ASPECTS OF DECOMPOSITION OF CELLULOSE IN CANADIAN SOILS: I. OBSERVATIONS WITH THE MICROSCOPE

Abstract

The course of cellulose decomposition in certain Canadian soils was followed by means of the microscope. Under the conditions of incubation provided, fungi initiated decomposition. Coarse mycelial forms, including a species of Rhizoctonia, were dominant. Species of Humicola and Botryotrichum and similar, sterile forms characterized by their "rooting branches" in cellulose film were subdominant. Following fungal growth, bacteria appeared and nematodes developed on both fungi and bacteria. The later stages of decomposition and disintegration of the cellulose were caused by larger fauna, including mites, collembolans, and enchytraeid worms. Nonhomogenous distribution of the various organisms in the soil samples resulted in considerable variation in rate and extent of decomposition of individual pieces of cellulose. Some pieces were entirely disintegrated, others were untouched after 5 weeks.