Navegando por Assunto "Ecologia das florestas tropicais - Amazônia"

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Efeito da monocultura da palmeira de dendê (Elaeis guineensis Jacq.) sobre a fauna de primatas na Amazônia Oriental
(Universidade Federal do Pará, 2016-04-25) MINEIRO, Ivo Gabriel Barros; OLIVEIRA, Ana Cristina Mendes de; http://lattes.cnpq.br/1199691414821581
Acesso aberto (Open Access)
Fatores determinantes do uso de habitats por mamíferos ungulados (Artiodactyla e Perissodactyla) na Amazônia Oriental
(Universidade Federal do Pará, 2022-04) ALVES, Michel Jacoby Pereira; OLIVEIRA, Ana Cristina Mendes de; http://lattes.cnpq.br/1199691414821581; https://orcid.org/0000-0002-7863-9678
Land use by human activities in landscapes of the eastern Amazon has been modifying and suppressing the native habitats of this region, altering the dynamics of ecosystems and negatively affecting biodiversity. Herbivorous-frugivorous ungulate mammals are among the groups of mammals most affected by these changes in ecosystems. Through the use of camera traps, we recorded ungulates and measured hunting pressure. Using satellite images, we evaluated the environmental characteristics and human pressures that may be influencing the abundance of tapirs (Tapirus terrestris), deer (Mazama americana and Mazama nemorivaga) and wild pigs (Pecari tajacu and Tayassu pecari) in habitats with different levels of disturbance. The species showed different responses to landscape and land use variables. Our result demonstrates that all species studied showed some degree of tolerance to disturbed habitats, except for abandoned pasture and oil palm plantation habitats. We also demonstrate that although the species use degraded habitats, they have a high dependence on forested habitats.
Acesso aberto (Open Access)
Movimentos sazonais de vertebrados terrestres entre florestas periodicamente alagadas e de terra firme
(Universidade Federal do Pará, 2014-04-01) COSTA, Hugo Cardoso de Moura; PERES, Carlos Augusto da Silva; http://lattes.cnpq.br/9267735737569372
The flood pulse is the main factor structuring and differentiating the ecological communities of Amazonian unflooded (terra firme) and seasonally-flooded (várzea) forests as they require unique adaptations to survive the prolonged annual floods. Therefore, várzea and terra firme forests hammer out a spatio-temporal mosaic of resource availability, which may result in landscape scale seasonal movements of terrestrial vertebrates between adjacent forest types. Yet the lateral movements of terrestrial vertebrates between hydrologically distinct neighbouring forest types exhibiting staggered resource availability remains poorly understood, despite the important implications of this spatial dynamic for the ecology and conservation of forest wildlife. We examined the hypothesis of seasonal movements between two adjacent forest types at two contiguous sustainable-use forest reserves in Western Brazilian Amazonia, investigating the effects of water level, landscape and anthropogenic disturbance on the overall species richness, composition, and abundance of nine major vertebrate trophic guilds. Species richness differed in neighboring terra firme forests between the high-and low-water phases of the flood pulse and terra firme forests were more species rich than várzea forests. There were clear differences in species composition between both forest types and seasons. Generalized Linear Models showed that water level was the main factor explaining aggregate abundance of all species and three trophic guilds. Anthropogenic disturbance and geographic setting of camera trap stations, including distance to the nearest urban center, the number of residents of the nearest community, elevation and the surrounding area of várzea of each camera trap station, had a variety of effects on the terrestrial vertebrate assemblage. Overall vertebrate biomass increased with distance from the nearest urban center. Our results indicate that the persistence of viable populations of large terrestrial vertebrates adjacent to major Amazonian rivers requires large, wellconnected forest landscapes encompassing different forest types to ensure large-scale lateral movements by forest wildlife.
Acesso aberto (Open Access)
O papel de mamíferos de médio e grande porte como modificadores do habitat na Amazônia Ocidental
(Universidade Federal do Pará, 2019-12) BORGES, Luiz Henrique Medeiros; OLIVEIRA, Ana Cristina Mendes; http://lattes.cnpq.br/1199691414821581; https://orcid.org/0000-0002-7863-9678; SILVA, Carlos Augusto Peres da; http://lattes.cnpq.br/9267735737569372; https://orcid.org/0000-0002-1588-8765
Medium to large-bodied terrestrial mammals have a wide diversity of forms, life history, behaviour, physiology, and consequently a high diversity of ecological roles played in natural and human-modified ecosystems. Ecological functions such as seed dispersal, seed predation, pollination, population control, nutrient cycling and transport, and ecosystem engineering help maintain tropical ecosystems and regulate species diversity. Ecosystem engineers are species that by their presence and/or activity alter the biotic and abiotic environment, modulating the availability of resources and modifying habitat structure for other species. The way organisms can affect each other is diverse and occurs mainly through ecological interactions such as predation, competition and commensalism or facilitation, which in turn encompass several ecological processes such as pollination, dispersal, herbivory and prey control. The first chapter of this thesis assessed the role of Priodontes maximus (Giant Armadillo; tatu canastra) as an ecosystem engineer in southwestern Amazonian forests. Our results showed that a wide diversity of terrestrial vertebrates benefit from P. maximus burrows. Sites with high local diversity tend to increase the amount of interactions between vertebrate species and armadillo burrows. In addition, we identified the purpose for which most vertebrates use the burrows of this large excavator, showing that the interaction established in the burrows is broadly and strongly connected for a variety of purposes. In the second chapter of this thesis, I examine how medium and large-bodied mammals can interfere with the regeneration process of man-made treefall clearings formed by low-impact selective logging in southwestern Amazonia. Based on the relative abundance of species, damage to artificial seedlings was measured within both clearings and otherwise comparable shaded-understorey environments. Based on the results, I can infer that medium and large mammals affect seedling recruitment process in clearings. The impact of mammal-induced seedling mortality (via trampling and/or herbivory) is much greater within natural and logging clearings than in closed understorey environments.