Distribution and abundance of benthic invertebrates in a Sonoran Desert stream

Abstract

Numbers and biomass of benthic invertebrates generally varied in proportion to standing crops of filamentous algae. This association of invertebrates and algae may indicate the importance of autochthonous production in the trophic relations of the stream. Summer flash flooding was also a significant factor affecting the seasonal abundance of invertebrates by critically reducing population levels. In spite of such severe flooding, recovery by invertebrates was consistent, and the stream was able to support annual mean standing crops of benthic invertebrates comparable to those in streams of other regions where floods are not as frequent and intense.