ABSTRACT This study evaluated soft-bodied benthic algae from seven streams located in protected areas of central Brazil (Parque Nacional de Brasília, Parque Nacional da Chapada dos Veadeiros and Parque Estadual de Terra Ronca), and related them to abiotic factors. We addressed the following questions: A) how algal community structure in Cerrado streams is influenced by the marked seasonality typical of the region; and B) how karst geology influences algal communities in Parque Estadual de Terra Ronca, as compared to streams in other Cerrado areas. Samples were collected between 2012 and 2013 from a single site in each stream, and upstream and downstream of caves present in Parque Estadual de Terra Ronca. Altogether, 159 taxa were recorded. Algal community structure varied significantly among sites, but not between seasons, despite relatively lower abundances during the rainy season, likely due to a negative influence of the faster currents in streams during this period. Some alkaliphilic species were observed only at sites near caves (e.g. the cyanobacterium Tolypothrix distorta), while acidophilic taxa were more frequent in the other streams (e.g. desmids and Cyanobacteria such as Scytonema caldarium, Hapalosiphon stuhlmannii and Stigonema ocellatum). We observed a rare green alga, Microthamnion kuetzingianum, and reported the cyanobacterium Rivularia aquatica for the first time in Brazil.

O objetivo deste estudo foi inventariar a fauna de Cladocera em zonas úmidas localizadas em duas grandes áreas que protegem fragmentos de Cerrado. Estas estão localizadas no Parque Nacional de Brasília, DF, e Campo de Instrução de Formosa, Goiás, e são formadas pelo afloramento de lençol freático, com extensa cobertura vegetal. Foram encontradas 24 espécies no Parque Nacional de Brasília e 30 no Campo de Instrução de Formosa. A riqueza observada alcançou, aproximadamente, 80% dos valores estimados para ambas as áreas protegidas. Além disto, a comunidade de Cladocera no tipo de ambiente estudado parece ser influenciada pela profundidade, com maiores valores de riqueza e similaridade para áreas com maiores médias de profundidade. Contudo, as zonas úmidas mais rasas contribuíram para a riqueza total com espécies exclusivas, o que mostra a importância desses ambientes para a riqueza de espécies.

The aim of this study was to inventory the cladoceran fauna in wetlands located in two large areas that protect fragments of Cerrado. Located in the Brasília National Park-DF and Campo de Instrução de Formosa-GO, these wetlands are formed by upwelling groundwater, with extensive vegetation cover. We found 24 species in the Brasília National Park and 30 in the Campo de Instrução de Formosa. The observed richness reached approximately 80% of the estimated values for both protected areas. Moreover, the community of cladocerans in the kind of environment studied appears to be influenced by depth, with higher values of richness and similarity in wetlands of higher average depths. However, shallow wetlands contributed to the total richness with exclusive species, which shows the importance of these habitats for species richness.