Composition and species richness phytoplankton in a subtropical floodplain lake: a long-term study

AIM: Phytoplankton species diversity in floodplain lakes is influenced by different conditions imposed by the hydrosedimentological regime of the main channel. This study evaluated the predictors of composition and species richness phytoplankton in the long-term scale, in a floodplain lake directly connected to the Paraná River. We hypothesized that species richness of the floodplain lake is directly related to the degree of connectivity with the main channel. METHODS: Quarterly samplings were conducted between February 2000 and March 2013 (except in 2001 and 2003), under the water surface of the pelagic zone of the lake. Data were analyzed with Spearman correlation, PCA, DCA, ANOVA and regression analysis. RESULTS: We identified 397 taxa with high contribution of rare species (72%). Chlorophyceans and diatoms were the most frequent groups. There was a trend of increasing of diatoms and decrease of cyanobacteria. The DCA showed differences in phytoplankton composition. The highest mean richness values were found in years with high number of days under potamophase. Significant differences between years were detected for total species richness and first axis of DCA. Regression analysis indicated that the predictors of species richness were Zeu and Zmax. CONCLUSION: The species richness phytoplankton of the floodplain lake is directly related to the level of connectivity with the main channel.

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Community structure of periphytic algae in a floodplain lake: a long-term study

Acta Scientiarum Biological Sciences ◽

10.4025/actascibiolsci.v36i2.19560 ◽

2014 ◽

Vol 36 (2) ◽

pp. 147 ◽

Cited By ~ 6

Author(s):

Luciana Carapunarla ◽

Dirceu Baumgartner ◽

Liliana Rodrigues

Keyword(s):

Community Structure ◽

Floodplain Lake ◽

Term Study ◽

Periphytic Algae ◽

Long Term Study

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Post-fire succession during the long-term absence of fire in coastal heathland and a test of the chronosequence survey method

Australian Journal of Botany ◽

10.1071/bt14345 ◽

2015 ◽

Vol 63 (7) ◽

pp. 572 ◽

Cited By ~ 7

Author(s):

Marc Freestone ◽

Timothy J. Wills ◽

Jennifer Read

Keyword(s):

Species Richness ◽

Fire History ◽

Species Abundance ◽

Tree Cover ◽

Survey Method ◽

Total Species Richness ◽

Historical Factor ◽

Declining Species ◽

Total Species

Post-fire vegetation succession in long-unburnt heathland in south-east Australia is not well understood. In the present study we investigated temporal change in vegetation along a 37-year post-fire chronosequence in coastal heathland in the Gippsland Lakes Coastal Park, Victoria, Australia. Fourteen sites were surveyed for vegetation characteristics approximately 10 years after an initial chronosequence survey, enabling an extension of the chronosequence to cover a longer fire-free interval as well as testing predictions of declining species richness and diversity from the initial chronosequence study. Total species richness, mean species richness, mean diversity and mean evenness declined with time since fire across the 14 sites. However, only diversity (H) and evenness (E) decreased within sites as predicted in the original chronosequence study. No decrease in species richness within sites was observed. The chronosequence correctly predicted changes in species abundance but not the number of species present. Tree cover also increased, suggesting that the heathland was becoming a woodland in the long-term absence of fire. Fire history, which is an uncontrolled historical factor, provides the most likely explanation for why species richness did not decrease as predicted by the initial chronosequence. This study advocates caution in using the chronosequence method to predict species richness during post-fire succession.

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Long-term assessment of the effect of introduced predatory fish on minnow diversity in a regional protected area

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f2012-105 ◽

2012 ◽

Vol 69 (11) ◽

pp. 1798-1805 ◽

Cited By ~ 1

Author(s):

James K. Aiken ◽

C. Scott Findlay ◽

François Chapleau

Keyword(s):

Species Richness ◽

Protected Area ◽

Negative Impact ◽

Predatory Fish ◽

Small Lakes ◽

Total Species Richness ◽

Total Species ◽

Overlapping Sets ◽

Fish Species Diversity

Introduced piscivorous fishes had a dramatic impact on small-bodied fish species diversity of small temperate lakes in Gatineau Park, Quebec, Canada, on the basis of three surveys carried out over a 38-year period from 1970 to 2007. For three overlapping sets of lakes based on different combinations of survey years (lakes surveyed in 1970–1971, 1991–1992, and 2006–2007 (N = 14); lakes surveyed in 1970–1971 and 2006–2007 (N = 21); and lakes surveyed in 1991–1992 and 2006–2007 (N = 16)), those with introduced piscivores showed substantial and consistent temporal declines in average minnow species richness but much weaker, if any, declines in total species richness. By contrast, lakes without introduced piscivores showed no such decline. Whereas lakes without piscivores showed a strong species–elevation relationship early in the record, the strength of this relationship was much lower in lakes with introduced piscivores. Moreover, the strength of the species–elevation relationship declined precipitously over time in lakes with introduced piscivores, but remained stable in lakes where introduced piscivores were absent. The negative impact of piscivore introductions on small-bodied fish biodiversity in small lakes underscores the importance of action to mitigate the risk of future introductions or invasions.

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