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České Budějovice, Czech Republic

Vlach P.,University of West Bohemia | Svatora M.,Vinicna 7 | Dusek J.,Institute of Applied Ecology
Knowledge and Management of Aquatic Ecosystems | Year: 2013

The diet and food niche overlap of five fish species in the Úpoř brook was evaluated. The supply of food represented by benthos was studied, and the proportion of total food particles in the intestine of brown trout Salmo trutta L., chub Squalius cephalus (L.), dace Leuciscus leuciscus (L.), bullhead Cottus gobio (L.) and stone loach Barbatula barbatula (L.) was measured. Evaluations were performed using a new index (Mtot p). All fish species except stone loach exhibited a balanced consumption of the food supply. The food components were systematically grouped, but no differences in the ingestion of these groups were found. However, a new approach in the evaluation of food competition based on observation of species-specific preferences/avoidance in ingestion of food particles was applied. The particles were divided into four ecological categories according to their availability for fish. Brown trout concentrated on easily accessible sources of benthos or that hiding below stones, and also distinctly preyed on terrestrial insects. Chub displayed a similar feeding habit, though concentrating more on drift and allochthonous sources. The food spectrum of dace was mostly composed of easily accessible benthic organisms, consuming fewer hidden benthos and terrestrial insects. The food of bullhead and stone loach was similar, both preferring benthos. Bullhead consumed hidden species while stone loach consumed more accessible species rather than hidden ones. © 2013 ONEMA. Source

Cizkova H.,University of South Bohemia | Kvet J.,University of South Bohemia | Comin F.A.,CSIC - Pyrenean Institute of Ecology | Laiho R.,University of Helsinki | And 2 more authors.
Aquatic Sciences | Year: 2013

The present area of European wetlands is only a fraction of their area before the start of large-scale human colonization of Europe. Many European wetlands have been exploited and managed for various purposes. Large wetland areas have been drained and reclaimed mainly for agriculture and establishment of human settlements. These threats to European wetlands persist. The main responses of European wetlands to ongoing climate change will vary according to wetland type and geographical location. Sea level rise will probably be the decisive factor affecting coastal wetlands, especially along the Atlantic coast. In the boreal part of Europe, increased temperatures will probably lead to increased annual evapotranspiration and lower organic matter accumulation in soil. The role of vast boreal wetlands as carbon sinks may thus be suppressed. In central and western Europe, the risk of floods may support the political will for ecosystem-unfriendly flood defence measures, which may threaten the hydrology of existing wetlands. Southern Europe will probably suffer most from water shortage, which may strengthen the competition for water resources between agriculture, industry and settlements on the one hand and nature conservancy, including wetland conservation, on the other. © 2011 Springer Basel AG. Source

Popovic V.,Serbian Institute of Field and Vegetable Crops | Malesevic M.,Serbian Institute of Field and Vegetable Crops | Drazic G.,Institute of Applied Ecology | Spasic M.,Agromaster Company | Stankovic S.,Technological Research Center
Genetika | Year: 2011

A three-year trial (2003-2005) was conducted under agro ecological conditions of Timočka Krajina (the experiment farm of Technological Research Center in Zaječar). Research object were six malting barley genotypes, which were top-dressed with the following amounts of nitrogen in the course of growing season: 40, 60, 80 and 100 kg ha-1. A non-fertilized variant served as a control. The obtained results indicated that the tested genotypes reacted to increased amounts of nitrogen by changing their morphological and biological characteristics as well as the technological values of grain. The effectiveness of the applied nitrogen depended significantly on the distribution of rainfall in periods of highest water uptake by malting barley. Source

Liu J.,Chinese Institute of Urban Environment | Liu J.,University of Rostock | Liu J.,University of Sheffield | Kang J.,University of Sheffield | And 3 more authors.
Landscape and Urban Planning | Year: 2013

Based on the loudness of different soundscape elements perceived on site, soundscapes were analysed in a multi-functional urban area in Rostock, Germany. The aim was to examine how urban soundscape composition changes spatiotemporally at different levels over a relatively large scale, and how soundscape perception is related to the underlying landscape. The results show that although anthropogenic sounds (anthrophony) dominated urban soundscape both spatially and temporally, certain biological sounds (biophony) and geophysical sounds (geophony), especially bird song, also played a significant role. Urban soundscapes showed diverse spatiotemporal patterns. Spatial variation of urban soundscape patterns was explained by underlying landscape characteristics, while temporal variation was mainly driven by urban activities, among which human activities were the major component. It is demonstrated that the thematic soundscape mapping techniques developed in this study is an effective tool. Landscape composition and configuration indicators could affect soundscape perception significantly, among which normalised difference vegetation index (NDVI) and landscape shape index (LSI) are the two most important predictors. The results highlight the importance of introducing more natural sounds into urban environments to achieve "noise control" through an ecological urban/landscape planning process. © 2013 Elsevier B.V. Source

Morbey Y.E.,University of Western Ontario | Coppack T.,Institute of Applied Ecology | Pulido F.,Complutense University of Madrid
Journal of Ornithology | Year: 2012

Our understanding of avian migration has progressed significantly, yet the selective conditions that favor the arrival of males before females at the site of reproduction remain largely unclear. Here, we review the leading adaptive hypotheses for protandry, highlight some key empirical studies that test protandry theory, and identify theoretical and empirical information demands. In general, protandry should evolve in species where the variance in male reproductive success is larger than in females if the costs to males of earlier arrival relative to calendar date (viability selection) can be balanced by increased mating opportunities (sexual selection). Early arrival by males can provide 'priority benefits' that help in the monopolization of resources or 'early bird draw benefits' that increase opportunities for extra-pair mating. While some empirical studies are consistent with theoretical predictions regarding the important selection factors that influence protandry (e. g., extrinsic mortality and extra-pair paternity), some are not, and some studies focus on ecological factors that have not been considered explicitly by theory. We call for an integrated theoretical approach to help formalize how protandry should evolve in response to the antagonistic roles of natural and sexual selection, the nature of competitive asymmetries among males or females, sex-specific costs and benefits of early arrival, and various climate change scenarios. © 2012 Dt. Ornithologen-Gesellschaft e.V. Source

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