Factors in Forest-Tree Litter Extracts affecting the Growth of Soil Micro-Organisms

Abstract

IT is well known that beech litter is less susceptible to decomposition than is the litter of many other species including maple. One reason for this may be the presence or absence of certain factors inhibiting or stimulating microbial growth. For example, factors inhibitory to various fungi have been shown to occur in leaf exudates of certain plants¹ and in many plant extracts^2,3,4, whereas factors stimulating certain mycorrhizal and saprophytic Hymenomycetes have also been observed³. Antibacterial factors have been demonstrated in extracts of oak and maple leaves⁵, spruce needles⁶, and in other species⁷. Autoclaving of the extract has been shown to increase the inhibition of fungi³ and bacteria⁵ under the experimental conditions used.