Litter Fall and Nutrient Turnover in Two Eucalypt Woodlands

Abstract

The components and chemical composition of litter fall and the litter layer of two woodlands growing close together near Narrabeen Lagoon, New South Wales, were examined over a 5-year period. Total litter fall peaked in the summer but some tree and shrub species in both communities showed peaks of litter fall in summer and autumn. Litter fall averaged 540 g m^-2 year^-1 for a hillside Angophora costata-Eucalyptus gummifera-dominated woodland on a gradational sand, and 745 g m^-2 year^-1 for a E. botryoides-E. robusta-A. floribunda-dominated community on podzolized sand at the slope foot. The accumulated litter masses averaged 2100 and 1900 g m^-2, respectively: calculated litter half-lives were 2.7 years and 1.8 years. The higher rates of litter fall and turnover of organic matter and nutrients in the E. botryoides-E. robusta-A. floribunda community, despite its poorer soil nutrient status, are postulated to result from a more reliable water supply and differing microbial activity at the litter-soil interface, leading to more rapid recycling of nutrients.