Periphytic community of reservoirs cascade in the Paranapanema river, Brazil - DOI: 10.4025/actascibiolsci.v27i3.1333

Abstract

Along its course, the Paranapanema River presents some hydroelectric dams. During the year 2001, seven of these (Chavantes, Salto Grande, Canoas II and I, Capivara, Taquaraçu and Rosana) had their periphytic community studied. Samples of periphyton in natural substratum of the epiphyton type were collected from the river banks during the dry and the rainy seasons. Overall, the periphytic biomass in reservoirs of the Paranapanema River was characterized according to the rain regime of the area with higher and irregular values in the rainy period. The periphytic community demonstrated higher values of biomass, composition and abundance in the reservoirs located in middle Paranapanema, especially in Salto Grande and Canoas I. The Rosana and the Capivara Reservoirs presented higher values of algal density, chlorophyll a and species richness. The structure of the phycoperiphytic community was controlled by several factors, especially oscillation in precipitation, secchi depth, depth, retention time, temperature and water nutrients