PHENOLOGY OF FICUS-VARIEGATA IN A SEASONAL WET TROPICAL FOREST AT CAPE-TRIBULATION, AUSTRALIA

We studied the phenology of 198 mature trees of the dioecious fig Ficu s variegata Blume (Moraceae) in a seasonally wet tropical rain forest at Cape Tribulation, Australia, from March 1988 to February 1993. Leaf production was highly seasonal and correlated with rainfall. Trees we re annually deciduous, with a pronounced leaf drop and a pulse of new growth during the August-September drought. At the population level, f igs were produced continually throughout the study but there were pron ounced annual cycles in fig abundance. Figs were least abundant during the early dry period (June-September) and most abundant from the late dry season (October-November) through the wet season (December-April) . The annual peak in reproduction actually reflected two staggered pea ks arising from gender differences in fig phenology. In this dioecious species, female and male trees initiated their maximal fig crops at d ifferent times and flowering was to some extent synchronized within se xes. Fig production in the female (seed-producing) trees was typically confined to the wet season. Male (wasp-producing) trees were less syn chronized than female trees but reached a peak level of fig production in the months prior to the onset of female fig production. Male trees were also more likely to produce figs continually. Asynchrony among m ale fig crops during the dry season could maintain the pollinator popu lation under adverse conditions through within- and among-tree wasp tr ansfers.