Biomass and Structure of a Subtropical Eucalypt Forest, North Stradbroke Island

Abstract

The plant biomass of a Eucalyptus signata-dominated forest 15 m tall growing on infertile sands off the Queensland coast is characterized in detail. The forest has a biomass of 180 t/ha, 90% of which is found in the nine species achieving > 2.5 m height. Of the total biomass, 42.5 % is below ground. Pteridium esculentum occupies 41 % of the understorey biomass, with 50 shrub and herb species partitioning the remainder. Dimension analysis of 10-11 individuals of each of three tree species- Eucalyptus signata, E. umbra subsp. umbra and Banksia aemula-has served to characterize the above- and below-ground growth forms of each species, and provide regressions of the mass of tree components on easily measured plant parts. The size distribution of tree and shrub stems on the site suggests that the major species have evolved quite different reproductive strategies for main- taining a steady-state population in the face of recurrent fires.