Changes in the taxonomic structure of periphytic algae on a free-floating macrophyte (Utricularia foliosa L.) in relation to macrophyte richness over seasons

Abstract

Periphyton has a strong relationship with aquatic macrophytes, which are key components of spatial heterogeneity in the littoral zone. We evaluated the relationship between the community structure of periphytic algae on Utricularia foliosa and macrophyte richness and coverage and limnological variables in a shallow reservoir. Water sampling for physical, chemical and biological analyses was performed at sites with contrasting macrophyte coverage and richness in each of the four main seasons of the year. Periphytic algae were evaluated for density and species composition. High densities of diatoms and filamentous cyanobacteria in the periphyton were observed at sites with high macrophyte coverage and richness, while high abundances of flagellates of Chrysophyceae and Chlorophyceae were found at sites with low macrophyte richness. Light and nutrient availability were determining factors of the temporal variability of the periphytic algae community. We concluded that the interaction between seasonality and spatial heterogeneity (macrophyte community structure and limnological variables), explained the variability in species composition and algal density of the periphyton. Therefore, seasonality and spatial heterogeneity acted as determining factors for periphyton structure on a free-floating macrophyte with high structural complexity.

Periphytic diatoms from an oligotrophic lentic system, Piraquara I reservoir, Paraná state, Brazil

“…Figure: 4AG Length: 20-35 µm; width: 4.5-5.6 µm; striae: 12-18 in 10 µm. Ecology: widely distributed in oligotrophic to eutrophic conditions (Bertolii et al 2010, Silva et al 2010, Marra et al 2016, Bartozek et al 2018, Santos & Ferragut 2018, but most commonly associated with low TP concentrations (Wang et al 2019). It occurred in all of our samples, in slightly acid to circumneutral pH (6-6.85), low conductivity (22.5-24.5 μS cm -1 ), and oligotrophic conditions.…”

Principal Determinants of Aquatic Macrophyte Communities in Least-Impacted Small Shallow Lakes in France

“…Macrophytes have a positive feedback on transparency, maintaining clear-water conditions through: (1) competition with microalgae and excretion of allelochemicals; (2) providing habitats and refuges from fish predation for zooplankton and invertebrates; and (3) providing habitat for piscivorous fish, limiting zooplanktivorous fishes [27]. Macrophytes also provide habitat for numerous other living organisms, such as periphyton [28,29], water birds [30], and amphibians [31]. As primary producers, they often dominate the production of organic matter, absorbing nutrients, ions, and aerial carbon dioxide [32].…”

Principal Determinants of Aquatic Macrophyte Communities in Least-Impacted Small Shallow Lakes in France

“…Macrophytes have a positive feedback on transparency, maintaining clear-water conditions through (1) competition with microalgae and excretion of allelochemicals, (2) providing habitats and refuges from fish predation for zooplankton and invertebrates, (3) providing habitat for piscivorous fish, limiting zooplanktivorous fishes [27]. Macrophytes also provide habitat for numerous other living organisms, such as periphyton [28,29], water birds [30] and amphibians [31]. As primary producers, they often dominate the production of organic matter, absorbing nutrients, ions and aerial carbon dioxide [32].…”