Variação sazonal da estrutura da comunidade de algas perifíticas emPanicum repens em um reservatório raso

Abstract

Este estudo avaliou a estrutura da comunidade de algas perifíticas em Panicum repens em pontos pluriespecíficos de macrófitas em reservatório raso (Lago das Ninféias, São Paulo, Brasil). O objetivo foi avaliar as mudanças na biomassa, abundância e composição espécies, bem como identificar as variáveis ambientais mais relacionadas à variação dos atributos estruturais da comunidade. Pontos de amostragem com a presença de três e quatro espécies de macrófitas (n=3) foram selecionados aleatoriamente (04/2010, 06/2010, 11/2010, 02/2011 AbstractThis study evaluated the periphytic algal community structure on Panicum repens at macrophytes pluriespecifics sites in shallow reservoir (Ninféias Reservoir, São Paulo, Brazil). The aim was to evaluate changes in species composition and abundance, as well as identify the environmental factors most related to the variation of the periphyton structural attributes. Sampling sites with presence of three and four macrophytes species (n = 3) were randomly selected in seasons (04/2010, 06/2010, 11/2010, 02/2011). Climate and water variables, cover macrophyte and periphyton structural attributes were analyzed. Bacillariophyceae and Chrysophyceae were the most abundant algal class and Frustulia crassinervia and Chromulina elegans were the most representative species. The highest biomass and algal density and the lowest autotrophic index were found in summer, showing the further development of the algal community. Our results showed that changes in the periphyton structure on P. repens were determined primarily by seasonality. We conclude that periphyton abundance, biomass and composition changed greatly between the seasons and the light and nutrients availability, particularly phosphorus, were the variables most associated with the community structural changes during the study period. Key words: biomass, periphyton, species composition, algal density, perifíton.Variação sazonal da estrutura da comunidade de algas perifíticas em Panicum repens em um reservatório raso Seasonal variation in the periphytic algal community structure on Panicum repens in a shallow reservoir

Environmental predictors of algal community structure of plankton, epipelon and epiphyton in a shallow tropical reservoir

“…In the epiphyton, M. contortum was the species most associated with the environmental conditions in the rainy season, especially in October, when there was high P availability. In contrast, the highest density of diatom species (Navicula cryptotenella, Achnanthidium catenatum, Brachysira vitrea) was found in the dry season, as reported in previous studies (e.g., Pellegrini and Ferragut 2012;Casartelli and Ferragut 2015b). In contrast, depth was the most important factor determining descriptor species in the epipelon, where Aphanocapsa grevillei and Geitlerinema unigranulatum were associated with the littoral sediment and Trachelomonas volvocinopsis with pelagic sediment.…”