Algal assemblages from shallow lakes of the Salado River Basin (Argentina)

IZAGUIRRE, IRINA; VINOCUR, ALICIA

HYDROBIOLOGIA

SPRINGER

Año: 1994 vol. 289 p. 57 - 64

0018-8158

Within the framework of a floristic and ecological survey on the phytoplankton communities of shallow lakes of the Salado River Basin (Argentina), algal assemblages were compared by means of a Cluster Analysis. Phytoplankton communities were typical of eutrophic and meso-eutrophic systems, with many species associated with brackish and alkaline waters. Algal assemblages separated between lakes with high and low development of macrophytes. In the latter, phytoplankton assemblages were dominated by blue-green algae of the genera Oscillatoria, Raphidiopsis, Anabaena, Lyngbya, Microcystis and Anabaenopsis, often constituting algal blooms, and accompanied by coccal green algae. In lakes largely colonized by macrophytes, phytoplankton assemblages comprised a large number of tychoplanktonic species from periphyton and benthos communities. Changes in water levels were frequent and played an important role in the structure of the algal communities. During dry periods, the proportion of diatoms typical of brackish waters increased. and accompanied by coccal green algae. In lakes largely colonized by macrophytes, phytoplankton assemblages comprised a large number of tychoplanktonic species from periphyton and benthos communities. Changes in water levels were frequent and played an important role in the structure of the algal communities. During dry periods, the proportion of diatoms typical of brackish waters increased. and Anabaenopsis, often constituting algal blooms, and accompanied by coccal green algae. In lakes largely colonized by macrophytes, phytoplankton assemblages comprised a large number of tychoplanktonic species from periphyton and benthos communities. Changes in water levels were frequent and played an important role in the structure of the algal communities. During dry periods, the proportion of diatoms typical of brackish waters increased.