Navegando por Assunto "Ecologia de comunidades"

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Desconhecido
Padrões espaciais em comunidades de aves amazônicas
(Universidade Federal do Pará, 2006) VALENTE, Renata de Melo; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Amazonia houses the world´s richest avifauna. To understand the processes that originated and have maintained this diversity, are required detailed studies concerning spatial variation of major patterns of bird assemblages as well as comparisons among them across different spatial scales. In addition, it is essential to use an approach that takes in to consideration different factors that can be acting on and influencing these patterns. This thesis is composed of three chapters. In the first chapter, the composition, ecological characteristics and vulnerability patterns of the avifauna at the Ferreira Penna Scientific Station (ECFPn), Eastern Amazonia, are described. An updated species list to that area, with information on the abundance, trophic guilds and habitat type is presented. Vulnerability for each species was determined by using rarity patterns. In the second chapter, the avifauna of ECFPn is compared with other sites representing the different areas of Amazonian bird endemism. Different taxonomic and ecological categories were considered in several comparisons to evaluate if patterns of distribution are different among these categories and determine which factors can influence the patterns observed. Finally, the third chapter presents an analysis of the spatial variation of richness, abundance and similarity across six 100-ha sites located within a homogeneous landscape dominated by upland forests. Variation in species composition was then correlated with geographical distance and vegetation structure of these sites. The combination of theses studies increases our knowledge about the area of endemism Xingu and uses for the first time several different approaches to investigate distribution patterns bird assemblage in Amazonia at different spatial scales.
Desconhecido
Similaridade morfológica e seus efeitos na distribuição da assembleias de percevejos semiaquáticos (Gerromorpha: Heteroptera) em igarapés da Amazônia Oriental
(Universidade Federal do Pará, 2017-02-07) GUTERRES, Alana Patricia Meguy; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029; SILVA, Rogério Rosa da; http://lattes.cnpq.br/5989181105383977
Studies on patterns of distribution and coexistence of species in natural communities are gaining prominence in the area of community ecology, as they serve as a basis for other studies, such as conservation studies, theoretical ecology and others. In this study, we used the aquatic insects of the Heteroptera Suborder (Infraorder Gerromorpha) to evaluate the relationship between morphological similarity and Gerromorpha coexistence patterns. Two hypotheses were tested: (i) the existence of morphological divergence between coexisting species; (ii) the environment has a low influence on the co-occurrence pattern of the species. The study was done in 32 creeks (streams) in and around a conservation unit in the Eastern Amazon. The hypothesis about morphological divergence between semiaquatic insect species and absence of an environmental effect in the assemblies was corroborated. Species of the Gerromorpha community presented a pattern of non-random co-occurrence. The morphological divergence between species may be the result of intense interspecific competition. In the Gerromorpha assemblages studied, the competition relations were more important than the environment, resulting in the displacement of morphological characters, with coexistent species more distant morphologically than expected for the evaluated models.