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 extracts2,3,4, 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. © 1959 Nature Publishing Group.