (Table 5). This group presents the highest risk for the local diversity of species: 12 of them are transformers, 8 are invasive proper, 29 - potentially invasive, 22 - naturalized species, whose invasive activity has not been manifested. In terms of life-forms, the list of alien woody species contains
30 species - trees, 26 species - shrubs, and 8 species - lianas, 7 species de- velop their life-form as a tree or a shrub, depending on their environment.
Table 5
The invasive activity of alien woody species in spontaneous flora of Ukraine
Family
Taxon
Life-form
Spread
Degree of naturalization*_Occurrence Invasive activity
Pinophyta
Cupressaceae Platycladus orientalis (L.) Franco
tree/shrub
seed
agriophytec
naturalized
Berberidaceae Berberis aquifolia Pursh
Berberidaceae B. vulgaris L.
Ranunculaceae Clematis flammula L.
Buxaceae Buxus sempervirens L.
Grossulariaceae Ribes uva-crispa L.
Vitaceae Parthenocissus quinquefolia (L.) Planch.
Vitaceae P. tricuspidata (Siebold & Zucc.) Planch.
Vitaceae P. vitacea (Knerr) Hitchc.
Vitaceae Vitis vinifera L.
Fabaceae Amorpha fruticosa L.
Fabaceae Caragana arborescens Lam.
Fabaceae Cercis siliquastrum L.
Fabaceae Colutea orientalis Mill.
Fabaceae Gleditsia triacanthos L.
Fabaceae Laburnum anagyroides Medik.
Fabaceae Pueraria montana var. lobata (Willd.)
Sanjappa & Prade
Fabaceae Robinia pseudoacacia L.
Rosaceae Amelanchier spicata (Lam.) K. Koch
Rosaceae Cydonia oblonda Mill.
Rosaceae Malus domestica Borkh.
Rosaceae Physocarpus opulifolius (L.) Maxim.
Rosaceae Prunus armeniaca L.
Rosaceae P. cerasus L.
Rosaceae P. cerasifera Ehrh.
Rosaceae P. domestica L.
_ P. domestica subsp. insititia (L.) Rosaceae
Bonnier & Layens
Rosaceae P. dulcis (Mill.) D.A. Webb
Rosaceae P. serotina Ehrh.
Rosaceae P. virginiana L.
Rosaceae Pyrus communis L.
Rosaceae Rosa rugosa Thunb.
Rosaceae Sorbaria sorbifolia (L.) A. Braun
Elaeagnaceae Elaeagnus angustifolia L.
Elaeagnaceae E. rhamnoides (L.) A. Nelson
Elaeagnaceae E. commutata Bernh. ex Rydb.
Rhamnaceae Rhamnus alaternus L.
Ulmaceae Ulmus pumila L
Moraceae Ficus carica L.
Moraceae Morus alba L.
Fagaceae Quercus ilex L.
Fagaceae Q. rubra L.
Celastraceae Celastrus scandens L.
Salicaceae Populus balsamifera L.
Salicaceae P. bolleana Lauche
Salicaceae P. x canadensis Moench
Salicaceae P. deltoides Marshall
Salicaceae P. nigra var. italica Münchh
Salicaceae P. suaveolens Fisch.
Salicaceae P. richocarpa Torr. & A. Gray ex Hook.
Salicaceae Salix x babilonica L.
Salicaceae S. x blanda Andersson
Anacardiaceae Toxicodendron radicans (L.) O. Kuntze
Aceraceae Acer negundo L.
Rutaceae Ptelea trifoliata L.
Simaroubaceae Ailanthus altissima (Mill.) Swingle
Tiliaceae Tilia americana L.
Thymelaeaceae Daphne laureola L.
Cornaceae Cornus alba L.
Cornaceae C. sericea L.
Hydrangeaceae Philadelphus coronarius L.
Solanaceae Lycium barbarum L.
Oleaceae Fraxinus americana L.
Oleaceae F. ornus L.
Magnoliophyta
shrub seed, vegetative way
shrub seed, vegetative way
liana seed, vegetative way
shrub seed
shrub seed, vegetative way
liana seed, vegetative way
liana seed, vegetative way
liana seed, vegetative way
liana seed, vegetative way
shrub seed, vegetative way
shrub seed
tree/shrub seed
shrub seed
tree seed
shrub seed
liana seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree/shrub seed, vegetative way
tree seed, vegetative way
shrub seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree/shrub seed, vegetative way
tree seed, vegetative way
tree/shrub seed, vegetative way
tree seed
tree/shrub seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
shrub seed, vegetative way
shrub seed, vegetative way
tree/shrub seed, vegetative way
shrub seed,vegetative way
tree seed, vegetative way
shrub seed, vegetative way
tree seed, vegetative way
tree/shrub seed
tree seed
tree seed
tree seed
liana seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
tree seed, vegetative way
shrub seed, vegetative way
tree seed
shrub seed, vegetative way
tree seed, vegetative way
tree seed
shrub seed, vegetative way
shrub seed, vegetative way
shrub seed, vegetative way
shrub seed, vegetative way
shrub seed, vegetative way
tree seed
tree seed
agriophyte epoecophyte agriophytec agriophytec ergasiophyte colonophytec, epoecophyte epoecophyte agriophyte agriophytec, epoecophyte agriophyte, colonophytec colonophytec, hemiagriophyte agriophytec agriophytec colonophytec, epoecophyte agriophytec
agriophytec
colonophytec, agriophyte agriophyte agriophyte agriophyte epoecophyte colonophytec, epoecophyte ephemerophytec, epoecophyte agriophyte colonophytec, ergasiophyte
agriophyte
agriophytec agriophyte ergasiophyte agriophyte ergasiophyte epoecophyte agriophyte agriophyte hemiagriophyte
agriophytec hemiagriophyte
agriophytec, ephemerophyte colonophytec, epoecophyte agriophytec emiagriophyte epoecophyte ergasiophyte ergasiophyte epoecophyte epoecophyte ergasiophyte ergasiophyte ergasiophyte ergasiophyte agriophyte ergasiophyte agriophyte agriophytec, hemiagriophyte agriophytec, epoecophyte ergasiophyte agriophytec ergasiophyte epoecophyte ergasiophyte agriophytec, epoecophyte epoecophyte _agriophytec_
local invasive
sporadic naturalized
sporadic potentially invasive
local potentially invasive
local potentially invasive
common transformer
rare naturalized
common transformer
common invasive
common ttransformer
common naturalized
rare naturalized
local invasive
sporadic naturalized
local potentially invasive
local potentially invasive
common transformer
sporadic potentially invasive
common potentially invasive
common potentially invasive
common naturalized
common naturalized
common naturalized
common invasive
common naturalized
common potentially invasive
local potentially invasive
common invasive
common potentially invasive
common naturalized
common naturalized
common potentially invasive
common transformer
common transformer
rare potentially invasive
local trnsformer
common potentially invasive
local potentially invasive
unique
common potentially invasive
local invasive
local potentially invasive
rare potentially invasive
rare naturalized
common naturalized
common naturalized
common naturalized
common naturalized
common naturalized
common naturalized
common naturalized
common trnsformer
local potentially invasive
common transformer
common potentially invasive
common trnsformer
common naturalized
local invasive
common potentially invasive
common potentially invasive
common naturalized
common ins potentially invasive
common naturalized
local transformer
Family Taxon Life-form Spread Degree of naturalization* Occurrence Invasive activity
Oleaceae F. pennsylvanica Marshall tree seed epoecophyte common potentially invasive
Oleaceae Syringa vulgaris L. shrub seed, vegetative way colonophytec, ergasiophyte common naturalized
Viburnaceae Viburnum tinus L. shrub seed, vegetative way agriophytec local invasive
Caprifoliaceae Lonicera etrusca Santi shrub seed agriophytec local potentially invasive
Caprifoliaceae L. tatarica L. shrub seed colonophytec, epoecophyte common naturalized
Caprifoliaceae Symphoricarpos albus (L.) S. F. Blake shrub seed, vegetative way epoecophyte common naturalized
Apiaceae Bupleurum fruticosum L. shrub seed, vegetative way agriophytec local transformer
Note: * - here and in Table 6 interlinear "c" marks "Crimea".
The prevailing majority of alien woody species have both seed dispersal and vegetative reproduction (56 species). Vegetative reproduction was not observed in nature for 15 species. In terms of the naturalization degree of alien woody species, 35 species are agriophytes, 5 -hemiagriophytes, 16 - epoecophytes, 18 - ergasiophytes, 15 - colono-phytes and 1 - ephemerophyte.
A number of species in specific regions have acquired different degrees of naturalization. For instance, Ficus carica is an agriophyte in the flora of the South Coast of Crimea, but an ephemerophyte - in the urban flora of Kyiv, Ailanthus altissima and Lycium barbarum are agriophytes in the Crimea, and in the rest of the territory they are epoecophytes. At the same time, Caragana arborescens and Robinia pseudoacacia have not naturalized completely on the peninsula, and have the status of colono-phytes, while on the mainland they are hemiagriophyte and agriophyte, respectively, etc. The following species spread as agriophytes only on the Crimean Peninsula: Bupleurum frvticosum, Buxus sempervirens, Clematis flammula, Cercis siliquastrum, Colutea orientalis, Daphne laureola, Laburnum anagyroides, Lonicera etrusca, Platycladus orientalis, Prunus dulcis, Pueraria montana var. lobata, Quercus ilex andRhamnus alaternus, etc.
Table 6
Non-native naturalizing woody species of spontaneous flora of Ukraine
The naturalization non-native woody species in plant communities in Ukraine
There are 111 non-native woody species whose naturalization has not completed yet (107 species, 2 varieties, and 2 hybrids), out of 65 genera and 35 families, 2 divisions - Pinophyta and Magnoliophyta (Table 6). In terms of life-forms, these are trees (45 species), shrubs (38 species), lianas (19 species), 9 have the life-form ofboth a tree and a shrub, they have seed dispersal (61), vegetative way of reproduction (4), or spread via both ways (46). The degree of occurrence of non-native species is reflected by the following spectrum: 7 - sporadic, 17 - local, 51 - occurring in 3-5 (7) localities, 13 - unique and 23 species which have dispersed by seed dispersal or vegetative way, having escaped the collections and expositions only in botanical gardens and arboretums. The species of this group are mainly ephemerophytes by the degree of naturalization. However, some of them are already acquiring the status of colonophytes: Allbizia julibrissin, Sophora japonica, Spartium junce-um, while Ficus carica and Juglans regia on the South Coast of Crimea are even agriophytes (Bagrikova, 2013).
Family Taxon Life-form Spread Degree of naturalization Occurrence Stage of naturalization
Pinophyta
Pinaceae Abies pinsapo Boiss. tree seed colonophytec rare reproduction
Pinaceae Cedrus atlantica (Endl.) Manetti ex Carrière tree seed colonophytec rare reproduction
Pinaceae C. deodara (Roxb. ex D. Don) G. Don tree seed colonophytec rare reproduction
Pinaceae Larix decidua Mill. tree seed ephemerophyte controlled reproduction
Cupressaceae Cupressus sempervirens L. tree seed colonophytec rare reproduction
Cupressaceae Thuja occidentalis L. tree/shrub seed ephemerophyte controlled reproduction
Magnoliophyta
Aristolochiaceae
Lauraceae
Berberidaceae
Magnoliaceae
Ranunculaceae
Ranunculaceae
Ranunculaceae
Ranunculaceae
Ranunculaceae
Ranunculaceae
Platanaceae
Hamamelidaceae
Grossulariaceae Grossulariaceae Grossulariaceae Grossulariaceae Grossulariaceae Vitaceae
Vitaceae
Vitaceae
Vitaceae
Vitaceae Vitaceae Fabaceae Fabaceae Fabaceae Fabaceae Fabaceae
Aristolochia macrophylla Lam. Laurus nobilis L. Berberis thunbergasiophyteii DC. Liriodendron thunbergii DC. Clematis gouriana Roxb. ex DC. C. jackmanii T. Moore. C. ligusticifolia Nutt C. tangutica (Maxim.) Korsh. C. vitalba L. C. viticella L.
Platanus acerifolia (Aiton) Willd.
Parrotia subaequalis (Hung T. Chang)
R.M. Hao & H.T. Wei
Ribes americanum Mill.
R. aureum Pursh
R. europaea (L.) Mill.
R. rubrum L.
R. spicatum Robson
Ampelopsis aconitifolia Bunge
A. delavayana var. glabra (Diels & Gilg)
C.L. Li
A. bodinieri (H. Lev. & Vaniot) Rehder A. glandulosa var. brevipedunculata (Maxim.) Momiy
Vitis coignetiae Bull. ex Planch
V. labrusca L.
Allbizia julibrissin Durazz
Cladrastis kentukea (Dum. Cours.) Rudd
Colutea arborescens L.
Gymnocladus dioica (L.) K. Koch
Halimodendron halodendron (Pall.) Voss
liana
tree/shrub shrub tree liana liana liana liana liana liana
tree
tree/shrub
shrub shrub shrub shrub shrub liana
liana
liana
liana
liana liana tree shrub shrub tree shrub
seed seed
seed, vegetative way seed, vegetative way seed, vegetative way seed, vegetative way seed, vegetative way seed, vegetative way seed, vegetative way seed, vegetative way
seed
seed
seed seed seed seed seed
seed, vegetative way
seed, vegetative way
seed, vegetative way
seed, vegetative way
seed, vegetative way seed, vegetative way seed, vegetative way seed seed seed seed
ephemerophyte unique records
colonophytec rare reproduction
ephemerophyte controlled survival
ephemerophyte unique records
ephemerophyte controlled establishing
ephemerophyte controlled establishing
ephemerophyte controlled establishing
ephemerophyte controlled establishing
colonophyte rare establishing
ephemerophyte controlled establishing colonophytec
unique records
ephemerophyte
ephemerophyte controlled reproduction
ephemerophyte colonophytec ephemerophyte colonophytec colonophytec ephemerophyte
ephemerophyte
ephemerophyte
ephemerophyte
ephemerophyte
colonophyte ephemerophytec colonophytec colonophytec ephemerophyte colonophyte
controlled rare rare rare rare controlled
controlled
controlled
controlled
controlled rare rare
sporadic
rare rare
local
reproduction reproduction reproduction reproduction reproduction survival
survival
survival
survival
survival reproduction
survival establishing survival survival establishing
Family
Fabaceae Fabaceae Fabaceae Fabaceae Fabaceae Rosaceae Rosaceae
Rosaceae
Rosaceae
Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae
Rosaceae
Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Rosaceae Ulmaceae Ulmaceae Ulmaceae Ulmaceae Moraceae Moraceae Moraceae Fagaceae
Fagaceae
Fagaceae
Juglandaceae
Juglandaceae
Juglandaceae
Juglandaceae
Juglandaceae
Juglandaceae
Celastraceae
Celastraceae
Celastraceae
Anacardiaceae
Anacardiaceae
Anacardiaceae
Anacardiaceae
Aceraceae
Aceraceae
Hippocastanaceae
Hippocastanaceae
Sapindaceae
Rutaceae
Tiliaceae
Cistaceae
Hydrangeaceae
Hydrangeaceae
Ebenaceae
Eucommiaceae
Oleaceae
Scrophulariaceae
Paulowniaceae
Bignoniaceae
Bignoniaceae
Taxon
Robinia hispida L. R. neomexicana A. Gray R. viscosa Vent. Sophorajaponica L. Spartium junceum L. Amelanchier ovalis Medik. Aronia melanocarpa (Michx.) Elliott Cerasus tomentosa (Thunb.) Wall. ex T.T. Yu & C.L. Li Chaenomeles japonica (Thunb.) Lindl. ex Spach
Cotoneaster glaucophyllus Franch. C. lucidus Schlecht. C. melanocarpus Fisch. ex A. Blytt Crataegus coccinea L. C. sanguineus Pall. C. submollis Sarg. Malus baccata (L.) Borkh. Mespilus germanica L. Persica vulgaris Mill. Prunus laurocerasus L. P. mahaleb L. P. padus L. P. vulgaris Schur
Pyracantha rogersiana (A. B. Jacks.) Coltm.-Rog.
Rubus macrophyllus Weihe & Nees
R. odoratus L.
Spiraea x billardii Hérin
S. chamaedryfolia L.
S. douglasii Hook.
S. salicifolia L.
S. x vanhouttei (Briot) Zabel
Celtis australis L.
C. caucasica Willd.
C. occidentalis L.
Zelkova carpinifolia (Pall.) K. Koch Maclura pomifera (Raf.) C. K. Schneid. Morus nigra L. M. rubra L. Castanea sativa Mill.
Quercus macranthera Fisch. & C. A. Mey. ex Hohen.
Q. palustris Moench Juglans ailanthifolia Carrière J. cinerea L. J. mandshurica Maxim. J. nigra L. J. regia L.
J. subcordiformis Dode Celastrus angulata Maxim. C. flagellaris Rupr. C. orbiculatus Thunb. Rhus glabra L. R. typhina L. R. typhina L. 'Laciniata' Toxicodendron pubescens Mill. Acer platanoides L. f. atropurpurea Krimson King' A. saccharinum L. Aesculus flava Sol. A. hippocastanum L. Koelreuteria paniculata Laxm. Phellodendron amurense Rupr. Tilia begoniifolia Steven Poncirus trifoliata (L.) Raf. Deutzia scabra Thunb. Philadelphus microphyllus A. Gray Diospyros lotus L. Eucommia ulmoides Oliver. Olea europaea L. Buddleja davidi Franch. Paulownia tomentosa (Thunb.) Steud.
Catalpa bignonioides Walter
Campsis grandiflora (Thunb.) K. Schum.
Life-form Spread Degree of naturalization Occurrence Stage of naturalization
tree seed, vegetative way colonophyte local establishing
tree seed, vegetative way colonophyte local establishing
tree seed, vegetative way colonophyte local establishing
tree seed colonophytec unique survival
shrub seed, vegetative way colonophytec sporadic establishing
tree/shrub seed ephemerophyte local establishing
tree seed ephemerophyte local establishing
shrub seed ephemerophyte rare reproduction
shrub seed, vegetative way ephemerophyte rare reproduction
shrub seed colonophytec rare reproduction
shrub seed ephemerophyte local reproduction
shrub seed ephemerophyte local reproduction
shrub seed ephemerophyte rare reproduction
shrub seed ephemerophyte rare reproduction
shrub seed ephemerophyte rare reproduction
tree seed ephemerophyte rare reproduction
shrub seed, vegetative way ephemerophyte rare reproduction
tree seed ephemerophyte rare reproduction
shrub seed, vegetative way colonophytec local establishing
shrub seed ephemerophyte rare reproduction
tree/shrub seed ephemerophyte rare reproduction
tree/shrub seed, vegetative way colonophytec sporadic establishing
shrub seed, vegetative way colonophytec rare reproduction
shrub seed, vegetative way ephemerophyte unique records
shrub seed, vegetative way ephemerophyte controlled survival
shrub seed, vegetative way ephemerophyte rare survival
shrub seed,vegetative way ephemerophyte rare survival
shrub seed, vegetative way ephemerophyte rare survival
shrub seed, vegetative way colonophyte rare survival
shrub seed, vegetative way ephemerophyte rare survival
tree seed colonophytec rare survival
tree/shrub seed colonophytec rare survival
tree seed ephemerophyte rare survival
tree seed colonophytec rare survival
tree seed, vegetative way colonophytec rare survival
tree seed colonophytec sporadic establishing
tree seed colonophytec sporadic establishing
tree seed colonophytec unique establishing
tree seed ephemerophyte controlled establishing
tree seed ephemerophyte rare reproduction
tree seed ergasiophyte local establishing
tree seed ergasiophyte local establishing
tree seed ergasiophyte local establishing
tree seed ergasiophyte local establishing
tree seed ergasiophyte sporadic establishing
tree seed ergasiophyte local establishing
liana seed, vegetative way colonophyte local survival
liana seed ephemerophyte local survival
liana seed ephemerophyte local survival
tree/shrub seed, vegetative way colonophyte rare survival
tree vegetative way colonophyte controlled survival
tree vegetative way colonophyte controlled survival
shrub seed, vegetative way ephemerophyte rare survival
tree seed ephemerophyte controlled survival
tree seed colonophyte sporadic survival
tree seed ephemerophyte unique records
tree seed ergasiophyte rare esablishing
tree seed colonophytec rare survival
tree seed ephemerophyte unique records
tree seed, vegetative way ephemerophyte rare survival
tree/shrub seed ephemerophyte rare reproduction
shrub seed, vegetative way ephemerophyte rare survival
shrub seed, vegetative way ephemerophyte rare reproduction
tree seed, vegetative way colonophytec rare survival
tree seed, vegetative way ephemerophyte unique records
tree seed, vegetative way colonophytec rare establishing
shrub seed, vegetative way colonophytec unique records
tree seed ephemerophyte unique records
tree seed, vegetative way colonophytec ephemerophyte unique survival
liana vegetative way colonophyte controlled establishing
Family Taxon Life-form Spread Degree of naturalization Occurrence Stage of naturalization
Bignoniaceae C. radicans (L.) Seem. liana vegetative way colonophy1e controlled establishing
Aquifoliaceae Ilex aquifolium L. 1ree seed, vegetative way ephemerophyte unique records
Caprifoliaceae Lonicera caerulea L. shrub seed ephemerophyte rare survival
Caprifoliaceae L. caprifolium L. shrub seed colonophytec rare survival
Caprifoliaceae L. standishii Jacques shrub seed colonophytec rare survival
Caprifoliaceae Weigela florida (Bunge) A DC. shrub seed, vegetative way ephemerophyte rare survival
Aracaceae Aralia elata (Miq.) Seem. shrub seed, vegetative way ephemerophyte controlled survival
A general overview of the course of invasion of woody species into the spontaneous flora of Ukraine
According to the results of our determination and analysis of the group of non-native woody species, this component of the spontaneous flora of Ukraine has a rather diverse taxonomy: 182 species, belonging to 95 genera and 45 families. These include 71 alien species, which have completely naturalized. Let us compare: the global database of invasive trees and shrubs contains 751 alien species (434 trees and 317 shrubs); the flora of Europe has 134 of them (Rejmánek & Richardson, 2013). It is evident that it has no significant relevance for the course of invasion whether the life-form is a tree or a shrub. The involvement of trees in the total list slightly exceeds the involvement of shrubs, and as for alien species - they are even (Table 7). The most intense distribution has been noted mainly for the species remarkable both for seed dispersal and vegetative reproduction, though most non-naturalized species have only seed dispersal. Mostly common and rare species are noted in the total list in terms of occurrence and distribution, which is explained by high involvement of these very species among alien and non-naturalized ones.
The course of invasion of non-native woody species, which are at the initial stages of migration - introduction, acclimatization, survival, adaptation of reproductive sphere and establishment (Blackburn et al., 2011) - and have not naturalized yet, takes place after overcoming the geographical barrier as a result of human activity. Continuing their introduction, they cross the barriers of controlled cultivation, a barrier to survival and adaptation of reproductive sphere, and start the formation and establishment of populations. According to our observations, only 30 of them have established local populations, have cryptic (hidden) invasion risk, and the rest of the non-naturalized species do not manifest any invasive activity. First of all, noteworthy are vegetatively mobile shrubs of Rhus typhina, R typhina 'Laciniata', Rubus odoratus and lianas Ampelopsis aconitifolia, A. delavayana var. glabra, A. bodinieri, A. glandulosa var. brevipedunculata, Campsis grandiflora, C. radicans, Clematis gouriana, C. jackmanii, C. ligustiafolia, C. tangutica, C. viti-cella and Vitis coignetiae. The global pattern of plant invasions demonstrates that under favourable conditions the species of these life-forms invade a territory fast and retain there hold on it. The studies on the naturalization in forests and parks of Kyiv demonstrated that 6 species of the genus Juglans (J. ailanthifolia, J. cinerea, J. mandshurica, J. nigra, J. regia, J. subcordiformis) (Burda & Koniakin, 2018) and Aesculus hippocastanum establish self-reproductive local populations. As for further successful or failing seed dispersal of trees (Acer platinoides f. atropurpurea Krimson King', Celtis australis, Larix decidua, Quercus macranthera), it is too early to forecast anything. The mentioned ornamental form of Acer platanoides is present in some parks of Kyiv, but there were no reports about self-dispersal. Non-naturalized and not high trees or shrubs (Aralia elata, Parrotia subaequalis, Thuja occidentalis) are still undergoing the processes of acclimatization and adaptation of reproductive sphere. Such shrubs as Berberis thunberii and Ribes ame-ricanum do not have abundant seed dispersal. Thus, the group of non-native woody species combines the species with hidden or non-expressed invasive activity. At first sight, they are completely undynamic, almost invisible in flora, plant communities, ecosystems and landscape. However, at the impact of some factors, for instance, factors of time, favourable conditions of reproduction, sharp change in environment, etc., their activity may be revealed. Most species, which have not naturalized, have not acquired sufficient vegetative development for at least some invasive activity, so they remain passive in terms of this feature for some time.
The picture of invasive activity of alien species is quite different. The species, which have formed secondary ranges within Ukraine, are known as invasively active species, at least within Europe and Northern 2A8s6ia. Transformer species in the spontaneous flora of Ukraine are revealed as the most wide spread in almost 40 regions of Europe: Robinia pseudoacacia (42 regions), Ailanthus altissima (40), Acer negundo (38) (Lambdon et al., 2008). Some of our non-native plant species are among the more than "100 worst" alien species in Europe (Nentwig et al., 2018). There are Pueraria lobata var. montana (rank 10 and total impact sum 29), Robinia pseudoacacia (13 and 28), Prunus serotina (59 and 17), Elaeagnus angustifolia (67 and 16), Rosa rugosa (76 and 13) and Buddleja davidii (80 and 11 respectively).
Table 7
The diversity of non-native woody species in spontaneous flora of Ukraine
Feature _Number of species_
total alien on-naturalized
Taxonomic diversity
of species 182 71 111
of genera 95 47 65
of families 45 28 35
Life-form
tree 75 30 45
shrub 64 26 38
tree or shrub 16 7 9
liana 27 8 19
Spreading
seed dispersal 77 15 62
vegetative way 4 0 4
both way 101 56 45
Occurrence
common species 44 44 0
local species 34 17 17
sporadic species 11 4 7
rare species 57 6 51
unique species 13 0 13
controlled species 23 0 23
*Degree ofnaturalization
agriophyte 35 35 0
hemiagriophyte 5 5 0
epoecophyte 16 16 0
ergasiophyte 23 15 8
colonophyte 42 0 42
ephemerophyte 61 0 61
*Invasive activity
transformer species 12 12 0
invasive species proper 8 8 0
potentially invasive species 29 29 0
naturalized species with no manifested 22 22 0
invasive activity
* Non-naturalized species, such stages of naturalization continue
introduction 10 0 10
survival 40 0 40
adaptation of reproduction sphere 31 0 31
establishment 30 0 30
Note: * - the highest level has been accepted for species, which is quite different by the degree features at the local level.
The expansion of Amorpha fruticosa is observed in neighbouring countries. In the flood plain of Kuban near the town of Temriuk A. fruti-cosa formed compact clumps, pushing out native plant communities of hygro- and hydrophytes. There were cases when the traditional shrub life-form ofA. fruticosa was changed to the tree life-form. The height of trees was 6 m with the trunk diameter of 15 cm (Shvydkaya & Kudino-va, 2013). About two dozen alien woody species of the spontaneous 2019, 27(3)
flora of Ukraine have spread in 25 and more regions as the most common alien species of Europe: Prunus cerasus (34), Quercus rubra (34), Rosa rugosa (34), Prunus domestica (31), P. cerasifera (30), Aesculus hippocastanum (30), Pyrus communis (30), Syringa vulgaris (30), Malus domestica (29), Berberis aquifolia (28), Parthenocissus quinquefolia (27), Symphoricarpos albus (27), Juglans regia (26), Populus x canadensis (26), Vitis vinifera (26) (Lambdon et al., 2008).
Thus, coming back to the issue on the source of diaspores in the course of woody plant invasions in Ukraine, we would like to highlight a probable role of interstate migrations of invasive woody species. It is also possible that some migrations go both ways. At present, Ukraine's botanical gardens and arboretums have abundant and rather old collections. Some introduction centers own over 2,000 species of trees and shrubs. During their history (from 1793 till 2019), these institutions have passed on many woody exotic species for creation of forest cultures, use by communal services, to private amateurs, etc. In our country, woody species, used in gardening by the botanical gardens and arboretums after initial introductory testing, are planted to create current greenery of the cities along with the local species. They ensure comfortable life of local residents, promote optimization of microclimate in agriophyteoecosystems, protect railways and highways from unfavourable weather effects, resist water and wind erosion of soils, etc. In this situation, reports about immediate facts of woody species escaping the botanical gardens and arboretums which have introduced them, and establishing spontaneous plantings, are almost absent. We have managed to find only one abovementioned case of the "escape" of Clematis vitalba from the Donetsk Botanical Garden of NAS of Ukraine, on the mainland. This species is usually estimated by specialists as an unstable element of flora (colonophyte), remarkable for potential invasive activity, conditioned by the ability of both fast vegetative reproduction, and easy dispersal of seeds in the wind. As for the Crimean Peninsula, there is a registered fact of native penetration of Bupleurum fruticosum and Fraxinus ornus into the nature reserve "Mys Martian" from the adjacent territory of the Nikitsky Botanical Garden, where both species were naturalized long time ago (Bagrikova et al., 2014). However, the question about the nature of Fraxinus ornus in the Crimea is still under discussion. P. S. Pallas considered F. ornus on the South Coast of Crimea, in particular, in the plant communities on Mys Martian, to be an aboriginal East Mediterranean species, even 18 years prior to the establishment of the Nikitsky Botanical Garden. This thought coincides quite well with the opinions of some modern botanists. However, taking into consideration successful seed dispersal of F. ornus in modern plant community complexes, it seems reasonable to accept it as a transformer species on the South Coast of Crimea (Kish et al., 2009; Protopopova et al., 2012). The consequences of invasions of woody trees from the introduction centers seem to be negligible on the background of the events in domestic spontaneous flora. This conclusion is in agreement with the status of naturalization for woody plants from collections and expositions of the N. V. Tsytsyn Main Botanical Garden, RAS. Its specialists have not observed any fact of an introduced woody species escaping the garden in 70 years of introduction tests (Yatsenko & Vino-gradova, 2018). They have described the following course of migration: 2,400 species have been involved in the introduction experiment; 1,317 species (55%) have overcome the ecological barrier and adjusted to new natural and climatic conditions; 66 species have overcome the reproductive barrier (5%); 12 species have actually "left the arboretum" and invaded natural forest cenoses within the territory of the Garden (8%). It should be noted that among 66 species, which have spread beyond the limits of cultivation, 10 species are aboriginal in the flora of Ukraine, and the rest are mostly mentioned in Tables 5 and 6.
Thus, the botanical gardens and arboretums of Ukraine as centers of plant introduction are neither direct sources of naturalization nor sources of spontaneous distribution of non-native woody species. The assumption about these institutions being the centers of initial introduction is surely reasonable.
In addition, the fact of seed dispersal, made by this or that species within the collection or under conditions, approximated to natural ones, is not a guarantee of its invasion in the nearest future. The way in which a plant migrates within a new territory is rather complicated, there may
be "boom" and "bust" situations, or other occasions (Blackburn et al., 2011). There have been many situations when the invasion of some species started with seed dispersal and ended with it. For instance, Par-rotia subaequalis was introduced into the arboretum of the M. M. Hryshko National Botanical Garden in 1950, the plants first blossomed in 1975 and the mature seeds had 98% germination. Abundant seed dispersal was observed the following year, however, the seedlings were soon eliminated. In the following years the plants of P. subaequalis blossomed, had seeds, but there was no seed dispersal (Doroshenko et al., 2013). In this respect, noteworthy are observations of the spreading of woody trees in the arboretum of the Donetsk Botanical Garden (Eremenko & Ostapko, 2011). Three tendencies of distribution were noted under the controlled conditions of the arboretum during 10 years of observations. As expected, the species with the positive tendency include most invasive species: Acer negundo, Ailanthus altissima, Par-thenocissus quinquefolia, potentially invasive: Morus alba, Ribes uva-crispa, and naturalized Gleditsia triacanthos, Berberis vulgaris and Juglans regia. The latter species sometimes establishes separate local self-reproducing populations in Donetsk on the background of abundant cultivation on private land. Decreasing dispersion was demonstrated by Berberis aquifolia, while Caragana arborescens, Ptelea trifoliata, Robinia pseudoacacia had a stable tempo of spreading.
In 55 years of observations, 227 alien woody species out of 73 genera and 31 families with seed dispersal were revealed in green plantings of Saint Petersburg. Among these, only about 10 species have become invasive and even threats to aboriginal plant communities (Firsov & Byalt, 2015). For instance, these are species: Cornus saricea, Aronia mitschurinii A. Scvorts. et Maitull., Acer negundo, Amelanchier spicata.
262 species of vascular plants, which escaped the collections and expositions, were determined in the Tsytsyn Main Botanical Garden, RAS and the Botanical Garden of Lomonosov of the Moscow State University (Mayorov et al., 2013). Aralia elata and Symphoricarpus albus, capable of independent distribution in botanical gardens of Ukraine, are among them. Contrary to the abovementioned, in the arboretum of the Tsytsyn Main Botanical Garden, natural forest communities of the Garden were invaded from the outside greenery of the city by Acer negundo, Cotoneaster lucidus, Malus domestica (Yatsenko & Vinogra-dova, 2018).
The phenomenon of naturalization of non-native species near collections and expositions of the botanical gardens and arboretums is of global character. Let us supplement the description of the experience of botanical gardens of Ukraine, Moscow and Saint Petersburg with the facts of Caragana arborescens, going out of cultivation within the Yakutsk Botanical Garden of the Institute of Biological Problems of Cryo-lithozone, the Siberian Division, RAS (on dry coastal shores of a lake, sometimes), which belongs to hemiagriophytes in Ukraine, and Sorba-ria sorbifolia (in a birch forest, near collection plots), which is an epo-ecophyte in our flora (Nikolaeva & Danilova, 2019).
Thus, important sources of naturalization of non-native woody species are green areas of cities, forest cultures, protective plantings of different intended purposes, private households, etc. The management of woody species invasion, the pragmatic unified framework for biological invasions (Blackburn et al., 2011), should be based on the global strategy on invasive alien species. The course of invasion of non-native woody species in the domestic flora dictates the following scheme of actions: preventing invasions, eradication - at the stages of survival and adaptation of the reproductive sphere, containment - after the species has overcome the barrier of reproduction and dispersal, and mitigation -on the final stages of invasion.
Conclusion
This is the first and preliminary determination and evaluation of non-native woody species in Ukraine's spontaneous flora. The data, presented in the article, demonstrate the active course of naturalization of non-native woody species and invasion of alien species in the spontaneous flora. The tendencies towards global increase of involvement and invasive activity of alien woody species in the spontaneous domestic flora have been confirmed.
The analysis of the occurrence, naturalization, distribution and the estimation of invasive activity of non-native species of trees, shrubs, and lianas in floras of 5 regions, 5 urban floras, over 30 floras of protected areas demonstrated as follows: there are 182 species from 95 genera and 45 families (75 trees, 16 trees or shrubs, 64 shrubs, and 27 lianas) are at different stages of naturalization in the spontaneous flora.
71 species have completely naturalized, 20 of which are invasive and pose the highest threat to local diversity (12 transformer species and 8 invasive proper ones). The rest of the naturalized species are potentially invasive (29 species) or do not demonstrate invasive activity (22 species).
111 species have overcome the geographical barrier due to human activity. These are undergoing the initial stages of invasion: survival, acclimatization, adaptation of reproductive sphere, establishment and formation of local populations.
In Ukraine, there are about 50 botanical gardens and arboretums -centers of initial introduction of plants, 2 of them have been working since the end of the 18th century, and 8 - since the 19th century. The collections of 1 arboretum exceed 2,000, 2 botanical gardens have about 2,000 species, and the number of woody species in 4 botanical gardens and 1 arboretum exceeds 1,000 species. There is information about controlled spreading of 23 woody species beyond collections and expositions of the introduction centers. There was only one described case of spontaneous escape of 2 invasive woody species beyond the introduction center (Bupleurum fruticosum and Fraxinus ornus) from the Nikitsky Botanical Garden to the adjacent nature reserve "Mys Martian".
The mitigation of the effects of invasive alien woody species on local biodiversity requires restoration of local natural plant community complexes, organization of land use and culture of taking care of woody plantings. Our conclusions are relevant for employees of introduction centers, nature protection bodies, communal services, and state quarantine while elaborating the system of preventive, radical (eradication, limitation of assortment), containment and mitigation of impacts of plant invasions.
References
Abduloyeva, O. S., & Karpenko, N. I. (2009). Traplyannya chuzhynnykh inva-ziynykh roslyn v syntaksonakh roslynnosti Ukrainy [The frequency of occurrence of alien invasive plants in syntaxons in Ukraine]. Chornomorski Botanical Journal, 5(1), 189-198 (in Ukrainian). Alokhin, O. O., Orlova, T. G., & Alokhina, N. M. (2019). Istoriya stvorennya ta suchasnyi stan kolektsii botanichnoho sadu Kharkivskoho natsionalnoho un-iversytetu imeni V. N. Karazina [History and current state of the collection of the Botanical garden of the V. N. Karazin Kharkiv National University]. In: Alokhin, O. O. (ed.). Plant introduction: Current state, problems and prospects. The papers of International scientific conference and workshop (Kharkiv, May 17-19, 2019), Collegium, Kharkiv, 11-20 (in Ukrainian). Bagrikova, N. A. (2013). Strukturnyi analiz adventivnoy fraktsii flory Krymskogo poluostrova (Ukraina) [Structural analysis of the alien fraction of the flora of the Crimean Peninsula (Ukraine)]. Ukrainian Botanical Journal, 70(4), 489507 (in Russian).
Bagrikova, N. A., & Bondarenko, Z. D. (2015). Chuzherodnye rasteniya Yaltins-kogo gorno-lesnogo prirodnogo zapovednika: Sostoyanie izuchennosti vo-prosa i perspektivy issledovaniya [Alien plants of Yalta Mountain Forest Nature Reserve: State of knowledge and prospects of research]. Russian Journal of Biological Invasions, 6(4), 2-13 (in Russian). Bagrikova, N. A., Krainyuk, E. S., & Resnikov, O. L. (2014). Osobennosti i per-spektivy izucheniya adventivnyh vidov rasteniy zapovednika "Mys Martyan" [Features and prospects of studying adventive plants of the reserve "Mys Martian"]. In: Mayorov, S. R. (Ed.). Invasion biology: Current state and prospects: The workshop materials, Moscow, September 10-13, 2014. Maks Press, Moscow. Pp. 12-15 (in Russian). Baranovski, B., Khromykh, N., Karmyzova, L., Ivanko, I., & Lykholat, Y. (2016). Anyalysis of the alien flora of Dnipropetrovsk province. Biological Bulletin of Bogdan Chmelnitskiy Melitopol State Pedagogical University, 6(3), 419-429. Blackburn, T. M., Essl, F., Evans, T., Hulme, P. E., Jeschke, J. M., Kuhn, I., Kumschick, S., Markova, Z., Mrugala, A., Nentwig, W., Pergl, J., Pysek, P., Rabitsch, W., Ricciardi, A., Richardson, D. M., Sendek, A., Vila, M., Wilson, J. R. U., Winter, M., Genovesi, P., & Bacher, S. (2014). A unified classification of alien species based on the magnitude of their environmental impacts. PLoS Biology, 12(5), e1001850. Blackburn, T. M., Pysek, P., Bacher, S., Carlton, J. T., Duncan, R P., Jarosik, V., Wilson, J. R. U., & Richardson, D. M. (2011). A proposed unified framework for biological invasions. Trends in Ecology and Evolution, 26, 333-339.
Borsukevych, L. M., & Prokopiv, A. I. (2014). Adventyvni vydy botanichnoho sadu Lvivskoho Natsionalnoho universytetu imeni Ivana Franka [Adventive species of the botanical garden of Ivan Franko National University of Lviv].
288 In: Glukhov, A. Z. (Ed.). Restoration of disturbed natural ecosystems: Materials of the V International scientific conference (Donetsk, May 12-15, 2014). Donetsk. Pp. 271-273 (in Ukrainian).
Burda, R (1997). The checklist of Donbass's urban flora. Donetsk Botanical Garden, NAS of Ukraine, Donetsk.
Burda, R. (2003). Alien trees and shrubs of the Ukrainian agricultural landscape. In: Zajac, A., Zajac, M., & Zemanek, B. (Eds.) Phytogeographical problems of synanthropic plants. Institute of Botany of Jagiellonian University, Cracow. Pp. 11-16.
Burda, R. (2007). Rezistentnist pryrodno-zapovidnoho fondu do fitoinvaziy [Resistance of natural-reserved fund to phytoinvasions]. Industrial Botany, 7, 1121 (in Ukrainian).
Burda, R. (2018). Alien plant species in the agricultural habitats of Ukraine: Diversity and risk assessment. Ekologia (Bratislava), 37(1), 24-31.
Burda, R. I. (2014). Spontanne poshyrennya Aristolochia macrophylla (Aristolo-chiaceae) u lisakh Koncha-Zaspy (Kyiv) [Spontaneous dispersion of Aristolochia macrophylla (Aristolochiaceae) in Koncha-Zaspa forests, Kyiv]. Ukrainian Botanical Journal, 71(5), 558-562 (in Ukrainian).
Burda, R. I., & Koniakin, S. N. (2018). Spontaneous dispersion of species of the genus Juglans L. in the forests and parks of Kyiv. Russian Journal of Biological Invasions, 9(2), 95-107.
Burda, R. I., Golivets, M. A., & Petrovych, O. Z. (2015a). Alien species in the flora of the nature reserve fund of the flatland part of Ukraine. Russian Journal of Biological Invasions, 6(1), 6-20.
Burda, R. I., Mulenkova, O. G., & Shpilyova, N. V. (1998). Spontanne poshyren-nya introdukovanykh roslyn na terytorii Donetskoho Botanichnoho Sadu [Spontaneous dispersion of introduced plants on the territory of the Donetsk Botanical Garden]. The Donetsk Botanical Garden, Donetsk (in Ukrainian).
Burda, R. I., Pashkevych, N. A., Boiko, G. V., & Fitsailo, T. V. (2015b). Chuzhoridni vydy okhoronnykh for Lisostepu Ukrainy [Alien species of the protected floras of Forest-Steppe of Ukraine], Naukova Dumka, Kyiv (in Ukrainian).
Cherevchenko, T. M. (Ed.). (2011). Botanichni sady i dendroparky RBSD Ukrainy: Dovidnyk [Botanical gardens and arboretums of the CBGA of Ukraine: Handbook]. Council of Botanical Gardens and Arboretums of Ukraine, Kyiv (in Ukrainian).
Didukh, Y., Plyuta, P., Protopopova, V., Ermolenko, V., Korotchenko, I., Karku-tsiev, G., & Burda, R. (2000). Ekoflora Ukrainy [Ecoflora of Ukraine]. Iss. 1. Phytosociocenter, Kyiv (in Ukrainian).
Doroshenko, O. K., Trofimenko, N. M., & Babitskyi, A. I. (2013). Parrotia persica v Natsionalnomu botanichnomu sadu [Parrotia persica in the National botanical garden]. In: Radchenko, V. G. (ed.). The role of botanical gardens and arboretums in maintaining and enriching of biological diversity in urban areas. Materials of the International Scientific Conference (Kyiv, May 28-31, 2013). Kyiv. Pp. 207-209 (in Ukrainian).
Doyko, N. M., Kalashnikova, L. V., & Doroshenko, Y. V. (2014). Invaziyno aktyvni derevni introdutsenty v dendroparku "Oleksandriya" [Invasively active introduced woody plants in the "Alexandria" arboretum]. In: Glukhov, A. Z. (Ed.). Restoration of disturbed natural ecosystems: Materials of the V International scientific conference (Donetsk, May 12-15, 2014). Donetsk. Pp. 274-275 (in Ukrainian).
Eremenko, Y. A., & Ostapko, V. M. (2011). Rasprostranenie adventivnyh dreves-no-kustarnikovyh rasteniy na territorii Donetskogo Botanicheskogo Sada NAN Ukrainy [Distribution of adventive trees and shrubs in the territory of Donetsk Botanical Garden, NAS of Ukraine]. Industrial Botany, 11, 135140 (in Russian).
Eremenko, Y. A., & Ostapko, V. M. (2014). Tendentsii k naturalizatsii nekotoryh drevesno-kustarnikovyh introdutsentov na territorii Donetskogo Botani-cheskogo Sada NAN Ukrainy [Tendencies to naturalization of some introduced trees and shrubs on the territory of Donetsk Botanical Garden, NAS of Ukraine]. In: Glukhov, A. Z. (ed.). Restoration of disturbed natural ecosystems: Materials of the V International Scientific Conference (Donetsk, May 12-15, 2014). Donetsk. P. 276 (in Russian).
Filatova, S. O., Osadcha, L. P., & Azarova, L. V. (2014). Introdutsenty botanich-noho sadu. Holonasinni [Introduced plants of the botanical garden. Gymnos-perms]. Odesa I. I. Mechnikov National University, Odesa (in Ukrainian).
Firsov, G. A., & Byalt, V. V. (2015). Obzor drevesnyh ekzotov, dayushchikh sa-mosev v Sankt-Peterburge (Rossiya) [Review of woody exotic species producing a self-sowing in Saint-Petersburg (Russia)]. Russian Journal of Biological Invasions, 6(4), 129-152 (in Russian).
Galkin, S. I., Doyko, N. M., & Boyko, N. S. (2017). Kolektsiynyi fond derevnykh roslyn arboretumu "Oleksandriya" [Collection fund of woody plants of the arboretum "Alexandria"]. Forestry and Gardening, 11 (in Ukrainian).
Gaskin, J. F. (2017). The role of hybridization in facilitating tree invasion. AoB Plants, 9, plw079.
Grevtsova, A. T. (ed.). (2000). Katalog rasteniy Krivorozhskogo Botaniheskogo Sada [Catalogue of plants of the Kryvyi Rih Botanical Garden]. Phytosoci-ocenter, Kyiv (in Russian).
Hirsch, H., Richardson, M. D., & Le Roux, J. J. (2017). Introduction to the special issue: Tree invasion: Towards a better understanding of their complex evolutionary dynamics. AoB Plants, 9, plx014.
Kish, R. Y., Andrik, Y. Y., & Kagalo, O. O. (2009). Yasen bilotsvityi. Fraxinus ornus L. [Flowering ash. Fraxinus ornus L.]. In: Didukh, Y. P. (ed.). Red data book of Ukraine. Vegetable Kingdom. Globalconsulting, Kyiv. P. 526 (in Ukrainian).
Kokhno, M. A. (1994). Okhorona henofondu derevnykh introdutsentiv v Ukraini [The protection of the gene pool of woody introduced plants in Ukraine]. In: Burda, R I. (ed.). Protection of the gene pool of plants in Ukraine. Abstracts of scientific conferences (Kryvyi Rih, May 1994). Donetsk. Pp. 145-146 (in Ukrainian).
Kokhno, M. A. (ed.). (1997). Katalog rasteniy TsRBS imeni N. N. Gryshko [Catalogue of plants of N. N. Gryshko CRBG]. Naukova Dumka, Kyiv (in Russian).
Kolisnychenko, O. V., Yakubenko, B. E., Slyusar, S. I., Shabarova, S. I., Hontar, V. T., Yakobchuk, O. M., Bilenko, V. G., Shevchuk, N. V., Mayevskyi, K. V., Chichikova, M. A., & Shulzhenko, G. P. (2011). Kataloh roslyn Botanichnoho Sadu NUBiP Ukrainy [Catalogue of plants of the Botanical Garden of the National University of Life and Environmental Scierces of Ukraine]. National University of Life and Environmental Scie^es of Ukraine, Kyiv (in Ukrainian).
Kondratyuk, E. N. (Ed.). (1988). Katalog rasteniy Donetskogo Botanicheskogo Sada [Catalogue of plants of the Donetsk Botanical Garden]. Naukova Dumka, Kyiv (in Russian).
Kormilitsin, A. M., & Golubeva, I. V. (1970). Katalog dendrologicheskih kollektsiy arboretuma Nikitskogo Botanicheskogo Sada [Catalogue of arboretum dendro-logical collections of the Nikitsky Botanical Garden]. Yalta (in Russian).
Kosenko, I. S. (ed.). (2000). Kataloh roslyn Dendrolohichnoho Parku "Sofiivka" [Catalogue of plants of the Arboretum "Sofiivka"]. Uman (in Ukrainian).
Kucherevsckyi, V. V., & Shol, H. N. (2009). Konspekt urbanoflory Kryvoho Rohu [List of plants of the Kryvyi Rih urban flora]. Press House, Kryvyi Rih (in Ukrainian).
Kvasha, V. V., Semenova, O. O., & Chuvikina, N. V. (2010). Zapovidni terytorii Ukrainy. Botanichni sady ta dendroparky [Protected areas of Ukraine. Botanical gardens and arboretums]. Maximus, Kyiv (in Ukrainian).
Lambdon, P. W., Pysek, P., Basnou, C., Hejda, M., Arianoutsou, M., Essl, F., Jarosik, V., Pergasiophytel, J., Winter, M., Anastasiu, P., Andriopoulos, P., Bazos, I., Brundu, G., Celesti-Grapow, L., Chassot, P., Delipetrou, P., Josefs-son, M., Kark, S., Klotz, S., Kokkoris, Y., Kühn, I., Marchante, H., Pergasio-phytelova, I., Pino, J., Vila, M., Zikos, A., Roy, D., & Hulme, P. E. (2008). Alien flora of Europe: Species diversity, temporal trends, geographical patterns and research needs. Preslia, 80, 101-149.
Lykholat, Y. V., Khromykh, N. A., Ivan'ko, I. A., Matyukha, V. L., Kravets, S. S., Didur, O. O., Alexeyeva, A. A., & Shupranova, L. V. (2017). Assessment and prediction of the invasiveness of some alien plants under the climatic changes in the Steppe Dnieper. Biosystems Diversity, 25(1), 52-59.
Lykholat, Y. V., Khromykh, N. O., Pirko, Y. V., Alexeyeva, A. A., Pastukhova, N. L., & Blume, Y. B. (2018a). Epicuticular wax composition of leaves of Tilia L. trees as a marker of adaptation to the climatic conditions of the Steppe Dnieper. Cytology and Genetics, 52(5), 323-330.
Lykholat, Y., Khromykh, N., Didur, O., Alexeyeva, A., Lykholat, T., & Davydov, V. (2018b). Modeling the invasiveness of Ulmus pumila in urban ecosystems under climate change. Regulatory Mechanisms in Biosystems, 9(2), 161-166.
Mayorov, S. R., Vinogradova, Y. K., & Bochkin, V. D. (2013). Illustrirovannyi katalog rasteniy, dichayushchih v botanicheskih sadah Moskvy [An illustrated catalogue of plants, escaping from cultivation in botanical gardens of Moscow, Russia]. N. V. Tsitsin Main Botanical Garden of Russian Academy of Sciences, Fiton XXI, Moscow (in Russian).
Medvedev, V. A., & Ilyenko, O. O. (2018). Dendrolohichna kolektsiya dendroparku "Trostyanets" NAN Ukrainy [Dendrological collection of the arboretum "Tros-tyanets", NAS of Ukraine]. In: Boyko, N. S., & Doyko, N. M. (Eds). The history of creation, species composition, long-term dynamics of protected diversity of flora in botanical gardens and arboretums: Traditions, modernity, prospects: Materials of the International Scientific Conference on the 230th anniversary of the arboretum "Alexandria", NAS of Ukraine, September 19-20, 2018. Bilo-tserkivdruk, Bila Tserkva. Pp. 278-284 (in Ukrainian).
Mosyakin, S. L. (2013). Rodyny i poryadky kvitkovykh roslyn flory Ukrainy: Prag-matychna klasyfikatsiya ta polozhennya u filohenetychnij systemi [Families and orders of Angiosperms of the flora of Ukraine: A pragmatic classification and placement in the phylogenetic system]. Ukrainian Botanical Journal, 70(3), 289-307 (in Ukrainian).
Mosyakin, S. L., & Yavorska, O. G. (2002). The non-native flora of the Kyiv urban area, Ukraine: A checklist and brief analysis. Urban Habitats, 1(1).
Nentwig, W., Bacher, S., Kumschick, S., Pysek, P., & Vila, M. (2018). More than "100 worst" alien species in Europe. Biological Invasions, 20, 1611-1621.
Nikolaeva, O. A., & Danilova, O. S. (2019). Konspekt flory sosudistyh rasteniy prirodnoy territorii Yakutskogo Botanicheskogo Sada [Сonspectus of the flo-
ra of vascular plants of natural areas of the Yakutsk Botanical Garden]. Phy-todiversity of Eastern Europe, 13(1), 70-94 (in Russian).
Ostapko, V. M., Mulenkova, O. G., & Boiko, G. V. (2013). Novi vidomosti pro spontanne poshyrennya roslyn z Donetskoho Botanichnoho Sadu [New data on the spontaneous escaping of plants from the Donetsk Botanical Garden]. In: Radchenko, V. G. (ed.). The role of botanical gardens and arboretums in maintaining and enriching of biological diversity in urban areas. Materials of the International Scientific Conference (Kyiv, May 28-31, 2013). Kyiv. Pp. 122-123 (in Ukrainian).
Pashkevych, N., & Burda, R (2017). Spread of alien plant species in the habitats of the Ukrainian Forest-Steppe. Ekológia (Bratislava), 36(2), 121-129.
Plugatar, Y. V., Koba, V. P., Gerasimchuk, V. N., & Papelbu, V. V. (2015). Dendro-logicheskaya kollektsiya arboretuma Nikitskogo Botanicheskogo Sada - sosto-yanie i perspektivy razvitiya [Dendrological collection of arboretum of Nikitsky Botanical Gardens: Current state and trend development]. Achievements of Science and Technology of Agriophyteiculture, 29(12), 50-54 (in Russian).
Pollegioni, P., Olimpieri, I., Woeste, K. E., De Simoni, G., Gras, M., Malvolti, M. E.
(2013). Barriers to interspecific hybridization between Juglans nigra L. and J. regia L. species. Tree Genetics and Genomes, 9(1), 291-305.
Prokopiv, A. (2004). Botanichnyi sad Lvivskoho Natsionalnoho Universytetu imeni Ivana Franka - istoriya ta suchasnist [The botanical garden of Ivan Franko National University of Lviv - history and the present]. Visnyk of Lviv University, Biology, 36, 3-9 (in Ukrainian).
Protopopova, V. V., Fedoronchuk, M. M., Shevera, M. V., & Shevchyk, V. L.
(2014). Vydy-transformery Serednoho Prydniprovya [Transformer species of the Middle Dnipro Region]. Ukrainian Botanical Journal, 71(5), 560-569 (in Ukrainian).
Protopopova V. V., Shevera, M. V., Bagrikova, N. O., & Ryff, L. E. (2012). Vydy-transformery u flori Pivdennoho Bereha Krymu [Transformer species in the flora of the South Coast of Crimea]. Ukrainian Botanical Journal, 69(1), 5468 (in Ukrainian).
Protopopova, V. V., Shevera, M. V., Chornei, I. I., Budzsak, V. V., Tokaryuk, A. I., & Korzhan, K. V. (2010). Vydy-transformery u flori Bukovynskoho Peredcar-pattya [Transformer species in the flora of the Bukovyna Cis-Carpathian Area]. Ukrainian Botanical Journal, 67(6), 852-864 (in Ukrainian).
Protopopova, V. V., Shevera, M. V., Mosyakin, S. L., Solomakha, V. A., Solomakha, T. D., Vasilieva, T. V., & Petryk, S. P. (2009). Vydy-transformery u flori Pivnichnoho Prychornomorya [Transformer species in the flora of the Northern Black Sea Region]. Ukrainian Botanical Journal, 66(6), 770-782 (in Ukrainian).
Protopopova, V. V., Shevera, M. V., Orlov, O. O., & Panchenko, S. M. (2015). The transformer species of the Ukrainian Polissya. Biodiversity: Research and Conservation, 39, 7-18.
Protopopova, V., & Shevera, M. (2002). A preliminary checklist of urban flora of Uzhgorod. Phytosociocenter, Kyiv.
Pysek, P., Meyerson, L., Simberloff, D. (2017a). Introducing 'Alien Floras and Faunas', a new series in Biological Invasions. Biological Invasions, 20(6), 1375-1376.
Pysek, P., Perg, J., Essl, F., Lenzner, B., Dawson, W., Kreft, H., Weigelt, P., Winter, M., Kartesz, J., Nishino M., Antonova, L. A., Barcelona, J. F., Cabezas, F. J., Cárdenas, D., Cardenas-Toro, J., Castano, N., Chacon, E., Chatelain, C. Dullinger, S., Ebel, A. L., Figueiredo, E., Fuente, N., Genovesi, P., Groom, Q. J., Henderson, L., Inderjit, Kupriyanov, A., Masciadri, S., Maurel, N., Meerman, J., Morozova, O., Moser, D., Nickrent, D., Nowak, P.M., Pagad, S., Patzelt, A., Pelser, P. B., Seebens, H., Shu, W., Thomas, J., Velayos, M., Weber, E., Wieringa, J. J., Baptiste, M. P. & van Kleunen, M. (2017b). Naturalized alien flora of the world: Species diversity, taxonomic and phylo-genetic patterns, geographic distribution and global hotspots of plant invasion. Preslia, 89, 203-274.
Rejmánek, M., & Richardson, D. M. (2013). Trees and shrubs as invasive alien species - 2013 update of the global database. Diversity and Distribution, 19(8), 1093-1094.
Rubtsov, A. F., Havrylenko, N. O., Slepchenko, L. O., Petrenko, Z. A., & Lytvy-nenko, Y. S. (2012). Kataloh roslyn Dendrolohichnoho Parku "Askaniya-Nova" [Catalogue of the plants of the Dendrological Park "Askania Nova"]. Askaniya-Nova.
Rubtsov, L. I., & Gordienko, I. I. (Eds.). (1971). Derevya i kustarniki. Golosemennye [Trees and shrubs. Gymnosperms]. Naukova Dumka, Kyiv (in Russian).
Shvydkaya, N. V., & Kudinova, A. F. (2013). Osobennosti adventivnoy dendrof-lory urbanizirovannyh territoriy Krasnodarskogo kraya. In: Features of adventive dendroflora of urbanized territories of the Krasnodar Region. Materials of the International Scientific Conference (Kyiv, May 28-31, 2013). Kyiv. Pp. 163-164 (in Russian).
Shynder, O. I. (2013). Botaniko-heohrafichna dilyanka "Kavkaz" - oseredok vydovoi riznomanitnosti kavkazkoi flory u m. Kyevi [Botanical and geographical area "Caucasus" - the center of the species diversity of the Caucasian flora in Kyiv]. In: Radchenko, V. G. (Ed.). The role of botanical gardens and arboretums in maintaining and enriching of biological diversity in urban
areas. Materials of the International Scientific Conference (Kyiv, May 28-31, 2013). Kyiv. Pp. 298-300 (in Ukrainian).
Slyusarenko, O. M., Osadcha, L. P., Azarova, L. V., Filatova, S. O., & Chaban, K. V. (2017). Introdutsenty botanichnoho sadu. Pokrytonasinni [Introduced plants of the Botanical Garden. Angiospermae]. Odesa I. I. Mechnikov National University, Odesa (in Ukrainian).
Solomakha, V. A. (Ed.) (2007). Botanichnyi Sad imeni O. V. Fomina. Kataloh roslyn [O. V. Fomin Botanical Garden. Index Plantarum]. Phytosociocenter, Kyiv (in Ukrainian).
Stankov, S. S. (1924-1925). O nekotoryh harakternyh kulturnyh i odichavshyh rasteniyah Yuzhnogo Berega Kryma [On some characteristic cultivated and wild plants of the South Coast of Crimea]. Journal on Applied Botany and Breeding, 14(4), 275-324 (in Russian).
Tarasov, V. V., Donchenko, Y. V., & Krasnorepoecophyteva, T. V. (1998). Adven-tivnaya flora Dnepropetrovskogo Botanicheskogo Sada, DGU [Adventive flora of Dnipropetrovsk Botanical Garden, DSU]. In: Glukhov, A. Z. (Ed.). Industrial botany: The state and prospects of development. Materials of the Third International Scientific Conference (Donetsk, September 3-5, 1998). Donetsk. Pp. 97-98 (in Russian).
Tyshchenko, O. V., Tyshchenko, V. M., & Kucheryava, L. F. (2013). Znakhidka Celastrus scandens L. (Celastraceae) v zapovidnomu urochyshchi Rizanyi Yar (Cherkaska oblast) [A new record of Celastrus scandens L. (Celastra-ceae) at protected area Rizanyi Yar (Cherkasy Region)]. Ukrainian Botanical Journal, 70(5), 646-648 (in Ukrainian).
van Kleunen, M., Dawson, W., Essl, F., Pergl, J., Winter, M., Weber, E., Kreft, H., Weigelt, P., Kartesz, J., Nishino, M., Antonova, L. A., Barcelona, J. F., Cabezas,
F. J., Cardenas, D., Cardenas-Toro, J., Castaño, N., Chacon, E., Chatelain, C., Ebel, A. L., Figueiredo, E., Fuentes, N., Groom, Q. J., Henderson, L., Indeijit, Ku-priyanov, A., Masciadri, S., Meerman, J., Morozova, O., Moser, D., Nickrent, D. L., Patzelt, A., Pelser, P. B., Baptiste, M. P., Poopaft, M., Schulze, M., Seebens, H., Shu, W. S., Thomas, J., Velayos, M., Wieringa, J. J., Pysek, P. (2015). Global exchange and accumulation of non-native plants. Nature, 525, 100-103.
van Kleunen, M., Essl, F., Pergl, J., Brundu, G., Carboni, M., Dullinger, M., Early, R., González-Moreno, P., Groom, Q. J., & Hulme, P. E. (2018). The changing role of ornamental horticulture in alien plant invasions. Biological Reviews, 93(3), 1421-1237.
Yatsenko, I. O., & Vinogradova, Y. K. (2018). Invazionnaya aktivnost drevesnyh rasteniy v Glavnom Botanicheskom Sadu im. N. V. Tsytsyna Rossiyskoy Academii Nauk [Invasive activity of woody plants in the Tsytsyn Main Botanical Garden of RAS]. Russian Journal of Biological Invasions, 9(4), 117131 (in Russian).
Zavyalova, L. V. (2010). A checklist of the Chernihiv urban flora. Phytosociocen-ter, Kyiv.
Zenni, R. D., Dickie, I. A., Wingfield, M. J., Hirsch, H., Crous, C. J., Meyerson, L. A., Burgess, T. I., Zimmermann, T. G., Klock, M. M., Siemann, E., Erfmeier, A., Aragon, R., Montti, L., & Le Roux, J. J. (2017). Evolutionary dynamics of tree invasions: Complementing the unified framework for biological invasions. AoB Plants, 9, plw085.
Zvyagintseva, K. O. (2015). An annotated checklist of the urban flora of Kharkiv. V. N. Karazin Kharkiv National University, Kharkiv.