It is shown that the fraction of forest and forest-edge species of the specific flora of the Donetsk Botanical Garden is 126 species, including 15 endemics, 2 relic and 15 sozophyte species. According to their origin these species are divided in four groups: 1) aboriginal for Donbass and specific flora (48 species); 2) aboriginal for the specific flora and «escaping from cultivation» (46 species); 3) introduced species, «escaping from cultivation», growing within their natural range (27 species); 4) introduced species, «escaping from cultivation», growing beyond their natural range (5 species). Spontaneous forest flora of Donetsk Botanical Garden is impoverished compared to similar floras of Krynka floristic subdistricts according to a number of autochthonous species, meanwhile it is enriched by «escaping from cultivation» species.

The paper presents data on six species of psyllids (Hemiptera: Psylloidea: Liviidae, Psyllidae, Triozidae) registered in the green spaces of Donbass in 2020, 2021, and 2023. All recorded species were observed for the first time in the region’s fauna. Among the alien invasive species is the Asian species Trioza neglecta Loginova, 1978, which established itself in the region following the introduction of Elaeagnus angustifolia L. The monophagous group comprises five species, while there is one oligophagous species (Cacopsylla ulmi (Foerster, 1848)). Five species are associated with woody plants and one species is associated with herbaceous plants (Trioza urticae (Linnaeus, 1758)). The identified species’ harmfulness in the Donbass region is relatively low, manifesting primarily as slight losses in decorative effect due to gall formation on the leaves.

Studies to assess the aggregate state of degraded farmland soils in the northern part of the Shakhtersk district of the Donetsk People’s Republic were carried out. In the vast majority of cases, the predominance of the fraction with a particle size of less than 0.5 mm was revealed: from 30.9 % (horizon B of area N 1) to 70.2 % (horizon A of area N 8). The exception is horizon B of area N 8: were predominant is the fraction of particles with a size of 5 mm – 2 mm – 34.0 %. By the content of agronomically valuable aggregates, the soils of the arable horizon of most of the studied areas are characterized by unsatisfactory condition, while for the sub-arable horizon, according to the gradation used, good (areas N 1–4) and excellent condition (areas N 6–8) were noted.

Based on the results of long-term expeditionary studies of invasive processes in the Southern Urals, key invasive species of the firstinvasive status (transformer species) are listed for 3 regions: Republic of Bashkortostan, Orenburg and Chelyabinsk oblasts. A total of 16 alien plant species, 6 species common to all regions among them, were classified as such. The majority of transformers are actively naturalized in natural and semi-natural phytocenoses with the expansion of the occupied area, their dispersal is associated with transport routes, human economic activity and ornamental horticulture. Dangerous invasive species should be the objects of constant environmental monitoring and population control, as they threaten biodiversity and lead to significant changes in natural ecosystems.

The publication presents the main results of the current stage of research of alien phytopathogenic fungi that infect trees and shrubs in the Donbass. Based on the results of many years of research, 105 alien species were recorded. Three main groups of alien species can be distinguished among all pathogens of woody plants according to the type of diseases causing a significant deterioration in the vital condition of many arboreal plants species in the Donbass: pathogens causing vascular mycoses (wilting); pathogens causing diseases of leaves or needles; pathogens causing bark necrosis, shoot dieback and cancer diseases. It is critically important to monitor the possible spread of two new dangerous phytopathogenic fungi in the region: Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz & Hosoya, causing ash dieback, and Cryptostroma corticale (Ellis & Everh.) P.H. Greg. & S. Waller, causing sooty bark disease of maples.

Based on an analysis of publications and author’s own research, it is shown that the south of Russia is a macro-region where the spread of new alien species of plant pathogens is observed, and this process will inevitably continue in the future. Brief information about the findings of several important phytopathogenic fungi previously unknown in Russia but discovered in the south of Russia, is provided. Monitoring the possible spread of newly found dangerous plant pathogens, especially Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz & Hosoya, which causes ash dieback, and Cryptostroma corticale (Ellis & Everh.) P.H. Greg. & S. Waller, which causes sooty bark disease of maples, is an extremely important task.

As a result of long-term studies of the flora of three specially protected natural areas in the KondoSosvinsky Ob region, 160 species of alien plants were identified, 66 species (15.6 % of the total flora) among them were registered in the Nature Reserve «Malaya Sosva», 94 species (20.9 %) in the Nature Reserve «Verkhne-Kondinsky», 103 species (29 %) – in the Natural Park «Kondinsky Lakes». There are 44 alien species common to all specially protected natural areas. Over the past 80 years, the number of alien species has increased in 3.2 times; the main routes of their introduction are transport corridors, cultivated fields, as well as the introduction of plants into populated areas and cordons.

Based on case study of some species (Astragalus testiculatus Pall.; Potamogeton sarmaticus Mäemets; Stuckenia filiformis (Pers.) Börner), we considered the origin and absence of need for protection status for locations of rare plant species in the northern part of Western Siberia, outside the natural range. It is shown that organization of special protection measures of rare native species in disturbed habitats is also usually impractical.

The paper gives information on the discovery of some previously unknown macromycetes in the Novosibirsk and Tomsk regions: Agaricus benesii (Pilát) Pilát, Agaricus xanthodermus Geven., Amanita olivaceogrisea Kalamees, Amanita phalloides (Vaill. ex Fr.) Link, Amanita populiphila Tulloss et E. Moses, Entonaema cinnabarinum (Cooke et Massee) Lloyd, Calonarius olearioides (Rob. Henry) Niskanen et Liimat., Chroogomphus filiformis Yan C. Li et Zhu L. Yang, Cortinarius balteatocumatilis (Rob. Henry ex P.D. Orton) Niskanen et Liimat., Cystolepiota buckhallii (Berk. et Broome) Singer et Clemencon, Hebeloma insigne A.H. Sm., V.S. Evenson et Mitchel, Hortiboletus bubalinus (Oolbekk. et Duin) L. Albert et Dima, Leccinum cyaneobasileucum f. chlorinum (Lannoy et Estadès) Klofac, Leucocoprinus straminellus (Bagl.) Narducci et Caroti. The locations of these species, features of their ecology, distribution in the world, Siberia, Novosibirsk and Tomsk region are noted, possible migration routes and invasive properties are analyzed.

We tested hypotheses about a decrease of species richness and an increase of the participation of alien species in communities invaded by Acer negundo L. in three remote regions – in the Belarusian Polesia, the Middle Volga region and the Middle Urals. In three regions, 39 pairs of sample plots invaded and noninvaded by A. negundo were described. It was found that when A. negundo dominates the total number of species and the number of native species are 20–47 % lower; the proportion of alien species is higher by 7–34 %. The weakening of the positions of native species and the weak strengthening of the positions of alien species indicate the presence of selectivity in the influence of boxelder maple on florogenetically different (native and adventitious) groups of plants.