scholarly journals Interannual variability of phytoplankton in the main rivers of the Upper Paraná River floodplain, Brazil: influence of upstream reservoirs

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 501-516 ◽  
Author(s):  
LC. Rodrigues ◽  
S. Train ◽  
VM. Bovo-Scomparin ◽  
S. Jati ◽  
CCJ. Borsalli ◽  
...  
Keyword(s):  
Species Richness ◽  
Interannual Variability ◽  
Climatic Variability ◽  
Paraná River ◽  
River Floodplain ◽  
Parana River ◽  
Phytoplankton Communities ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

The interannual variation of phytoplankton communities in the three main rivers of the Upper Paraná River floodplain is evaluated in relation to changes in the hydrosedimentological regime. These changes are a result of climatic variability and the formation of Porto Primavera Reservoir, located at the upper Paraná River. Phytoplankton species richness and density were investigated in rivers during a prior period (1993-1994) and eight years after reservoir impoundment (2000-2007). Multiple analyses were conducted to test the differences between these time periods in order to find predictor variables for phytoplankton attributes. A total of 454 phytoplanktonic taxa were found. The regression analysis revealed significant differences between periods. In the years following construction of the Porto Primavera dam, species richness was lower in the Paraná River and density was higher in the three rivers. In general, the algal density decreased from 2005 to 2007. Diatoms and cyanobacteria contributed significantly to the total density during the period from March 1993 to February 1994. The years 2000-2007 presented the lowest diatom contribution to species richness and the highest cyanobacteria contribution. From 2000 on, cryptomonads and cyanobacteria dominated. The interannual variability of phytoplankton was probably influenced by changes in hydrosedimentological regime due to climatic variations (La Niña and El Niño - Southern Oscillation events - ENSO) and the operational procedures associated with an upstream reservoirs. Studies on climatic variability and its effects on hydrosedimentological regimes of the Paraná, Baía and Ivinhema rivers and the biota therein are necessary to obtain subsidies for management, including decisions related to the operation of dams upstream and downstream of the study area, with the purpose of minimizing risks to the Environmental Protection Area.

scholarly journals Influence of tributaries on the periphytic diatom community in a floodplain

2017 ◽  
Vol 29 (0) ◽  
Author(s):  
Andressa Bichoff ◽  
Nicolli Cristina Osório ◽  
Daiane Trevisan Ruwer ◽  
Kisay Lorena Adame Montoya ◽  
Bárbara Dunck ◽  
...  
Keyword(s):  
Species Richness ◽  
Protected Area ◽  
Paraná River ◽  
Diatom Community ◽  
River Floodplain ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain ◽  
Periphytic Diatom

Abstract In impacted floodplains, small tributaries have an essential role in the maintenance of ecosystem biodiversity. Aim: We aimed to characterise the periphytic diatom community (Bacillariophyta) in a protected area at the Upper Paraná River floodplain considering the importance of tributaries as a source of propagules. The purpose of this study was to understand the influence of the tributaries in the periphytic diatom community (Bacillariophyta) in a protected area at the Upper Paraná River floodplain. We expect that species present in the main river channel (mainly in the last stretch) would be a subset of the community present in the tributaries. Methods The study area is located in the last non-dammed stretch of the Paraná River in this floodplain, with the contribution of several tributaries. Sampling was performed in 2014 in two tributaries and three sites at the Paraná River main channel, and the periphytic material was obtained from petioles of the aquatic macrophyte Eichhornia azurea (Sw.) Kunth. Results We identified 115 diatom taxa. Higher values of species richness were registered in the tributaries, and higher densities in the tributaries and at sampling sites under the direct influence of the tributaries. We also observed a higher similarity between the tributaries, which are located in the preserved side of the floodplain. The results of beta diversity showed that closer sites had lower values, and that the species turnover was the component more important in this floodplain. Conclusion In this way, these results reinforce the importance of tributaries mainly on the algae establishment and development reflected in the density of species. It demonstrates that sites in preserved area present a higher species richness and can serve as a pool of propagules for downstream environments.

scholarly journals Biodiversity of zooplankton communities in the Upper Paraná River floodplain: interannual variation from long-term studies

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 539-549 ◽  
Author(s):  
FA. Lansac-Tôha ◽  
CC. Bonecker ◽  
LFM. Velho ◽  
NR. Simões ◽  
JD. Dias ◽  
...  
Keyword(s):  
Species Richness ◽  
Interannual Variation ◽  
Paraná River ◽  
Continuous Increase ◽  
River Floodplain ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

We investigated the effect of interannual variation of hydrosedimentological regime and connectivity on the zooplankton biodiversity in the Upper Paraná River floodplain. Zooplankton samplings were undertaken between 2000 and 2007, in different environments of the floodplain, including connected and isolated floodplain lakes, backwaters, rivers and channels. The zooplankton included 541 species. Rotifers showed the highest species richness and abundance. Among the zooplankton species, 71 represent new occurrence records for the floodplain. The species accumulation curve showed a continuous increase in gamma diversity, demonstrating the importance of long-term research for accurate knowledge of biodiversity in heterogeneous and dynamic ecosystems, such as the floodplains. Interannual beta diversity among studied years indicated a lesser alteration in community composition in 2001, when a long limnophase period was observed. In most of the environments, the highest species richness values were related to the greatest flooding amplitudes. Flooding amplitude, which is associated with connectivity, favors faunal exchange amongst the environments and between the pelagic and littoral zones. This explains the occurrence of both planktonic and non-planktonic species within the community. On the other hand, mean zooplankton abundance values were higher when a long isolation period occurred. Differences between the potamophase and limnophase amplitude associated with connectivity among the environments were the most important factors for the structure and dynamics of the zooplankton community in the Upper Paraná River floodplain.

scholarly journals Phytoplankton diversity in the Upper Paraná River floodplain during two years of drought (2000 and 2001)

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 637-647 ◽  
Author(s):  
PAF. Borges ◽  
S. Train
Keyword(s):  
Species Richness ◽  
Paraná River ◽  
Mean Values ◽  
Phytoplankton Diversity ◽  
River Floodplain ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Lotic Environments ◽  
Paraná River Floodplain

Floodplain lakes and lotic environments of the High Paraná River floodplain present notable biodiversity, especially in relation to phytoplanktonic community. The goal of this work was to evaluate phytoplankton diversity (alpha, beta and gamma) in three subsystems during two years of drought (2000 and 2001). We sampled 33 habitats at the pelagic zone subsurface during February and August. Due to low hydrometric levels of the Paraná and Ivinhema Rivers, there was no clear distinction between the potamophase and limnophase periods for the two hydrosedimentological cycles analysed. We recorded 366 taxa. The values obtained for gamma diversity estimators ranged from 55.5-87.8%. DCA and variance analyses revealed only spatial differences in the phytoplankton composition. The mean values of species richness, evenness and Shannon diversity were low, especially when compared to those obtained in previous periods for Baía subsystem. The highest mean values of species richness were verified in the connected floodplain lakes. The highest beta diversity was obtained from the Paraná subsystem and lotic environments in 2001. In general, we observed that the Upper Paraná River floodplain has the highest values of species richness, evenness and H' during the potamophase period, when the flood facilitates dispersion. However, this pattern was not observed in 2000 and 2001, years influenced by La Niña. Besides the low precipitation observed during that period, we must consider the influence of the Porto Primavera impoundment, which also altered the discharge regime of the Paraná River by decreasing the degree of connectivity between fluvial channels and the lentic environments of the floodplain. Thus, the prevalence of conditions characterising the limnophase during 2000 and 2001 explains the lack of significant variability registered for most components of phytoplankton diversity over the study period. We conclude that variations in phytoplankton diversity during the study period were related to the absence of conspicuous potamophase, and that observed variations were more closely related to spatial heterogeneity. These results reveal the importance of conservation in the Área de Proteção Ambiental das Ilhas e Várzeas do Rio Paraná, with its subsystems and diverse aquatic habitats.

scholarly journals Periphytic and planktonic algae records from the upper Paraná river floodplain, Brazil: an update

Hoehnea ◽  
2018 ◽  
Vol 45 (4) ◽  
pp. 560-590 ◽  
Author(s):  
Bárbara Dunck ◽  
Maria Gabriela Junqueira ◽  
Andressa Bichoff ◽  
Matheus Vieira da Silva ◽  
Alfonso Pineda ◽  
...  
Keyword(s):  
Geographic Distribution ◽  
Paraná River ◽  
State University ◽  
Conservation Units ◽  
River Floodplain ◽  
Planktonic Algae ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

ABSTRACT The upper Paraná river floodplain is a strategic area for the Brazilian biological and environmental patrimony and contains several conservation units. We aimed to record the occurrence and the geographic distribution of microalgae in this floodplain during 30 years of research carried out by the Center for Research in Limnology, Ichthyology and Aquaculture - State University of Maringá. We consulted 80 publications (national and international journals and books published from 1986 to 2016). We considered only published works that referenced algae at the generic and infrageneric levels. The results indicated 938 species of algae (562 periphytic, 482 planktonic), which 103 co-occur in the two habitats. Cosmarium was the richest genera for periphyton and Traquelomonas for phytoplankton. This study increased the knowledge of microalgae biodiversity in Brazil and provided data for future ecological and biogeographic studies.

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