Fruiting Phenologies of Rainforest Plants in the Illawarra Region, New South Wales, 1988-1992

Abstract

Phenological patterns of fruit production have an important influence on the ecology of frugivores, and vice versa. A longitudinal study of fruiting cycles in rainforest plants was carried out in the Illawarra region between 1988 and 1992 as part of an investigation on food resources for frugivorous birds. A total of 82 species of fruit-producing plants were recorded, and seasonal availability of fruiting plants was examined by the mean number of species in crop production per month. Fruiting plants were available year round, with peaks occurring in autumn and early winter. The crop periods of most species were subject to substantial variability from year to year. There were no positive correlations between the monthly numbers of trees, and vines and climbers in fruit and climatic variables such as rainfall and temperature. Rainforests in southeastern Australia have lower botanical diversity than those of lower latitudes, attributing to substantial geographical variation in frugivore-plant relationships. Core crop periods were determined in 23 species of trees, three species of shrubs, six species of vines and climbers. Fruiting patterns in the remaining species were sporadic. Data presented in this paper provide baseline data for further studies, with important implications for natural resource and conservation management.