Phytoplankton biodiversity changes in a shallow tropical reservoir during the hypertrophication process

摘要: Study aimed at evaluating phytoplankton biodiversity changes in a shallow tropical reservoir during its hypertrophication process. Samplings were carried out monthly 8 consecutive years (1997-2004) 5 depths. Conspicuous limnological the derived from presence and/or removal of water hyacinth, characterized 3 different phases. Over time series, changed typical polymictic eutrophic system to hypertrophic one, leading reduction approximately 70 species (average 37%). Chlorophyceae accounted for highest richness (46%) among all algal classes and strictly followed total variation. Internal feedback mechanisms intensification over phase III clearly promoted sharp decrease biodiversity. Highest decreases, mainly springs, occurred simultaneously Cyanobacteria blooms. Increased turbidity due heavy blooms suppressed other groups, so that end present study even decreased. Total dissolved phosphorous was included most best selected models used analyze temporal patterns loss. Present data show loss following trophic change not single dimension factor but, rather, template factors (e.g. light, stability) co-varying consequence larger levels biomass supported reservoir.