Trophic Web
Mostrando 25-36 de 45 artigos, teses e dissertações.
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25. ASPECTOS DA BIOGEOQUIMICA DO MERCÚRIO EM LAGOS NA PLANICIE COSTEIRA DO SUL DO RIO GRANDE DO SUL
Mercury is one of the most hazardous contaminant in aquatic environment. Mercury contamination in aquatic environment food webs can be severe and persistent, and fish are a major source of mercury contamination in humans across food web. In this study: - Was measured mercury levels at three lakes in southern Brazil and assessed relationships between mercury
Publicado em: 2006
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26. Analysis of the fish and the trophic web of an stretch of the river current - go / Análise da comunidade de peixes e da teia trófica de um trecho do rio corrente - go
In this work, fishes of Corrente river, affluent of Paranaíba River (Paraná basin, Brazil), were studied. Five surveys in the period of June of 2003 had been carried out until June of 2005. The sampling was executed in 8 points distributed in the stream, riverbed and lagoon. In each point had been used a set of gillnets with different mesh size (between 12
Publicado em: 2006
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27. INFLUÊNCIA DO PULSO DE INUNDAÇÃO NA COMPOSIÇÃO ISOTÓPICA (d13C E d15N) DAS FONTES PRIMÁRIAS DE ENERGIA NA PLANÍCIE DE INUNDAÇÃO DO RIO PARAGUAI (PANTANAL MS) / SEASONAL PATTERN DETERMINING PRIMARY ENERGY SOURCES d13C AND d15N IN THE PARAGUAY RIVER FLOODPLAIN TROPHIC WEB, PANTANAL WETLAND - BRAZIL
The food web of the Pantanal wetland in Brazil was investigated during a complete hydrologic cycle (1998-99) using a multiple stable isotope approach (d13C and d15N) with the goal of identifying the primary carbon sources, which drive the system energy flux. The sampling was done in a representative marginal lake (Baía do Castelo) of Paraguay River floodpla
Publicado em: 2003
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28. Diversidade dos Cyclopoida (Copepoda, Crustácea) de água doce do estado de São Paulo: taxonomia, ecologia e genética.
In the present work, the diversity of the Copepoda Cyclopoida from Sao Paulo State was studied. Samples of zooplankton were collected along with water samples were collected in 22 Hydrographic Management Units (UHGRH) of the State. Different environments, such as Reservoirs, Ponds, and Rivers were sampled totalizing 207 water bodies. All of them were positio
Publicado em: 2003
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29. Food-web constraints on biodiversity–ecosystem functioning relationships
The consequences of biodiversity loss for ecosystem functioning and ecosystem services have aroused considerable interest during the past decade. Recent work has focused mainly on the impact of species diversity within single trophic levels, both experimentally and theoretically. Experiments have usually showed increased plant biomass and productivity with i
National Academy of Sciences.
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30. Trophic links of community food webs.
This report describes and explains regularities in the numbers and kinds of trophic links in community food webs. To a first approximation, the mean number of trophic links in a community food web is proportional to the total number of trophic species. The mean number of trophic links between any two categories of trophic species (basal, intermediate, and to
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31. Resource edibility and trophic exploitation in an old-field food web.
I tested a food web model that predicts how environmental productivity (nutrient supply) and top carnivores should mediate interactions among herbivores, edible plants, and plants that are resistant to herbivory because they possess anti-herbivore defenses. Feeding trials with the dominant grasshopper herbivore at the study site confirmed that certain plant
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32. Ecological community description using the food web, species abundance, and body size
Measuring the numerical abundance and average body size of individuals of each species in an ecological community's food web reveals new patterns and illuminates old ones. This approach is illustrated using data from the pelagic community of a small lake: Tuesday Lake, Michigan, United States. Body mass varies almost 12 orders of magnitude. Numerical abundan
The National Academy of Sciences.
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33. The more food webs change, the more they stay the same
Here, we synthesize a number of recent empirical and theoretical papers to argue that food-web dynamics are characterized by high amounts of spatial and temporal variability and that organisms respond predictably, via behaviour, to these changing conditions. Such behavioural responses on the landscape drive a highly adaptive food-web structure in space and t
The Royal Society.
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34. Stable isotopes document the trophic structure of a deep-sea cephalopod assemblage including giant octopod and giant squid
Although deep-sea cephalopods are key marine organims, their feeding ecology remains essentially unknown. Here, we report for the first time the trophic structure of an assemblage of these animals (19 species) by measuring the isotopic signature of wings of their lower beaks, which accumulated in stomachs of stranded sperm whales. Overall, the species encomp
The Royal Society.
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35. Food-web structure and ecosystem services: insights from the Serengeti
The central organizing theme of this paper is to discuss the dynamics of the Serengeti grassland ecosystem from the perspective of recent developments in food-web theory. The seasonal rainfall patterns that characterize the East African climate create an annually oscillating, large-scale, spatial mosaic of feeding opportunities for the larger ungulates in th
The Royal Society.
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36. Interaction strength combinations and the overfishing of a marine food web
The stability of ecological communities largely depends on the strength of interactions between predators and their prey. Here we show that these interaction strengths are structured nonrandomly in a large Caribbean marine food web. Specifically, the cooccurrence of strong interactions on two consecutive levels of food chains occurs less frequently than expe
National Academy of Sciences.