Modern diatom assemblages in surface sediments from shallow lakes and streams in southern Pampas (Argentina)

HASSAN; TIETZE, ELEONOR; DE FRANCESCO, CLAUDIO G.

AQUATIC SCIENCES

BIRKHAUSER VERLAG AG

Lugar: BASEL; Año: 2009

1015-1621

Abstract Diatom assemblages preserved in continentalsedimentary successions of the southern Pampas (Argentina)can provide useful indicators of past environmentalchanges. Ecological data, however, are scarce. In order toprovide modern data for diatom-based paleoenvironmentalreconstructions, sediments from shallow lakes and streamsof the region were analyzed. A total of 131 diatom specieswere identified. Canonical correspondence analysis wasused to identify the physical and chemical environmentalparameters that best explained the distribution of taxa.Cocconeis placentula, Hippodonta hungarica, Naviculaveneta, Cyclotella meneghiniana and Nitzschia amphibiawere the most widely extended species. The highest percentagevariance in diatom data was explained byconductivity and nutrient concentrations. Diatom assemblagecomposition was more variable in shallow lakes thanin streams, which is in agreement with the differenthydrological and geomorphological characteristics of theseenvironments. The results obtained in the present workprovide useful analogues for paleoenvironmental reconstructionsof water bodies in southern Pampas.EN ESTE ARTICULO SE ME AGRADECE LA COLABORACION POR LOS ANALISIS REALIZADOS