INALI   02622
INSTITUTO NACIONAL DE LIMNOLOGIA
Unidad Ejecutora - UE
capítulos de libros
Título:
Benthic Invertebrates
Autor/es:
EZCURRA DE DRAGO, INÉS; MARCHESE, MERCEDES; MONTALTO, LUCIANA
Libro:
The Middle Paraná River. Limnology of a subtropical wetland
Editorial:
Springer
Referencias:
Lugar: New York, Estados Unidos; Año: 2007; p. 251 - 275
Resumen:
The Middle Paraná River floodplain includes secondary channels of different flow and and discharge, lake of different origin and morphometry, different susseccional stages, according with the degree of connectivity  and location in the floodplain, as well as a wide range of temporary wetlands. Therefore, there are representatives of almost all invertebrates taxonomic groups in the benthos of this system. In this chapter we summarize studies carried out on benthic organisms since 1969 in floodplain water bodies, since 1980 in the main channel and secondary channels of the Middle Paraná Medio River, and sice 2001 in marginal wetland. The Middles Paraná River system as a mosaic of habitats undergoing susseccion. Key factors controlling benthic strusture and composition are hydrosedimentological flood poulse, hydraulic conditions, hydrological connectivity degree, aquatic plants cover and water quality. A gradient from the main channel to permanent flow secondary channels, to isolated lakes and temporary marginal fluvial wetlands was observed, whith a decrease in density and increase in biomass, richness and diversity of species, in the same direction, an increase in the complexity of funtional groups and trophic webs, and in the connectance, is produced. Spatial heterogeneity, habitat structure, temporal instability and higth productivity determine the higer importance of the lateral dimention than the longitudinal dimention in large floodplain rivers.