Navegando por Assunto "Anuro - Amazônia"

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Acesso aberto (Open Access)
Uma abordagem funcional das savanas amazônicas: atributos de anuros em um mosaico de paisagens naturais
(Universidade Federal do Pará, 2018-02-28) PASCHOALINO, Rosana Campos; PINHEIRO, Leandra de Paula Cardoso; http://lattes.cnpq.br/1114107627897774; SANTOS-COSTA, Maria Cristina dos; http://lattes.cnpq.br/1580962389416378
The structure of natural assemblages may result from selection of species and functional traits, according to their tolerance to certain environmental factors, which are related, for example, to vegetation type and water availability, may influencing functional diversity in ecosystems. We investigated the influence of different phytophysiognomies of Amazonian savannas on functional diversity of anurans, in the Carajás National Forest, Brazil. We also investigated a possible divergence of functional traits among the phytophysiognomies due to environmental differences using a null model. Three field expeditions were conducted in 2008 and 2010, during rainy season, dry season and the transition period between rainy and dry seasons. We sampled 32 sample units distributed in three sites: North highland, South highland and Tarzan highland. Each sample unit was distant at least 200 m from each other. Surveys for the presence of anurans were based in active visual and acoustic searches. We calculated functional diversity using the MPD index, considering the occurrence of anurans in each assemblage. Functional diversity of anurans did not differ among the vegetation types. According to null model, there was a functional convergence, that is, the sites are similar in species and functional traits. Our results suggest that despite the mosaic distribution and environmental differences, the landscapes are surrounded by Amazonian savanna matrix, which, due to some factors (historic, spatial, and environmental), did not differ in the functions performed by anurans in each phytophysiognomy. In any case, we found that anurans play important roles in local ecosystem functions.
Acesso aberto (Open Access)
Efeito da paisagem sobre a diversidade de vertebrados terrestres em fragmentos florestais na Amazônia Oriental
(Universidade Federal do Pará, 2019-01-17) SILVA, Jacqueline Almeida da; MASCHIO, Gleomar Fabiano; http://lattes.cnpq.br/7967540224850999
Context: The advance of anthropic activities on the Amazonian frontier has provoked an intense process of forest fragmentation that reduces biodiversity and subjects the species to a situation of high vulnerability. Objectives: To test the relation of fragment size, isolation and characterization of the forest fragments matrix, on the wealth of amphibians of the order Anura, reptiles of the order Squamata and mammals of small, medium and large size. Methods: The study was carried out in 12 fragments in the northeast of the Amazon. The size of the fragment was calculated in hectares, the isolation in ENN_MN (mean of the euclidean distance of the nearest neighbors) and the matrix was organized into categories. These landscape metrics were considered as explanatory variables and calculated on three spatial scales: 1, 2 and 3 km. The relationship of the metrics with the richness of terrestrial vertebrates was evaluated through multiple regressions with model selection. Results: 130 species of terrestrial vertebrates were recorded. There was no significant effect of fragment size on spatial scales for any group of species. The isolation was significant only in the 3 km scale for the group of amphibian and snake species. The category of open areas in the matrix was significant in the three spatial scales for the group of species of lizards and mammals of medium and large size. Conclusions: The landscape configuration is extremely important in the context of fragmentation, there were different responses from taxonomic groups, possibly due to differences in habitat use.