Teses em Ecologia (Doutorado) - PPGECO/ICB
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Item Acesso aberto (Open Access) Desenvolvimento colonial em abelhas nativas sem ferrão Amazônicas (Apidae: Meliponini): tamanho populacional, nutrição e alocação fenotípica(Universidade Federal do Pará, 2019-11) LEÃO, Kamila Leão; MENEZES, Cristiano; http://lattes.cnpq.br/9845970576214577; CONTRERA, Felipe Andrés Léon; http://lattes.cnpq.br/0888006271965925; https://orcid.org/0000-0002-7078-5048Meliponines or stingless bees comprise a diverse and abundant group of eusocial bees, which live in perennial colonies and have a wide range of behavioral characteristics. The general objective of this thesis is to understand population dynamics and developmental patterns of Amazonian stingless bee species. In Section I, we evaluated the population size and several biological characteristics of colonies (e.g. worker external activity, queen egg-laying rate) of five stingless bee species in order to understand how colony characteristics relate to population size. We found an average adult population of 1,046.00 in Melipona flavolineata, Friese, 1900, 592.75 in Melipona fasciculata, Smith, 1854, 7,404.00 in Scaptotrigona aff. postica (Latreille, 1807), 2,425.33 in Frieseomelitta longipes (Smith, 1854) and 404.75 in Plebeia minima (Gribodo, 1893). External activity was the variable that best explained population size. In Section II we investigate the longevity of stingless bee workers fed soy-based diets. Our objective was to compare the effect of a semi-artificial soybean diet versus a natural diet on the longevity of adult workers of two stingless bee species (Melipona flavolineata Friese, 1900 e Scaptotrigona aff. postica (Latreille, 1807)). We found a higher longevity in workers that consumed only pollen compared to those that consumed the soybean diet for both species studied. Finally, In Section III we evaluated the phenotypic allocation in stingless bees. In this work we investigate phenotypic allocation as a response to climatic and environmental variation, using the stingless bee Melipona fasciculata Smith, 1854 as a model species. Our results reveal that phenotypic allocation in M. fasciculata was strongly associated with seasonal variation and not the quality of the environment (local). The production of virgin queens was influenced by season and year (being higher in the dry season), but not by location. Male production was explained by season and local environmental variables and season and study year influenced the percentage of workers produced, showing differences between years. We believe that this thesis contributes to our understanding of the natural history of Amazonian stingless bees and the development of regional meliponicultural practices.Item Acesso aberto (Open Access) Efeitos da inundação e da antropização sobre padrões de diversidade de árvores da floresta de várzea amazônica(Universidade Federal do Pará, 2019-05-29) MAGALHÃES, Jose Leonardo Lima; LOPES, Maria Aparecida; http://lattes.cnpq.br/3377799793942627; https://orcid.org/0000-0002-6296-5487The white-water floodplain forest in Amazon (locally várzea) is a highly heterogeneous floodplain ecosystem that encompasses a large number of adapted species. It is distributed along the entire length of the main channel of the Amazon River and of tributaries of Andean origin. In addition, due to periodic flooding by waters with high sediment load, it has high fertility when compared to other Amazonian systems. What on the one hand is important for high primary productivity also makes it the target of human colonization for its benefits to food production. In this sense, because it presents continental dimensions and crosses almost all the biome from East to West, it has been the main access route of present and previous human populations to the most distant points of the basin. All these factors contribute to these forests being an important model for testing diversity patterns along natural and anthropogenic gradients. This thesis is presented in two chapters that use distinct approaches, focusing on different aspects of forest diversity and structure. Chapter 1 examines the phylogenetic structure of the arboreal component of floodplain forests in the Central and Eastern macro-regions and investigates whether the current human presence has modified it, specifically reducing the number of tree lineages present and leading to the phylogenetic homogenization of these forests. Chapter 2 investigates whether the taxonomic diversity and the local and regional tree species found today in the macro-regions of the study are associated with historical patterns of human density since the arrival of Europeans in the region. To reach the objectives, seven areas were sampled along the 2,400 km stretch of the Brazilian portion of the Amazon River, which covers different flood regimes and human influences. Thus, tree individuals with DBH ≥ 10 cm were sampled and data were collected in situ and in databases available to be used as predictors variables in modeling tree diversity at different scales. With the results, it was detected that the flood regime is the main factor that influences the phylogenetic structure whereas the human density of almost three centuries ago is responsible for the patterns of taxonomic diversity that are currently found. The diversity patterns were detected in the evolutionary and ecological scale, where it was shown that human influences may have a long-delayed response after they have occurred. Because várzea is a system of relatively easy access in the region and has few protected areas, it is necessary to understand how these forests are important for the maintenance of essential ecosystem services, even though they have been affected by human influence for a long period.Item Acesso aberto (Open Access) Estudos sobre longevidade e atividade de forrageio em abelhas nativas sem ferrão amazônicas(Universidade Federal do Pará, 2021-06) GOMES, Rafael Leandro Corrêa; CONTRERA, Felipe Andrés Léon; http://lattes.cnpq.br/0888006271965925; https://orcid.org/0000-0002-7078-5048Item Acesso aberto (Open Access) Padrões de diversidade, ocupação e coexistência de mamíferos terrestres na região neotropical(Universidade Federal do Pará, 2019-05-10) SANTOS, Fernanda da Silva; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029; PERES, Carlos Augusto da Silva; http://lattes.cnpq.br/9267735737569372Community structure and diversity result from a complex and dynamic phenomenon, determined by a large number of processes in space and time, which are driven by environmental conditions, spatial factors, resource availability, and species interactions, including competition and predation. This study used the terrestrial mammal group as a model to investigate part of the processes shaping communities, and to understand patterns of diversity, occupancy, and coexistence in the Neotropical forests. Data from a long-term camera trapping monitoring of terrestrial vertebrates across eight protected area sites were combined. The study sites comprise eight areas distributed through six countries (Costa Rica [1], Panama [1], Ecuador [1], Peru [2], Suriname [1] e Brazil [2]), and include both intact forest and fragmented forest landscapes. Firstly, β diversity was estimated among the eight mammal communities to identify: which sites and species contributed to differences in the variation of community composition (LCBD and SCBD, respectively); which process (species replacement or richness difference) explain the observed β-diversity patterns; and which factors affect local contribution (LCBD) and species contribution (SCBD) to β diversity. Posteriorly, data from five sympatric cat species [jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus pardalis), jaguarundi (Herpailurus yagouaroundi) and margay (Leopardus wiedii)], that potentially occur across the eight sites, were used to examine mechanisms that allow coexistence among ecologically similar species. Finally, data from one of the sites was used to test the hypothesis that terrestrial mammals, mainly frugivores and granivores, move seasonally as a response to resource availability fluctuation (e.g., water and fruits) between rainy and dry seasons in a terra-firme forest. The results indicated that fragmented forests contribute more to β diversity than intact forest sites, and that variation in species composition is determined by richness difference rather than replacement. The eleven species ranked as the most important in structuring the communities were also the ones with the highest abundance variation among sites. Regarding felids’ coexistence, the study reveals an apparent spatial and temporal partitioning for most species pairs, with prey abundance being more important than species interactions to the local occurrence and spatial distribution of Neotropical forest cats. Concerning seasonal dynamics, only three species presented differences on occupancy between dry and rainy seasons, while the other analyzed species did not seem to move as a response to variation in water and food availability. In summary, the results provide a broad characterization of terrestrial mammals occurring in the Neotropical region, assessing their conservation status, factors that influence their occurrence, as well as the spatial and temporal patterns of several felid species along eight Neotropical protected forests.Item 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/0000-0002-1588-8765Medium 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.