Orientador: Paulo Roberto Guimarães Júnior / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T07:48:51Z (GMT). No. of bitstreams: 1 Marquitti_FlaviaMariaDarcie_M.pdf: 1225354 bytes, checksum: 120811efd17809715c9eb6454a6b9c34 (MD5) Previous issue date: 2011 / Resumo: Os mutualismos são interações importantes do ponto de vista ecológico e evolutivo, uma vez que influenciam a sobrevivência de diversos organismos, podendo determinar a organização da comunidade. Dada a importância ecológica e evolutiva das interações mutualísticas, é importante estudar quais fatores influenciam a sua organização. Como organismos aparentados compartilham características fenotípicas similares, é comum que espécies filogeneticamente próximas interajam com um conjunto de espécies similar, levando a um padrão conhecido por conservação filogenética do nicho. Apesar de este padrão ocorrer com frequencia, condições bióticas e abióticas locais podem levar à variação geográfica nas interações. A presença ou ausência de potenciais parceiros mutualísticos também podem alterar o padrão local de interações de uma espécie. Estudando interações entre morcegos frugívoros e plantas, investiguei como os padrões de interação de espécies em dez redes mutualísticas variavam conforme a distribuição geográfica. Nesse sentido, duas hipóteses principais guiaram este trabalho: a hipótese da conservação de nicho das interações e a hipótese da variação geográfica das interações. Caracterizei o padrão de interação das espécies de morcegos nas redes por meio de diferentes métricas usadas no estudo de redes ecológicas. Analisei a conservação de nicho das interações e a variação geográfica de espécies de morcego que ocorreram em um maior número de redes. Espécies filogeneticamente próximas não tenderam a apresentar padrões de interação mais parecidos entre si. Algumas das espécies mais frequentes apresentaram características dos padrões de interação em gradiente ou mosaico ao longo de sua distribuição geográfica. Estes resultados evidenciam que algumas características do padrão de interação de morcegos frugívoros, como grau de generalismo e o grau padronizado dentro do módulo são conservadas pela filogenia. No entanto algumas espécies apresentaram o grau de generalismo e o papel em relação aos módulos da rede variando ao longo da geografia, seguindo previsões da teoria do mosaico geográfico coevolutivo / Abstract: Mutualisms are important interactions to ecology and evolution because they affect the survivorship of many organisms and may shape community organization. Therefore, it is important to study which factors affect their organization. As related organisms share similar phenotypic traits, it is common that close phylogenetic species interact with a similar set of species, resulting in a pattern known as phylogenetic niche conservatism. Although this pattern frequently occurs, biotic and abiotic local conditions may lead to geographic variation of the interactions. The presence or absence of potential mutualistic partners may also change local interactions of a species. I studied interactions between frugivorous bats and plants and I investigated how species interactions patterns varied geographically across ten mutualistic networks. Two main hypotheses guided this work: the interaction niche conservatism hypothesis and the geographical variation hypothesis. I delineated the interaction patterns of bat species in the networks through different metrics used in ecological network studies. I analyzed the niche conservatism and geographical variation of bat species which occurred frequently in the networks. Related species did not tend to have similar patterns of interaction. Within their geographical range, some species vary markedly in their patterns of interaction and this variation often occurs as mosaics or, less frequently, as gradients. These results point out that some patterns of interaction of frugivorous bats, as the specialization degree and the standardized within-module degree, are conserved by phylogeny. However, some species showed variations through geography both in the specialization degree and in their role regarding the network modules, leading to a geographic mosaic of coevolution with potential implications to ecology and coevolution / Mestrado / Ecologia / Mestre em Ecologia

M.Sc. / The grassland biome of South Africa harbours rich ecosystem diversity. Some of the distinctive features of grassland biodiversity in South Africa include globally significant centres of plant endemism, half of the country's endemic mammal species, a third of its endangered butterfly species and 10 of 14 of its globally threatened bird species. Grassland is one of the most inadequately maintained biomes in Southern Africa because 23% is under cultivation, 60% is irreversibly transformed and most of the remaining natural area is used as rangeland for livestock. Only 2% of the grassland biome is currently protected. Grasslands provide essential ecosystem services for economic development, but this biome also supports a large human population whose resource demands have serious environmental implications that threaten the grasslands‘ biodiversity. Urbanisation is possibly one of the major immediate threats to the grassland ecology in South Africa. This is also the case in the Cradle of Humankind World Heritage Site (COHWHS) and adjacent areas. New housing complexes and informal housing are encroaching on the COHWHS. Indigenous fauna and flora are being affected by ecologically insensitive urban development. This poses a major threat to the fauna of this region including the insects that occur in grassland habitats. The insects play a vital role as pollinators in grassland habitats and form an essential food source to a range of predators, including grass owls, shrews, bull frogs, lizards and bats. In order to conserve the insects and therefore the food web of which they form part, it is necessary to understand the diversity of the insects in the grassland in the dolomitic areas. The COHWHS is a world renowned heritage site devoted to the origin of humankind and is characterised by dolomitic caves. These caves are also the home of a large population of bats consisting of several species. The negative impact on the grasslands in the COHWHS and surroundings pose a threat to the survival of these bat populations if the food source they depend on is negatively affected. For this reason it is important to determine which flying nocturnal insect species are available in the grasslands surrounding bat roosts in the COHWHS and surroundings. 3 The choice of location for the primary trap site was made on the basis of its proximity to known bat roosts and the fact that it is situated in a nature reserve that, although the river is polluted, contains an otherwise relatively unspoilt grassland habitat. Sampling took place over a period of 14 months during which fluctuations in the insect population was observed. The fluctuations can be ascribed to seasonal climate changes and the three veld fires that occurred during this period. This fluctuation was most evident in the representatives of the Orders Lepidoptera and Coleoptera sampled.