<b>Structure of the periphytic algae associated with a floating macrophyte in an open lake on the upper Paraná river floodplain, Brazil</b> - doi: 10.4025/actascibiolsci.v35i4.18663

Abstract

We aimed to access the knowledge of the structure of the periphytic algae community on a floating substrate, the macrophyte Ricciocarpus natans (L.) Corda, during two hydrological periods in a connected environment at the Paraná river floodplain. Attached algal was removed from the substrate with the aid of a softbristled brush and distilled water jets and was fixed immediately for qualitative and quantitative analysis. The total richness of the periphytic algae was 188 taxa. February showed the highest species richness (154 taxa), while total species density exhibited an inverse pattern, with the highest values occurring in June (273.4 10 3 ind. cm-2). Bacillariophyceae comprised the largest fraction of density, which was reflected by the abundance of Achnanthidium minutissimum (Kütz.) Czarn. Community structure of periphytic algae in R. natans followed the same pattern of other substrates, as previously determined. This suggests that main factor acting on the structure of periphyton at the Paraná river floodplain is primarily the floodpulses regime. The hydrochoric dispersion of R. natans across the various environments comprising the floodplain favors its communities associated, as the periphytic algae, subject to passive transport via water movement. Floating rhizoids of R. natans also may act as a mesh retainer, promoting the colonization of many metaphytic and planktonic species. However, in order to better understand and delineate patterns of ecosystem functioning, it is recommended that natural substrates be used which have greater stability in the environment, such as rooted or submerged macrophyte species.

Periphytic algae in a floodplain lake and river under low water conditions

“…Studies in this floodplain that have evaluated periods of both high and low water levels have shown that diatoms dominate the periphyton under these two hydrological conditions (Fonseca & Rodrigues 2005b, Algarte et al 2006, Biolo & Rodrigues 2013, Carapunarla et al 2014. In these studies, at low water levels, the diatoms were favoured by environmental conditions such as low temperatures and concentrations of phosphorus forms, higher concentrations of dissolved oxygen and nitrogen for both environments.…”

Subfossil and periphytic diatoms from the upper Paraná river, Brazil: last ~1000 years of a transition period

“…Given the high dominance of diatoms in periphytic samples (Biolo & Rodrigues 2013, Bichoff et al 2016, the periphytic community was sampled in order to identify diatom communities from the current environment. The sampling of the periphytic diatom community was made in April 2016 after a period of flooding.…”

Effects of the hydrological cycle on the phycoperiphyton assemblage in an Andean foothill stream in Colombia

“…Such hydrological variability is associated with changes in factors involved with the flow, such as the water speed and depth, and constitutes a disturbance that triggers changes in the phycoperiphyton assemblage and its succession due to their small size, passive dispersal method and generally limited mobility (Connell, 1978;Townsend, 1989;Winemiller et al, 2010, Passy, 2007Algarte et al, 2014). However, the phycoperiphyton is probably the assemblage that is most resilient to variations in flow because it responds very rapidly to environmental changes due to its short life cycle (days), high reproduction rate and adaptations or forms of attachment to the substrata in many genera that affect the drifting velocity (Biolo and Rodrigues, 2013).…”