Variación estacional de la comunidad microfitoplanctónica del curso medio del río Colorado (La Pampa, Argentina)

We analyzed the seasonal variation of the phycoflora in the Colorado River alluvium with the aim of expanding knowledge of algal biodiversity in lotic environments of the province of La Pampa. The study area is located in the middle basin of the Colorado River (38º 49’ S and 64º 59’ W), Lihue Calel,...

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Bibliographic Details
Authors: Biasotti, A. E., Álvarez, S. B., Bazán, Graciela Inés, Martínez de Fabricius, A. L.
Format: article
Status:Published version
Publication Date:2014
Country:Argentina
Institution:Universidad Nacional de La Plata
Repository:SEDICI (UNLP)
Language:Spanish
OAI Identifier:oai:sedici.unlp.edu.ar:10915/56941
Online Access:http://sedici.unlp.edu.ar/handle/10915/56941
Access Level:Open access
Keyword:Ciencias Naturales
ficoflora
La Pampa (Argentina)
Fitoplancton
ambientes lóticos
Description
Summary:We analyzed the seasonal variation of the phycoflora in the Colorado River alluvium with the aim of expanding knowledge of algal biodiversity in lotic environments of the province of La Pampa. The study area is located in the middle basin of the Colorado River (38º 49’ S and 64º 59’ W), Lihue Calel, which is the natural limit between La Pampa and Río Negro provinces. The site is located 122 meters above sea level with a channel width of 113 m. Samples were collected according to the standard methodology for lotic environments during autumn 2010 - autumn 2011. Physicochemical parameters were measured in situ. Water temperature ranged from 3.4 to 24°C for winter and summer respectively. The pH ranged between 8.1 and 8.6, the conductivity varied between 938 and 1950 μS cm-1 and the flow velocity ranged between 0.5 and 0.9 m sec-1. Phytoplankton samples were deposited in the Herbarium SRFA (UNLPam). 163 taxa were identified mostly belonging to Bacillariophyceae (42%). Chlorophyceae contributed 36%, while 17% Cyanobacteria, Euglenophyceae, Dinophyceae, Rhodophyceae and Xanthophyceae were found as companions taxa. The similarity of biodiversity in the alluvial section of the Colorado River is almost 70% as observed in the dendrogram resulting from the application of the Bray Curtis index, and grouped according to a seasonal sampling sequence.