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 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 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 Environmental changes and human work in the region of the Upper Paraná River floodplain: processes and interactions

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 583-589 ◽  
Author(s):  
EA. Tomanik ◽  
LM. Paiola ◽  
JB. Martínez-Fernández ◽  
SL. Fernandes
Keyword(s):  
Environmental Changes ◽  
Work Relationships ◽  
Paraná River ◽  
River Floodplain ◽  
Parana River ◽  
Two Factors ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain ◽  
Working And Living Conditions

The environment and society constitute a complex of elements and interactions. Thus, an understanding of the processes in which the environment and psychosocial elements are involved may not be gained from knowledge of just one isolated variable. Based on such premises, the present paper, which summarizes the results of a series of studies, adopts work relationships as its main focus, but in addition, it has two complementary objectives. One is to present some analyses on the interaction between human actions and the environmental changes that have been taking place in the region of the Upper Paraná River floodplain and in its boundaries. A secondary aim is to show how those two factors have been changing people's working and living conditions and the identity configuration of some of the human groups that live at that site.

scholarly journals Characterization of habitats based on algal periphyton biomass in the upper Paraná River floodplain, Brazil

2008 ◽  
Vol 68 (3) ◽  
pp. 503-509 ◽  
Author(s):  
JA. Leandrini ◽  
IA. Fonseca ◽  
L. Rodrigues
Keyword(s):  
Hydrological Regime ◽  
High Water ◽  
Paraná River ◽  
River Floodplain ◽  
Parana River ◽  
Relevant Role ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Periphyton Biomass ◽  
Paraná River Floodplain

Considering the relevant role played by the hydrological regime on the structure and functioning of floodplains, this study aims at characterizing different types of aquatic environments according to periphyton biomass and evaluating the influence of the fluviometric levels of the Paraná River and other forcing functions upon the periphytic community. Periphyton (chlorophyll a) was analyzed in 28 habitats, during the years 2000 and 2001, in high and low water seasons. Both years were characterized by lacking the characteristic high water season. The Principal Components Analysis revealed two groups. The first component was positively associated with hydrometric level, electric conductivity, pH and transparency, and negatively with total nitrogen and total phosphorus, dissolved organic carbon and turbidity. The second component separated the habitats of Paraná River in the period of low waters from other environments, mainly for hydrometric level and high transparency values. Periphytic biomass of the habitats demonstrated that the maintenance of the functional integrity of the Upper Paraná River floodplain is closely related to its hydrologic cycle.

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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