The article is devoted to Yuri Zakharovich Kulagin, a Soviet scientist, Doctor of Biological Sciences, Professor, Head of the Department of Botany at Bashkir State University (1965–1970) and the Laboratory of Forestry at the Institute of Biology of the Bashkir Branch of the USSR Academy of Sciences (1970–1983). Kulagin Yu.Z. is the founder of the scientific direction of industrial dendroecology.

The article presents an overview of long-term mycological and phytopathological studies of phytopathogenic fungi affecting woody and tree-like plants in the «Subtropical Botanical Garden of Kuban» (SBGK) (park of the sanatorium «White Nights») in Sochi. Based on the results of long-term studies, 217 species of phytopathogenic fungi have been identified in the «Subtropical Botanical Garden of Kuban», among which Ascomycota predominate. Totally, 43 species were recorded for the first time in the Krasnodar region, and 32 species were recorded for the first time in Russia. The taxonomic and ecological-biological features of key groups of phytopathogenic fungi on ornamental woody and tree-like plants are analyzed, the most vulnerable groups of plants are identified, and the important role of SBGK as a testing ground for the study of plant diseases in the humid subtropics of Russia is presented.

Present-day distribution of Ailanthus altissima (Mill.) Swingle, including spontaneous spread, in the areas of settlements and agricultural lands of the Novoazovsk district of the Donetsk People’s Republic was under consideration. Self-sustaining tree groups of A. altissima and infection sources of this invasive species in recreationally valuable coastal territories of the Novoazovsk district have been identified. It is necessary to take measures to limit the expansion of this species and eliminate existing thickets and seeding trees. Centers of the spread of A. altissima are abandoned territories where regular maintenance work is not carried out. In accordance with the available global experience, control measures over the spread of this species should include a set of regularly repeated mechanical and chemical application techniques.

The study analyzed the impact of topographic metrics (TPI, TRI, VRM, slope, aspect) on the productivity of grass communities in Donbass, measured using NDVI. Although all metrics showed statistical significance, their contribution to explaining NDVI variation was low (maximum 3.17 % for TPI). The results confirm the need for multi-factor models to more accurately assess productivity, considering the complex interactions between topographic and other ecological factors.

A comparison was made of the soils of an area with absolute reserved regime and an area for grazing livestock in the Khomutovskaya Steppe Nature Reserve. According to the results of the analysis, livestock grazing significantly changes the granulometric composition of soils. The aggregate state of the soils in the humus-accumulative and illuvial horizons of the study areas is characterized by excellent condition according to the selected rating scale, but livestock grazing significantly aggravates this indicator.

The specific formation of the greenhouse plant collection of the Botanical Garden of the Institute of Biological Problems of the Cryolithozone of the Siberian Branch of the Russian Academy of Sciences is considered. The conditions of the growth of introduced plants in the specific natural and climatic conditions of Central Yakutia are highlighted. According to the results of the 2023 inventory, the collection includes 2,000 taxa, of which 500 species from 200 genera and 75 families. The largest number of genera and species diversity are represented by the families Araceae (11 genera, 45 species), Acanthaceae (9 genera, 12 species), Amaryllidaceae (9 genera, 10 species), Arecaceae (9 genera, 9 species), Crassulaceae (7 genera, 32 species), Bromeliaceae (7 genera, 8 species). In terms of life forms, the most numerous group consists of perennial grasses – 200 species. In terms of the number of species, the most widely represented are the Circumboreal (52 species), New Caledonian (41), Brazilian (32), Madagascar (32), Andean (26) and Mediterranean (12) floristic regions.

The intermediate results of the woody plants’ inventory of A.K. Malinovsky Botanical Garden of Ivanovo State University are presented. A total of 72 tree species from 33 genera, 15 families, 2 classes and 2 divisions were identified. The largest numbers of genera in the Magnoliophyta division belong to the Rosaceae family (7 genera), in the Pinophyta division the same relate to Pinaceae (5 genera). The richest genera in terms of species are Quercus L. (9 species, 13.8%) and Acer L. (7 species). Among the trees growing in the Botanical Garden, introduced species predominate – 58.3%, the share of native flora species is 41.7%. By geographical origin, the collection is dominated by species of the North American florogenetic element (18 species, 25%).

The history of cultivation of representatives of the genus Hemerocallis L. in Russia is considered. At present a significant reduction is noted in the distribution of retro varieties and their active replacement by modern varieties. At the same time, old varieties have an important set of features, the preservation of which in the cultural flora is an important task. Retro varieties of hybrid daylily remain promising in breeding work in order to obtain a stable regional assortment. Features of growth and flowering, vandal resistance and general unpretentiousness, simple agricultural technology and possibility of mass obtaining inexpensive planting material make the use of retro varieties in modern landscape design relevant.

The article presents a variant of the detailed classification of plant resources grouped according to their use, application, types of raw materials and biologically active substances. This classification comprises 13 groups and 66 subgroups with smaller divisions. Examples of plants are given for each classification unit. The role of plants in human life was studied basing on ethnobotanical data on the species available in the collection of the Sochi «Dendrarium». The collected gene pool forms the background for the development of many areas, including forestry with the production of valuable timber species, industries using natural raw materials, alternative energy, agriculture, food industry, forage production, biomaterial science, pharmaceutical industry, the creation of safe and comfortable human habitats in populated areas, the development of domestic tourism, education and raising environmental awareness.

The effect of different illumination levels on the germination of Psidium guajava L. seeds in the greenhouse complex of the Donetsk Botanical Garden was studied. It was determined that a 25 and 50 % decrease in the illumination level reduces the germination of P. guajava seeds by 22.5 % and 42.5 %, whereas the light level of 7124.3 ± 242.7 lux (without shading) facilitates germination of this species in 6,7 days earlier compared to the conditions when it was reduced by 25 % and 50 %. The statistical significance of the illumination level effect on the germination rates in P. guajava seeds was revealed.