Macroinvertebrate assemblages’ distribution along a saline wetland in hard environmental conditions from Centre-West of Argentina. .

SCHEIBLER, E.E.; CIOCCO, N.F.

LIMNOLOGICA

ELSEVIER GMBH

Año: 2009

0075-9511

 The goal was to examine how macroinvertebrate taxonomic richness and density respond tospatial-temporal changes and to the influence of water physicochemical characteristics along theBañado Carilauqen (BC). Benthic samplings were conducted seasonally and environmental parameters were recorded in five reaches of the BC. Cluster analysis was applied to compare taxonomic richness among sites. Community structure and spatial-temporal variation were explored using logarithmic regression. CCA was applied to explore the relationship between species and environmental variables.A total of 36 taxa were identified, predominantly insects. A growing gradient of conductivity andhardness was registered between headwaters (HD; relatively soft waters) and outlet (OL; very hard and saline waters). Total density of taxa showed significant differences among sampling sites and climate seasons. A decline in richness and density was observed from HD to OL. The spatialconductivity gradient is the major factor modulating macroinvertebrate distribution along this saline arid wetland. With the exception of the headwaters, hard, eutrophic, polysaprobic and contaminated waters such of those of the BC represent critical conditions for the development of macroinvertebrate assemblages.