Estudo comparativo de parâmetros limnológicos de duas bacias de drenagem da região Centro-Sul do estado do Paraná, Sul do BrasilComparative study of the limnological parameters of two drainage basins in the mid-southern region of Paraná state, souther

Duas bacias de drenagem localizadas na região Centro-Sul do estado do Paraná foram estudadas comparativamente com a finalidade de se analisar as características limnológicas de seus ecossistemas lóticos. Dez segmentos de rios e riachos foram avaliados em cada uma das bacias no período de 4 a 28 de junho de 2007. As seguintes variáveis físico-químicas da água foram avaliadas: temperatura, condutividade específica, saturação de oxigênio, pH, turbidez, velocidade da correnteza e profundidade. As duas bacias de drenagem apresentaram valores nominais similares para todos os parâmetros investigados. Diferenças significativas entre os dois ambientes foram obtidos para temperatura, pH e saturação de oxigênio. O dendrograma revelou a formação de cinco pequenos grupos de pontos de amostragem, cada um com características limnológicas particulares. A Análise de Componentes Principais (PCA) confirmou a distinção entre as duas bacias de drenagem. Estes resultados sugerem a influência tanto de fatores regionais quanto locais sobre as características limnológicas dos rios e riachos das duas bacias de drenagem estudadas.Abstract Two drainage basins located in the mid-southern region of Paraná state were comparatively studied for analysis of limnological characteristics in lotic ecosystems. Ten segments of rivers and streams were evaluated in each basin, from June 4th through to June, 29th , 2007. The following physical and chemical parameters were measured: water temperature, specific conductance, oxygen saturation, pH, turbidity, current velocity and depth. The two drainage basins presented similar nominal values for all parameters investigated. There were significant differences between the two environments in relation to temperature, pH, and oxygen saturation. Cluster analysis revealed five small groups of samplings, each one with particular limnological characteristics. The Principal Components Analysis (PCA) confirmed the difference among the drainage basins. These results suggest an influence of regional and local factors in limnological characteristics of rivers and streams in the studied drainage basins

Diagnóstico da qualidade da água do rio Cascavel, município de Guarapuava, Estado do ParanáDiagnosis of the Cascavel River water quality, at the municipality of Guarapuava, Paraná State, Brazil

Diagnósticos da qualidade da água são importantes contribuições para ações de manejo em ambientes lóticos. No presente estudo, variáveis ambientais foram analisadas e o perfil longitudinal foi caracterizado quanto ao nível de poluição da água. Com o auxílio da Análise dos Componentes Principais (PCA) evidenciou-se o padrão encontrado na análise descritiva, a qual permitiu concluir que ocorreu aumento no nível de poluição no sentido montante/jusante e depuração próxima à foz. A análise dos resultados permitiu demonstrar elevado nível de pressão antrópica, sugerindo a necessidade de aplicação de ações de restauração neste ambiente lótico e nos ecossistemas a ele relacionados. Abstract Diagnoses of the water quality are important contributions for management actions in riverside systems. In the present study, environmental variables were analyzed and the longitudinal profile was characterized in relation to the water pollution level. With the aid of Principal Component Analysis (PCA) the pattern found in the descriptive analysis was evidenced, which allowed for the conclusion that an increase of the pollution level in the upstream/downstream direction took place, while depuration occurred near the river mouth. The analysis of the results indicated a high level of human impact, suggesting the urgency of restoration plans in this riverside environment and its related ecosystems

Algas verdes coloniais em riachos de Unidades de Conservação do Sul do Brasil: taxonomia e aspectos ecológicos Colonial green algae from streams of Conservation Units in Southern Brazil: taxonomy and ecological aspects

Espécies de algas verdes coloniais de 10 Unidades de Conservação da região Sul do Brasil foram investigadas. As amostragens foram conduzidas em 105 segmentos de riachos consistindo em transeções de 10 metros de comprimento. Além dos dados biológicos, foram mensuradas algumas variáveis ambientais: profundidade, velocidade da correnteza, temperatura da água, turbidez, condutividade específica, pH, oxigênio dissolvido e nutrientes (nitrogênio total e ortofosfato). Foram registradas três espécies de algas verdes coloniais [Ecballocystis pulvinata Bohlin var. pulvinata, Tetraspora gelatinosa (Vaucher) Desvaux e Tetraspora lubrica (Roth) C. Agardh] as quais foram descritas e ilustradas. Baseando-se nos dados ambientais, foram observados alguns padrões de distribuição ecológica destas espécies, entre os quais a ocorrência de E. pulvinata var. pulvinata em ambientes com temperatura da água e velocidade da correnteza mais elevadas, enquanto as espécies de Tetraspora ocorreram tipicamente em ambientes com valores mais baixos de nitrogênio total, ortofosfato e condutividade específica.AbstractSpecies of colonial green algae from 10 Conservation Units from the Southern Brazil were surveyed. The samplings were carried out in 105 stream reaches, consisting of 10 m length transects. In addition to biological data, some environmental variables were measured: depth, current velocity, water temperature, turbidity, specific conductance, pH, dissolved oxygen and nutrients (total nitrogen and orthophosphate). Three species of colonial green algae [Bohlin Ecballocystis pulvinata var. pulvinata, Tetraspora gelatinosa (Vaucher) Desvaux and T. lubrica (Roth) C Agard] were recorded and these species were described and illustrated. Based on the environmental data, it was observed some patterns of ecological distribution, including the occurrence of E. pulvinata var. pulvinata in environments with higher water temperature and current velocity values, while Tetraspora species typically occurred in environments with lower total nitrogen, orthophosphate and specific conductance values

Ecological distribution of stream macroalgae in different spatial scales using taxonomic and morphological groups

We examined the ecological distribution of macroalgal communities in streams using species groups (taxonomic units = algal phyla, and morphological = morphological types) with similar structures and functions instead of the species themselves. The study was conducted from June to July/2007 in two drainage basins located in mid-southern region of Paraná State , Brazil. Evaluations of macroalgal communities took into consideration the following spatial scales: the drainage basin (the Pedras river and Marrecas river basins), shading regime (open and shaded stream segments), mesohabitats (riffles and pools), and microhabitats (sampling units of 0.05m2). A total of 29 taxa (23 subgeneric, one generic, and five vegetative groups) were identified. on these, 12 taxa belong to Chlorophyta, 11 to Cyanobacteria, four to Heterokontophyta, and two to Rhodophyta. The proportions of morphological types were: 24% free filaments, 17.25% mats, tufts, gelatinous colonies, and gelatinous filaments, 7% crusts. In terms of spatial scales, we observed a predominance of Chlorophyta in open stream segments and Cyanobacteria in shaded stream segments, reflecting the loss of competitive advantage of green algae in sites with low energy availability. In the mesohabitats, the morphological types recorded in pools were predominantly poorly adapted to fast currents (free filaments), while those found in riffles (mats, tufts and gelatinous filaments) were highly resistant to fast water flows. As such, the use of species groupings based on algal taxonomy associated with morphological characteristics proved to be useful to understanding the distributions of these organisms in lotic environments.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Distribution of stream macroalgae in the eastern Atlantic Rainforest of São Paulo State, southeastern Brazil

Fifty-two stream segments were sampled from 16 August to 13 September in 1993 in the eastern Atlantic Rainforest of São Paulo State, southeastern Brazil (22°55′-25°00′S, 44°48′-48°03′W). Forty-two macroalgal subgeneric taxa were found and the most widespread species were Audouinella pygmaea (21% of sites), Compsopogon leptoclados and Microcoleus subtorulosus (19%). Macroalgal species number per sampling site ranged from 0 to six (2.6 ± 1.7) and was positively correlated to species abundance, whereas species cover ranged from 0 to 70% of the stream bed (15.5 ± 20.8%). No significant correlation was found among macroalgal species number and abundance with any physical or chemical variable analyzed. Most sites were dominated by one or few macroalgal species, mainly, Audouinella macrospora, C. leptoclados and M. subtorulosus. No significant difference was found between the frequency distribution of variables measured for streams and for total macroalgae but the most widespread species (A. pygmaea) differed significantly for current velocity, specific conductance, turbidity and pH. Overall means for macroalgal occurrence include the following values: temperature (X̄ = 19.9°C), current velocity (X̄ = 45 cm s-1), oxygen saturation (X̄ = 66%), specific conductance (X̄ = 59.6 μS cm-1), turbidity (X̄ = 5 NTU) and pH (X̄ = 7.1). This pattern of patchy distribution and dominance by few species has been suggested as typical of stream macroalgal communities and has been ascribed to the rapid fluctuation of physical and chemical conditions. Total macroalgal species richness as well as mean species number per sampling site were considerably lower than found in similar studies of other regions. The Intermediate Disturbance Hypothesis was applied to explain these results: the same factor (high precipitation) responsible for the maintainance of the high species diversity in the surrounding forest can be, paradoxically, a constraint to the development of a more diverse macroalgal flora in streams. © 1996 Kluwer Academic Publishers

Basicladia emedii (Cladophorales, Chlorophyta): a new freshwater epilithic species from Brazil

Basicladia emedii sp. nov. is described based on material from six streams in Parana and Rio Grande do Sul States of Brazil. This is only the second species of Basicladia recorded from South America. The new species is distinguished based on small filaments with short and wide basal cells of upright axes. It is only the second (out of six) species that is only known with an epilithic habit and is not associated with either snail shells or turtle carapaces.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq