The atmosphere as a lens

The advent of manned satellites has made it possible for man to observe Earth from great distances. Many new phenomena have been discovered in the atmosphere. These are evidently caused by reflection, scattering or refraction of light on crystals and drops of water. It is possible to see small objects on the surface of Earth because of these anomalies

Two-proton radioactivity and three-body decay. IV. Connection to quasiclassical formulation

We derive quasiclassical expressions for the three-body decay width and define the ``preexponential'' coefficients for them. The derivation is based on the integral formulae for the three-body width obtained in the semianalytical approach with simplified three-body Hamiltonian [L.V. Grigorenko and M.V.\ Zhukov, arXiv:0704.0920v1]. The model is applied to the decays of the first excited $3/2^{-}$ state of $^{17}$Ne and $3/2^{-}$ ground state of $^{45}$Fe. Various qualitative aspects of the model and relations with the other simplified approaches to the three-body decays are discussed.Comment: 9 Pages, 2 figure

Phytoindication approach to assessing factors determining the habitat preferences of red deer (Cervus elaphus)

The study examined the possibility of using the phytoindication technique to describe habitat preferences of red deer in a relatively homogeneous area. Two alternative hypotheses were tested. Hypothesis 1 suggests that the relationship between red deer and vegetation is due to a trophic factor, so preferences for individual plant species cause vegetation to influence the distribution of animal numbers. Hypothesis 2 suggests that environmental factors influence vegetation, structuring and determining the productive level of the community as a whole. Therefore, environmental factors, rather than individual plant species, cause vegetation-animal interactions. The research was conducted on Biryuchiy Island Spit, where the Azov-Sivash National Nature Park is located. The geobotanical surveys were performed in three types of ecosystems: sandy steppe (vegetation class Festucetea vaginatae), saline meadows (vegetation class Festuco–Puccinellietea), and artificial forest plantation (vegetation class Robinietea). 250 releves were recorded according to the Brown-Blanquet approach. The number of fecal pellets and the number of groups of pellets of red deer was recorded together with geobotanical surveys in the same sample plots. The pellet groups counted in the field were converted to deer densities in specific vegetation classes taking into account the number of pellet groups on the site and the decay rate of the fecal pellets. The vegetation types were distinguished by the number of deer fecal pellets per unit area. The highest number of fecal pellets was found for the plant class Festucetea vaginatae, somewhat fewer fecal pellets were in the plant class Robinietea, and the lowest number was in the plant class Festuco-Puccinellietea. A geometric distribution model is adequate for explaining the experimental data on the number of fecal pellets. A total of 59 species of flowering plants were found. Based on the species composition and projective cover of species, the ecological regimes of ecotopes were identified by phytoindication. The correspondence analysis of the vegetation revealed two ordination axes. The ordination axis 1 (CA1) was able to explain 11.3% of community inertia, and the ordination axis 2 (CA2) was able to explain 5.2% of community inertia. The maximum excretory activity of animals was recorded for the central part of the ordination space, indicating the presence of an optimum zone in the gradient of environmental factors that structure plant communities. The forward selection procedure allowed the Nutrients Availability variable to be selected as the most important variable to explain variation in the plant community structure. The number of deer fecal pellets exhibited different patterns of response in the Nutrients Availability gradient. The response within the plant class Festucetea vaginatae could best be explained by Model III from the list of HOF-models. The response of the excretory activity of deer within the class Festuco-Puccinellietea could best be fitted by the model IV, which represents a symmetric Gaussian curve. The response of excretory activity in the Robinietea vegetation class was asymmetrical bimodal. The ecological properties of the red deer ecological niche in both the drier and less mineralized part of the range of ecological conditions and the wetter and more mineralized part should be assessed in the context of the prospects for future studies

Time turnover of species in bird communities: the role of landscape diversity and climate change

The challenge of searching for patterns of species turnover dynamics in communities of living organisms is directly related to solving problems of stability and functioning of ecosystems. Avian communities are an essential structural and functional component of terrestrial and aquatic ecosystems which are highly diverse and play an important role in a wide range of ecosystem functions. The issue of changes in the dynamics of amphibiotic landscape complexes, where terrestrial and aquatic ecosystems conjugate, is practically not solved. In this connection, a study was carried out within a landscape system, which presents terrestrial and aquatic ecosystems that were in different degrees of anthropogenic transformation. The dynamics of bird communities was considered in the context of recent global climate change. The investigation was conducted in the landscapes of the south and south-east of Ukraine in the nesting seasons 1988–2018. Within the landscape system associated with the Molochny estuary, the ten most important types of ecosystems were distinguished, which included : agricultural lands, artificial forest belts, meadows, islands and spits, reed beds, urban areas, solonchaks, steppe, cliffs, artificial forests. The temporal turnover of the bird communities was decomposed into two parts: the first term (D1) related to the amount of change in community composition, and the second term (D2) being dependent only on the amount of change in community size sensu its abundance. The contribution ratio of the species and of the environment variable were calculated to identify drivers that influence the turnover measure. The average annual temperature and the sum of annual temperatures were considered as environment variables. The bird metacommunity of the studied landscape system was represented by 132 species from 86 genera, 42 families and 13 orders. During the research period the average annual temperature varied from 9.5 to 12.5 ˚C. and the temperature dynamics were subject to the linear trend. An oscillatory component was also present in the temperature dynamics. The annual rainfall ranged 220–761 mm. A coherent change in precipitation and temperature was observed in the period until 2011. After that, the temperature growth stabilized and the amount of precipitation began to fall sharply. The steppe bird community was represented by an extremely small number of species, but demonstrated the ability to maintain a stable structure for a long time. The main fluctuations of the community were quantitative changes in abundance, while the turnover of species was practically absent. Species of the community replace each other cyclically, but there were no targeted changes in community structure. Temperature and precipitation were the main drivers of the bird community in the steppe. The bird communities on salt marshes were characterized by a stable abundance, but a constant directed turnover of species. Reduced water levels and the disappearance of islands in the salt marshes increased the risk of threats from predators, which could lead to a decrease in the abundance of some species. The islands and spits were characterized by high species turnover with quasi-cyclical population dynamics. The main feature of the community dynamics was a decrease in the role of precipitation and an increase in the role of the time factor. The role of temperature remained stably low. The species richness of bird communities in agrarian lands was higher than in steppe communities. The turnover measure was significant because of the increased abundance of Alauda arvensis. Over time, the role of precipitation in the community dynamics has been decreasing and the role of time has been increasing. The value of temperature varied, but was at a stationary level. The turnover of species was compensated by an increase in the abundance of bird communities. The obtained results are in line with findings indicating that despite more stable land use intensities in recent years, climate change has not overtaken land use intensities as the main driver of bird population dynamics

The importance of relief for explaining the diversity of the floodplain and terrace soil cover in the Dnipro River valley: The case of the protected area within the Dnipro-Orylskiy Nature Reserve

Floodplains are centers of species diversity, so floodplain habitats often contain protected areas. However, conservation strategies pay little attention to soils, on which the functional stability of both individual ecosystems and landscape chains as a whole depends. Soil morphology provides structural and functional information about floodplain ecosystems. The spatial and temporal heterogeneity of soil morphology is a cost-effective ecological indicator that can be easily integrated into rapid assessment protocols for floodplain and riverine ecosystem restoration projects. Therefore, the aim of our work was to consider the morphological features of soils of the Dnipro-Orylskiy Nature Reserve and assess the role of soil diversity as a factor of structural and functional sustainability of ecosystems of the protected area, as well as to identify the significance of geomorphological predictors for differentiation of soil types to create a soil map of the territory. The World Reference Base for Soil Resources reference soil groups were classified using geomorphological predictors. Soil types were able to explain 90% of the variation in elevation occupied by soils. Arenosols occupied a statistically significantly higher position in topography than other soil types. In turn, Eutric Arenosols occupied a higher position (68.91 ± 0.48 m) than Eutric Lamellic Arenosols (63.32 ± 0.54 m). Other soils occupied positions in the topography that were not statistically significantly different in height. Soil types were able to explain 38% of the variation in elevation that the soils occupied. The highest Topography Wetness Index values were found for Fluvisols (12.73 ± 0.23) and Solonetz (13.06 ± 0.28 m). Differences between these soils were not statistically significant. Topography Wetness Index was slightly lower for Cambisols (11.80 ± 0.21) and Eutric Lamellic Arenosols (12.21 ± 0.28), which also did not differ on this measure. The lowest Topography Wetness Index value was found for Gleysols (11.15 ± 0.17) and Eutric Arenosols (10.95 ± 0.24), which did not differ from each other on this index. Eutric Arenosols and Eutric Lamellic Arenosols are formed at great depths of the water table (7.89 ± 0.50 and 2.62 ± 0.46 m, respectively). Gleysol and Solonetz form at close groundwater level to the surface (0.28 ± 0.27 and 0.21 ± 0.46 m, respectively) compared to Fluvisol and Cambisol (0.46 ± 0.38 and 0.41 ± 0.35 m, respectively). Elevation was the most informatively valuable predictor, but Topography Wetness Index and Vertical Distance to Channel Network significantly improved discrimination. Arenosols were very different from other soils which occupy an automorphic position. Cambisols occupied a transitional position. Other soils occupied hydromorphic positions. Fluvisols and Solonetz occupied wetter positions, while Gleysol occupied less wet positions. Fluvisols and Solonetz differed in the groundwater table. Solonetz predominantly occurred at close groundwater levels. The classification matrix confirmed the possibility of using geomorphological predictors to build a model of spatial variation of soils in the study area. The spatial model demonstrates the organization of the soil cover of the reserve. Calculations showed that Cambiosols occupy 20.7% of the area, Eutric Arenosols occupy 16.0%, Eutric Lamellic Arenosols occupy 17.9%, Fluvisols occupy 15.2%, Gleysols occupy 28.7%, and Solonetz occupy 1.5%

Application of remote sensing data for monitoring eutrophication of floodplain water bodies

The aim of this article was to investigate the influence of structural features of the floodplain water network on the spatial and temporal dynamics of chlorophyll-a concentration as an indicator of eutrophication. The research was conducted in the waters of the “Dnipro-Orilskiy” Nature Reserve. The geographic information base with polygonal objects which represented water bodies of the reserve was created on the basis of detailed geographical maps and the high resolution space images. The water bodies were characterized using such parameters as the distance of the water body centroid from the nearest shore of the Dnipro River, the area of the water body, the order of the water body and the connectivity of the water body. Chlorophyll-а concentration was estimated based on the surface algal bloom index. The information was obtained about 148 water bodies, 141 of which are water bodies in the floodplain of the Dnipro River. The area of floodplain water bodies within the reserve was 3.28 million m2. The area of floodplain water bodies ranged from 300–232,500 m2. Trophic State Index allows us to estimate the trophic level of Dnipro River waters as mesotrophic, water bodies of first and second order as eutrophic, and water bodies of third and fourth order as hypereutrophic. The dynamics of chlorophyll-a content in water followed the seasonal course of temperatures. The concentration was lowest in the cold period of the year and reached its maximum in the second half of summer. The autumn decrease occurred at the end of September. The seasonal course of air temperature was superimposed on the peculiarities of the temperature regime of a particular water body, which depended on its depth and flow rate. The time, water body area, distance from the Dnipro River channel, connectivity and order of water bodies were the statistically significant predictors of chlorophyll concentration in water and were able to explain 85% of the variation of this indicator. The increase in chlorophyll-a concentration with increasing order of a water body is due to a decrease in the intensity of water exchange and a decrease in the depth of water bodies of higher order. An increase in the order of a water body is accompanied by a branching network of water bodies, the ability of water bodies to clear sediments decreases. Sediment accumulation leads to a decrease in their depth. Warming of shallow ponds and accumulation of organic matter in them are factors of intensive growth of blue-green algae. The evacuation of surplus organic matter, which results from mass vegetation development with excessive nutrient inputs, is a key driver of the eutrophic regime of water bodies. The increasing importance of regulatory processes develops in agreement with an increase in chlorophyll-a concentration in a water body. The importance of the considered factors reaches the highest level in summer time, when simultaneous maximum warming of water bodies and minimum water level in them take place. Accordingly, the differences between deep and relatively cool water bodies and shallow water bodies that warm up quickly, which significantly stimulates the growth of organic mass, reach the greatest contrast. The spatial patterns of variation in chlorophyll-a concentration have a complex multiscale structure, indicating the multiple nature of the acting factors. The spatial variability was represented as a composition of broad-scale and medium-scale spatial processes. The broad-scale process is most dependent on connectivity, whereas for the medium-scale process the leading one is the effect of water body order

Increased soil penetration resistance drives degrees of hemeroby in vegetation of urban parks

Urban parks provide a variety of ecosystem services, and a range of management practices promote their maximisation. The species diversity of plant communities is a factor in the maintenance of ecosystem services. The reconstruction of parks is one of the management practices, but the environmental impact of such activities is not clear. The reconstruction of parks affects vegetation and soil cover, and the interconnection of these components of the urban park ecosystem has not been studied before. The study revealed the features of variability of physical properties of soil and vegetation cover and identified their interconnection in the conditions of urban park reconstruction. The study was conducted in the recreational area of the Botanical Garden of Oles Honchar Dnipro National University (Ukraine). The park was studied in the area where reconstruction activities had previously been carried out. During the reconstruction process, walkways were restored, shrubs were removed, old or damaged trees were excavated, and tree crowns were trimmed. Young trees were planted in place of the removed old trees. Old outbuildings that significantly impaired the aesthetic impression of the park were also dismantled. The reconstruction involved transport and construction equipment. Samples were collected within transects, two of which were located in the reconstruction area, and two other transects were located in a similar area of the park where no reconstruction was carried out. The plant community was found to consist of 65 species. The mean level of alpha diversity was 11.5 species and beta diversity was 5.7. The alpha diversity was higher in the reconstructed park. The principal component analysis of the variability of soil properties extracted four principal components with eigenvalues greater than one. The principal components 1 and 3 reflect the variability of soil properties induced by the park's reconstruction, while the principal components 2 and 4 reflect variability that may be caused by other anthropogenic factors unrelated to the park's reconstruction, or may be due to natural variability of the soil cover. The principal component 1 indicates a uniform increase in the soil penetration resistance as a result of the application of technological processes during the reconstruction. This effect may be the result of the direct technological impact of the mechanisms employed and the large number of employees involved in the park's reconstruction. The condition of the crown space of the park plantation can explain the variation in soil penetration resistance. The increase in the height and projective cover of the grass vegetation is due to a decrease in the closure of the stand crowns, but the effect of such coordinated stand and grass dynamics on soil penetration resistance is observed only at a depth of 25–55 cm. This effect can be explained by the influence of the plant root system on the physical state of the soil. The root system of herbaceous plants is capable of loosening the soil and reducing its soil penetration resistance. The reconstruction of the park led to an increase in the hemeroby of the plant community. The criterion for the success of the reconstruction may be an increase in the attractiveness of the park for visitors without the risk of increasing hemeroby. The trend of increasing hemeroby clearly coincides with the direction of transformation of soil conditions, which are indicated by the principal component 1. The increase in the soil penetration resistance is a driver of the growth of vegetation cover hemeroby. The physical environment of the soil cover acts as an important environmental filter that affects the structure of the vegetation cover and the species composition of plant species complexes

The peculiarity of animal complexes of chernozem

Генетичний зв’язок тваринного населення і грунтового покриву лежить в основі діагностичних властивостей тварин для виявлення і кількісної оцінки процесів, що відбуваються в грунті. Екологічний вигляд і своєрідність тваринного населення мають найбільшу діагностичну цінність. Тваринне населення ґрунтів степу і його трансформація під пологом штучних лісових насаджень розглядається в цій роботіГенетичний зв’язок тваринного населення і грунтового покриву лежить в основі діагностичних властивостей тварин для виявлення і кількісної оцінки процесів, що відбуваються в грунті. Екологічний вигляд і своєрідність тваринного населення мають найбільшу діагностичну цінність. Тваринне населення ґрунтів степу і його трансформація під пологом штучних лісових насаджень розглядається в цій роботіThe genetic connection of animal complexes and soil cover is in the basis of diagnostic ability of animals to indicate and quantity assessment of soil processes. The ecoiGgical view and peculiarity of soil animal complexes has the most impotent value. The soil animal complexes of steppe and their trans-formation under artificial forest are discusse

Ecological diversity and taxonomic organization of animal communities

Видове та таксономічне різноманіття – важливі складові екологічного різноманіття угруповань. У роботі проаналізовано сучасні підходи до кількісної оцінки таксономічного різноманіття екосистем. Проведено тестування індексів у гіпотетичному експерименті для вивчення властивостей у відношенні відображення таксономічного ускладнення угруповання. Індекси різноманіття були застосовані для аналізу сукупності реальних угруповань ґрунтових тварин. Видове та таксономічне різноманіття – важливі складові екологічного різноманіття угруповань. У роботі проаналізовано сучасні підходи до кількісної оцінки таксономічного різноманіття екосистем. Проведено тестування індексів у гіпотетичному експерименті для вивчення властивостей у відношенні відображення таксономічного ускладнення угруповання. Індекси різноманіття були застосовані для аналізу сукупності реальних угруповань ґрунтових тварин. The species and taxonomy diversity are the impotant components of ecological diversity of living organism’s complexes. The article analyses the modern approaches of quantitative estimation of the ecosystem diversity. In hypothetical experiment the indexes have been tested to study the properties dealing with taxonomy complexity reflection. Diversity indexes have been used to analyze some real soil invertebrate’s complexes