Distribución espacial de las diatomeas en el fitoplancton de un lago somero andino patagónico

BASTIDAS NAVARRO, MARCELA; DÍAZ VILLANUEVA, VERÓNICA

BOLETíN DE LA SOCIEDAD ARGENTINA DE BOTáNICA

Año: 2004 vol. 39 p. 33 - 40

0373-580X

Spatial distribution of diatoms in the phytoplankton from an Andean Patagonian shallow lake.In this study, we described diatom species diversity from lake Escondido (Parque Municipal Llao-Llao,Bariloche, Río Negro) and determined differences between the littoral zone, which is colonized by themacrophytes Schoenoplectus californicus and Potamogeton linguatus and the pelagic zone. Samplingwas carried out on spring 2002 and summer 2003, along a transect which included both littoral andpelagic zones. A total of 50 taxa was described, belonging to 20 genera. The dominant species wereAchnanthes minutissima and Fragilaria pinnata. In the summer sampling, differences between zoneswere more evident than in the spring sampling. The different communities were compared through aPrincipal Component Analysis, which reveled the presence of three groups. One of them was conformedby summer pelagic samples and it was characterized by the presence of F. pinnata and F. bicapitata.Another group consisted in spring and summer littoral samples and it was characterized by Cymbellafallaisensis. The third group consisted in spring samples and it was characterized by C. cymbiformis.The shallowness of lake Escondido and its extended vegetated littoral zone were reflected by aphytoplankton with a high proportion of tycoplanktonic species.