Effects of Invertebrate Shredders and Leaf Type on Leaf Breakdown in Streams

Abstract

Leaf litter is a vital source of nutrients for stream-dwelling organisms and the rate at which these nutrients are released by decomposition is important to the overall functioning of the stream1. Both microorganisms and aquatic “shedders” (invertebrates that feed on leaves) are important for breaking down leaves that fall into streams, but their relative contributions to leaf breakdown may vary among tree species. We hypothesized 1) that leaves from native trees of oak and maple would decompose more slowly in streams compared to non-native species of buckthorn and black locust2, and 2) amphipod shedders (Fig. 1) would consume more native than non-native leaf biomass because they are adapted to consuming native leaves.