scholarly journals Modern condition and analysis of anthropogenous-climatic transformation of vegetation of lakes of the northern Steppe land

2018 ◽  
Vol 29 (2) ◽  
Author(s):  
N. O. Roshchyna

In this article, the current and former distribution of higher aquatic vegetation has been analyzed for floodplain lakes, arenas lakes and third terraces lakes in the valleys of large and medium North-Steppe Dnieper rivers. The article is devoted to the current state analysis of the higher aquatic vegetation at North-Steppe Dnieper lakes, its dynamics over a long-term period, as well as the determination of the nature and extent of anthropogenic-climatic changes in vegetation. Anthropogenic influence is a major threat to the development and functioning of most aquatic ecosystems. Since the twentieth century, it has been intensified by trends to long-term climate changes, which are also largely result of human activity. Increasing temperature of the winter season does not contribute to snow accumulation. Reduction of snow accumulation (frequent thaws during the winter), regulation of river flow (formation of a reservoirs cascade and ponds) and accumulation of melt water in artificial reservoirs led to the smoothing of the peak of the spring flood. Thus, the factor that provided spring washing of floodplain lakes, limited their overgrowing by air-water vegetation and their waterlogging disappeared. The anthropogenic factors that influence negatively include: intensification of agriculture, plowing of coastal areas, unreasonable land reclamation, overgrazing, development of transport and engineering infrastructure, urbanization, recreation, and chemical pollution. The presented data was obtained on the basis of processing our own research materials of 2009–2018 and literary and archival materials analysis (the herbarium of the Dnipropetrovs’k National University and the archive of the Research Institute of Biology). Natural Northern Steppe Dnieper lakes are located mainly in river valleys, so the study area was conventionally divided into sections: the large river valley (Dnieper) and the middle rivers valleys (Samara and Orel). Three ecological groups of macrophytes were reviewed and compared: hydatofites (submerged species), pleistophytes (species with floating leaves) and helophytes (air-water species). The vegetation of Dnieper floodplain lakes practically did not change for all three formation groups. The number of immersed plants communities within the floodplains of medium-sized rivers has decreased by three. The pleistophytes and helophytes associations decreased to fragments of associations. The lakes vegetation within the sandy Dnieper terrace practically did not change for all three formation groups. The submerged lakes plants associations within the sandy medium-sized rivers terraces have been reduced by two. As part of the lakes vegetation on the Dnipro saline terraces, fragments of associations of the two species are considered extinct. A new association of southern adventive species Ruppia maritima L. has appeared within the limits of the middle rivers saline terrace. Changes in higher aquatic vegetation are characteristic of all types of lakes. Changes occur in the direction of crowding out higher aquatic vegetation communities by airborne plant communities. The consequence of the anthropogenic-climatic transformation of aquatic ecosystems is increased mineralization, siltation, and, as a result, intensive overgrowing of lakes by aboriginal and adventive species with a wide ecological amplitude (replacement of sensitive to environmental changes species).

Author(s):  
Stadnychenko A.P. ◽  
Uvayeva O.I. ◽  
Ihnatenko О.О.

For the first time, the influence ofCr (III) ionsin maximum concentration limits (MCL) from 0.5 –3 on the way of life, nutrition and digestion of Lymnaea vulnerata (Küster, 1862) and L. monnardi (Hartmann, 1844), –the different life forms of pondsnailsof the hydrographicnetwork of Ukraine,–was explored. Due to the long-term natural selectionamongthese specieswhich took place in extremely different ecological environmental conditions, the adaptive radiation of the shell of the ancient original form of pondsnailwas carried out by rheophilicL. monnardi and stagnophilicL. vulnerata,in opposite directions -divergently.The ampla-shaped shell of L. monnardi (flattened, low, compact, streamlined, with a large mouth) and a large flat sole prevent its driftingby thewater current, while the stagnicola-liketurret-shapeshell of L. vulnerata (elongated, high, narrow, with curls and flat turns, andsmall mouth)reliably protects it from excessive water consumption in the process of pulmonary respiration, thatis important for this ordinary inhabitant of mostly drying out ponds, experiencing conditions of desiccation, which hidesin the cracks of drying out bottom.The autochthonous fodder diet of these pondsnailsis represented by algae and higher aquatic vegetation (different in species composition for each of the species of mollusks studied).Under the maximum concentration limits of 0.5, MCL, 2MCL, 3MCLof Cr(III) ions in the environment, a 5-phase process of poisoningis being developed among the pond snails(0.5MCL-indifference; MCLand 2MCL-stimulation; 3MCL-depressive, sublethal, lethal phases). Its symptoms are clearly illustrated by the values ofthe main trophological parameters in poisoned individuals, depending on the course of the relevant phases of the pathological process.Key words : Lymnaea, life forms, Cr (III)ions, way of life, nutrition, digestion. Серед полютантів, які потрапляють із скидами чи стоками як у природні, так і у штучні водойми, одними з найнебезпечніших для гідробіонтів є іони важких металів. Актуальність дослідження впливу іонів важких металів на різні прояви життєдіяльності гідробіонтів пов’язана як із широкою розповсюдженістю їх наразі у поверхневих водах, так і з явно недостатнім на сьогодні ступенем дослідженості впливу значної частини із них на водних черевоногих молюсків. Саме до числа таких важких металів і належить Cr (III), рівень вмісту якого у гідромережі України. Уперше з’ясовановплив 0,5ГДКр –3ГДКр іонівCr (III) на спосіб життя, живлення і травлення Lymnaea vulnerata(Küster, 1862) i L. monnardi (Hartmann, 1844) –різних життєвих форм ставковиків гідромережі України. Внаслідок тривалого природного добору, котрий відбувався у цих тварин у вкрай відмінних екологічних умовах довкілля, адаптивна радіація черепашки прадавньої вихідної форми ставковиків здійснювалася реофілом L. monnardi і стагнофілом L. vulnerataу протилежно скерованих напрямках –дивергентно. Амплаподібна черепашка L. monnardi (сплющена, низька, компактна, обтічної форми, з великим устям) і велика плоска підошва ноги запобігають знесенням її течією, тоді як стагніколаподібна баштоподібна черепашка L. vulnerata(витягнутої форми, висока, вузька, з плоскими обертамизавитка і невеличким устям) надійно оберігає його від зайвих витрат води у процесі легеневого дихання, що важливо для цього звичайного мешканця здебільшого пересихаючих водойм, переживаючих умови десикації, забившись у щілини розтрісканого від пересиханнядна.Автохтонний кормовий раціон цих ставковиків представлений водоростями і вищою водяною рослинністю (різними за видовим складом щодо кожного з видів досліджених молюсків).За 0,5ГДКр, ГДКр, 2ГДКр, 3ГДКр іонів Cr (III) у середовищі у ставковиків розвивається 5-тифазний процес отруєння (0,5 ГДКр –байдужість; ГДКр і 2ГДКр –стимуляція; 3ГДКр –депресивна, сублетальна, летальна фази). Симптоматика його чітко ілюструється значеннями основних трофологічних показників у отруєних особин, залежних від перебігу у них відповідних фаз патологічного процесу.Ключові слова: Lymnaea, життєві форми, Cr (III), спосіб життя, живлення, травлення


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Niloufar Nouri ◽  
Naresh Devineni ◽  
Valerie Were ◽  
Reza Khanbilvardi

AbstractThe annual frequency of tornadoes during 1950–2018 across the major tornado-impacted states were examined and modeled using anthropogenic and large-scale climate covariates in a hierarchical Bayesian inference framework. Anthropogenic factors include increases in population density and better detection systems since the mid-1990s. Large-scale climate variables include El Niño Southern Oscillation (ENSO), Southern Oscillation Index (SOI), North Atlantic Oscillation (NAO), Pacific Decadal Oscillation (PDO), Arctic Oscillation (AO), and Atlantic Multi-decadal Oscillation (AMO). The model provides a robust way of estimating the response coefficients by considering pooling of information across groups of states that belong to Tornado Alley, Dixie Alley, and Other States, thereby reducing their uncertainty. The influence of the anthropogenic factors and the large-scale climate variables are modeled in a nested framework to unravel secular trend from cyclical variability. Population density explains the long-term trend in Dixie Alley. The step-increase induced due to the installation of the Doppler Radar systems explains the long-term trend in Tornado Alley. NAO and the interplay between NAO and ENSO explained the interannual to multi-decadal variability in Tornado Alley. PDO and AMO are also contributing to this multi-time scale variability. SOI and AO explain the cyclical variability in Dixie Alley. This improved understanding of the variability and trends in tornadoes should be of immense value to public planners, businesses, and insurance-based risk management agencies.


2021 ◽  
Author(s):  
Tadanobu Nakayama

<p>Inland waters including rivers, lakes, and groundwater are suggested to act as a transport pathway for water and dissolved substances, and play some role in continental biogeochemical cycling (Cole et al., 2007; Battin et al., 2009). Quantifying the physical and chemical connections between land and associated fresh and coastal waters is critical for understanding the dynamics of carbon cycle in aquatic ecosystems. Recently, process-based National Integrated Catchment-based Eco-hydrology (NICE) model (Nakayama and Watanabe, 2004) was developed to couple with various biogeochemical cycle models in biosphere, aquatic ecosystems, and carbon weathering, etc. in global major river basins (NICE-BGC) (Nakayama, 2017; Nakayama and Pelletier, 2018). NICE-BGC also included the feedback between soil organic content and overland carbon fluxes, and succeeded to simulate inter-annual variations of carbon cycle in a terrestrial-aquatic continuum greatly affected by the extreme weather patterns (Nakayama, 2020). To evaluate global changes in the carbon cycle due to anthropogenic factors, such as application of fertilizer and manure, in major rivers including 130 tidal estuaries over an 18-year period (1998-2015), the present study expanded NICE-BGC to estuary in land and ocean margins where it is generally considered to be net heterotrophic ecosystems and show significant supersaturation of CO<sub>2</sub> (Frankignoulle et al., 1998; Regnier et al., 2013). The new model used Dirichlet boundary condition at the downstream of global major rivers by using some variables (water temperature, salinity, dissolved oxygen, nutrient, alkalinity, and pH, etc.) in coastal ocean. The simulated result showed that total nitrogen and phosphorus fluxes in overland flow were found to increase with nutrient application. In contrast, total suspended sediment decreased in some regions because the vegetation was able to expand to cover the ground, resulting in less erosion. NICE-BGC simulated the difference in carbon budget in major rivers with and without nutrient application. Generally, CO<sub>2</sub> degassing above water decreased and particulate organic carbon (POC) increased in most rivers through variations in carbon budget, reflecting various hydrologic and biogeochemical conditions. The simulated result also showed that the estuarine carbon cycle was sensitive to intense anthropogenic disturbances reflected by nutrient load, seawater temperature, increases in sea level, and ocean acidification. Extension of previous studies only by categorizing MARCATS segment numbers showed that the estimated total CO<sub>2</sub> flux from the world’s estuaries was 0.14 Pg C/yr. The simulation generally showed that incorporation of the nutrient cycle into the terrestrial-aquatic-estuarine continuum improved estimates of net land flux and carbon budget in inland waters, thus emphasizing that the effect of estuarine inland water should be explicitly included in the global carbon model to minimize the range of uncertainty.</p>


Author(s):  
Nara de Oliveira-Ferreira ◽  
Rafael R. Carvalho ◽  
Elitieri B. Santos-Neto ◽  
Bárbara M. R. Manhães ◽  
Emi B. Guari ◽  
...  

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
O Klyachenko ◽  
◽  
I Shliakhtun ◽  

National Nature Park “Pyryatynsky” is a valuable reserve of flora and vegetation of the Left-Bank Dnipro. The extensive hydrological network of the Udai River and the wide representation within this nature reserve of floodplain reservoirs are the reason for the high diversity of plant communities of higher aquatic vegetation. In this article we classified the communities of order Callitricho-Batrachietalia in National nature park "Pyryatynskyi" and identify the features of their syntaxonomic and ecological differentiation. Fragmentary and non-comlete information about this type of vegetation are existed in literature, however, without geobotanical releves and detailed characteristics of the structure of phytoceonoses, synecology and synchorology. All obtained results based on original field data. In total, 22 geobotanical releves were performed during the period 2010–2017. The description of communities was carried out within their natural boundaries. Treatment of fitosociological data was performed with the JUICE software package. The nomenclature of syntaxons was consistent with the International Code of Phytosociological Nomenclature (ICFN).The order of Callitricho-Batrachietalia on the territory of NPP "Pyriatynsky" is represented by alliance Batrachion aquatilis Gehu 1961 and 4 associations (Batrachietum aquatilis Gehu 1961, Potameto perfoliati–Batrachietum circinati Sauer 1937, Hottonietum palustris Sauer 1947, Veronico beccabungae–Callitrichetum stagnalis (Oberdorfer 1957) Th. Müller 1962). This is first prodrome of order Callitricho-Batrachietalia for territory of National Nature Park “Pyryatynskyi”. The communities of this syntaxon occupy small areas and have a limited distribution in the region. Most of them are rare and vulnerable to changes in environmental conditions. Monitoring of their structure, chorology and dynamics is an important task to maintain and preserve the species and coenotic diversity of NPP "Pyryatynsky".


1998 ◽  
Vol 27 ◽  
pp. 125-129 ◽  
Author(s):  
Gordon S. Hamilton ◽  
Ian M. Whillans ◽  
Peter J. Morgan

Ice-sheet thickening or thinning rates in Antarctica are measured using the “coffee-can” or “submergence velocity” method. in this, repeated measurements of the positions of firn anchors are obtained using the global positioning system (GPS). The thickness change is (lie difference between vertical velocity so obtained and long-term rate of snow accumulation. Minor corrections for firn settling and downslopc motion are made. The technique avoids difficulties of short-term fluctuations in snowfall or snow den-sification. The result for Byrd Station is near balance, -0.004 (0.022) ma−1, and for the Dragon, just outboard of Ice Stream B, thinning at -0.096 (0.044) ma−1. Uncertainties with these first results are mainly due to the short occupation times during the first GPS surveys.


Author(s):  
Zhanna Sergeevna Makakhaniuk ◽  
Valentina Mikhailovna Zubkova ◽  
Lyubov Anatolievna Rozumnaya

The article describes the purpose of the work, which is determining the distribution and relationships between the composition of pollutants in coastal soil, bottom sediments and higher aquatic vegetation in the small river Khodtsa. There have been presented the data of the laboratory research based on the results of the field work onselecting samples, on concentration of toxicants (cadmium, lead, iron, nitrogen, ammonium and petroleum products) in deposit media, as well as in Carex aquatilis plants of the small river Hodza. This plant species is limiting throughout the river due to the low intensity of biological absorption. The studies were carried out during the summer low water season in 2019 on the river section from the source (Elektrostal city) to the river mouth in the area of Pavlovsky Posad. In all the studied objects there have been found increased concentrations of iron. In the coastal ground and bottom sediments the pollution with heavy metals is manifested to a much greater extent: at the source and intermediate point. Petroleum products and ammonia nitrogen are distributed unevenly in space. A correlation analysis of the experimental data obtained in the components of the environment of the studied territory (the Khodtsa river) was performed. In general, the highest measurement results are observed in the upper reaches of the small river Khodtsa in the industrial city of Elektrostal. The obtained data on the heavy metals migration in the system “сoastal ground – bottom sediments – higher aquatic vegetation” of the small river Khodtsa can be successfully used as indicators an environmental monitoring system and serve as the basis for organizing further research, as well as for developing a strategy for environmental management and environmental protection in the Moscow Region.


2017 ◽  
pp. 3-21 ◽  
Author(s):  
D. A. Kaverin ◽  
A. V. Pastukhov

The specificities of temperature regime of automorphic clayey soils forming under the suffruticous and shrub vegetation within the zone of tundra and forest tundra in the European North-East were studied. As the objects of investigation we chose the organic cryometamorphic soils and cryometamorphic gleezems; in the both soil types the CRM cryometamorphic horizon is developed. The soils are formed in conditions of long-termed seasonal freezing at the absence (deep occurrence) of the permafrost rocks. The dynamics near the zero temperatures (zero curtains) is characterized. The hypothesis, concerning the role of zero curtains in the sustaining of the specific angular-grainy structure within the mass of cryometamorphic horizons is formulated. The mass of cryometamorphic horizons and the depth of present-day zero curtains, which observed at the long-term seasonal soil freezing, correlate to each other. The impact of suffruticous and shrub vegetation on the specificities of winter and summer soil temperature regime is determined. We discovered that the main differences between the soils developing under suffruticous and shrub vegetation tundras are stipulated by the different intensity of the snow accumulation within these areas. The soils that are developed under the shrub vegetation are warmer than soils developed under the suffruticous tundra, where permafrost may occur at the depth of 2-3 cm. In general, seasonaly freezing tundra soils are located in the middle of the range of the automorphic clay loamy soils in the tundra-taiga ecotone of European North-East of Russia, and occupy the niche between permafrost tundra and non-permafrost north taiga soils.


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