Influence of environmental predictors on hyphomycete assemblages in subtropical streams

Abstract

Hyphomycetes are important aquatic organisms for organic matter decomposition, releasing inorganic nutrients to the environment. Understanding distribution patterns of hyphomycetes among different types of habitats can reveal important environmental characteristics that affect their assemblages and, as a consequence, can change stream functioning. We evaluated the effects of environmental predictors over hyphomycete assemblages in a field experiment in 12 subtropical Atlantic Forest streams. We identified 21 species of aquatic hyphomycetes, where Lunulospora curvula, Flagellospora curvula and Aquanectria submersa are dominant species, occurring in 10 streams, while Anguillospora sp., Campylospora parvula and Mycocentrospora acerina were found in only one stream. The variables dissolved oxygen, electrical conductivity and pH-influenced hyphomycete assemblages. Electrical conductivity acts as filter for spore output, while dissolved oxygen, electrical conductivity and phosphate are environmental filters for species richness. Our findings highlight the importance of environmental predictors over aquatic hyphomycete assemblages. The influence of environmental predictors over spore output and species richness may change stream functioning, since these organisms play an important role in leaf breakdown.