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Limnological study of Serbian oxbow shaped Lake Srebrno, with special emphasis on the benthic community composition and structure

Abstract

Detailed limnological study of the Lake Srebrno (Serbia) bottom fauna was performed in March 2007. Investigations included qualitative, quantitative, and saprobiological analysis of bottom fauna communities, physical and chemical analysis of sediments and determination of chlorophyll a concentration, as well as saprobic and trophic status analyses. Samples were collected at eighteen sites distributed along a shoreline and in deeper sections of the lake. Twenty taxa from nine macroinvertebrate groups were recorded. Family Chironomidae had the biggest index of participation, the highest species diversity and the largest density of populations in benthocenoses of Lake Srebrno. Faunistic similarity between sites was estimated according to Sorensen’s Quotient of Similarity (QS). The majority of benthocenoses - 56% showed a medium level of faunistic similarity (QS = 21-60%), and 42% of benthocenoses showed a high level of faunistic similarity (QS = 61-100%). The classification of Lake Srebrno based on saprobic and trophic levels was assessed. Saprobic level was in the range from alpha-meso- to poly-alpha-mesosaprobity. The water quality of the lake ranged from class III and between IV and III class. Generally, Lake Srebrno had eutrophic status with the gradation to hypertrophy.

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Formation of Inter-Species Links in Ungulates in the Azov-Sivash National Nature Park.

Abstract

The succession of ungulate fauna was studied under conditions of artificially high density and limited residential area on the Biryuchy Island of the Azov-Sivash National Nature Park. Forming of inter-specific relationships between populations of the moufflon, red-deer and fallow-deer were revealed. The social hierarchy of the mentioned species, which are at the same trophic level, is determined. For the population of each species the factors influencing the dynamics of its number are given. Competition of species in steppe habitat is based solely on trophic relationships because the protective properties of the land are minimized. The forage base creates equal conditions for different species, since there is no woody vegetation in the steppe, which makes the large size of the red deer not important for the food obtaining. Concerning the fallow-deer, there is activation in reproductive potential, which is the part of the strategy in competition for resources and indicates its wider ecological lability in comparison with the red-deer. Meanwhile, a high level of adaptation to the conditions of the open steppe is noted in the moufflon, which (together with high reproductive capacity) rationally uses pasture potentials while the fallow-deer and red-deer have a certain level of stenophagy.

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The conceptual structure of evolutionary biology: A framework from phenotypic plasticity

Abstract

In this review, I approach the role of phenotypic plasticity as a key aspect of the conceptual framework of evolutionary biology. The concept of phenotypic plasticity is related to other relevant concepts of contemporary research in evolutionary biology, such as assimilation, genetic accommodation and canalization, evolutionary robustness, evolvability, evolutionary capacitance and niche construction. Although not always adaptive, phenotypic plasticity can promote the integration of these concepts to represent some of the dynamics of evolution, which can be visualized through the use of a conceptual map. Although the use of conceptual maps is common in areas of knowledge such as psychology and education, their application in evolutionary biology can lead to a better understanding of the processes and conceptual interactions of the complex dynamics of evolution. The conceptual map I present here includes environmental variability and variation, phenotypic plasticity and natural selection as key concepts in evolutionary biology. The evolution of phenotypic plasticity is important to ecology at all levels of organization, from morphological, physiological and behavioral adaptations that influence the distribution and abundance of populations to the structuring of assemblages and communities and the flow of energy through trophic levels. Consequently, phenotypic plasticity is important for maintaining ecological processes and interactions that influence the complexity of biological diversity. In addition, because it is a typical occurrence and manifests itself through environmental variation in conditions and resources, plasticity must be taken into account in the development of management and conservation strategies at local and global levels.

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Comparison of offshore macrozoobenthos of the eutrophic Lake Gardzień and the alloiotrophic Lake Stęgwica

Comparison of offshore macrozoobenthos of the eutrophic Lake Gardzień and the alloiotrophic Lake Stęgwica

The aim of the present paper was to compare offshore macrozoobenthos and selected abiotic parameters of water and bottom sediments of two shallow lakes: Lake Gardzień, a "typical" eutrophic lake, and the polyhumic, alloiotrophic Lake Stęgwica. As both lakes are located very close to each other and have a similar morphometry and trophy level, it is highly probable that the observed differences may be the effect of a different humic substance content.

It was found that the presence of humic substances did not significantly affect the taxonomic composition and the biodiversity of the bottom fauna. In contrast to the similar taxonomic composition, the density of zoobenthos in the polyhumic Lake Stęgwica was over 10 times greater than in Lake Gardzień, which was the consequence of the more numerous occurrence of all groups of bottom fauna, particularly Oligochaeta and Chaoborus larvae.

A distinct increase in the abundance of bottom fauna in the polyhumic lake may be the consequence of an improvement in the nutritional conditions in the sediments (an increase in the calorific value, development of microorganisms), as well as a decrease in the negative effect of any toxic substances.

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Trophic Relationships and Status of Reservoirs with and without Occurrence of Dreissena ssp. (Mollusca, Bivalvia) Built on Bulgarian Danube River Tributaries

statistics software package for education and data analysis, Palaeontologia Electronica , 4, 1, 9, http://palaeoelectronica.org/2001_1/past/issue1_01.htm 7. Idrisi N., Mills E. L., Rudstam L. G. and Stewart D. J., 2001 − Impact of zebra mussels (Dreissena polymorpha) on the pelagic lower trophic levels of Oneida Lake, New York, Canadian Journal of Fisheries and Aquatic Sciences , 58, 1430-1441. 8. ISO 10260, 1992 − Water quality – Measurement of biochemical parameters – Spectrometric determination of the chlorophyll-a concentration, 1-4. 9. IUCN, 1999

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An analysis based on rotifer indices of the effects of water and sewage management on water quality in the system of interconnected glacial lakes

-522. Ejsmont-Karabin J., 2012, The usefulness of zooplankton as lake ecosystem indicators: rotifer trophic state index, Pol. J. Ecol. 60: 339-350. Grochowska, J., Gawrońska H., 2004, Restoration effectiveness of a degraded lake using multi-year artificial aeration, Pol. J. Environ. Stud. 13: 671-681. Jaeger D., 1994, Effects of hypolimnetic water aeration and iron-phosphate precipitation on the trophic level of Lake Krupunder, Hydrobiologia 275/276: 433-444. Jiang J.-G., Shen Y.-F., 2006, Estimation of the natural purification

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Stability and Hopf bifurcation analysis for a Lotka-Volterra predator-prey model with two delays

(5): 2603-2613. May, R. M. (1973). Time delay versus stability in population models with two and three trophic levels, Ecology   4 (2): 315-325. Prajneshu Holgate, P. (1987). A prey-predator model with switching effect, Journal of Theoretical Biology   125 (1): 61-66. Ruan, S. and Wei, J. (2003). On the zero of some transcendential functions with applications to stability of delay differential equations with two delays, Dynamics of Continuous, Discrete and Impulsive Systems Series A

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Determination of lotaustralin in Rhodiola species

(12):616-8. 17. Rojas MG, Morales-Ramo JA. Tri-trophic level impact of host plant linamarin and lotaustralin on Tetranychus urticae and its predator Phytoseiulus persimilis. J Chem Ecol 2010; 36:1354-1362. 18. Nyirenda DB, Chiwona-Karltun L, Chitundu M, Haggblade S, Brimer L. Chemical safety of cassava products in regions adopting cassava production and processing - Experience from Southern Africa, Food Chem Toxic 2011; 49:607-612. 19. Burns AE, Howard Bradbury J, Cavagnaro TR, Gleadow RM. Total cyanide content of cassava food products in

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Light Stable Isotope Analysis of Diet in Corded Ware Culture Communities: Święte, Jarosław District, South-Eastern Poland

., Drucker D. 2003 Trophic level isotopic enrichment of carbon and nitrogen in bone collagen: case studies from recent and ancient terrestrial ecosystems. International Journal of Osteoarchaeology 13: 46-53. Bonsall C., Cook G.T., Hedges R.E.M. 2004 Radiocarbon and stable isotope evidence of dietary change from the Mesolithic to the Middle Ages in the Iron Gates: new results from Lepenski Vir. Radiocarbon 46: 483-495. Carvalho A. F., Petchey F. 2013 Stable isotope evidence of Neolithic palaeodiets in the coastal regions of Southern Portugal. The Journal of

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Climatic Influence on the Phytoplankton Communities of the Upper Reaches of the Southern Bug River (Ukraine)

ABSTRACT

A total of 98 taxa of algae were observed in phytoplankton, sampled monthly, from the Khmelnitsky monitoring station in the Southern Bug River, Ukraine, between April 2010 and March 2011. Chlorophyta species are the richest taxonomic group with 46 taxa, followed by Bacillariophyta, Euglenophyta, Cyanoprokaryota, Dinophyta, Chrysophyta, Streptophyta, and Xanthophyta. Seasonal dynamics of species distribution in taxonomic divisions shows that the role of Bacillariophyta in communities was high in January-March, which were replaced by greens in March-September. Euglenoids were developed in February-December and bluegreen algae in summer communities only. Strong positive correlations between temperature and species richness was observed. Abundance and biovolume of phytoplankton were maximal in summer, caused mostly by Dolichospermum flos-aquae (Lyngb.) Wacklin, Hoffmann and Komarek and Ceratium hirundinella (O. Müll.) Bergh. The river ecosystem has two periods of trophic levels - high at summer and low at winter. Bioindication characterizes the river as low alkaline and low mineralized with a moderate organic pollution level, revealed aspects of seasonal changes and revealed the main source of organic pollution as flowing from the catchment area during ice melting and rains. Organic pollution indices fluctuate within narrow limits suggesting relative stability of the river ecosystem that is shown also by Shannon indices. The calculated indices, comparative statistics, CCA, and bio-indication analysis exhibits a low pollution level in the Khmelnitsky monitoring station that can be used as a model of aquatic community dynamics under seasonal fluctuation in the southern boreal province climate, applicable for monitoring of the Southern Bug River.

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