Leaf Litter Processing and the Associated Invertebrate Fauna in a Tallgrass Prairie Stream

Abstract

Processing rates and invertebrate colonization of leaf material were measured from November 1980 through April 1981 in a tallgrass prairie stream. Processing rates of artificial leaf packs varied among species (hackberry > elm > chinquapin oak > bur oak> sycamore) and between sites (riffle > pool). Sycamore and bur oak packs were colonized by more invertebrates (primarily collector-scrapers) than were hackberry, elm and chinquapin oak. Both leaf packs and samples of natural leaf aggregations from riffles contained more organisms (shredders in natural aggregations and collector-scrapers in the artificial leaf packs) than did leaf samples from the pools. Differences in invertebrate density between riffle and pool were greater for artificial leaf packs than for natural leaf aggregations. These differences may result from leaf pack construction as well as the natural distribution of leaf material within the stream. In Kings Creek, the slow processing rates, the relatively low densities and diversity of macroinvertebrates, as well as their types and distribution, suggest that (1) leaf material is used more as habitat than as a food source, and (2) macroinvertebrates are not likely to play a major role in degradation of leaf litter.