Título :	Dinâmica da comunidade fitoplanctônica e a dominância sazonal das cianobactérias na várzea de Curuai, Santarém-PA
Autor :	Kraus, Cleber Nunes
Orientador(es)::	Vieira, Ludgero Cardoso Galli
Assunto::	Fitoplâncton de água doce Zooplâncton Enriquecimento nutricional Processos hidrológicos
Fecha de publicación :	24-mar-2020
Data de defesa::	31-jul-2019
Citación :	KRAUS, Cleber Nunes. Dinâmica da comunidade fitoplanctônica e a dominância sazonal das cianobactérias na várzea de Curuai, Santarém-PA. 2019. 107 f., il. Tese (Doutorado em Ciências Ambientais) — Universidade de Brasília, Brasília, 2019.
Abstract:	The processes in tropical floodplain lakes enable maintaining phytoplankton nutrient requirement over hydrological year. The nutrients such as nitrogen, phosphorus, and carbon compounds play an essential role in phytoplankton growth. However, the way that nutrients and phytoplankton interact and how this relationship varies seasonally in tropical freshwater ecosystems is not clear. Also, hydrological periods drives a complex interaction between different aquatic planktonic groups. In the Curuai floodplain, there is variation in phytoplankton and zooplankton community structure between different hydrological periods, and these differences are in part, consequential responses due to the interaction between these communities. Most of the phytoplankton species belong to a few functional groups in the same way that zooplankton belongs to a few taxa. Using the phytoplankton functional approach, we verified how their ability to respond to hydrological and environmental variations reflects the ecological conditions and investigated how these interactions work. In this thesis, we evaluate the relationship between phytoplankton-nutrients over the hydrological cycle in Amazonian floodplain lakes and verify if this relationship influences the biomass of cyanobacteria. We also check what factors linked to nutrients act in structuring phytoplankton community. We also evaluated if the phytoplankton-zooplankton relationship structure results in a feedback system that conduces to a coexistence pattern between the zooplankton and the phytoplankton group of cyanobacteria in the Amazonian Curuai floodplain. Our results demonstrated that seasonal hydrological variation produces functional changes in the phytoplankton community through fluctuations in nutrient concentrations. These processes make it possible to maintain the phytoplankton nutrients requirements, even after nutrient input from river water has decreased. Phytoplankton biovolume is dominated by cyanobacteria during the low flow period. Cyanobacteria, together with other organisms, play an important role in maintaining nutrient stability throughout hydrological periods. However, the hydrological periods have different influences on the superficial and bottom layers in the structuring of phytoplankton functional diversity. There is a significant influence of spacetime interaction on the structuring of the functional phytoplankton community in the months between layers and different types of environmental variables act on different layers and months. The phytoplankton functional community reflects the ability of different groups to make more efficient use of available resources. The results also showed that light is a crucial resource that can act in the structure of phytoplankton functional diversity in the Amazonian floodplains. The difference in beta diversity between layers is linked to hydrological dynamics. Along with environmental changes, the relationship between phytoplankton and the zooplankton community is also a factor driving plankton structure. Positive and negative feedback has proven to be a mechanism by which communities interact in the Amazon floodplain system. This feedback system allows the coexistence between zooplankton and cyanobacteria in the floodplains.
metadata.dc.description.unidade:	Faculdade UnB Planaltina (FUP)
Descripción :	Tese (Doutorado em Ciências Ambientais) — Universidade de Brasília, Faculdade UnB - Planaltina, Programa de Pós-Graduação em Ciências Ambientais, Planaltina, 2019.
metadata.dc.description.ppg:	Programa de Pós-Graduação em Ciências Ambientais
Licença::	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
Agência financiadora:	Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Aparece en las colecciones:	Teses, dissertações e produtos pós-doutorado

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