More than 1700 species of vascular plants are known in the flora of Penza region, including alien fraction with about 400 species, 25 species of these being classified by us as the most dangerous invasive plants for ecosystems and public health in the region. These dangerous species are recommended for inclusion in the Black Book of the Penza region and the Black Book of the Volga Basin.

The study of phytophages and phytopathogens adapted to invasive species Helianthus tuberosus L. and H. subcanescens (A. Gray) E.E. Wats. (Asteraceae) was conducted in 2022–2023 in Moscow and Kaluga regions. The identification of collected samples was carried out in the plant protection laboratory of the Main Botanical Garden of RAS. Three species of phytophages were found that occur sporadically and do not cause serious damage to plants. These species are generalized polyphages; we have not found specialized phytophages. The powdery mildew pathogen of sunflower, namely Erysiphe cichoracearum DC. f. helianthi Jacz. was the most adapted to invasive Helianthus species. Other pathogens were not detected in invasive populations due to the relative resistance of latter to phytopathogens and unfinished process of consortial relationship formation.

A review of recent scientific articles (2020–2023) on the problems of invasion plant biology is presented. Results of the inventory of alien and invasive species are briefly characterized, and the invasive statuses of plants in the collections of botanical gardens are analyzed. Data on biological features, genotypic variability, allelopathic activity and micromorphology of the most aggressive invasive plants are given. Invasibility of habitats is discussed

Studies of the actual, metabolic and hydrolytic acidity of soils in agricultural lands of the southern part of Shakhtersk district of the Donetsk People’s Republic were carried out. It has been shown that in terms of actual acidity, agricultural soils differ depending on the extent to which the land has been withdrawn from use, the type of crop being cultivated, and the link in the crop rotation system. Farmland soils are characterized by higher acidity values compared to the control plot, with pH values ranging from 5.37 to 6.88. The greatest changes in metabolic and hydrolytic acidity towards an increase in its indicators affected the arable and subarable horizons of areas that were fallow after growing a number of agricultural crops.

In this study, the feeding preferences of the leaf beetles Bromius obscurus Linnaeus, 1758 (Coleoptera: Chrysomelidae) were investigated in relation to two plant species of the Onagraceae family: the native Chamaenerion angustifolium (L.) Scop. and the invasive Epilobium adenocaulon Hausskn. During experiments with choice and subsequent assessment of plant damaged areas, it was established that B. obscurus prefers the native Ch. angustifolium. Experiments with traps showed the ability of leaf beetles to find their preferred plant by odour. These results are consistent with the Enemy Release Hypothesis, showing a greater vulnerability of native plants to phytophages. The olfactory analyzer plays an important role in recognizing the food plant.

In the Bryansk region, intensive spread of the pest Agrilus planipennis Fairmaire, 1888 was recorded within the urban area of Bryansk. Artificially created plantings of the North American introduced species Fraxinus pennsylvanica Marsh. are most susceptible to damage in urban xero-mesophytic habitats. In ash stands in the river valleys of the urban area and in tree communities with spontaneous dispersal of this species we noted uneven damage caused by A. planipennis. The use of the damage index, easily accessible for study, based on the number of ejection holes, has shown its low effectiveness, since no reliable dependence of its values on other indirect signs of damage was identified.

The article presents research results on the species composition of plants in urbanized plant communities with the dominance of boxelder maple (Acer negundo L.) in the Kemerovo region. The studies were carried out at survey sites located in the mountain-taiga and forest-steppe zones of the Siberian region. The species diversity of vascular plants in the studied sites amounted to 41 species. The leading families in terms of the species number are Asteraceae, Fabaceae and Poaceae families. It was revealed that the species diversity of vascular plants decreases by an average of 55 % in communities with the participation of this invasive species, compared to communities without its participation

The article presents the results of a retrospective analysis of a collection of plants of the genus Pyrus L. (Rosaceae) in the arboretum of the Donetsk Botanical Garden for the period from 1965 to 2022. The largest number of seed samples of pear species came from introduction points in the 1970s. 25 species underwent introduction testing in collection plantings. Currently, the collection includes 11 species, 1 hybrid and 1 subspecies – 143 specimens aged 45–50 years. Most of the plants (81% of the total number of trees) are in satisfactory condition.

The paper contains data about 5 species of scale insects (Hemiptera: Coccidae, Eriococcidae) registered in the green spaces of Donbass in 2007, 2018–2020 and 2023. All species are recorded for the first time in the region’s fauna. Among them, three species are monophagous, while two are polyphagous. Potentially dangerous pests of ornamental crops, the state of which needs to be controlled, include alien invasive species – the yew scale Parthenolecanium pomeranicum (Kawecki, 1954) and the box scale Eriococcus buxi (Boyer de Fonscolombe, 1834), included in the list of objects of state forest pathological monitoring of the Donetsk People’s Republic. These species are currently known from isolated local outbreaks within the territory of Donetsk.

The results of flora studies on 10 railways segments in the Nizhny Novgorod region are presented. An analysis of correlations between the Jaccard coefficients of floristic similarity, calculated for fractions of floras of the studied segments, and the distances between these segments showed a statistically significant correlation with the distance between the segments for a fraction of rare species, which can directly characterize the process of their dispersal. The results obtained confirm that methodology used for collecting and analysis of floristic data is logically interpretable and promising for further usage.