scholarly journals Effects of recurrent disturbances on the periphyton community downstream of a dammed watercourse

2013 ◽  
Vol 73 (2) ◽  
pp. 253-258 ◽  
Author(s):  
JE Zanon ◽  
NR Simões ◽  
L Rodrigues
Keyword(s):  
Paraná River ◽  
Water Levels ◽  
Algal Community ◽  
River Floodplain ◽  
Periphytic Algae ◽  
Parana River ◽  
Periphyton Community ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

We evaluate experimentally the effect of a sequential disturbance—desiccation—on the structure and dynamics of a periphytic algal community in a semilotic environment of the Upper Paraná River floodplain. We tested the hypothesis that the presence of recurrent disturbances have a direct negative effect on the attributes of the periphyton community. The sequential effect of desiccation on the periphytic community promoted its significant decrease in density, while the same was not observed in species richness. When desiccation was induced in a mature community, there was no difference in the community compared to control. The sequential disturbances on the community of periphytic algae in a mature stage, was characterised by greater stability. It is believed that the effects of variation in water levels caused by upstream reservoirs can likewise also modify the structure and stability of periphytic algae in the Upper Paraná River floodplain.

scholarly journals Periphytic algal community in lentic environments of the Upper Paraná River floodplain: seasonal and spatial variation

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Kisay Lorena Adame ◽  
Barbara Dunck ◽  
Liliana Rodrigues
Keyword(s):  
Species Richness ◽  
Seasonal Variation ◽  
Hydrological Regime ◽  
Paraná River ◽  
Algal Community ◽  
River Floodplain ◽  
Periphytic Algae ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River

Abstract Aim: This study aimed to evaluate the influence of seasonal variation in the hydrological regime and of limnological variables on species richness of periphytic algae in lakes of the Upper Paraná River floodplain. Methods The study area is located in the last undammed stretch of the Paraná River in this floodplain, in which three lakes were sampled quarterly (May, August and November 2014, and February and May 2015) for one year. The periphytic material was obtained from petioles of the aquatic macrophyte Eichhornia azurea (Sw.) Kunth. Results We registered 149 taxa of periphytic algae, distributed in 9 classes. Algal richness changed as a function of the seasonal dynamics of the Paraná River’s hydrological regime. Water level fluctuations directly influenced periphytic algae species. During periods of high water level, species richness increased. Limnological variables showed a close relationship with the hydrological regime, and the dissolved nutrients and turbidity were the abiotic factors that most influenced the algal community. The following species were present in all lakes: Fragilaria capucina Desmazières, Gomphonema gracile Ehrenberg and Navicula cryptotenella Lange-Bertalot (Bacillariophyceae) and two species of the genus Oedogonium (Oedogoniophyceae). Conclusions The hydrological regime of the Paraná River played an important role in structuring communities of periphytic algae. Seasonal variation in hydrological regime and in limnological variables together influenced the species richness of these organisms in these floodplain lakes.

scholarly journals Periphytic algae of the Garças Lake, Upper Paraná River floodplain: comparing the years 1994 and 2004

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 459-468 ◽  
Author(s):  
EA. Murakami ◽  
DC. Bicudo ◽  
L. Rodrigues
Keyword(s):  
Environmental Changes ◽  
Hydrological Regime ◽  
Paraná River ◽  
Nutrient Concentrations ◽  
River Floodplain ◽  
Periphytic Algae ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

The changes imposed by dams on hydrological regime, water transparence and nutrient concentrations downstream affect biodiversity in relation to species richness and specific composition of the community. The aim of this work was evaluate this effect on periphyton, comparing richness and composition of periphytic algae in the Garças Lake, Upper Paraná River floodplain, between the years 1994, before construction of the Porto Primavera Reservoir, and after its operation in 2004. This floodplain lake showed an increase in species, from 113 in 1994 to 159 in 2004. A few species, however, were common during the last year, dominated by Zygnemaphyceae and some Bacillariophyceae species. The increase in algal diversity in 2004 may be the result of the ability of the system to adapt to environmental changes. However, the large change in the periphyton species composition suggests further impacts on the food web, demanding continuity of long-term studies in order to determine their consequences on the biodiversity as a whole.

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.

scholarly journals Vascular flora of the Upper Paraná River floodplain

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 735-745 ◽  
Author(s):  
MC. Souza ◽  
K. Kawakita ◽  
SR. Slusarski ◽  
GF. Pereira
Keyword(s):  
Ricinus Communis ◽  
Paraná River ◽  
Pennisetum Purpureum ◽  
Panicum Maximum ◽  
River Floodplain ◽  
Parana River ◽  
Number Of Species ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

The purpose of this study was to update the floristic inventory found in the Upper Paraná River floodplain. Floristic surveys were performed from February 2000 through March 2008, as part of the Brazilian Long-Term Ecological Research Program (PELD/CNPq -Site 6). The material collected was identified from 774 species, 442 genera, and 116 families. The ten families with high species richness were Leguminosae, Poaceae, Rubiaceae, Asteraceae, Euphorbiaceae, Myrtaceae, Cyperaceae, Solanaceae, Sapindaceae, and Orchidaceae, which contributed to 46.1% of the total number of species. Genera with high richness were Solanum, Cyperus, Panicum, Eugenia, Tillandsia, Serjania, Casearia, and Polygonum, which together contributed to 10.2% of the total number of species. These data, combined with information published in 1997, recorded 955 species, 575 genera, and 128 families. These organisms were from several riparian environments and were distributed as herbs, shrubs, trees, climbers and epiphytes. Panicum maximum, Pennisetum purpureum, Ricinus communis, and Urochloa decumbens are considered weeds due to the wide distributions determined for these species. The results presented herein suggest the need to further investigate the control of these potential weed species.

scholarly journals Inter-annual variations in the abundance of young-of-the-year of migratory fishes in the Upper Paraná River floodplain: relations with hydrographic attributes

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 649-660 ◽  
Author(s):  
HI. Suzuki ◽  
AA. Agostinho ◽  
D. Bailly ◽  
MF. Gimenes ◽  
HF. Júlio-Junior ◽  
...  
Keyword(s):  
Water Levels ◽  
Migratory Species ◽  
River Floodplain ◽  
Annual Variations ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Young Of The Year ◽  
Paraná River Floodplain ◽  
Migratory Fishes

In this study, we identified and characterized the hydrographic attributes related to the success of recruitment of migratory fishes in the Upper Paraná River floodplain. To achieve our objectives, we analyzed inter-annual variations in the abundance of young-of-the-year (YOY; index of recruitment) of six migratory species and their relations with hydrographic attributes. Recruitment was related to the intensity, duration (in different fluviometrical levels), elasticity, number of pulses, greater uninterrupted overflow and delay of the floods (all obtained using the PULSO software). Collections of fish were conducted in the period between January 1987 and November 2007 in distinct environments (river channels, secondary channels and connected and disconnected floodplain lakes) distributed along three subsystems (Paraná, Baía and Ivinheima). Relations between recruitment and the attributes of interest were determined through analysis of covariance. In the studied period, the highest abundances of YOY were registered in 2007, followed by 1992, 1993, 2005 and 1988. The abundance of YOY was positively correlated with an intensity of high water levels (potamophase) and the duration of potamophase 1 and negatively with the duration of low water levels (limnophase) and a delay of flood. Higher hydrometric levels (540 and 610 cm for Paraná and 325 and 450 cm for Ivinheima) and greatest uninterrupted overflow presented different relations (significant interactions) among subsystems, but all with positive effects on recruitment. Results evidenced that recruitment responded better when floods started in January with potamophase intensities above 610 cm and water levels above 450 cm over a period of 50 days and repeated every two years (or > 610 cm for 38 days and repeated every two or three years). Therefore, artificial control of the floods at intervals of two or three years by manipulating the discharge of dams located upstream from the floodplain in a way that promotes potamophases with the potential to ensure recruitment of migratory species may become an important tool for conservation of migratory fish species in the floodplain.

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