Seasonal Changes in the Quantity and Nitrogen Content of Coarse Detritus in a Southern Ontario Stream

Abstract Seasonal changes in standing crop of coarse, benthic detritus at five locations across a second‐order stream were studied between May 1971 and May 1972. Standing crop near the banks varied seasonally with highest quantities in the autumn and winter, whereas near midstream seasonal changes in standing crop were negligible. Mean annual standing crop was 747 g/m2 (ash‐free dry weight) near the banks and 225 g/m2 (AFDW) at midstream. Deposition experiments showed that standing crops of detritus came to equilibrium in 2–3 days at midstream and in about one week near the banks. Nitrogen content of coarse detritus, which ranged between 0.65 and 3.51% (AFDW), did not vary seasonally but was significantly greater near the banks than at midstream.