Work on the selection assessment and reproduction of the gene pool of pedunculate oak for afforestation in the Lower Volga region is presented. The importance of preserving and studying the diversity of oak climatypes playing a key role in the formation of forest ecosystems in this arid region is considered. In the process of selection assessment of the oak ecotypes, it is found that, when choosing the most promising plants within ecotypes, attention should be paid to leading factors such as flowering, fruiting, drought resistance, and pollen quality, as well as the height of trees and the degree of damage caused to them by pests and diseases. It is revealed that oak propagation via seeds shows promise for afforestation. To obtain high-quality offspring, it is important to take into account the peculiarities of fruiting in different phases of acorn development and potential yields. Studies have shown that oak plantations in the Chapurnikovskaya and Grigorovaya gullies are characterised by the most intensive growth and development rates and early flowering and fruiting, as well as by the length of the catkins. In these geographical areas, there is also a predominance of trees with a male type of flowering (57–63%), while in the old-age plantations of the Volga–Akhtuba floodplain, this indicator is 13–28%. A high transpiration intensity (618.3) was noted in oaks from the clone plantation of the Novoanninsky forestry, which indicates the degree of water saturation of the plant’s leaf cells and their high drought resistance. The analysis of the seed material showed the potential and actual yield of oak in the range of 4455–6572 individuals, which makes the studied plantations promising for further selection. To ensure the safety and improvement of seed quality in the designated areas, it is necessary to carry out regular phytosanitary measures to protect against diseases and pests, as well as to carry out agrotechnical care, which will help reduce the number of acorns damaged by insects and, as a result, reduce their mortality.

This article presents data on the study of the drought resilience limits of Scotch pine trees (Pinus sylvestris L.) in the south of the East European Plain in connection with changes in the forest-steppe climate and an increase in the number and intensity of droughts. It is shown that the rate of global warming in the 20th century was 0.11°C/10 years, while in the 21st century it has become 0.35°C/10 years. The goal of this work is to determine the drought resilience limits of Scotch pine trees on different life cycle stages in the forest-steppe zone of the East European Plain. The object of study was the northern (Kaluga and Ryazan), central (Voronezh), and southern (Belgorod) pine populations growing in the ecologically favored territory of the forest-steppe zone of the Russian Plain. As a result of studying the pine response to six severe droughts (early 1991 and 2007, summer 2010 and 2020, and late 2014 and 2020) and an 8-year heat wave (2007–2014), the threshold of resistance of the stages is determined, which, according to the descending vector, represent the following series: ontogenesis, sporogenesis, embryogenesis, and gametogenesis. The cause for the poor harvest in 2012 was the cumulative effect of two droughts on the megasporogenesis processes (2010 in the year of the megasporogenesis initiation and 2012 in the year of fertilization). The impact of the 1991 drought on early embryogenesis led to a fivefold decrease in pine yield and overall lower seed viability. The weather stress of 2010 during late embryogenesis affected vital indicators of the future plants such as growth rate, phenotypic variability, and seasonal development rhythms. It caused the mass death of 1-year-old seedlings and the appearance of many morphoses and developmental deviations in 2-year-old plants. The severe droughts of 2007, 2010, 2012, and 2014 during the 2007–2014 heat wave triggered destabilization and a transition of Scots pine forests into a weakly non-equilibrated system. The return of Scots pine to equilibrium lasted for three optimal years.

Whatever level of recurrent plus breeding cycle is achieved, there is a need of additional supplement of breeding population with new elite tree specimens. Therefore, investigations concerning the confluence of ecological, genetic, and intracelomic factors facilitating their appearance is ever more relevant. Five elite and three normal stands, which included 71 elite trees growing within the northern taiga subzone, were studied in 2021–2023. Most of the stands were relatively even-aged because of their formation after total catastrophic events, such as clear cuts and windfalls. The “elite” phenomena for new pine stand became possible precisely because of some kind of catastrophic event accompanied by fire (slash fire or natural fire), which cleared space, and was followed soon by abundant crop of pine seeds from surrounding stands. Specimens belonging to the leading group of trees, which germinated in the first phase (0–15 years) of pine self-regeneration, had the maximum probability to evolve into elite ones. The genetic proximity of trees of all selection categories can be explained by the fact that all of them belong to the same generation period (about 30 years). At the same time, the actual genetic features of elite trees most commonly remain unrevealed and special trials with vegetative and seed progenies are needed to bring them to light.

Myricaria bracteata Royle and Myricaria longifolia (Willd.) Ehrenb. (Tamaricaceae) are used as herbal medicines in Mongolia, China, and Russia (Siberia). M. bracteata has been domesticated and is used in landscaping thanks to its high winter hardiness, drought resistance, and decorative properties. M. bracteata and M. longifolia leaves are reported to contain derivatives of 17 flavonoid aglycones, as well as ellagic acid and its derivatives. A principal component analysis of 10 populations of each of these species, based on 56 parameters of the phenolic composition of twigs, has shown a high similarity between the species. The native populations of M. bracteata from Tajikistan and Khakassia, as well as native and cultivated populations of both species from Altai Republic, exhibit the most significant differences from most samples in the composition of the analyzed components. Populations of M. longifolia of Altai origin are distinguished by the maximum content of the sum of phenolic compounds (up to 107.7 mg per 1 g of dry weight), hyperoside (18.1 mg/g), and quercitrin (2.8 mg/g). The composition of the exudative compounds of the twigs of these species is also characterized by a high similarity. Differences in the concentrations of compounds by year are revealed. The exudates exhibit higher antioxidant activity (IC50 34.2 and 42.2 μg/mL) when compared to the extracts (IC50 110.7 and 172.2 μg/mL). Histochemical visualization shows the localization of phenolic compounds in the salt glands, vascular tissue, and chlorenchyma in leaves and stems. The results uncover the high potential of native and cultured plants of the Siberian Myricaria species as sources of pharmacologically valuable compounds, in particular, in the phyllosphere of plants, which allows us to consider these species to be elements of natural air purification and a way to improve environmental air quality parameters.

The distribution of Viscum album L. in Bryansk oblast has been studied. The assessment of distribution is performed on a grid basis. In the 20th century, mistletoe was noted in 8 cells, and now the species has been registered in 95 cells out of 378 squares of grid mapping. Recently, the species range in the region has significantly expanded in the northeastern direction. Most often, mistletoe is noted in the central, southern, and southeastern regions of Bryansk oblast; the species has not been found in the southwestern regions on the border with Belarus in the 21st century. There have been no finds north of Bryansk in the region. In Bryansk oblast, mistletoe has been noted on 29 species of woody plants; in natural habitats it is most often recorded on Betula pendula. Within the boundaries of populated areas, V. album is most often found on Betula pendula, Sorbus aucuparia, Acer platanoides, Populus tremula, Pyrus communis, Prunus domestica, and Malus domestica. V. album has been occasionally found on Pinus sylvestris and Picea abies. V. album attacks young plants with unformed bark and weakened old-growth trees with soft wood confined to forest belts along highways, river valleys, old manor parks, and urban plantings. In parkland, V. album is found mainly on isolated trees that are well lit by the sun. The main distributor of mistletoe in the region is Bombycilla garrulus. The features of V. album dispersal in a model settlement (village of Dobrun, Bryansk district) are considered, where the species has spread over the plantings of the entire village territory in 20 years. Pregenerative and young generative plants predominate in the studied population.

The helminth fauna of three shrew species of the genus Sorex (Sorex araneus, S. caecutiens, and S. minutus) of the Kola Peninsula is studied. Based on our own data and the literature data, a complete taxonomic list is compiled which consists of 21 helminth species: 14 cestodes species of the families Dilepididae, Hymenolepididae, and Mesocestoididae; 4 nematodes species of the families Strongyloididae and Heligmosomidae; and 3 trematodes species of the families Omphalometridae and Brachylaemidae. The greatest diversity of worms is found in S. araneus: ten species of cestodes, four species of nematodes, and three species of trematodes. Seven cestode species, three nematode species, and three trematode species are recorded in S. caecutiens. Eight cestode species, three nematode species, and three trematode species are found in S. minutus. About 80% of the shrews are infected with helminths. A comparative analysis of the helminth fauna of shrews in Eastern Fennoscandia (the Kola Peninsula, Finland, and Karelia) is carried out from the south to the north of the region in the latitudinal range (59°–61° N, 62°–65° N, 66°–69° N). A high similarity between the quantitative and qualitative composition of the helminth fauna of shrews in the territory of Eastern Fennoscandia (Finland, Karelia, and the Kola Peninsula) in the latitude range of 62°–69° N (Cj = 0.85) is found, which may be due to climatic conditions favorable for the completion of the life cycle of helminths.

The dynamics of vegetation and soil properties formed during the primary succession (for about 30 years) in the middle taiga subzone of the European Northeast of Russia is studied. By the end of the third decade, the grass-to-forest community replacement in the posttechnogenic territory is practically finished, and a dense tree layer and grass cover dominated by forest and forest-edge species are formed. The forest ecosystem is formed by differentiation of groups of tree plants (parcels) with the litter formation: leaf–needle litter in pine parcel and leaf–grass litter in birch parcel. The grass-to-forest community replacement is accompanied by a transition from humus-impregnated humus pelozems to humus-impregnated eluviated pelozems. At the tree stand development stage, soil morphological structure and chemical properties are determined by the parcel structure of forest community. Variations in the content of Corg and biogenic elements in litter and organic–mineral soil horizon are caused by the different composition of plant communities in parcels and, consequently, different mineralization rates of plant residues. By the end of the third 10-year period of succession, the upper 0–20 cm soil layer accumulates organic carbon to 24.5 t/ha in pine parcel and to 28.7 t/ha in birch parcel.