Litter Decomposition in a Red Maple Woodlot Under Natural Conditions and Under Insecticide Treatment

A coring technique was used to intensively sample the litter layer of a red maple (Acer rubrum) woodlot in the vicinity of Ottawa, Canada. Monthly changes in the litter standing crop provided an accurate estimate of the decomposition rate of red maple litter during 2 summers and 1 winter both under natural conditions and when treated with the insecticide Carbofuran®. The Standing crop of litter ranged annually between °275 and 700 g/m 2 and decomposed at a rate between 1.48 and 2.19 g°m ( —2)°day ( —1) under natural conditions between May and November. A common carbamate insecticide (Carbofuran®) applied at recommended rates reduced the decomposition rates to between 0.99 and 1.26 g°m ( —2)°day ( —1) resulting in an increase in standing crop.