Overstorey and Understorey Litter Fall in a Eucalypt Forest: Spatial and Temporal Variability

Abstract

Annual litter accession dynamics were investigated in the mixed eucalypt forest of the Griffith University study area, with use of several litter-trapping techniques. The annual rate of accession varied between 1.8 and 3.6t/ha, similar to rates recorded in other open eucalypt forests. The overstorey components dominated the litter fall: overstorey leaves 57-61%; non-leaf litter 30%; understorey litter 8-15%. The shrub leaves, in the localized patches in which they fell, dominated the understorey litter fall, and contributed up to 33% of the total leaf litter. Although the understorey litter was not a major component of the litter fall, it may have important effects on the rate of turnover of the overstorey litter, and in the return of nutrient elements. Litter traps placed on the ground collected significantly more litter than those raised above the layer of low shrubs and grasses. More overstorey litter was collected in traps placed between rather than under the shrubs, particularly those with dense foliage, while the most reliable estimates of the shrub litter were obtained from traps placed directly under randomly selected shrubs.