Processing of Maple Leaf, Grass and Fern Packs and Their Colonization by Invertebrates in a Stream

Abstract

ABSTRACT Processing of maple leaf, grass and fern packs (MLP, GP and FP) was investigated in a riffle area of Canagagigue Creek, Ontario where the stream flows through a small woodlot surrounded by agricultural fields. Processing was faster in spring at higher water temperatures than in autumn and % weight loss in general was in the order MLP > FP > GP. Loss of C in MLP was greater (P < 0.01) than in GP and FP in spring and autumn, whereas % N and % P content was greater (P < 0.01) in MLP than FP and GP (% N of FP in autumn was an exception) and was in the order MLP > FP > GP. Colonization of GP by invertebrates was greater (P < 0.05) than that of MLP in spring (GP > FP > MLP), but no difference was seen in autumn (MLP > GP > FP). Baetis preferred to colonize MLP (P < 0.05) than GP and FP, whereas snails, Physa, preferred GP and FP (P < 0.05) to MLP. These plant litters were not only processed at different rates, but exhibited marked differences in nutrient dynamics.