Isótopos de carbono e nitrogênio explicam diferenças em fontes de energia e segregação trófica de peixes em planícies de inundação Neotropicais.
Stable isotope analyzes have become a popular tool among ecologists. stable carbon, nitrogen, hydrogen and sulfur are currently used to examine an ecological attributes series of populations, communities and ecosystems. Stable isotopes most commonly used by freshwater ecologists are carbon (δ13C) and nitrogen (δ15N), which are used as "markers" natural biotic and abiotic molecules, which are applied to rebuild ecological processes or draw ecological activities. Among the numerous freshwater ecosystems, river-floodplain systems attract attention because it is extremely complex ecosystems, with high biodiversity and high habitat heterogeneity, which makes these environments suitable to elucidate patterns and processes through the analysis of stable isotopes. Thus, it is extremely important to recognize the factors that affect the variability of C and N isotopes as isotopic mapping of natural environments (isotopic landscape - isoscapes) has proven a great tool to elucidate migratory animal movement patterns, of origin and fate of organic matter, including that of anthropogenic origin. Besides the isotopic landscapes, the elucidation of trophic niches through stable isotopes (eg isotopic niche) has also been widely used, especially when it comes to competition for food resources between native and non-native species. Thus, the use of stable isotopes goes beyond the application of ecological theories, constituting an important tool for decision-making when incorporated anthropogenic factors to the analysis. This work addresses two issues: the first evaluates the factors that affect the variation of δ13C and carbon sources δ15N in four Neotropical plains (Paraná, Pantanal, Araguaia and Amazon), highlighting local standards (limnological factors) and regional (identity basin). The second evaluates the trophic interactions of the population of a species of invasive fish (Serrasalmus marginatus) and a native species (S. maculatus), through the analysis of stable isotopes in two floodplains, (Pantanal, where the two species they are native, Paraná, where S. marginatus is not native and potential competitor of S. maculatus). It is noteworthy that, due to greater heterogeneity within versus between ecosystems addressed explicitly should be considered the spatial scale to control the heterogeneity of carbon sources. Considering the trophic interactions of piranhas, we found no evidence of niche overlap between species studied, indicating that the coexistence of species not native to the co-occurrence environment is modulated by niche segregation.
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| Format: | Thesis/Dissertation biblioteca |
| Language: | Portuguese |
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Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
2015
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| Subjects: | Serrasalmus, Nicho isotópico, Brasil, Planícies de inundação, Espécies não-nativas, Teia alimentar, Interação trófica, Nicho trófico, Isótopos estáveis, Biogeoquímica, Fluxo energético, Produtores primários, Competição, Ciências Ambientais, |
| Online Access: | http://hdl.handle.net/1834/9931 |
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