Periphyton assemblages and their relationships with environmental variables in a eutrophic shallow lake from Pampa Plain, Argentina

ESQUIUS, K.S. & A.H. ESCALANTE

Pan-American Journal of Aquatic Sciences

Pan American Journal of Aquatic Sciences

Año: 2012 vol. 7 p. 57 - 72

1809-9009

The aim of this paper was to test the effect of changes in turbidity and chemical composition on periphyton community growing on Schoenoplectus californicus, a littoral macrophyte that is dominant in freshwater systems of Pampa Plain. Periphyton samples were collected and physico - chemical variables were monitored during a year at two sites in Los Padres Lake which differed in turbidity and some chemical variables scores. Our results showed that periphyton communities from both sampling sites were different in terms on biomass, density and dominant species. In general, periphyton from Station 1 (with higher turbidity) had a predominance of prostrate and erect diatoms (as Rhoicosphenia abbreviata, Navicula cryptocephala and N. zanoni) and was lesser developed than that from Station 2 (with lower scores of the mentioned environmental variable). Periphyton from Station 2 was more diverse, with a higher density of cyanobacteria, chlorophytes and euglenophytes beside diatoms like Epithemia adnata, E. sorex, N. zanoni and Synedra acus. Regression and multivariate analysis indicated that turbidity was the main variable affecting the amount of periphyton meanwhile this factor, together with CO32- concentration were crucial for periphyton species composition.