INVESTIGADORES
PIZARRO Haydee Norma
artículos
Título:
Relative importance of periphyton and phytoplankton in turbid and clear vegetated shallow lakes from the Pampa Plain (Argentina): a comparative experimental study
Autor/es:
SÁNCHEZ, M.L.; PIZARRO, H; TELL, G.; IZAGUIRRE, I.
Revista:
HYDROBIOLOGIA
Editorial:
SPRINGER
Referencias:
Lugar: The Netherlands; Año: 2010 vol. 646 p. 271 - 280
ISSN:
0018-8158
Resumen:
We analyzed experimentally the relative
contribution of phytoplankton and periphyton in two
shallow lakes from the Pampa Plain (Argentina) that
represent opposite scenarios according to the alternative
states hypothesis for shallow lakes: a clear lake
with submerged macrophytes, and a turbid lake with
high phytoplankton biomass. To study the temporal
changes of both microalgal communities under such
contrasting conditions, we placed enclosures in the
littoral zone of each lake, including natural phytoplankton
and artificial substrata, half previously
colonized by periphyton until a mature stage and
half clean to analyze periphyton colonization. In the
clear vegetated shallow lake, periphyton chlorophyll
a concentrations were 36 times higher than those of
the phytoplankton community. In contrast, phytoplankton
chlorophyll a concentrations were 761,325
times higher than those of periphyton in the turbid
lake. Here, under light limitation conditions, the
colonization of the periphyton was significantly lower
than in the clear lake. Our results indicate that in
turbid shallow lakes, the light limitation caused by
phytoplankton determines a low periphyton biomass
dominated by heterotrophic components. In clear
vegetated shallow lakes, where nitrogen limitation
probably occurs, periphyton may develop higher
biomass, most likely due to their higher efficiency
in nutrient recycling.