Herbivory

Abstract

The importance of autotrophs to lotic food webs and the complexity of their interrelationships with herbivores were largely unappreciated until roughly the late 1970s. An emphasis on detrital energy pathways (chapter 5) and on abiotic control of autotrophs may have contributed to a comparative neglect of herbivory. However, with the growing realization that the extent of primary production in running waters likely has been underestimated (Minshall, 1978) there also is recognition that, even in woodland streams, herbivory can play a substantial role Some 50 of the 75 common taxa in Linesville Creek, Pennsylvania, contained substantial amounts of diatoms and algae in their diet, and roughly onefifth of the invertebrate biomass was believed to be supported by periphyton (Coffman, Cummins and Wuycheck, 1971). In Bear Brook, New Hampshire, where algal production was estimated to contribute less than 1% of the total energy inputs (Fisher and Likens, 1973), a moderately abundant caddis larva was found to depend heavily on consumption of periphyton for most of its spring growth (Mayer and Likens, 1987).