Effects of Burial on Food Value and Consumption of Leaf Detritus by Aquatic Invertebrates in a Lowland Forest Stream

The effects of burial on leaf processing in a lowland forest stream were determined by comparing decomposition rates, changes in chemical composition and palatability of leaf packs that had been buried or incubated at the surface. Surface incubated leaves lost weight faster and contained a lower organic and caloric content than buried leaves. There were no significant differences in crude protein content between buried and surface incubated leaves. In the laboratory, Acer and Populus leaves that had been serially incubated either below or above the sediments were fed to three invertebrate consumers, Tipula, Gammarus and Pycnopsyche. Significantly more of surface incubated Acer and Populus were consumed than buried leaves. Differences in percent organic matter, caloric content and percent crude protein are considered as factors responsible for the observed differences in leaf processing and palatability. The significance of leaf burial as a homeostatic mechanism is also discussed.