Relation between environmental variables and aquatic megafauna in a first order stream of the Atlantic Forest, southern Brazil

摘要: The study was done in a first order stream the southern portion of Brazilian Atlantic Rain Forest. Samples aquatic megafauna (amphibians, crustaceans and fishes) were taken with aim describing spatial (longitudinal) temporal (seasonal) patterns species composition abundance. Thirty four structural limnological variables at macro mesoscales from three sampling reaches analysed. spatio-temporal analysis richness diversity indicated gradient which values increased an upstream–downstream direction, independently season year. results showed strong influence environmental on community structure. Furthermore, they revealed hierarchical relation between macroscale mesoscale their abundance various units distribution Carvao creek strongly influenced by presence waterfalls, being progressively richer more diverse downstream. Waterfalls seem to function as selective filters than absolute barriers, presenting different efficiencies for species.