Succession of fungi in leaf litter of Eucalyptus regnans

Abstract

The succession of fungi associated with the decomposing leaf litter of Eucalyptus regnans F. Muell. has been studied over a period of 60 weeks. A technique for separating the litter into layers in order to relate the degree of decomposition of the leaves to the mycofloral population is described. Species of Coelomycetes and some Moniliales were the important initial elements of the mycoflora in the litter, but species of Penicillium and Mucorales succeeded them on leaves in advanced stages of decomposition. Loss of activity from radio-active leaves placed on the litter was used to follow changes in the decomposing leaves as a source of nutrients for the fungi. The growth of certain species on leaves at definite stages of decomposition, and their ability to utilize specific substances in vitro, were studied in an attempt to clarify the physiological reason for fungal succession. The results suggest that fungi capable of utilizing cellulose or pectin are the important initial colonizers.