The effects of flooding and sediments on the structure of a stream midge assemblage

Abstract

Sediment structure and degree of flooding were shown to affect the distribution and abundance of an assemblage of chironomid midges in a sandy bottom area of a fourth order midwestern stream. There was significant change in midge abundance with time, and the rate of change of abundance was inversely related to the degree of flooding. Abundances ranged from 0.115 to 110 organisms/10 sq. cm. In experimental studies of colonization of different sediments, species demonstrated strong resource partitioning, however, there was no evidence for further intraspecific partitioning of the habitat by instars.