The authors of the article announce a new Russian scientific electronic journal “Timiryazev Biological Journal” founded in 2023, but having more than 150-year history. The most important mission of the journal, according to the authors, is to provide highly qualified information support to topical biological research, for which a solid team of editors and reviewers, who are experts in different branches of biological sciences, is created. The authors invite scientists as well as their young colleagues, post-graduates and PhD students to publish in the journal “Timiryazev Biological Journal”, and express the hope that in the near future the journal will become an important platform for biologists to exchange relevant scientific information, and continue to develop the traditions of academic and applied science, established in the walls of the oldest agrarian university In Rusia Russian State Agrarian University – Moscow Timiryazev Agricultural Academy.

The respiratory system of birds is maximally adapted to the high efficiency of air exchange necessary to maintain an increased level of metabolic processes. The mucus of the respiratory tract plays an important role in mucociliary clearance, in the normal state of the respiratory system, without allergic and inflammatory reactions, an increase in the amount of mucus and the structures that produce it can be interpreted as a positive fact, but too much mucus can be a response to mucosal irritation and contributes to airway obstruction. As a result of two studies repeating each other, the dependence of the state of the tracheal wall in Ross-308 cross broilers on air circulation in industrial premises was confirmed. Ensuring the circulation of air flows in poultry rearing halls has a positive effect on the histological and histochemical structure of the trachea. In the first experiment, this is reliably evidenced by an increase in the thickness of the epithelial layer by 1.3 times (by 23.3%) and the height of the cilia by 3.1 times (by 67.5%). In the second experiment, this is confirmed by an increase in the height of the epithelium by 40% and the height of the cilia layer by 70%. In addition, the histological picture of the mucosa corresponds to the norm, there are no violations of the integrity of the epithelium, the cilia are smooth, without deformations and creases. With the provision of air circulation in closed rooms in the first experiment, the thickness of the tracheal mucosa decreases by 2.6 times (by 61.9%), and its own plate by 2.9 times (by 65.4%). In the second experiment, no such pattern was found in the own plate, but destructive changes in the tracheal mucosa, an increase in the number of glycoproteins and proteoglycans in the experimental groups confirm the influence of the ventilation factor.

Identification of optimal temperature regimes to obtain the best values of productive indicators (reduction of development duration and feed costs, increase in size and survival rate) is the most crucial task for the development of amphibian breeding technologies. The paper presents the results of a study of the effect of temperature on the larval development of the green toad (Bufotes viridis). The offspring of a pair of green toads caught in the Kaluga region (Russia) served as the material for the work. Spawning was stimulated by injections of surfagon. During the transition of larvae to exogenous feeding, 144 individuals were selected from them for further growing. For experiments, containers measuring 39 × 28 × 28 cm filled with 18 liters of water were used. The animals were grown at a density of one larva per liter of water at the following temperatures: 20°C, 23°C, 26°C and 29°C. The larvae were fed daily with “TetraMin Flakes”. When the forelimbs appeared and when emerging from the water, the body length was measured in young toads. It is noted that with all temperature regimes (from 23°C to 29°C), the green toad larvae grew and metamorphosed successfully. Increasing temperature reduces the duration of larval development, but does not affect the size of the young emerging from the water. However, decreases in temperature below 23°C and increases above 26°C contribute to a decrease in survival. Based on the aforesaid, it is recommended that green toad larvae should be grown at 23–26°C to produce juveniles with body lengths of 11.20–20.83 mm and survival rates of 94–100% in 28–59 days.

The results of the research of radial growth of Pinus nigra trees growing in the foothill-forest-steppe zone (in Belogorosk district) with continental climate type of the Crimean Peninsula are presented. The research was conducted to evaluate the influence of the location of the growth site on the local slope on the total width of the annual ring. Geomorphologically, the sampling points were located along the profile of a gentle convex slope of eastern exposure. Wood samples were collected at sites within the lower, middle and watershed parts of the slope, as well as at the top of the Biyuk-Karasu River watershed. Generalised tree-ring chronologies were obtained for each part of the slope, the average age of the chronologies being 50 years. As a result of the research, a synchronism in growth dynamics of trees growing in the lower part of the slope and in the watershed was established; the radial growth of Pinus nigra trees in the middle parts of the slope reacts the earliest to the influence of environmental factors. The reaction lag of radial growth in the watershed part of the slope is about 11 years. Analysis of the constructed chronologies shows that over the past 50 years, the radial growth is comparable to the dynamics of meteorological parameters. The analysis of correlations of the obtained chronologies with the values of average monthly air temperatures and annual precipitation according to the data of the Simferopol meteorological station was carried out. For the lower and middle parts of the slope, as well as for the watershed, the amount of precipitation is more significant than air temperature. Correlations have been established between the radial growth index of the lower and middle parts of the slope, as well as watershed and the sum of precipitation in May, and the summer months of both the current and previous years. For Pinus nigra trees growing on the watershed parts of the slope, air temperatures of summer months of the current and previous year are more significant. The established close relationship can be used to reconstruct climatic conditions of Pinus nigra trees.

Forest fires cause significant damage to protective plantations in the Rostov region. The largest area of forest fires in the steppe zone is in areas where the predominant species of protective plantations are Crimean pine or Scots pine. According to the adapted classification of fireplaces, the forest stands affected by ground fires are evaluated as heavily damaged. Despite an increase in the area of light, the projective cover of herbaceous vegetation reaches 80–100% only in the 4th-5th year after the fire. Natural regeneration of protective plantations occurs at the expense of invasive species of woody vegetation, such as maple ash, small-leaved elm, and green ash. In order to study the rate and extent of natural regeneration of the stand after ground fires, an assessment of plantations in the Shakhtinsky forest area of the Rostov region that were affected by ground fires in 2018–2022 was carried out.

The relevance is due to the paucity of official data on the state of surface water ecosystems In Rusia in terms of hydrobiological indicators and the prospects for the development of hydrobiological research as part of engineering and environmental surveys. The aim of the work is to continue the research of the ecological conditions of the Likhoborka basin with the identification of spatial and temporal patterns in the state of zooplankton. The objectives of the work were: to assess the study of the Likhoborka aquatic ecosystem; to perform a comprehensive environmental survey with plankton sampling and hydrobiological analyses; to link the values of water quality indicators along the length of the river to sources of pollution. The article presents the results of an ecological survey of the Likhoborka river watershed: a list of pollution sources, methods of reconnaissance, detailed examination and hydrobiological analysis of samples taken in the middle stream in June 2022. The work is the next stage of the educational environmental monitoring of the water protection zones of the rivers of Moscow. Throughout the surveyed area from the Golovinsky Ponds to Dmitrovskoe Highway, the degree of water pollution according to the Pantle and Buck index is moderate. Daphnia are abundant in Golovinsky ponds. Along the length of the area, rotifers predominate. The total salinity increases from 185 to 821 mg/l. The greatest contribution to pollution is made by polluted waters of the Likhoborka and the Norishka, which are concentrated through the reservoirs. There are practically no living hydrobionts in the Likhoborka reservoir.

At present, much attention is paid to the study of the adventive component of the flora of urban forests, the appearance of which is due to anthropogenic impact. The aim of the work is to evaluate the contribution of alien species to the diversity of the flora of the Forest Experimental Station of Russian State Agrarian University – Moscow Timiryazev Agricultural Academy. Adventive species from the current floristic list of the Forest Experimental Station were identified. It was established that 99 vascular plant species belonging to 66 genera and 34 families are adventive. The largest number of these species belong to Magnoliophyta (91 species). Among the families of the adventive fraction, Rosaceae (22 species) and Aceraceae (10 species) are the most multispecies. The dominant position is occupied by the genus Acer, which includes 10 adventive species. The analysis of the florogenetic structure revealed that most of the representatives of the adventive flora are representatives of the North American, European and European-West Asian florogenetic groups. This is associated with the introduction experiments in the Forest Experimental Station. An analysis of the distribution of species of adventive flora of the Forest Experimental Station by life forms indicated the predominance of trees (38%) and shrubs (34%) over herbaceous plants (28%). It was established that the proportion of adventive species in the flora is 28.1%, which allows it to be considered natural and slightly disturbed and indicates the resistance of plant communities to an aggressive urban environment despite the high level of recreational load and pollution from road transport. The biogeocenoses of the Forest Experimental Station continue to retain signs of a natural object that correspond to the natural conditions of the Moscow region.

Chlorella is a green eukaryotic microalga (Chlorella vulgaris). The microscopic cell is spherical, 2–10 μm in diameter. This microalga is one of the most important and promising for biomass production. Chlorella is cultivated in ponds or bioreactors with specified parameters that create favorable conditions for the growth of chlorella biomass. Each set of conditions creates the opportunities for changing the growth rate and output of individual products. Two strains of chlorella were the object of the study: 1 – chlorella with a thin cell wall (Chlorella vulgaris VKPM Al-24); 2 – chlorella with a thick cell wall (Chlorella vulgaris Beijer). The culture of chlorella was cultivated on modified Tamiya nutrient medium, at 24°C and 24-hour illumination. It was cultivated for 5 days in 1000 ml flasks, in opaque grow boxes with different lighting regimes. The control variant was grown in a light room with white fluorescent lamps with an intensity of 150 μmol/m2 s, and the culture was also grown in the dark. Laboratory experiments studying the effect of spectral composition of light on growth of two strains of chlorella culture allowed identifying some regularities: 1 – the largest increase in biomass is observed when using white fluorescent lamps (T = 2700K); 2 – in the case of using FR>R or FR=R, their inhibitory effect on the growth of the studied strains of chlorella was observed. In addition, similar results were obtained when determining the optical density of the cultures, suggesting that the chlorella strains studied are similarly responsive to the action of different spectral compositions of light. Analyzing the absorption spectrum, it should be noted that it has a continuous character. It has been experimentally established that the first maximum is located in the red region (660 to 690 nm) and the second in the blue region (430 to 450 nm). The minimum absorption is observed in the green light region (500 to 610 nm).

A comparative assessment of bacterial communities of meadow-serozem soils of different degrees of salinity was carried out. Significant differences in the structure of microbiomes of arable horizons of weakly saline and highly saline meadow-serozem soil were revealed. A significant reduction in the diversity of the microbiome at the phylum level with an increase in the level of soil salinity was established (on the example of meadow-serozem soils of the Shaulder irrigation massif). The structure of bacterial communities of the meadow-serozem highly saline soil is represented by four bacterial phyla: (Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria), while 13 bacterial phyla were identified in weakly salinized soil (Proteobacteria, Actinobacteria, Bacteroidetes, Verrucomicrobia, Acidobacteria, Chloroflexi, Firmicutes, Gemmatimonadetes, Planctomycetes, Saccharibacteria, Cyanobacteria, Chlorobi, Nitrospirae). According to the Shannon index, the species diversity of the microbiome of the meadow-serozem soils of the Shaulder irrigation massif is about 20% higher on weakly saline soils compared to highly saline ones. The Chao1 index and the number of taxonomic units (OTUs) also indicate a roughly halving of alpha diversity in the highly saline soil microbiome. The ecological significance of the problem of secondary soil salinization was confirmed. With an increase of salt content in soils, the species diversity of the bacterial community decreases, which can be considered as one of the indicators of soil degradation.

This article discusses the results of the practical use of microscopic analysis as an express test to obtain information about the freshness of chilled poultry meat. Poultry meat was selected according to the criteria of consumption in the food market. Before the research, the samples were encrypted for the objectivity of the assessment. In accordance with the objectives of the study, several products of different types of poultry of domestic producers were studied, sold in the largest quantities and having different expiration dates. The samples were tested on the first, seventh and fifteenth days of product storage. Microscopy data were compared with organoleptic studies, which were performed in parallel, guided by the regulated expiration date indicated on the labeling of each test sample. In addition, microscopy results and the actual shelf life of products were compared. Based on the results obtained, conclusions are drawn about the potential possibility of using this method as an express test in conditions of limited shelf life or insufficient technical equipment of experimental laboratories.

Trypsin is produced by the pancreas and hydrolyzes food protein to polypeptides and amino acids in the intestine. However, the function of the enzyme extends far beyond the digestive organs, as it is involved in the regulation of blood pressure, inflammatory reactions, blood clotting, and pancreatic function. Trypsin-activated PAR receptors have been found to affect cellular processes in the body. The effect of trypsin on animal metabolism has not been studied before. Therefore, the aim of the present study was to compare trypsin activity in different animals and in laying hens of different productivity to gain new knowledge about the signaling role of trypsin in the regulation of metabolism. Results of studies on cows, goats and poultry showed that the maximum trypsin activity in blood serum was observed in broiler chickens, which exceeded the level of laying hens by 385.4% for cows, by 89.4% for goats and by 22.6% for laying hens. An analysis of the enzyme activity in the blood of laying hens has identified the hens capable of laying eggs compared to those that have not yet laid eggs. Calculation of the correlation indicates a strong positive relationship between egg-laying and trypsin activity. Consequently, trypsin activity can be used as an indicator of metabolic processes in animals.