Alpha and beta diversity of phytoplankton in two subtropical eutrophic streams in southern Brazil

Abstract

This paper reports the alpha and beta diversity of phytoplankton communities of two streams differing in land use. We analyzed which environmental conditions affect diversity of the phytoplankton communities and tested the hypothesis that stream stretches protected by forests will have lower species richness, whereas higher beta-diversity would occur among the non-protected stretches. Samples were taken quarterly, from February to November 2012, in nine stretches, including four non-protected stretches, two partially protected stretches and three totally forest-protected stretches. Eleven abiotic variables and their coefficients of variation were analyzed. Phytoplankton was analyzed for species richness (alpha diversity), frequency of occurrence and beta-diversity. Species richness was calculated by first and second order jackknife indexes. Biotic data were submitted to Sørensen similarity analysis. A total of 429 infrageneric taxa were reported, representing 88% of the estimated expected species richness. The phytoplankton composition was typical for lotic environments with high richness values of Bacillariophyceae (66.0%). High phytoplankton richness values occurred in all the sampled stretches, even though beta-diversity was moderate and indicated similarity between the sampled stretches, therefore only a part of the original hypothesis was corroborated.

Diversity and Species Composition of Microbiota Associated with Mosquito Breeding Habitats: A Study from Kurunegala District in Sri Lanka

“…e density classes were accepted following [30], satellite species (D < 1%); subdominant species (1 < D < 5%); dominant species (D > 5%). All types of microbiota, that is, phytoplankton, bacterioplankton planktonic protists, and zooplankton occurrence frequencies were categorized as constant for species found in >50% of the habitats; common when found between 25% and 50% of the habitats; and accidental or rare species when found in <25% of the habitats [31].…”

Variability in phytoplankton community structure and influence on stabilization pond functioning

“…Thereby, βW in the facultative pond was high in September (20.7) and low in October (12), whereas it was high in April (20.2) and lower in October (8.6) in the maturation pond. Both ponds had relatively low βW, indicating a low turnover in the phytoplankton community, i.e., ponds have high similarity (Schuster et al, 2015) and environments with high productivity can present low βw (Zorzal-Almeida et al, 2017). The maturation pond had higher βW in the rainy season, whereas it was higher in the dry season in the facultative pond.…”

Cymbella loescherae sp. nov. (Bacillariophyceae) from First-Order Streams of Southern Brazil

“…Schuster et al (2015) found it in a first-order stream with a small strip of riparian vegetation and adjacent areas with corn crop in Santa Catatina State. Here we describe and illustrate a new Cymbella species found in first-and second-order oligotrophic streams from Rio Grande do Sul State (Brazil) in areas that have not previously been the subject of diatom studies.…”

“…The Cymbella aspera group is rarely recorded to Brazil; only Metzeltin and Lange-Bertalot (1998) and Schuster et al (2015) have cited it. Schuster et al (2015) found it in a first-order stream with a small strip of riparian vegetation and adjacent areas with corn crop in Santa Catatina State.…”