Biosystems Diversity (E-Journal - Dnipro National University)
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Studying the genetic structure of Quercus robur forest stands on anthropogenically transformed territories using introns of the β-tubulin gene
Get PDFBased on the analysis of the intron polymorphism of β-tubulin genes, the genetic variability of old Quercus robur L. trees from “Holosiivsky” NPP was investigated. The genotyping of 55 old Q. robur trees was carried out; 40 polymorphic and one monomorphic (about 880 bp) TBR fragments were found. High frequency (70–90%) of occurrence of fragments with an approximate molecular weight of 275, 490, 500, and 1110 bp was observed.The genetic polymorphism of old Q. robur trees was assessed as quite high: РІС is 0.22 – 0.39, the effective number of alleles per locus was 1.174–1.268. The Shannon information index was in the range of 0.204–0.269.The geographical differentiation of the genetic structure of centuries-old oak trees from “Holosiivsky” NPP was not pronounced. The share of inter-selection genetic variability (AMOVA) accounts for about 6% of genetic variability, and the geographic component – about 1%. Around 93% of genetic variability is concentrated on the individual level. Using the ТВР method, we found that Q. robur forest stands do not have a stabilized genetic and visible spatial structure, but at the same time they possess a sufficiently large genetic diversity. The absence of a spatial genetic structure may indicate the artificial origin of Q. robur trees from different seed materials, and also that a small number of the plants have survived to this time. In this case, the main influence on the structure of oak stands in “Holosiivsky” NPP was from anthropogenic factors, both in the form of cutting down trees and, possibly, the introduction of alien seed material
Contamination of animal-keeping premises with eggs of parasitic worms
Get PDFToday, one of the important problems in the cultivation and maintenance of agricultural and domestic animals, both in industrial and private farms, is the spread of ecto- and endoparasites, which cause a significant decline in animal productivity, endanger their health and cause economic losses. The study of the level of distribution and conducting of diagnostic studies on parasitoses of animals in farms with different production orientation is an important and integral part of the overall complex of preventive and health-improving measures. The research was carried out during 2007–2017 in livestock enterprises of Kharkiv Oblast. As a part of the research work, 540 samples were collected from livestock farms, of which 180 were from the premises for keeping pigs, 100 from premises for keeping sheep, 120 from premises for keeping cattle, 80 from premises for dogs and 60 – from the surrounding territories of the livestock enterprises. We found that the objects of livestock rearing (pig complex, sheep farm, dairy farm, cynological center) in Kharkiv Oblast have a significant level of sanitary contamination with exogenous forms of helminths (21.7–45.6%) and the soil of the territories (20.0–36.6%). From samples taken from premises for pigs, eggs of four morphotypes were isolated (Ascaris suum – 5.3%, Trichuris suis – 14.6%, Oesophagostomum dentatum – 60.6%, Strongyloides ransomi – 19.4%), from premises for sheep – three morphotypes (Dicrocoelium lanceatum – 3.8%, Trichuris ovis – 29.3%, Strongylata spp. – 46.9%), from premises for cows – three morphotypes (Neoascaris vitulorum – 2.7%, Trichuris skrjabini – 12.9%, Strongylata spp. – 34.5%), premises for dogs – four morphotypes (Toxocara canis – 6.1%, Toxascaris leonina – 5.4%, Trichuris vulpis – 20.6%, Ancylostoma caninum – 17.5%). It should be noted that the places most contaminated with eggs of helminths were manure gutters (100%) and the floor of livestock buildings (50.0–86.7%). It has also been determined that, in the conditions of the cynological center, the Musca domestica was the source of environmental contamination with exogenous forms of Toxocara canis and Trichuris vulpis, and that the Muscina stabulans and Stomoxys calcitrans can be the source of spread of larvae of Ancylostoma caninum and eggs of Trichuris vulpis respectively
Formation of the structure of microbiocenoses of soils of agroecosystems depending on trophic and hydrothermal factors
Get PDFGround soil, as the product primarily of the activity of microbiota, is under the permanent influence of ecological and anthropogenous factors. Soils are especially subject to pressure in agroecosystems, which increases due to the considerable fluctuation of climate system parameters. Using graph analysis, we have estimated the results of multiyear monitoring research on the functioning of microbiocenoses of three soil types in agroecosystems depending on the fertilizing and hydrothermal mode. It enabled us to detect peculiarities of formation of the structure soil microbiocenoses and to better understand ecologically important relations between functional groups of microorganisms in the soil depending on action of different factors. It has been determined that neither application of organic and mineral fertilizers into chernozem nor action of hydrothermal factors (temperature air and humidity) is a crucial characteristic of changing in the structure of its microbiocenosis. Microorganisms-producers of exopolysaccharides, which have a strong relationship with all trophic groups of microorganisms as they are their structural components, turned out to be the main block constructing factor, which is due to their strong influence on total content of microbal mass in soil. For soil of agroecosystems with dark-grey type of soil characteristic of content of total biomass of microorganisms is a basis for block constructing gremium, which affirms the state of microbiocenosis and processes occurring there under the action of researched biotic and abiotic factors. Microbiocenosis of sod-podzolic soil, unlike the other researched types of soils, reacted distinctly on applying of fertilizer and depended on the action of hydrothermal factors. Contrast in the range of hydrothermal regime caused a chaotic character of interaction between the basic characteristics in microbiocenosis of sod-podzolic soil with appearance of a direct and mediated relationship among them. Regardless of changes in hydrothermal factors , interactions between characteristics of total microbial mass content, eutrophic microorganisms, which use mineral and organic forms of nitrogen, and producers of exopolysaccharides were stable. It has been proved that estimating of ecological state of soil and influence of applicable agromeasures on it should be conducted according to the indices of total microorganism biomass content in the soil and correlation between the number of microorganisms which form the graph gremium.Ground soil, as the product primarily of the activity of microbiota, is under the permanent influence of ecological and anthropogenous factors. Soils are especially subject to pressure in agroecosystems, which increases due to the considerable fluctuation of climate system parameters. Using graph analysis, we have estimated the results of multiyear monitoring research on the functioning of microbiocenoses of three soil types in agroecosystems depending on the fertilizing and hydrothermal mode. It enabled us to detect peculiarities of formation of the structure soil microbiocenoses and to better understand ecologically important relations between functional groups of microorganisms in the soil depending on action of different factors. It has been determined that neither application of organic and mineral fertilizers into chernozem nor action of hydrothermal factors (temperature air and humidity) is a crucial characteristic of changing in the structure of its microbiocenosis. Microorganisms-producers of exopolysaccharides, which have a strong relationship with all trophic groups of microorganisms as they are their structural components, turned out to be the main block constructing factor, which is due to their strong influence on total content of microbal mass in soil. For soil of agroecosystems with dark-grey type of soil characteristic of content of total biomass of microorganisms is a basis for block constructing gremium, which affirms the state of microbiocenosis and processes occurring there under the action of researched biotic and abiotic factors. Microbiocenosis of sod-podzolic soil, unlike the other researched types of soils, reacted distinctly on applying of fertilizer and depended on the action of hydrothermal factors. Contrast in the range of hydrothermal regime caused a chaotic character of interaction between the basic characteristics in microbiocenosis of sod-podzolic soil with appearance of a direct and mediated relationship among them. Regardless of changes in hydrothermal factors , interactions between characteristics of total microbial mass content, eutrophic microorganisms, which use mineral and organic forms of nitrogen, and producers of exopolysaccharides were stable. It has been proved that estimating of ecological state of soil and influence of applicable agromeasures on it should be conducted according to the indices of total microorganism biomass content in the soil and correlation between the number of microorganisms which form the graph gremium
The effect of vortex structures in the river bed on the concentration and size differentiation of the fish population
Get PDFOn the basis of recent hydroacoustic method with using “PanCor” computerized program-technological complex, research was conducted on the distribution of fish of different taxonomic groups in the water area of Irtysh, a large trans-border river on the bend (meander) with a vortex zone. A hydroacoustic complex allows one to conduct remote size-taxonomic identification of fish. It is demonstrated that on the examined area of the river, fish of different taxonomic groups and sizes concentrate in the zones of increased turbidity and intense whirlpools (vortices) which form as a result of opposite currents at the river meander. The largest concentrations of fish form in the deepest zone of the examined water area and in front of it – vortex zone. It was determined that in the zone of recorded vortices, the number of fish of different taxonomic groups (Cyprinidae, Percidae, Coregonidae, Esocidae, Acipenseridae, Lotidae) is on average 2.14–2.61 times reliably higher compared to the observations at the studied part of the river with no vortices at comparable parameters of depth. The size structure of the fish was dominated by small individuals (<10 cm) in the vortices, and large fish out of these zones, which can be an additional element of the survival strategy. The peculiarities of the studied area of the river with vortices, on one hand, are the factors of formation of fish concentrations, and on the other hand – factors of differentiation by taxonomical and size parameter, related to inability of certain groups of organisms to resist the hydrodynamic force of the vortex structure.On the basis of recent hydroacoustic method with using “PanCor” computerized program-technological complex, research was conducted on the distribution of fish of different taxonomic groups in the water area of Irtysh, a large trans-border river on the bend (meander) with a vortex zone. A hydroacoustic complex allows one to conduct remote size-taxonomic identification of fish. It is demonstrated that on the examined area of the river, fish of different taxonomic groups and sizes concentrate in the zones of increased turbidity and intense whirlpools (vortices) which form as a result of opposite currents at the river meander. The largest concentrations of fish form in the deepest zone of the examined water area and in front of it – vortex zone. It was determined that in the zone of recorded vortices, the number of fish of different taxonomic groups (Cyprinidae, Percidae, Coregonidae, Esocidae, Acipenseridae, Lotidae) is on average 2.14–2.61 times reliably higher compared to the observations at the studied part of the river with no vortices at comparable parameters of depth. The size structure of the fish was dominated by small individuals (<10 cm) in the vortices, and large fish out of these zones, which can be an additional element of the survival strategy. The peculiarities of the studied area of the river with vortices, on one hand, are the factors of formation of fish concentrations, and on the other hand – factors of differentiation by taxonomical and size parameter, related to inability of certain groups of organisms to resist the hydrodynamic force of the vortex structure
The interpolation of cadmium in soils of an urbanized territory of the steppe Dnieper region using geoinformation modeling methods
Get PDFWe collected data on the content of gross and mobile forms of cadmium in the genetic horizons of the main types of soils of the steppe Dnieper region in anthropogenically contaminated landscapes (for instance, the city of Kamianske). The content and distribution of gross and mobile forms of cadmium are shown laterally and radially. The highest concentration of cadmium content is noted for profiles 1 to 6, in particular for a root-saturated ground horizon (up to 50 cm). For soil horizons located at a depth of 50–150 cm, there is a slight excess (4–6 mg/kg) of the mean (2–4 mg/kg) for all urban systems. Minimal concentrations of gross forms of cadmium are observed along the soil profile of 25–29 (up to 1 mg/kg), but anomalous excesses are noted at intersections of major highways, which is characteristic for all arranged profiles. The distribution of mobile forms of cadmium for each araigned profile usually duplicates the situation of distribution of gross forms of heavy metal content. The ArcGIS Spatial Analyst's software capabilities in assessing the ecological status of the Kamianske soil according to the content of cadmium are demonstrated in the study. The results of interpolation of cadmium concentration (gross and mobile forms) on the territory of the city for the corresponding soil horizons are given. According to the conducted simulation, it has been established that the soils of almost the entire eastern part of the city (east of the soil profile of 1 to 6) are characterized by the content of the gross form of cadmium in the range of 3 to 4 mg/kg, except for the wooded ravine Vodyana, within the territorial boundaries of which the values of 2 to 3 mg/kg are forecast, as well as in the soils of the southern and central parts of the city. The interpolation of the results of measurements of cadmium content indicates that the abnormal zone is gradually decreasing by area, however, it maintains the maximum values for the city's territory
Ecological and faunistic survey of the true bugs of the infraorder Pentatomomorpha (Hemiptera) in the urban cenoses of Kharkiv City (Ukraine)
Get PDFA total of 63 species of true bugs in 53 genera and 11 families of the infraorder Pentatomomorpha was recorded from the city of Kharkiv. For one species, Carpocoris purpureipennis (Pentatomidae), we obtained the first record from Left-Bank Ukraine. Formerly, this species was known from Western and Central Ukraine only. Four species of the family Lygaeidae (Nysius ericae, Perithrechus geniculatus, P. gracilicornis, Taphropeltus contractus) are new to Kharkiv Region. The families Lygaeidae (23 species of 19 genera, 38.3% of the total collected bugs), Pentatomidae (16 species of 14 genera, 26.7%), Rhopalidae (7 species of 5 genera, 11.7%), and Coreidae (6 species of 6 genera, about 3%) were the most rich in species and individual numbers. The families of Berytidae, Cydnidae and Scutelleridae were represented by two species each (3.3% out of the total collected bugs). Six species (Myrmus miriformis, Lygaeus equestris, Scolopostethus pictus, Aelia acuminata, Graphosoma lineatum, and Pyrrhocoris apterus) were abundant, eight species common, 14 species rare, and 32 species belonged to occasional elements of the urban cenoses. The true bug species composition and individual abundance were the highest in the suburban meadows and large city parks (44 and 27 species, respectively). By contrast, only seven species were registered in the green areas of the city centre (lawns, public gardens). Faunal similarity (Jaccard / Chekanovsky-Sørensen indices) of the true bug assemblages was the lowest when comparing public gardens of the city centre with the habitats of the suburbs and city parks (0.04–0.06 / 0.07–0.12), and the highest between the meadows and urban parks with glades and grassy vegetation under low recreational pressure (0.52 / 0.68). Jaccard similarity indices for the other six pairs of compared urban cenoses were low (0.1‒0.42). The average Pentatomomorpha similarity in different urban cenoses was also low (Jaccard index 0.27, Chekanovsky-Sørensen index 0.39). The essential faunal differences can be explained by both the low number of most Pentatomomorpha species and their ecological peculiarities. The proportions of various ecological groups of bugs in different urban cenoses were analyzed and discussed. Major differences were observed in the species habitat distributions while the lesser differences concerned trophic groups and hygropreferences of most species. Hortobiont and herpetohortobiont polyphytophagous species dominated all the habitats
Comparison of commonly used ecological scales with the Belgard Plant Ecomorph System
Get PDFThere are several ecological scales developed both for phytoindication of ecological factors and plant ecomorphs. Among them, the scales of Ellenberg and Tsyganov are the most commonly used. L. G. Ramensky and P. S. Pogrebnyak had developed a phytoindication method; they also were founders of first ecological scale of plant species in relation to various environmental factors. One of first ecomorph systems was developed by Alexander Lyutsianovich Belgard. In 1947, Belgard presented a tabular ecomorph system in his doctoral dissertation, and later in monograph “Forest vegetation of the South-East of Ukraine”. In the system he used abbreviated Latin names applying terminology proposed in the late 19th century by Dekandol, Warmin and other authors. He considered ecomorphs as adaptations of plants to environmental conditions in forests of the steppe zone of Ukraine where forest cenoses are exposed to processes of steppization, prairification, swamping, salinization, and thus clarification of relationships between forest, meadow, steppe, marsh and weed plant species was essential. Therefore, development and introduction of cenomorph terms as “adaptation of plant species to phytocenosis as a whole” were an absolutely new contribution to the concept of ecomorph system. In environmental factor scales of Ellenberg and other authors, environment characteristics based on phytoindication were underlined; in the Belgard Plant Ecomorph System, ecomorphs reflect ability of plant species to grow within certain ranges of a given factor. These approaches are quite comparable, and ecomorphs of the Belgard system correspond to certain grades of the Ellenberg and Tsyganov scales. The Belgard ecomorph system has been applied in a number of fundamental and applied works on plant ecology and phytocenology. It is convenient for characterizing ecological features of plant species growing in the steppe zone with a wide range of environment factors such as lighting, humidity, and soil richness. Other authors have expanded and supplemented the Belgard Plant Ecomorph System based on its strategy. A number of ecomorphs was introduced; they reflect intermediate or extreme gradations of factors. A new cenomorph – silvomargoant – has been proposed by the authors of this paper
Effects of different fertilizer systems and hydrothermal factors on microbial activity in the chernozem in Ukraine
Get PDFGroups of microorganisms in soils perform the role of global biogeochemical membrane which provides metabolism of substances and energy between the pedosphere, lithosphere, hydrosphere and living organisms. Сlimate change has resulted in a complex combination of unpredictable changeability of the environment, which is a serious test for the stability and productivity for the natural and anthropogenically transformed ecosystems. Changeability of the hydrothermal factors causes serious changes in the structure and metabolic activity of soil microorganisms, the quality and properties of soil. We studied the impact of hydrothermal factors on the content of carbon, microbial biomass and organic substance in deep chernozem of a natural ecosystem (fallow) and an agroecosystem under different systems of fertilization of winter wheat. A close relationship (r = 0.69–0.79) was determined between the content of microbial biomass in soil and hydrothermal factors (air temperature and moisture). Excessive drought and high parameters of air temperature led to decrease in the content of microbial biomass by 1.5–2.8 times compared to the years with optimum parameters of hydrothermal regime (HTC = 1.0). Leveling out the impact of high temperatures on the productivity of the soil microbiota occurs at a sufficient amount of moisture, and also available nutrients. Drought (HTC = 0.4) and excessive moisture (HTC = 2.0) following heightened air temperatures reduce the release of СО2 from soil. Fallow soil usually has a high content of microbial carbon in the organic compounds of soil (Сmic/Сorg was 2%). In the agroecosystem, there was recorded a decrease by 26–32% of the Сmic specific share in the content of the organic compound of the soil compared to the natural analogue. With organic and organic-mineral systems of fertilization, an increase in Сmic/Сorg parameter occurs and the soil parameters become close to the soil of a natural ecosystem. The calculated ecological coefficients of the orientation of microbial processes in soil indicate a possibility of a balanced functioning of the microbial group and introducing organic and organic-mineral fertilizers, creating optimum conditions for the productivity of winter wheat
Prediction of sweet corn yield depending on cultivation technology parameters by using linear regression and artificial neural network methods
Get PDFArtificial neural networks and linear regression are widely used in particularly all branches of science for modeling and prediction. Linear regression is an old data processing tool, and artificial neural networks are a comparatively new one. The goal of the study was to determine whether artificial neural networks are more accurate than linear regression in sweet corn yield prediction. In the study we used a dataset obtained from field experiments on the technological improvement of sweet corn cultivation. The field experiments were conducted during the period from 2014 to 2016 on dark-chestnut soil under drip irrigated conditions in the Steppe Zone of Ukraine. We studied the impact of the moldboard plowing depths, mineral fertilizer application rates and plant densities on the crop yield. A significant impact of all the studied factors on the sweet corn productivity was proved by using the analysis of variance. The highest yield of sweet corn ears without husks (10.93 t ha–1) was under the moldboard plowing at the depth of 20–22 cm, mineral fertilizers application rate of N120P120, plant density of 65,000 plants ha–1. Data processing by using the linear regression and artificial neural network methods showed that the latter is a great deal better than linear regression in sweet corn yield prediction. Higher accuracy of the artificial neural network prediction was proved by the higher value of the coefficient of determination (R2) – 0.978, in comparison to 0.897 for the linear regression prediction model. We conclude that artificial neural networks are a much better data processing tool, especially, in the life sciences and for prediction of the non-linear natural processes and phenomena. The main disadvantage of the neural network models is their “black box” nature. However, linear regression will not lose its popularity among scientists in the nearest future. Linear regression is a much simpler data analysis tool, it is easier to perform the prediction, but it still provides a sufficiently high level of accuracy.Artificial neural networks and linear regression are widely used in particularly all branches of science for modeling and prediction. Linear regression is an old data processing tool, and artificial neural networks are a comparatively new one. The goal of the study was to determine whether artificial neural networks are more accurate than linear regression in sweet corn yield prediction. In the study we used a dataset obtained from field experiments on the technological improvement of sweet corn cultivation. The field experiments were conducted during the period from 2014 to 2016 on dark-chestnut soil under drip irrigated conditions in the Steppe Zone of Ukraine. We studied the impact of the moldboard plowing depths, mineral fertilizer application rates and plant densities on the crop yield. A significant impact of all the studied factors on the sweet corn productivity was proved by using the analysis of variance. The highest yield of sweet corn ears without husks (10.93 t ha–1) was under the moldboard plowing at the depth of 20–22 cm, mineral fertilizers application rate of N120P120, plant density of 65,000 plants ha–1. Data processing by using the linear regression and artificial neural network methods showed that the latter is a great deal better than linear regression in sweet corn yield prediction. Higher accuracy of the artificial neural network prediction was proved by the higher value of the coefficient of determination (R2) – 0.978, in comparison to 0.897 for the linear regression prediction model. We conclude that artificial neural networks are a much better data processing tool, especially, in the life sciences and for prediction of the non-linear natural processes and phenomena. The main disadvantage of the neural network models is their “black box” nature. However, linear regression will not lose its popularity among scientists in the nearest future. Linear regression is a much simpler data analysis tool, it is easier to perform the prediction, but it still provides a sufficiently high level of accuracy.Artificial neural networks and linear regression are widely used in particularly all branches of science for modeling and prediction. Linear regression is an old data processing tool, and artificial neural networks are a comparatively new one. The goal of the study was to determine whether artificial neural networks are more accurate than linear regression in sweet corn yield prediction. In the study we used a dataset obtained from field experiments on the technological improvement of sweet corn cultivation. The field experiments were conducted during the period from 2014 to 2016 on dark-chestnut soil under drip irrigated conditions in the Steppe Zone of Ukraine. We studied the impact of the moldboard plowing depths, mineral fertilizer application rates and plant densities on the crop yield. A significant impact of all the studied factors on the sweet corn productivity was proved by using the analysis of variance. The highest yield of sweet corn ears without husks (10.93 t ha–1) was under the moldboard plowing at the depth of 20–22 cm, mineral fertilizers application rate of N120P120, plant density of 65,000 plants ha–1. Data processing by using the linear regression and artificial neural network methods showed that the latter is a great deal better than linear regression in sweet corn yield prediction. Higher accuracy of the artificial neural network prediction was proved by the higher value of the coefficient of determination (R2) – 0.978, in comparison to 0.897 for the linear regression prediction model. We conclude that artificial neural networks are a much better data processing tool, especially, in the life sciences and for prediction of the non-linear natural processes and phenomena. The main disadvantage of the neural network models is their “black box” nature. However, linear regression will not lose its popularity among scientists in the nearest future. Linear regression is a much simpler data analysis tool, it is easier to perform the prediction, but it still provides a sufficiently high level of accuracy
Зона временного затопления малых рек как участок повышенного флористического разнообразия
Get PDFDuring fluctuating water levels in the lower reaches of rivers, large areas of shallow water are exposed, forming a zone of temporary flooding (TFZ). The level regime of the water body determines the conditions for the growth of plants, the period available for vegetation of species and the path of seed migration. The seed bank is an integral part of a riparian biocenosis, experiencing the characteristics of environmental factors which influence its structure. Our study of the vegetation cover was carried out by the method of route survey of ecotopes in the estuaries of the Korozhechna and Ild rivers, tributaries of the Rybinsk Reservoir. Species composition of the flora is given in accordance with APG IV. The cenotic structure is characterized in terms of the Brown-Blanke school. To assess the species composition of the seed bank, a transect was placed along the width of the TFZ, on which cores were selected. Flora of the Korozhechny river is represented by 59 species from 24 families and 45 genera. Most numerous families: Poaceae (12%), Cyperaceae (10%), Polygonaceae (10%), Asteraceae, Ranunculaceae and Brassicaceae (by 7%). Flora of the Ild river is represented by 42 species from 18 families and 29 genera. Most numerous families: Cyperaceae (21%), Ranunculaceae (14%), Poaceae (12%), Plantaginaceae (7%). We found two rare species: Carex bohemica – on the Ild river and Ranunculus reptans – on both rivers. The difference in the species composition is explained by the greater riparian area of the TFZ on the Korozhechna river, characterized by a wide low floodplain. Phytocenosis form multicomponent complexes and are represented by associations Scirpetum lacustris, Phalaroidetum arundinaceae, Caricetum gracilis, Phragmitetum communis – on both rivers, Hippuridetum vulgaris и Batrachietum circinati – in terrestrial form on the Korozhechna river, and Eleocharitetum palustris and Oenantho-Rorippetum on the Ild river. In the seed bank composition of the TFZ of the transition zone of the Korozhechna river receiver 25 species were found, Ild river – 30 species. The ecological structure of the flora of both rivers and the seed bank is dominated by species of waterlogged and humid habitats. Their share (hygrophyte and hygromeso-and mesophyte) accounts for about 50%. With prolonged drying, they can normally develop in the TFZ. In the biomorphological structure, the main part of the flora and seed bank species are perennial grasses, characterized by great environmental plasticity, adapted to extreme conditions of habitat, having wide ecological amplitude with respect to the ground and which can withstand considerable fluctuations in the water level. As a result, our work has confirmed that the seed bank is a hidden component of plant communities and reflects the floristic potential of ecologically unstable territories.При колебаниях уровня воды в низовьях рек обнажаются значительные площади мелководий, формируя зону временного затопления (ЗВЗ). Уровенный режим определяет условия произрастания растений, период, доступный для вегетации видов и пути миграции семян. Банк семян – неотъемлемая часть прибрежно-водных биоценозов, испытывающая на себе особенности экологических факторов ЗВЗ, которые оказывают влияние на его структуру. Изучение растительного покрова проводили методом маршрутного обследования экотопов устьевых участков рек Корожечна и Ильд – притоков Рыбинского водохранилища. Видовой состав флоры приведен по APG IV. Ценотическая структура охарактеризована в терминах школы Браун-Бланке. Для оценки видового состава банка семян закладывали трансекту по ширине ЗВЗ, на которой отбирали керны грунта. Флора р. Корожечны представлена 59 видами из 45 родов 24 семейств. Ведущие семейства: Poaceae (12%), Cyperaceae (10%), Polygonaceae (10%), Asteraceae, Ranunculaceae, Brassicaceae (по 7%). Во флоре реки Ильд отмечено 42 вида из 29 родов 18 семейств. Ведущие семейства: Cyperaceae (21%), Ranunculaceae (14%), Poaceae (12%), Plantaginaceae (7%). Отмечено два редких вида: Carex bohemica – на р. Ильд и Ranunculus reptans – на обеих реках. Разница в видовом составе объясняется большей площадью ЗВЗ на р. Корожечна, характеризующейся широкой низкой поймой. Фитоценозы образуют многокомпонентные комплексы и представлены ассоциациями Scirpetum lacustris, Phalaroidetum arundinaceae, Caricetum gracilis, Phragmitetum communis – на обеих реках, Hippuridetum vulgaris и Batrachietum circinati – в наземной форме на р. Корожечна, а также Eleocharitetum palustris и Oenantho-Rorippetum, на р. Ильд. В составе банка семян переходной зоны приемника р. Корожечна выявили 25 видов, р. Ильд – 30. В экологической структуре флоры обеих рек и банка семян преобладают виды переувлажненных и влажных местообитаний. На их долю (гигрофиты, гигромезо- и мезофиты) приходится около 50%. При длительном обсыхании они могут нормально развиваться в ЗВЗ. В биоморфологической структуре основную часть видов флоры и банка семян составляют многолетние травы, отличающиеся большой экологической пластичностью, приспособленные к экстремальным условиям обитания, обладающие широкой экологической амплитудой по отношению к грунтам и выдерживающие значительные колебания уровня воды. В результате работы получили подтверждение, что банк семян является скрытым компонентом растительных сообществ и отражает флористический потенциал экологически нестабильной территории.При колебаниях уровня воды в низовьях рек обнажаются значительные площади мелководий, формируя зону временного затопления (ЗВЗ). Уровенный режим определяет условия произрастания растений, период, доступный для вегетации видов и пути миграции семян. Банк семян – неотъемлемая часть прибрежно-водных биоценозов, испытывающая на себе особенности экологических факторов ЗВЗ, которые оказывают влияние на его структуру. Изучение растительного покрова проводили методом маршрутного обследования экотопов устьевых участков рек Корожечна и Ильд – притоков Рыбинского водохранилища. Видовой состав флоры приведен по APG IV. Ценотическая структура охарактеризована в терминах школы Браун-Бланке. Для оценки видового состава банка семян закладывали трансекту по ширине ЗВЗ, на которой отбирали керны грунта. Флора р. Корожечны представлена 59 видами из 45 родов 24 семейств. Ведущие семейства: Poaceae (12%), Cyperaceae (10%), Polygonaceae (10%), Asteraceae, Ranunculaceae, Brassicaceae (по 7%). Во флоре реки Ильд отмечено 42 вида из 29 родов 18 семейств. Ведущие семейства: Cyperaceae (21%), Ranunculaceae (14%), Poaceae (12%), Plantaginaceae (7%). Отмечено два редких вида: Carex bohemica – на р. Ильд и Ranunculus reptans – на обеих реках. Разница в видовом составе объясняется большей площадью ЗВЗ на р. Корожечна, характеризующейся широкой низкой поймой. Фитоценозы образуют многокомпонентные комплексы и представлены ассоциациями Scirpetum lacustris, Phalaroidetum arundinaceae, Caricetum gracilis, Phragmitetum communis – на обеих реках, Hippuridetum vulgaris и Batrachietum circinati – в наземной форме на р. Корожечна, а также Eleocharitetum palustris и Oenantho-Rorippetum, на р. Ильд. В составе банка семян переходной зоны приемника р. Корожечна выявили 25 видов, р. Ильд – 30. В экологической структуре флоры обеих рек и банка семян преобладают виды переувлажненных и влажных местообитаний. На их долю (гигрофиты, гигромезо- и мезофиты) приходится около 50%. При длительном обсыхании они могут нормально развиваться в ЗВЗ. В биоморфологической структуре основную часть видов флоры и банка семян составляют многолетние травы, отличающиеся большой экологической пластичностью, приспособленные к экстремальным условиям обитания, обладающие широкой экологической амплитудой по отношению к грунтам и выдерживающие значительные колебания уровня воды. В результате работы получили подтверждение, что банк семян является скрытым компонентом растительных сообществ и отражает флористический потенциал экологически нестабильной территории