Data about floristic records of Ionoxalis tetraphylla (Cav.) J. Rose(Oxalis tetraphylla Cav.) (Oxalidaceae), a new alien species of Ukrainian flora were presented. Species has Central American origin, its primary area are covers Mexico, Panama, Guatemala, Costa Rica, Caribbean islands. Secondary area spreads on Europe, Asia and Australia. It was found in neighboring countries with Ukraine, including Russia and Belorussia. As a naturalized species it was tagged in some countries of Southern Europe. The main centers of species introduction in Ukraine are M.M. Hryshko National Botanical Garden of NAS of Ukraine, Acad. O.V. Fomin Botanical Garden of Taras Shevchenko Kyiv National University, Botanical Garden of Oles’ Honchar Dnipro National University, Botanical Garden of V.N. Karazin Kharkiv National University, Botanical Garden of V.I. Vernadsky Taurian National University, Syretskyi dendrological park (Kyiv), private gardens and greenery managements in Kyiv and Kyiv Region, Odesa, Kamyanets-Podilskyi (Khmelnytskyi Region) and other regions of the country. Information about spontaneously distribution of the plants in Ukraine nowdays is absent. At the first time some escaped plants of the I. tetraphylla were recorded in 2019 near village Dovzhyk of Zhymomyr District of Zhytomyr Region. Some individuals grew in old pine forest margins near path. Plants successfully overwintered at 2019/2020 years. Taxonomical and morphological characteristics, chorological data (primary and secondary areas) and ecological peculiarities are presented. According to the time of immigration this species is kenophyte, according to the way of introduction – ergasiophyte and according to the degree of naturalization in Ukraine it is ephemerophyte. The species is mesotroph, mesophyte, scio-heliophyte. In conditions of Ukraine it blooms profusely but almost never forms seeds, and reproduces vegetatively – by daughter bulbs. The map of the species distribution (spontaneously and in culture) in Ukraine is presented.

The paper contains a synopsis of rare component of flora of Halych National Nature Park forest ecosystems, as well as evaluation of distribution trends of rare vascular plant species and the state of their populations. Being established in 2004, the Park is located in Halych district of Ivano-Frankivsk region on the area of 14684.8 ha. Forests occupy the biggest part of its territory (81.1 %), among which predominate poor and mixed oak (Querceta roboris), beech (Fageta sylvaticae) and hornbeam (Carpineta betuli) woods. Inventory check of plant cover of the forest ecosystems has been done between 2008-2019 years. According to the results of our study, within the forests and forest margins grow 303 vascular plant species, out of which 63 are rare (20.8 %). The list of rare species is composed of species included to the Red Data Book of Ukraine, of species protected by international conventions and directives and complemented by species that are threatened within the study region. Species were considered as threatened if the number of localities and / or population size were small. Regionally rare species were selected based on the analyzes of results of our field survey and materials of herbarium collections. We have found that the third part of rare species (33.3 %) has high coenotic amplitude and a bit less species (26.2 %) favor forest margins. Rare species having low coenotic amplitude are confined to beech woods (19.1 %). Rare species are considerably distinguished by occurrence. Species with scarce occurrence predominate. For instance, 61 % of the species were found in 1-5 localities, of which 25 species occur only in one or two sites. Share of species growing in 6-10 localities within the Park is equal to 26.6 %. Only a small percentage (6.2 %) of rare species comprises species with relatively frequent occurrence (11–20 localities as well as more than 20 cites). Rare species of the Park forests with the highest occurrence rate are Lilium martagon and some members of Orchidaceae family. Predominantly, rare species have populations of small size, for instance, 81.2 % of the species were found in quantities of a few plants – several hundreds of individuals. The most threatened are species general number of which at the Park area is several plants (15.6 %). These species are as follows: Circaea alpina, Atropa bella-donna, Campanula latifolia, Phyteuma spicatum, Epipactis atrorubens etc. The biggest groups comprise species with general number of few tens and several hundreds of individuals (totally 65.6 %). Species with big populations represent far smaller part of forest rare species. Nine rare species grow in the number of several thousands of plants within the Park and three species (Allium ursinum, Galanthus nivalis and Leucojum vernum) – over a million. It has been established that 52.4 % of rare species populations taken together remain in critically bad state, 28.6 % of the populations – in bad state, 14.3 % – in satisfactory state. Only 4.8 % of populations are in good state. Our results show that about 95 % of species are in need of protection and continuous monitoring of population number. Furthermore, 51 species of rare plants, having low number and bad state of populations, require to work out and implement management plans for their restoration.

The article describes the role and prospects of using modern phytosociological databases for complex geobotanical researches. Based on the analysis of foreign and national experience in creating such information resources, the need for their development and standardization by forming a national infrastructure for the input, accumulation, and storage of phytosociological data of Ukraine is substantiated. Such infrastructure provides the development and implementation of unified technical protocols and normative-methodical rules of digitalization, compilation, management, and the use of phytosociological data for complex meta-analyses. Within the one software technical protocols should combine a single taxonomic list to enter data about the species composition of phytocoenoses, as well as a unified form of header data to add other information on plant communities. Based on the analysis of the existing floristic lists used by Ukrainian phytosociologists, the need to create a new most complete species list with current taxonomic data, which will be periodically updated, is provided. Such a list should unite all taxa of vascular plants and cryptogams known from the territory of Ukraine, be as complete and correct as possible. A standard metadata structure has been developed to enter information on the vertical and horizontal structure of phytocoenoses, ecological and physical-geographical conditions, sozological value, as well as habitat and syntaxonomic affiliation of each geobotanical relevé. A communication system is proposed to obtain phytosociological information necessary for specific research, as well as possible forms of control over the move and use of information protected by copyright. Forms of access to data, mechanisms for obtaining them, and a list of rules for regulating compliance with copyright and scientific ethics in the use of data in the analysis process have been developed.

The history of floristic research related to dry meadows in the Middle Russian province of the Forest-Steppe in Ukraine since the XIX century was analysed. More than 200 literary sources were included to this investigation. There are general works by naturalists, floristic lists and distribution data of rare species on the territory of Sumy and Kharkiv geobotanical districts. We concluded that the most works until 1900 were floristic. Howewer, the total number of works provided data about rare species began to increase. From the 30's of the last century, scientists worked in detail with plant geography and taxonomy. The next direction is the study of plant communities, which has been actively developing since the 60's. The nature protection direction began to develop after the establishment the State Committee for Nature Protection in 1967. Since 2000, there has been a sharp jump in the number of works that are somehow related to the flora of dry meadows. Today we can find more conservation works, especially devoted to the study of botanical reserves. It was established that the largest number of works connected with the territories of Kharkiv, Sumy, Bohodukhiv, Okhtyrka, Trostyanets. Since the end of the last century, important centers of long-term research of dry meadows are biological station of the Faculty of Biology of V. N Karazin Kharkiv National University in the village Gaidary (Kharkiv region) as well as biological station "Vakalivshchyna" of Sumy State Pedagogical University named after A. S Makarenko (Sumy region). A common feature of most of the studied works is that the authors write about the need to preserve dry meadows, because due to excessive agricultural activity they are almost completely plowed. An analysis of published data, we see that dry meadows were studied in fragments.

To assess the spatial distribution of bryophytes in Eastern Europe, more than 53,000 localities of 1296 species were analyzed in 397 squares of 100 x 100 km. The number of species within (or density) of one square varies from 591 (southwest of the Kola Peninsula to less than 50 (in arid steppe and semi-desert regions in the southern part of Eastern Europe and in some of arctic and north-taiga poorly studied territories). 8 centers of bryophytes species diversity have been identified in Eastern Europe: Kola Peninsula, South Karelian, Ural, Estonian, Smolensk-Moscow Upland, Carpathians, Black Sea, Caucasian, as well as 7 intermediate sub-centers: Arkhangelsky, Timansky, Narochansky, Volzhsko-Kamsky, South Ural, Belovezhsky, Kiev-Mozyrsky. Their characteristics and unique species for each centers are given. A structural model of the organization and interrelationships of bryofloras in Eastern Europe is proposed. The elevated mountain regions are the concentration of maximum diversity and refuge for many rare species of bryophytes in the region. The central connecting core of the system is the Smolensk-Moscow Upland. It is through this center, there is a connection between the western and eastern parts of the bryoflora of Eastern Europe. The most related element of the spatial structure of bryophytes in Eastern Europe is the Kyiv-Mozyr subcenter (5 ribs), through which the main migration of bryophytes from north to south and vice versa occurs. The Belovezhsky and Narochansky subcenters each have 4 ribs and also actively contribute to the migration process. Through the elevated areas of the Arkhangelsky and Timan subcenters, the Kola Peninsula and South Karelian regions are connected with the Urals. The most isolated in the region is the Caucasus, which maintains links with other centers through the Black Sea center.

The article presents the results of the study of the content of carotenoids of L. sulphureus mycelium under the action of LED lasers: BRP–3010–5, with red spectrum radiation with a wavelength of 635 nm, BBP–3010–5 with blue spectrum radiation with a wavelength of 405 nm and BGP–3010–5 with green spectrum radiation with a wavelength of 532 nm (irradiation energy 51.1 mJ/cm²) when cultured on nutrient medium with different concentrations of glucose. The irradiated mycelium served as a control. It was found that is most effective for the synthesis of carotenoids the use of glucose-peptone medium with a glucose concentration of 10 g/dm³ in combination with irradiation of mycelium with green light at a wavelength of 532 nm (irradiation energy 51.1 mJ/cm²). Under the action of this irradiation regime for strain L.s.-18 the content of carotenoids in the mycelium increased by 66.1% according to the control. Laser irradiation of mycelium with blue light with a wavelength of 405 nm (irradiation energy 51.1 mJ/cm²) increased the content of carotenoids for strain L.s.-18 by 46.7%. Irradiation with red light with a wavelength of 635 nm (irradiation energy 51.1 mJ/cm²) contributed to an increase in the content of carotenoids for strain L.s.-16 of the fungus L. sulphureus by 28.9%. It was found that the use of glucose-peptone medium with a glucose concentration of 8 g/dm³ in combination with irradiation of the mycelium with green light with a wavelength of 532 nm (irradiation energy 51.1 mJ/cm²) was less effective. Under these conditions, the content of carotenoids in the mycelium increased for strain L.s.-17 by 62.3%. Laser irradiation of mycelium with blue light with a wavelength of 405 nm (irradiation energy 51.1 mJ/cm²) increased the content of carotenoids for strain L.s.-17 by 30.6%. Irradiation with red light with a wavelength of 635 nm (irradiation energy 51.1 mJ/cm²) contributed to an increase in the content of carotenoids for strain L.s.-18 of the fungus L. sulphureus by 16.8% respectively. For strain L.s.-16 the number of carotenoids in the mycelium no increase. The use glucose-peptone medium with glucose concentrations of 6 and 4 g/dm³ in combination with laser irradiation of mycelium with red (wavelength 635 nm), blue (wavelength 405 nm) and green (wavelength 532 nm) light with irradiation energy 51.1 mJ/cm² was no increase in the content of carotenoids in the mycelium.