ILPLA   05424
INSTITUTO DE LIMNOLOGIA "DR. RAUL A. RINGUELET"
Unidad Ejecutora - UE
capítulos de libros
Título:
Lotic and lentic environments of the Pampean Plain
Autor/es:
SOLARI L.C.; MAC DOANGH, M.E.
Libro:
FRESHWATER PHYTOPLANKTON FROM ARGENTINA
Editorial:
Advances in Limnology
Referencias:
Lugar: Stuttgart; Año: 2014; p. 143 - 165
Resumen:
The Pampean Plain landscape is characterized by a great number of shallow lakes (fl ushing,backwater,
and seepage lakes) with different degrees of interconnection with
rivers and wetlands. The Salado River is the major autochthonous water
course of the Buenos Aires Province and is a typical lowland river. The
fi rst phytoplankton studies in these shallow lakes were published
during the middle of the last century, whereas investigations in lotic
environments did not start until 1980. Cyanobacteria and Chlorophyta are
usually dominant in all water bodies of the region, while
Bacillariophyceae are abundant in certain environments. Chlorophyta and
Cyanobacteria are mainly represented by euplanktonic species, whereas a
high proportion of the diatoms are brought in from the periphytic and
benthic communities. Shallow lakes of this region are characterized
according to the presence or absence of submerged and emergent
macrophytes and by the relative predominance of inorganic and organic
suspended solids. These conditions infl uence the temporal and spatial
variability of the phytoplankton structure because of the changes in
water transparency, nutrient balance, and the zooplankton structure
related to macrophyte development. The shallow lakes connected to the
Salado River act as an alluvial valley, exchanging organisms between the
river and the lakes, though this infl uence depends on the direction of
the water fl ow, which can reverse during fl ooding events. The
differences in the structure and dynamics of the phytoplankton of lotic
and lentic environments of the Pampean Plain are related to the
hydrological regime and geomorphologic-hydrologic features, to the
incorporation of inocula from connected systems, and to the colonization
of submerged macrophytes. In recent years, several hydraulic
constructions have been made, which have modifi ed the natural dynamic
system and thus, influenced the normal exchange of phytoplankton
assemblages in this complex system.