The importance of crayfish in the breakdown of rhododendron leaf litter at the Coweeta Hydrologic Laboratory in 1999

Rhododendron (Rhododendron maximum) is a common evergreen shrub in riparian areas of the southern Appalachians, where its leaves can comprise a large proportion of leaf litter in streams. However, they are relatively refractory and generally considered a low quality food resource for detritivores. Our objective was to assess whether macroconsumers (primarily crayfish (Cambarus bartonii)) influence rhododendron leaf breakdown in a forested southern Appalachian stream in both summer (when leaves other than rhododendron are relatively scarce) and autumn (when other leaves are relatively abundant). We conducted two leaf decay experiments, one in summer and one in autumn, using pre-conditioned leaves. Macroconsumers were excluded from the benthos of a fourth-order stream using electric fences; we predicted that excluding macroconsumers would reduce the decay rate of rhododendron leaves in both summer and autumn.