Strangler Figs in a Stand of Dry Rainforest in the Lower Hunter Valley, NSW
Abstract:A complete census was conducted of all hemi-epiphytic Ficus individuals within a single stand of dry rainforest. Substrate analyses were conducted on the material from potential hemi-epiphyte germination sites in an attempt to understand the factors influencing the distribution of hemi-epiphytic Ficus individuals within the stand. In all, 191 individuals of Ficus macrophylla ssp. macrophylla (Moreton Bay fig) and 65 individuals of Ficus superba var. henneana (deciduous fig) were found within the stand, providing a mean hemi-epiphyte density of 13.5/ha. Clear host preferences were shown for both fig species with two species, Olea paniculata (native olive) and Drypetes deplanchei (yellow tulip), shown to host 60 per cent and 21 per cent, respectively, of all hemi-epiphytes within the stand. These host trees are characterised by humus pockets that accumulate in depressions on their branches and trunk, as well as in branch axils. Their host potential is thought to be enhanced by the increased visitation of birds that feed on the fruit from both the hemi-epiphytes and these potential host trees. Substrate analyses revealed that while the highly organic epiphytic and rock-surface substrates had a high field capacity, their moisture holding capacity was low. The ponding of water and the reduced desiccation afforded by the microtopography of the germination sites ensures that these sites are more likely to maintain a viable moisture content. It appears that desiccation of the germination substrate could be the major cause of the high rate of juvenile hemi-epiphytic Ficus mortality.
Document Type: Research Article
Affiliations: University of Sydney, Australia
Publication date: July 1, 2000