Litter Fall and Leaf Decomposition in a River Red Gum (Eucalyptus camaldulensis) Swamp

Abstract

Litter fall and leaf decomposition rates were measured in Murrumbidgil Swamp, a river red gum (Eucalyptus camaldulensis) swamp near Booligal, New South Wales. Total litter fall, excluding large branches, was about the same as in other eucalypt and overseas hardwood forests (369-580 g m^-2 year^-1), but the proportion of leaf fall (21-29%) was lower. Litter fall was greater after the swamp dried out following a prolonged period of flooding than during the flood period. Ionic concentrations in the leaf litter were higher than in other eucalypts, but accessions were similar because leaf fall was lower in the red gum forest. The order of nutrient input was Ca > N > Mg ≈ Na ≈ K > S > P > Fe. Decomposition of red gum leaves submerged in the swamp was rapid at first (up to 19.2% loss in weight in 24 h) and then slowed down. The half life of the leaves decomposing over 4 months was 80 days. It is suggested that E. camaldulensis litter may provide an important food source for detritivorous invertebrates and hence for waterfowl in red gum swamps.