The actual patterns of forest stand dynamics can be revealed only if observational data on permanent sample plots are available. The aim of the study is to identify the characteristics of the age changes of stand indicators in permanent birch sample

plots of the Kologrivsky Forest Nature Reserve (Kostroma Region). The object of the study was forest stands in birch stands located in the core of the Kologrivsky Forest Nature Reserve. At present they are represented by mature and over-mature birch stands with the predominance of spruce undergrowth in narrow clearings of 1928 with a width of 100‑150 m. In the permanent sample plots trees were counted according to individual forest elements with the distribution of 4 cm in thickness steps. For 20‑25 trees, heights were measured in the range of varying diameters with further graphical alignment of the values. The stock was calculated using stem volume tables, and the biomass of the stand fractions was calculated using allometric equations. An analysis of the age changes of stand indicators (average height and diameter, number of trees, basal area, stock, biomass fractions, carbon content in biomass) for the period from 1981‑1983 to 2018‑2022 was carried out. In the sample plots considered, the dominant forest element in each age interval is birch. At present, however, the forest stands are approaching the stage of initial decay. Instead of pure birch stands, mixed spruce-linden stands will develop in the future. Comparing the changes of the stand indicators on the plots with a model of the growth of birch stands in the sorrel spruce forest type, it was found that the changes of the average heights of the actual stands are synchronous with the curve obtained from the model, while for other indicators there are significant discrepancies.

At present, the range of modern grape varieties suitable for cultivation in the conditions of the Non-Black Earth zone of the Russian Federation is represented by hybrids of different species origin derived from Vitis berlandieri Planch., Vitis Amurensis Rupr., Vitis riparia Michx., Vitis Labrusca L., which are characterized by low ability to vegetative propagation. Therefore, the development of techniques to improve the technology of accelerated propagation of these varieties, including the technology of clonal micropropagation is currently urgent. However, most studies in the field of in vitro propagation of grapes are devoted to laboratory experiments, but there is little information on the influence of the propagation method on the development indicators and vegetative productivity of grape mother plantations in protected and open ground conditions. Therefore, the purpose of this study was to develop methods of application of Revitalize liquid to increase the adaptability and stress resistance of ex vitro grape plants during summer transplanting into the open ground to create mother plantations. The research objectives are to reveal the effectiveness of feeding (root, foliar, combined) with Revitalize liquid during summer transplanting ex vitro grape plants of grape varieties Kishmish № 342, Moscow White and Kober 5BB rootstock into the open ground. The obtained results indicate that double combined treatments (root 500 ml: 500 ml H₂O + foliar 25 ml:1000 ml H₂O) are effective for pre-growing of ex vitro mother plants of Kishmish № 342 and Kober 5BB rootstock in open ground conditions, and double root feeding (at a concentration of 25 ml:1000 ml H₂O) with Revitalize liquid is promising for Moscow White variety.

The article is devoted to the issues of updating the morphological and fractional composition of municipal solid waste (MSW) of the Biysk urban district. Currently, many regions of the Russian Federation in the process of development of territorial waste management schemes, are guided by average data in terms of morphological and fractional composition, however, the specific composition of MSW in the regions may differ from the average values determined 15‑20 years ago. The study was conducted for three days; the sorting was done manually at the landfill of the Biysk urban district. As a result, this example revealed the need to adjust the territorial scheme for municipal solid waste management in Altai Krai.

The article presents the results of studies on the sorption of pollutants by moisture-loving plants when using peat soil under different anthropogenic loads. The comparative cultivation of moisture-loving plants on sod-podzolic soil, typical for this area, and on peat soil revealed their specificity in the sorption of heavy metals: there was a decrease in the content of lead and copper in peat soil under moisture-loving plants. In typical sod-podzolic soil under moisture-loving plants the opposite dynamics was observed. As for the zinc content, it was found that it increased in peat soil under moisture-loving plants, with the exception of reed. The experiment was conducted on the territory of the Ecological Station of the Russian State Agrarian University – Moscow Timiryazev Agricultural Academy in Moscow in 2019‑2022. Thus, moisture-loving plants grown on peat soil as a substrate can be used to reduce the content of mobile forms of heavy metals (lead and copper) in urbanized soils.

The aim of the study was to identify the features of the structure of the herbaceous cover and natural regeneration in the southern taiga spruce forests of the Kostroma region using the example of the Kologrivsky Forest Nature Reserve. To achieve this goal, twelve temporary square sample plots (SP) with an area of 0.0625 ha were established. Forest type, canopy density, soil and topography were determined. To characterize the forest stands, a taxonomic survey of the sample plots was carried out. To describe the vegetation cover, a combined method was used, including the Braun-Blanke and Drude-Uranov methods, which assumes the distribution of typical plant complexes over a large number of plant species growing together. Geobotanical descriptions were processed according to the method of D.N. Tsyganov, which consisted in using two tables: ecological amplitudes of species and scales of factors. Correlation analysis was used for data processing. The obtained statistical data set was presented in histograms and graphs for the sake of clarity. The frequency of occurrence, errors, participation rate, and average projective cover of the species were calculated according to generally accepted methods. In the course of the work, all sample plots were characterized by a tree-by-tree census. As the sample plots were located in very different parts of the reserve, the taxonomic indicators varied. In most cases, however, the dominant species was spruce. Its viable regrowth was 95%, indicating a high renewal potential. In the studied forest areas, the dominant species of the living ground cover were Northern linseed (Linnaea borealis) and blueberry (Vaccinium myrtillus), oak fern (Gymnocarpium dryopteris) and wood sorrel (Oxalis acetosella). The practical significance of the conducted research lies in the expansion of the ideas about the structure of the herbaceous cover formed under the canopy of spruce forests in the conditions of the Kologrivsky Forest Nature Reserve, as well as about the peculiarities of the process of natural regeneration in different conditions of the growth site.

The article presents the results of the use of protein supplements of animal origin compared to the addition of feed yeast. Experiments were conducted in laying hens with ileal fistula. The results showed that the introduction of protein additives of animal origin reduced the amount of urine produced per day in laying hens. The amount of calcium excreted in the urine increased by 13%. And the phosphorus level decreased by 80%. Trypsin activity in the serum of chickens fed fishmeal was 30% higher than in the control group, and in the group fed meat-and-bone meal it was 26% higher than in the control group.

The article presents the data on the use of higher aquatic vegetation (HAV), such as naiads, as an alternative source of plant proteins in poultry feeding. The use of non-traditional raw materials contributes to the development of immunity in poultry without the need for antibiotics, which is relevant in the context of combating antibiotic resistance. The developed feed composition can not only significantly improve the quality of poultry feed, but also provide consumers with high quality and safe products. The results of the research can be promising for poultry feeding practice and contribute to the sustainable development of poultry farming.

The article shows the physiological features of the survival ability of stallion semen at a temperature of 2 to 5°C with different antigenic features according to blood group systems. It was shown that in the presence of the antigens cgm/ceg, ad/dk, cgm/dk, cgm/d, dg/di on D system erythrocytes, the semen survival ability at 2 to 5°C was observed for a maximum of 50 hours. The carriers of the antigens cegm/cgm, ad/de, cgm/cgm, аd/bcm, bcm/dg, ad/d, cegm/dg, bcm/cgm, bcm/de, cegm/d, de/cgm, cegm/dk, dk/d, de/d, de/dk, cgm/dg, dk/de antigens have obtained a medium sperm resistance to cooling with a semen survival time of 50 to 75 hours. Stallions with the antigens bcm/d, bcm/dk, ad/cgm, dg/dk, cgm/de, dg/cgm, dk/dk of the D blood group showed a high semen resistance to cooling at 2 to 5°C in the form of a survival time of more than 75 hours. When the experimental stallions inherited the a/- antigen of the K system, the semen survival ability was increased by 7.24 h (P < 0.05) and the absolute survival ability by 24.18 standard units (P < 0.05) compared to the absence of this system antigen. The absence of -/- erythrocytic antigens of the C blood group is associated with an increase (P < 0.05) of 10.21 h in the survival ability and 30.29 standard units in the absolute semen survival ability compared to ejaculates from stallions with the a/- antigen of this erythrocytic system. The absence of the -/- antigen of the A system in stallions and the presence of the а/- antigen are followed by an increase in ejaculate resistance to cooling by 14 h (Р < 0,05) as compared to the control. At the same time, the absolute semen survival ability is 38.69 and 45.94 standard units higher than the control values (P < 0.01). Inheritance by stallions of the ad/- antigen by stallions was followed by a higher semen resistance to cooling as compared to the control by only 9.63 h (Р < 0.05) and a lower resistance compared to а/- and -/- by 5 h. The practical application of the data obtained is that it becomes possible to predict the shelf life of freshly dissolved cooled semen before artificial insemination, which is especially important for long transport of semen doses.

Sports training in cyclic sports with the predominant manifestation of endurance, including rowing, is associated with processes of adaptation to the load for 1 to 1.5 hours. The sources of energy during long intensive training are not only muscle glycogen, but also fat and fat-like substances. In this connection, the authors studied the processes of restructuringand adaptation of the organism of rowers to different intensities of physical load by lipid metabolism. The study involved 15 athletes (males) aged 18 to 21 years with the sport qualification «Candidate Master of Sports in Rowing». The main fractions of the lipid spectrum were studied: phospholipids, free cholesterol, non-esterified fatty acids, mono-, di-, triacylglycerols, cholesterol esters, as well as the spectrum of lipoprotein fractions: chylomicrons, pre-β-lipoproteins, remnants, β-lipoproteins, α-lipoproteins, a complex of non-esterified fatty acids with albumin. The studies showed that among the main fractions of the lipid spectrum, the concentration of the non-esterified fatty acid complex was higher than normal by 22.6% after the 7-minute exercise and by 49.6% after the 60-minute exercise, i.e. good functioning of the transport form for free fatty acids, which is important for energy exchange, was recorded. There was a 12.8% increase in phospholipids after the 7-minute exercise and a 17.6% increase after the 60-minute exercise. There was also a 25.3% increase in free cholesterol after the 7-minute exercise and a 36.8% increase after the 60-minute exercise. Unesterified fatty acid content was normal (greater than 0.45 g/l) before the test exercise, but increased by 49.1% (p < 0.05) after the 7-minute exercise. At the 60-minute exercise, this increase flattened and decreased by 17.7% (p<0.05) compared to the 7-minute exercise, but remained 22.6% (p<0.05) above the initial value. It is concluded that non-esterified fatty acids make an important contribution to the supply of lipids for oxidation during endurance exercise.

Candidamycosis of the digestive tract (CDT) causes significant economic damage to the poultry industry. It is poorly studied in quails, appears suddenly and is fatal in 90‑100% of cases. The causes of CDT of quails are various factors: violation of conditions and technologies of keeping, feeding, veterinary manipulations, which are perceived by the organism of young quails as stress factors. In the stressed organism the reproduction of opportunistic Candida albicans with increased virulence factors is activated. In this regard, it is necessary to search for drugs that do not have a suppressive effect on the quail organism and contribute to the restoration of the disturbed immune status and microbiocenosis against the background of the development of Candida albicans. Such preparations include biologically active bee products (BAPP). In the bone marrow of CDT-infected quails, when wax moth extracts (EWM), drone homogenate extracts (EDH) and propolis extracts (EP) are added to the diet: a) the production of pseudo-eosinophils is stabilized and phagocytosis is restored; b) inflammatory reactions are stopped, which is manifested by a decrease in the number of lymphocytes; c) the production of erythroid cells is increased. These extracts contribute to the restoration of the microbiota of the large intestine: a) the content of normoflora increases (Lactobacillus spp. – 6.38; 10.0 and 8.84 times, Bifidobacterium spp. – 4.53; 8.31 and 6.81 times); b) the multiplication of opportunistic microorganisms is inhibited compared to the reference values (Candida albicans – 3.3; 4.61 and 3.97 times; Staphylococcus aureus – 4.0; 7.78 and 4.51 times; Pseudomonas spp. – 3.05; 5.32 and 3.95 times).

Spring barley is widely used for fodder and food purposes. Modern farming systems involve the use of short crop rotations, which leads to a deterioration in the phytosanitary condition of the fields, so improving the structure of the fields is a priority. The potential of the crop will not be fully exploited if local resources are used irrationally. Weed components, in turn, inhibit crop growth and reduce the amount of product obtained. Successful weed control is based on a systematic approach involving agrotechnical, biological and chemical measures. The pursuit of yield without the optimization of technological processes leads to low profitability of agricultural production, so a properly selected predecessor is the key to profit for agricultural producers. The aim of the study is to regulate barley weeds in the Tver region using biological methods. Crop rotation is the cheapest method without material costs. Predecessors have a different effect on the species and quantitative composition of weeds. The maximum clogging in the sum of weed vegetation, including biological groups, was found for the oat predecessor (62 pcs/m² of juvenile weeds and 53 pcs/m² of perennial weeds). The best predecessor for spring barley in the experiment is corn for silage, after which the number of Erysimum cheiranthoides decreased to 3 pcs/m², which caused an increase in the yield of the studied crop from 4.5 to 7.4 t/ha.