Consequences of dam construction upstream of the Upper Paraná River floodplain (Brazil): a temporal analysis of the Chironomidae community over an eight-year period

Brazilian Journal of Biology

Gc. Rosin¹  Dp. Oliveira-mangarotti¹  Am. Takeda²  Cmm. Butakka¹ 

[1] ,Universidade Estadual de Maringá Programa de Pós-graduação em Ecologia de Ambientes Aquáticos Continentais Maringá PR ,Brazil

关键词: temporal and spatial variation;    Chironomidae;    floodplain;    damming;    variações espaciais e temporais;    Chironomidae;    planície de inundação;    represamento;   

DOI  :  10.1590/S1519-69842009000300014

来源: SciELO

【 摘 要 】

Our study aimed to identify patterns of temporal variation and changes in the structure of the community of Chironomidae larvae in two rivers in the Upper Paraná River floodplain after the construction of a reservoir upstream (Porto Primavera). Samples were taken with a Petersen grab, and were obtained between 2000 and 2007. Chironomidae larvae were identified down to the lowest taxonomic level possible. The high richness of Chironomidae observed in the Paraná and Ivinhema Rivers (100 morphospecies) in comparison to the world average of rivers of the same size (44 species) emphasizes the importance of these habitats for the maintenance of biodiversity. The composition and density of Chironomidae in the years 2000 and 2001 differed from the other years. This period was characterized by extreme changes in the Paraná River flow caused by the closing of the Porto Primavera Dam, which added to a severe dry period in late 2001. The different compositions of morphospecies and the higher similarities in subsequent years are indicative of the recovery and adaptation of the community. In spite of the changes in the composition of morphospecies, diversity was maintained and the community continued to respond to fluctuations in the hydrometric level.

【 授权许可】

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