Phytoplankton biodiversity changes in a shallow tropical reservoir during the hypertrophication process
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Data
2008-11
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Editor
Instituto Internacional de Ecologia
Resumo
Study aimed at evaluating phytoplankton biodiversity changes in a shallow tropical reservoir during its hypertrophication process. Samplings were carried out monthly during 8 consecutive years (1997-2004) in 5 depths. Conspicuous limnological changes in the reservoir derived from the presence and/or removal of the water hyacinth, characterized 3 different phases. Over the time series, reservoir changed from a typical polymictic eutrophic system to hypertrophic one, leading to a reduction of approximately 70 species (average 37%). Chlorophyceae accounted for the highest species richness (46%) among all algal classes and strictly followed total species richness variation. Internal feedback mechanisms intensification over phase III clearly promoted the sharp decrease in biodiversity. Highest decreases, mainly during springs, occurred simultaneously to the highest Cyanobacteria blooms. Increased turbidity due to heavy phytoplankton blooms suppressed all other algal groups, so that at the end of the present study even Cyanobacteria species richness decreased. Total dissolved phosphorous was included in most of the best selected models used to analyze the temporal patterns in species richness loss. Present data show that biodiversity loss following trophic change was not a single dimension of a single factor but, rather, a template
Descrição
Palavras-chave
Biodiversity loss, Cyanobacteria bloom, Phosphorus, Species richness, Water hyacinth, Aguapé, Floração de cianobactérias, Fósforo, Perda de biodiversidade, Riqueza de espécies
Citação
CROSSETTI, L. O.; BICUDO, D. C.; BICUDO, C. E. M.; BINI, L. M. Phytoplankton biodiversity changes in a shallow tropical reservoir during the hypertrophication process. Brazilian Journal of Biology, São Carlos, v. 68, n. 4, suppl., p. 1061-1067, Nov. 2008.