Fitoplancton, epipelon, materia orgánica y fósforo de una laguna arreica en relación a fases claras y turbias

MAC DONAGH, M. E.,; CASCO, M. A.; CANO, M. G.,

Biología Acuática

Instituto de Limnología R. A. Ringuelet

Lugar: Florencio Varela; Año: 2009 p. 133 - 142

0326-1638

In the last years, the alternative state hypothesis has been revised owning to the differences found among shallow lakes from temperate zones and those from other latitudes and climates. Researches in the pampean region showed that the temporal and spatial changes and the interactions between algal communities are very complex. In these shallow lakes the epiphyton and epipelon have a significant role, comparable with the phytoplankton function. In Lacombe, three different phases of equilibrium were defined, one of them with intermediate characteristics between clear and turbid phases. The aim of this paper was to analyze the individual fit to this conceptual scheme of some estimators of system dynamics with infrequent application in the equilibrium state definition. The differences among phases were mainly identified in water variables, whereas sediment variables showed a great stability to state changes. Chlorophyll a, phytoplankton density and water organic matter were the best indicators of the phases. With respect to sediment variables, the three phases were only differentiated by the settled phytoplanktonic algae. Keywords: shallow lake, alternative states, phytoplankton, epipelon, total phosphorus