Seasonal dynamics of the structure of epiphytic algal community on different substrates from a Neotropical floodplain

Abstract

This study aimed at analyzing the structure of epiphytic algal community on aquatic macrophytes morphologically different and in distinct hydrological periods at a lentic environment (Pombas Lake) located in the Upper Paraná River floodplain. In this study we tested the hypothesis that epiphyton richness, diversity, density, and composition, associated with submerged macrophytes are affected by hydrological dynamics and by habitat heterogeneity. The macrophytes used as substrates were Eichhornia azurea Kunth, an emergent macrophyte, and Egeria najas Planch, a submerged macrophyte. The samplings were performed quarterly in 2009, the species richness, diversity, density, and composition of the epiphytic algal community were evaluated. The species richness was not different between the substrates. Regardless of the evaluated substrate, the month of March had the highest species richness and diversity, especially of Desmids and Chlorophyceae. E. najas recorded the greater variation in abundance, compared with E. azurea. Bacillariophyceae, independent of the period and substrate, represented over 50 % of total density. The species composition was different among the periods, in which March and June (low water) were more similar and formed the group I, while September and December (high water) formed the group II. In summary, the hypothesis was accepted, since we verified that the hydrological dynamics of the floodplain is the direct controlling factor on structure of epiphytic algal community, and the substrate heterogeneity is the indirect controlling factor.

Composition and taxonomic similarity of the periphytic algal community in different natural substrates in a neotropical floodplain, Brazil

“…In this study, Biolo and Rodrigues (2013) showed no significant differences reported in the mean values of specific richness between the same substrates, only for sampled periods and for interaction "time x substrate"; and significant differences between periphytic algae from distinct substrates were registered only for average values of density. Furthermore, Neif et al (2013) also found no significant differences in the species composition and richness of periphytic algae of different submerged macrophytes at the same floodplain, including the attribute density, but only between periods. Our study provides first steps for understanding comparative structure of periphytic algal communities in E. azurea, N. amazonum and O. cubense.…”

“…Richness of taxa in this region is very low, with only 26 taxa recorded by these authors. At the upper portion of the floodplain, Neif et al (2013) analyzed the periphyton structure from two macrophytes, E. azurea and Egeria najas Planch -of a lake, both submerged macrophytes. Regarding macrophytes covered in the present study, Nymphaea amazonum Martius & Zuccarini and Oxycaryum cubense (Poeppig and Kunth) Lye, knowledge of the composition and similarity of periphyton is still scarce, with previous data published related to the specific richness and density of periphytic communities in these macrophytes (Biolo and Rodrigues, 2013) as part of the major project which originated this study.…”