Dissertações em Ecologia (Mestrado) - PPGECO/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/8938
O Mestrado Acadêmico foi criado em 2015 e pertence ao Programa de Pós-Graduação em Ecologia (PPGECO) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA) em parceria com a Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA).
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Navegando Dissertações em Ecologia (Mestrado) - PPGECO/ICB por Orientadores "SANTOS, Raphael Ligeiro Barroso"
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Item Acesso aberto (Open Access) Efeitos de atividades de subsistência de ribeirinhos sobre a heterogeneidade ambiental e a diversidade de insetos aquáticos em diferentes níveis espaciais de riachos amazônicos(Universidade Federal do Pará, 2021-09) COSENZA, Jorge Felipe Abreu; FARIA, Ana Paula Justino de; http://lattes.cnpq.br/6041546003155327; https://orcid.org/0000-0003-2729-5358; SANTOS, Raphael Ligeiro Barroso; http://lattes.cnpq.br/7227882802366966; https://orcid.org/0000-0001-9717-5461The deleterious effects of large-scale impact activities such as agriculture, intensive ranching, dam construction and mining on Amazonian biodiversity have been constantly studied. On the other hand, the effects of smaller-scale impact activities are neglected. An example is the activities practiced by traditional populations, such as riverside populations, who have lived for generations on the banks of rivers and streams in the Amazon basin. There are still few studies that evaluate the effects of anthropic activities considered to have less impact on the diversity patterns of aquatic insects at different spatial scales using taxonomic and functional approaches concurrently. Thus, we evaluated how subsistence activities practiced by riverside populations affect the taxonomic and functional alpha and beta diversity of aquatic insects of the orders Ephemeroptera, Plecoptera and Trichoptera - (EPT), at different spatial levels (between sampling units within streams and between streams). We tested the hypotheses that (H1) the altered streams have less environmental heterogeneity among themselves and the composition of environmental characteristics different from the control streams; (H2) altered streams have lower alpha taxonomic and functional diversity than control streams; (H3) the taxonomic and functional beta diversity between sampling units and between altered streams is lower than between sampling units and control streams; (H4) the beta diversity observed between sampling units and between altered streams is generated primarily by richness difference, while between sampling units and control streams, the replacement of species/functional groups predominates. We conclude that the disturbance caused by the riverside populations subsistence activities, specially navigation, altered the characteristics of the habitats and, in certain aspects, the EPT assemblages of the streams of the Caxiuanã region. Beta diversity patterns did not change, but there was a loss and increase in abundance of some genera as a result of the changes. Thus, the maintenance of beta diversity is not necessarily a sign of high diversity and ecological integrity, as the increased variation in the composition of these assemblages may be a result of the loss of sensitive species and the increase of more generalist species. The functional approach responded similarly to the taxonomic one in all environments and spatial levels, which suggests that this effect is dependent on the biological group analyzed and on the type and intensity of change in the environment. The activities practiced by the riverside populations altered the local community of aquatic insects in a less impactful way compared to other activities commonly practiced in the Amazon, such as logging, agriculture, palm plantation, grazing and mining. To reduce a possible loss of species in the streams in the region, it is necessary to maintain the natural conditions of the habitats, such as a high density of vegetation cover on the banks, a large number of leaf banks in the riverbed and a high frequency of slow flows.Item Acesso aberto (Open Access) Efeitos de perturbações antrópicas sobre os fatores ambientais e espaciais na estruturação de metacomunidades de insetos aquáticos na Amazônia Oriental(Universidade Federal do Pará, 2022-07) OLIVEIRA, Stéfany Vitória Santos; FARIA, Ana Paula Justino de; http://lattes.cnpq.br/6041546003155327; https://orcid.org/0000-0003-2729-5358; SANTOS, Raphael Ligeiro Barroso; http://lattes.cnpq.br/7227882802366966; https://orcid.org/0000-0001-9717-5461Anthropogenic pressures resulting from changes in land use have great potential to impact the dynamics of aquatic insect metacommunities, once they alter the environmental quality of streams, and may impose barriers to dispersal. The objective of this study is to evaluate the structuring of aquatic insect assemblages (Ephemeroptera, Plecoptera and Trichoptera orders - EPT) in Amazonian streams under natural conditions (control streams) and under disturbance by human activities (altered streams) is influenced by characteristics of fluvial habitats and by the spatial structure. Our hypotheses is that in control streams, habitat characteristics are the main structuring factor of EPT assemblages, and that in altered streams, habitat characteristics related to human disturbances and spatial structure are the main assemblage structuring factors. A total of 74 streams were sampled in the Capim River basin, Pará, Brazil, wich 38 are control streams and 36 are altered streams. In each of them, environmental variables associated with water chemistry, channel hydromorphology, sediment types, riparian vegetation and insect shelter were measured, in addition to the proportion of land uses and EPT assemblages. Our results showed that several environmental characteristics of the streams were affected by human activities. Environmental factors had a greater influence on the structuring of EPT assemblages than the other factors evaluated, both in the control and altered streams. The influence of the spatial factor was weak. The assemblages of altered streams were structured both by environmental variables affected by disturbances and by variables subject to natural variation, demonstrating that the assemblages in these environments are not governed only by environmental changes. Our study demonstrates the importance of the species sorting process in metacommunities of Amazonian streams, and the role of disturbance in this process.