Forest-steppe Zone Research Articles

Characteristics of spring barley cultivar for productivity of the Southern Forest-Steppe zone of Ukraine

Characteristics of spring barley cultivar for productivity of the Southern Forest-Steppe zone of Ukraine

ВОДНЫЙ РЕЖИМ ПОЧВЫ И ВОДОПОТРЕБЛЕНИЕ ЯРОВОЙ ПШЕНИЦЫ В ЗЕРНОПАРОВЫХ СЕВООБОРОТАХ ЮЖНОЙ ЛЕСОСТЕПИ ЗАПАДНОЙ СИБИРИ

The data of studies for 2016-2022 on the study of the influence of steam precursors on the water regime of meadow-chernozem soil in field grain-steam four-field crop rotations in the conditions of the southern forest-steppe zone of Western Siberia are presented. Crop rotation scheme: steam-wheat-wheat-wheat. Pure black and chemical, as well as sideral rapeseed vapors were used as steam precursors. Rapeseed was sown in July, plowed in September in the flowering phase. In pure black steam during the fallow period, cultivations were carried out as weeds overgrown. The chemical vapor was treated twice during the summer with glyphosate-containing herbicides. Changes in the reserves of productive moisture in the meter layer of soil were tracked, starting from the beginning of fallowing and up to the harvesting of wheat, which is the third crop after steam. There was a weak accumulation of productive moisture in the steam fields. By sowing the first crop, the increase was from 8.8 mm after chemical steam and up to 11.6 mm after pure black. The coefficient of water consumption of the first wheat coming after steam predecessors reached 780 in the crop rotation with sideral steam and 841 in the crop rotation with chemical steam. In the second culture, the water consumption for the formation of 1 ton of grain increased to 828-881 tons, and in the third culture, the amount of moisture consumed already reached 1018-1132 tons. The lowest moisture consumption for the formation of 1 ton of spring soft wheat grain was observed in the crop rotation with sideral rapeseed steam. The highest coefficient of water consumption was obtained in the crop rotation with chemical steam.

Influence of growth stimulants on the rooting of green cuttings of Shepherdia argentea in the conditions of the forest-steppe zone of the Omsk region

Influence of growth stimulants on the rooting of green cuttings of Shepherdia argentea in the conditions of the forest-steppe zone of the Omsk region

Dynamics of paleo-fires in the forest-steppe zone of the Western Siberia

Abstract. In this work we present the results of reconstruction of the dynamics of paleo-fires over the last 3300 cal. yr BP in the Barabinsk forest-steppe of the Western Siberia based on macrocharcoal analysis and radiocarbon dating of peat deposits of the Nikolaevsky ryam. The authors identified 18 local fire episodes using the CharAnalysis program. At the end of the Subboreal period, 6 local fires occurred, probably caused by dry and cold conditions. In the subAtlantic period of the Holocene, 12 fires were recorded with a peak of pyrogenic activity at 1200-1000 cal. yr BP. This peak of fires is probably associated with the warm and dry conditions of the Medieval Climate Optimum. As a result of the study, it was concluded that the intensity and frequency of paleo-fires in the area of Nikolaevsky ryam were influenced by climatic changes: in dry climatic periods, an increase in fire activity was observed.

The impact of mineral fertilizers on the consumption of mineral elements and the Siberian-bred oat grain

This paper presents the findings of long-term field experiments to study the influence of increasing doses of mineral fertilizers on the technological and agrochemical features of Siberian-bred oat. The studies were performed in the forest-steppe zone of the Trans-Urals on leached chernozem. We have studied the varieties of cultivated oat of local selection: Talisman, Foma and Otrada on a natural soil preparation (control) and while applying fertilizers, in doses calculated to obtain the planned yield from 3.0 to 6.0 t/ha. It has been revealed that modern varieties of oat have genetic features for the assimilation of nutrients from the soil and fertilizers. It affects the content of protein, fat and starch in the grain. Accounting for the totality of indicators of the chemical composition, the Foma variety was distinguished. Its grain on fertilized variants contains: protein 10.8-15.3; fat - 3.0-3.6; starch - 33.0-45.7%. The use of mineral fertilizers results in an increase in the nitrogen content in grain and straw, and potassium - only in straw. The biological removal of nutrients depended on the level of mineral nutrition and the variety, giving ground for the development of a varietal system of fertilizers for oat in Western Siberia.

. Productivity changes of wetland and grassland ecosystems along a latitudal gradient

The aim of the study. Analysis of changes in the productivity of dwarf shrub-moss-lichen, pine-dwarf shrub-sphagnum and sedge-sphagnum and grass ecosystems along the latitudinal gradient. Methodology. For a number of bog and grass ecosystems located along a latitudinal gradient from 65 to 50° N in the range of longitudes from 63 to 95° E the stocks of live and dead, aboveground and belowground phytomass, as well as the values of aboveground (ANP), belowground (BNP) and total production (NPP) were analyzed. The data are given for 45 ecosystems grouped into 12 types from forest-tundra mires to desert steppes. The vegetation of ecosystems is represented by bog one (mosses, shrubs and grasses) to the steppe (mesoxerophytic and xerophytic grasses). Since the spread of data on stocks and production for individual ecosystems is large, we present averaged data for ecosystem types. Main results. The largest stock of green phytomass was obtained for floodplain meadows (7 t/ha), the smallest stock was found in the desert steppes (0.8 t/ha). The stock of dead aboveground phytomass was maximal in the fens of the forest-steppe zone (10 t/ha) and minimal in the oligotrophic hollows of boreal bogs (0.3 t/ha). The stock of living belowground organs decreases along a latitudinal gradient from 20 (true steppes) to 3 t/ha (desert steppes), whereas the stock of dead belowground organs decreased from 79 (fens of the forest-steppe zone) to 4 t/ha (in the ryams of the middle taiga and desert steppes). Above-ground production was estimated as highest in the fens of the forest-steppe zone (12), decreasing along the latitudinal gradient down to the desert steppes (1 t/ha per year). Belowground production in all types of ecosystems studied was higher than the above-ground one, ranging from 45 (fens of the forest-steppe zone) to 3 t/ha per year (mires in the forest-tundra). The NPP value in some of the studied ecosystems varied from 57 (fens of the forest-steppe zone) to 5 t/ha per year (mires in the forest-tundra). The BNP/ANP ratio averaged over ecosystem types was maximal in the desert steppes (5.9) and minimal in floodplain meadows (1.9). In the range of latitudes 56-52°N, where steppe meadows, meadow steppes and true steppes located, the NPP, averaged over these ecosystems, varied from 22 to 24 t/ha per year. These ecosystems the most fertile soils of the region, i.e. meadow chernozem and ordinary chernozem (Phaeozems) were developed. To the north and south of this area, the NPP value decreases: to the north due to the lack of heat, and to the south due to lack of moisture. Conclusions. In the biotic cycle in mires differs from that in meadows and steppes by the annual sequestration of a part of the carbon influx in the forming peat. This amount of carbon sequestration is about 10% of the NPP of the wetland ecosystem. In the climax grass ecosystems, the carbon influx is equal to its outflux. These ecosystems are acting as gas exchangers between plants, soil and atmosphere. In contrast to grasslands, wetlands are acting as carbon accumulators that lower the CO2 in the air.

ОЦЕНКА КОЛЛЕКЦИОННЫХ ОБРАЗЦОВ ЯРОВОЙ МЯГКОЙ ПШЕНИЦЫ НА СКОРОСПЕЛОСТЬ И КОРОТКОСТЕБЕЛЬНОСТЬ

In the forest-steppe zone of the Middle Volga region, precocity, shortness of stem and resistance to lodging are important economic and biological signs that affect the productivity of wheat in a certain way. The object of research was 300 collectible samples of spring soft wheat of domestic and foreign origin. Field experiments were laid in 2019-2021 on the basis of the laboratory of breeding and seed production of spring wheat of the Volga Research Institute of the Russian Academy of Sciences on the fields of the first selection crop rotation. As a result of research in 2019-2021, the duration of the germination-earing period (PVK) in collection samples varied from 31 to 52 days. In 2020, a weak negative relationship was revealed between the duration of PVK and the yield of samples (r = -0.18) with a critical value of coefficients r005 = 0.113, r001 = 0.148, in 2021 – an average negative relationship between PVK and the yield of samples (r = -0.35). On the basis of precocity, 13 genetic sources were identified: 2019 - Ural Cuckoo, Chelyabinsk Early (Chelyabinsk region), Odeta, Libertina (Czech Republic), Chi Mai (China); 2020 - Rifor 1, Rifor 6, LT-9 (Leningrad region), Arabeska (Poland); 2021 - Albidum 2030 (Orenburg region), Odintsovo (Chelyabinsk region), Dalira (Khabarovsk region), Zarco (Spain).Over the years of research, the height of plants in the studied samples by the end of the growing season varied from 40 to 124 cm. Short-stem varieties and hybrids were mainly of foreign origin. 15 genetic sources were identified based on shortness of stem: 2019 - KWS Torridon (Great Britain), KWS Jetstream (Germany), Florens, Eleganza (France), Long Fu 13 (China); 2020 - Odeta, Libertina (Czech Republic), Shiraz (Great Britain), Bryza (Germany), Boett (Sweden), Iona (USA); 2021 - H15-3 (Lipetsk region), KWS Sunny (Germany), Stanga (Switzerland), Dian 852-184 (China). The selected samples are recommended to be used in the breeding process.

WINTER HARDINESS OF UKRAINIAN BEES OF INTRABREED TYPE «GADYATSKY»

Introduction. Winter hardiness is an important criterion for the quality of bees. Each breed of bees, depending on the area of detention and types of honey collection in a given area, manifests them differently. Ukrainian steppe bees are the most widespread and in demand in the Forest-Steppe of Ukraine. The work is devoted to the study of winter hardiness of bees of Ukrainian steppe breed of intra-breed type "Gadyatsky" in comparison with the local population, which is an important factor influencing their economic value. The goal of the work. Investigate the nature of winter hardiness of bees of the Ukrainian steppe breed of intra-breed type "Gadyatsky". Materials and methods of research. The research was carried out in the forest-steppe zone of Ukraine on the basis of the apiary of NSC “Institute of Beekeeping P.I. Prokopovych” (Poltava region) on bee families of Ukrainian steppe breed and local bees. Winter hardiness of bee colonies was characterized by a weakening of the strength of the families, the cost of food per family of wintering bees, their development in the spring by the strength of the nest and the presence of brood. The intensity of metabolism in the body of bees was also determined by the indicators of mass fraction of water, fecal load and catalase activity. Results of research and discussion. Ukrainian steppe bees of the intra-breed type "Gadyachsky" are dominated by local bees on their departure in the flightless period by 3.11%, feed consumption - by 6.04 %, by force in the spring by 1 %. 1.81 % lower water content in the body of purebred bees contributes to their better adaptation to changes in club conditions during the winter. A higher rate of catalase activity by 15.74% and a lower filling of fecal masses of the large intestine by 8.16% indicates a favorable wintering of bees. Conclusions and prospects for further research. Good winter hardiness of Ukrainian steppe bee families and high reproductive capacity of queen bees of the Gadyatsky type in the Forest-Steppe of Ukraine compared to the local population indicate a higher level of their evolutionary adaptation to the climatic conditions of this zone and efficient use of its honey harvest. The established levels of determinants can be used in the selection of the best families and to develop effective measures for the conservation, reproduction and rational use of aboriginal bees of the Ukrainian steppe breed.

The use of natural minerals and brines in the growing of spring barley under the conditions of the Forest-steppe zone of Ukraine

The use of natural minerals and brines in the growing of spring barley under the conditions of the Forest-steppe zone of Ukraine

Занятие охотой у татар Большереченского района Омской области в прошлом и в настоящее время (по новым полевым материалам)

The hunting is considered in the settlements of the Tatars of the Bolsherechensky district of the Omsk region over the past three years on the basis of field ethnographic materials. The objects of hunting, lands, forms and methods of hunting are briefly characterized, some preserved worldviews related to hunting are listed. The hunting is currently of an amateur nature, is the leisure of men and one of the elements of their daily life. А collective driven hunt for a wolf on a horse are described also. This is one of the important specific features, in the past, characteristic of the northern forest-steppe zone.

Сравнительная географо-генетическая характеристика почвообразования на основе накопленной фитомассы в почвах антропогенных ландшафтов лесостепи Западной Сибири

When studying the direction of soil formation in soils of anthropogenic landscapes of any natural zones and belts, one should always consider primarily biological processes, namely, synthesis, accumulation, mineralization and humification of organic matter. Therefore, the aim of the study was to determine the leading soil-forming biological processes in the anthropogenic landscapes of the forest-steppe zone of Western Siberia to determine and compare the soil-ecological status. The tasks were: to determine the soil composition of landscapes based on the morphological properties of soils; to estimate the total phytomass in different types of soils of anthropogenic landscapes and compare it with the phytomass of zonal soils; determine the leading biological processes occurring in soils. The research was based on comparative morphological, comparative genetic and comparative geographical methods. The article deals with soil-biological processes that occur in the anthropogenic landscapes of the forest-steppe. It was found that the soil cover is mosaic. In its composition, humusogenic technozems and all types of embryozems are morphologically determined. Each type of embryozems corresponds to a certain stage of development of phytocenoses: initial embryozems correspond to the stage with pioneer vegetation; organo-accumulative embryozems - a simple plant grouping; sod embryozems - a complex plant grouping; to humus-accumulative embryozems and humusogenic technozems - a closed phytocenosis. The total phyto-mass and its composition increases and becomes more diverse in the genetic series from initial and organo-accumulative embryozems to sod and humus-accumulative embryozems. Nevertheless, the total terrestrial phytomass of the most genetically developed humus-accumulative embryozems is below the zonal values. The leading biological processes in the embryozems of the initial stages of the formation of an ecosystem are the synthesis and accumulation of organic matter; in humus-accumulative embryozems and in humusogenic technozems, in addition to synthesis and accumulation, the rudiments of mineralization and humification processes are noted. The soil and ecological status has been established. On the dumps of the Bungur coal mine, it is satisfactory, since the soil cover contains humus-accumulative embryozems and humusogenic technozems. The soil-ecological status of the dumps of the Gorlovsk anthracite section is unsatisfactory.

Синтаксономический обзор мезофитных широколиственных лесов союза Aceri campestris–Quercion roboris Bulokhov et Solomeshch in Bulokhov et Semenishchenkov 2015 Юго-Запада России

Mesophilous broad-leaved forests predominating in south-western part of Russia were included in alliance Aceri campestris–Quercion roboris Bulokhov et Solomeshch in Bulokhov et Semenishchenkov 2015, association Fraxino excelsioris–Quercetum roboris Bulokhov et Solomeshch 2003 and three geographic subassociations. The subassociation F. e.–Q. r. typicum Bulokhov et Solomeshch 2003 in Bulokhov et Semenishchenkov 2015 unites communities occurring mainly in the broad-leaved forests zone of the Central Russian Upland. The subassociation F. e.–Q. r. stellarietosum nemori Semenishchenkov et al. 2015 occurs in the northern part of the association range in the zone of broad-leaved forests and close to the southeastern border of the hemiboreal subzone. Mesophilous broad-leaved forests occurring in the forest-steppe zone of the Central Russian Upland were included in the subass. F. e.–Q. r. crataegetosum curvisepalae Semenishchenkov in Bulokhov et Semenishchenkov 2015. The geographical distribution of the syntaxa is related to the climate continentality gradient — from the subass F. e.–Q. r. crataegetosum curvisepalae (the largest continentality indices) to the subass. F. e.–Q. r. stellarietosum nemori (the smallest continentality indices). The associations Aceri campestris–Tilietum cordatae Zaugolnova et Braslavskaya 2003 (nom. inv.) from the Kaluga and Tula Regions (Zaugolnova, Braslavskaya, 2003) and Aceri campestris–Quercetum roboris (nom. inv.) (var. Acer tataricum) described from the Voronezh Region (Starodubtseva, Khanina, 2009) were included in the association Fraxino excelsioris–Quercetum roboris after comparative syntxonomical analysis. On the basis of a comparative analysis, diagnostic combinations of subassociations were compiled, consisting of species with constancy above 20 % and values of the statistical φ-coefficient for selections above 20: F. e.–Q. r. stellarietosum nemori — Carex sylvatica (5059.9), Equisetum hyemale (2842.3), Galeobdolon luteum (10087.4), Matteucia struthiopteris (4257.7), Ranunculus cassubicus (5857.9), Stellaria nemorum (3349.6); F. e.–Q. r. crataegetosum curvisepalae — Acer tataricum (5362.0), Crataegus rhipidophylla (5964.0), Poa nemoralis (2736.9), Pyrus pyraster (3840.8), Scilla siberica (4558.4), Viola odorata (3440.5). Analysis of the differentiaal table of mesophilous broad-leaved and spruce-broad-leaved forests syntaxa made it possible to conclude that associations previously (Onyshchenko, 2009) assigned in Ukraine to alliance Scillo sibericae–Quercion roboris have a high floristic similarity with the syntaxa of Aceri campestris–Quercion roboris from the South-West of Russia, especially in the forest-steppe part of its range. Selections of three subassociations of the association Mercurialo perennis–Quercetum roboris from Ukraine floristically close to the syntaxa of alliance Querco roboris–Tilion cordatae from the South-West of Russia. In the dendrogram of cluster analysis, the compared syntaxa are grouped into two blocks corresponding to the rank of alliances: Aceri campestris–Quercion roboris and Querco roboris–Tilion cordatae. Based on the review, the authors believe that the «Hierarchical floristic classification system…» (Mucina et al., 2016) may be amended in terms of recognizing the syntaxonomical independence of the alliance Aceri campestris–Quercion roboris and its geographical interpretation. Derivative communities disturbed by humans in the place of mesophylous broad-leaved forests are classified as anthropogenic variants and non-rank «communities» named after the dominant species: Betula pendula, Populus tremula, Tilia cordata. Forests with a poor floristic composition, in which the diagnostic species of association and subassociation drop out of the coenoflora are classified as inops variants. They are characterized by a noticeable decrease in the average floristic saturation in comparison with typical communities. Derivative forests with a predominance of Betula pendula have a higher species richness in comparison with aspen or linden forests, as well as typical phytocoenoses of the association.

ПРИМЕНЕНИЕ РЕГУЛЯТОРА РОСТА НА ПОСЕВАХ ОЗИМОЙ ПШЕНИЦЫ ЛЕСОСТЕПНОЙ ЗОНЫ РЕСПУБЛИКИ СЕВЕРНАЯ ОСЕТИЯ – АЛАНИЯ

Weeds are an ecological group of plants that has developed as a result of their growth together with cultivated plants in the process of continuous struggle with them. In order to successfully fight weeds, it is necessary to know their biological characteristics, classification, distribution and reproduction of weeds. The number of weeds does not always reflect the degree of their harmfulness, since it is largely determined by the power of development of the above-ground mass of weeds. Different types of weeds react differently to changes in the level of fertilizer, the method of basic tillage, the structure of crops and the rotation of crops in crop rotation. The advantage is given to those species for which all these changes are favorable and contribute to their growth, development and distribution in phytocenoses. In addition to them, weed species that have endurance and resistance to adverse environmental factors survive and maintain their population density. According to many scientists, the mass and number of weeds reflect different aspects of relationships in the community. The number shows the interaction in the surface layer of the soil, at a low altitude, as well as in the initial phases of development, and the mass of the weed component characterizes the coenotic relationships in the middle and upper tiers at later stages of development. The purpose of our research was the influence of agrometeorological conditions on the species composition, abundance, dry biomass and the ratio of biological and ecological groups of weeds in the winter wheat agrocenosis. Our research was carried out in 2017–2021. on the experimental experimental field of the SKNIIGPSh VSC RAS in the forest-steppe zone of North Ossetia - Alania The object of research was winter wheat variety Trio. The plot area is 100 m², repeated three times. This crop was part of a five-field soil-protective crop rotation. We have found that in the forest-steppe zone of North Ossetia - Alania, agrometeorological conditions largely affect the species composition, abundance and biomass of harmful weeds.

Эффективность весеннего подкашивания люцерны при выращивании ее на семенные цели в условиях Чеченской Республики

When growing alfalfa for seminal goals, problems often arise associated with excessive moisture in the spring, which causes increased development of the autonomic mass of alfalfa, and during the flowering period, mass falling of inflorescences and the lie of plants. In order to prevent this problem in practice, they use the method of spring pumping of herbal. The purpose of the research is to establish the optimal scientific and founded periods of spring tinging alfalfa for a steady increase in the seed productivity of alfalfa in the conditions of the forest-steppe zone of the Chechen Republic. The work is devoted to the study of the impact of the time of spring tinging alfalfa on seed productivity. The object of research was the crops of alfalfa on the 2nd year of life (Agnia variety). In the experiment, three deadlines for the tanking alfalfa were studied in comparison with control (without a drawbar). The soil of the experimental plot is a typical, medium -fitting, underlying, underlying pebble. The reaction of the soil solution pH 6.9. The content of humus in the arable layer is 4.2%, gross nitrogen-18-28 mg/kg of soil, mobile phosphorus-18-21 mg/kg and exchange potassium-120-150 mg/kg. Studies have revealed that at first, the early -agent tingling of alfalfa at first led to a noticeable lag in crops in growth and development. Over time, the breaks were gradually smoothed out options. The optimal period of the lining of alfalfa (the end of April - in the branching phase) was set, which ensured the highest productivity of the alfalfa seeds - 314.1 kg/ha, exceeding control by 41.2%. The herbal alfalfa in this embodiment was much cleaner from weeds and is less susceptible to hopping. The formation of seeds took place in conditions favorable for the flight of pollinators.

Indicators of sustainable development of safety land use and assessment of degradation processes development of soil cover using gis models

The article describes some of the UN-adopted indicators of sustainable development of land use safety associated with the development of soil degradation processes, approaches to assessing the development of soil degradation using mathematical modeling tools, namely geoinformation models. Indicator 15.3.1 of sustainable development goals reflects the ratio of the area of degraded land to the total land area of the assessed area, and degradation is considered as an integral indicator of such parameters as land productivity, soil organic matter content and type of land use. It is established that when using remote sensing data obtained from open sources, which serve as a basis for calculating land degradation indices by the Trends.Earth tool via QGIS software, it is possible to establish such changes at the administrative level (map scale 1: 100000) and spatio-temporal analysis of such changes. At the same time, it is difficult to ensure higher spatial resolution, which would allow the analysis at the level of an individual farm or an enterprise. This is due to the spatial resolution of the data that form the basis for such a calculation. In the Forest-Steppe zone of Ukraine, the predominant type of land use is agricultural activity with land plowing. Some farms practice minimizing tillage, which, in particular, should affect the value of the indicator of land degradation. With some convention of such an approach, the indicator allows to display in the map space the data of changes in the condition of the land, the loss of soil organic carbon according to remote sensing data and the nature of soil degradation for the selected time interval. Due to difficult economic conditions, part of the lands for the period 2001-2019. was not used in agricultural production, some fields were overgrown with woody vegetation and were not actively cultivated, which was reflected in the indicators of indicator 15.3.1. At the same time, most of the lands (over 66%) did not undergo positive or negative changes during the studied period. The use of indicators of soil condition, monitoring of the development of degradation processes based on operational data and the possibility of their comparison for different time intervals plays a particularly important role in the context of the impact of global climate changes on the soil cover, prospects for agricultural production and, in general, on the quality of life of people.

Современные эколого-эпизоотологические и эпидемиологические особенности природных очагов бешенства в Омской области

The aim of the work is to study modern ecological, epizootological and epidemiological features of rabies in the Omsk region at the beginning of the 21st century, as this region is traditionally considered a rabies-prone territory. The paper describes the cases of rabies infection in human in the Omsk region in 1962–2020 and determines the features of treatment-seeking behaviour after traumatic contacts with animals in 2001–2020. The features of the epizootic process within the period 2001-2020 were studied. The number of foxes and raccoon dogs, i.e., the main natural hosts and distributors of rabies was analyzed. The epizootic index and infection density in different districts of the region for 2001-2020 were revealed. A modern epidemiological zoning was carried out and the risk of rabies incidence in different districts of the Omsk region was determined. The epizootic process of rabies in the region was determined to undergo significant changes at the beginning of the 21st century. A pronounced downward trend was revealed in the number of detected animal diseases. Epizootics form persistent foci, localized during the study period mainly in the subzone of the northern forest steppe. This previously unobserved feature of the landscape confinement of foci to the northern forest-steppe zone is apparently associated with a change in the population structure of natural hosts of the infection and a significant increase in the number of raccoon dogs. Conclusions: to optimize preventive measures, it is necessary to pay attention to the vaccination of all groups of animals involved in the epizootic process, to continue oral vaccination of wild predators. There are conditions for the formation of persistent natural foci of infection and the possibility of epizootics to get activated. This determines the relevance of constant virological monitoring of the populations of foxes, raccoon dogs, corsacs and badgers, as well as monitoring the density of populations of these species.

Fishes of Rivers of the Forest-Steppe Zone of the Dnieper Basin: Long-Term Changes of the Species Composition and Abundance

The paper deals with analysis of changes of the species composition and relative abundance of 63 species of fishes and Cyclostomata of the upper section of the Middle Dnieper and its 12 tributaries. The analysis covered period from the native ichthyocenoses state (1931-1972) to the crisis period (2001-2021). Over the considered period 7 aboriginal species have become extinct, at the same time 18 invasive species have settled. Over the last 50 years portion of the invasive species in the rivers on average increased from 10.1 to 30.2%, and their portion in the catches from 2.1 to 25.3%. Average species number per river increased by 7.9, decreased by 7.3, whereas constant component amounted to 19.8. The species diversity was also redistributed, it increased within the same river, but decreased between the rivers owing to universalization of the species composition (by 4.9% in terms of the Jaccard coefficient). The large-scale changes mean that deformation of ichthyofauna of the upper section of the Middle Dnieper basin exceeds the average-European level. At this, the general tendency consists in replacement of the autochthonous species by the allochthonous, whereas the rheophilic benthos-eating long-mature fishes with the prolong migration paths are the first to extinct. The critical group comprises eight commercial species, four of them (Acipenser gueldaenstaedtii, A. stellatus, Huso huso, Rutilus frisii) are extinct in the region, and populations of four more (Acipenser ruthenus, Chondrostoma nasus, Leuciscus idus, Vimba vimba) reduced tens and hundreds of times. These species need special protection, and V. vimba - inclusion to the Red Data Book of Ukraine.

Grain yield of corn hybrids of the kskp kkz "kuban" in the southern forest-steppe zone of the Republic of Bashkortostan

Grain yield of corn hybrids of the kskp kkz "kuban" in the southern forest-steppe zone of the Republic of Bashkortostan

Adaptability and stability of potato samples in the forest-steppe conditions of the Northern Caucasus

This work aimed to study the response of 10 potato varieties to changes in environmental conditions during the 2018-2020 growing season in the forest-steppe zone of the Republic of North Ossetia-Alania. Ecological adaptability, stability, and genetic flexibility were evaluated for 8 varieties and 2 hybrids of the North Caucasian Research Institute of Mountain and Piedmont Agriculture (SKNIIGPSKh) breeding. Analysis of variance revealed that the proportion of the influence of genotype (factor-variety) on the yield of the studied samples for three years of observation was 40%. The effect of weather conditions on the variability of potato productivity during the years of research was 42% and the effect of other factors was 18%. Complex evaluation of flexibility, stability, genetic flexibility was carried out according to the methods of S.A. Eberhart and W.A. Russell, A.A. Rosielle and J. Hamblin, V.V. Khangildin and N.A. Litvinenko. The calculated indices of flexibility, stability, homeostability, and genetic flexibility allowed us to identify a group of intensive varieties responding with increased yield under optimal conditions: Udacha, El Mundo, Hybrid 0.4.560/4. The second group included extensive varieties: Sambo, Primabel, hybrid 04.573/1. The hybrid 04.573/1 selected by SKNIIGPSKh is adapted to forest-steppe conditions, resistant to stress (Ymin-Ymax)=8, and shows genetic flexibility (Ymax+Ymin)/2=31.2. In the hot year of 2020, it gave the yield higher than all the studied samples (27.7t/ha). Hybrids o4.560/4 and 04/573/1 are being prepared for state variety testing.

Principles of formation of field crop rotations in the conditions of the forest-steppe of western Siberia

The article analyzes soil and climatic zoning of the territory of the forest-steppe of Western Siberia, population degree, contour of fields, biological economic features of crops, including the leading - spring wheat. The adaptive landscape approach to the zonal features of crop alternation was used in the work, which makes it possible to determine a reasonable ecological niche for each one, select crops in accordance with biological requirements, productivity, profitability of production, as much as possible to reduce repeated and monocrops. Monitoring of economic activity over the past 35 years has shown a tendency for commodity producers to be stratified by resource capabilities, technical equipment, and, above all, the level of agriculture intensification. In this regard, recommendations for optimizing field crop rotations are focused on expanding to 8-10 crops and adaptive varieties, considering their profitability and "soil improvement", limiting resowing, excluding continuous cultivation of agricultural crops. In conditions of limited intensive agriculture, about 5-10% of the arable land area belongs to crop rotations with winter, tilled crops, legumes, melilot, rapeseed, millet, clover, annual multicomponent grasses, the efficiency of which in terms of the yield of fodder units often surpasses grain-fallow crop rotations with short rotation. It is noted that in recent years, special attention has been paid to alternate crop rotations, which allow, with increase in farming standards and use of intensification means, to slightly reduce the fallow field and optimize the structure of arable land use, to increase the biodiversity of a set of crops and adaptive varieties. The tendency to switch to rotation crop, among commodity producers of a more humidified forest-steppe zone, is possible only with the use of fertilizers and the improvement of agrophytocenoses. The expansion of alternate crop rotations and the reduction of repeated sowing of spring wheat is also due to positive changes in hydrothermal conditions in arid soil and climatic zones of Western Siberia.