Gregarious flowering in a lowland tropical rainforest: A possible response to disturbance by Cyclone Winifred

Abstract

AbstractObservations in tropical lowland rainforests damaged by Cyclone Winifred on 1 February 1986 suggest that the disturbance has been followed by an unusual burst of flowering. Fifty‐four species of concurrently flowering shrubs and trees were recorded in early March along a 4 km road transect in a cyclone‐damaged forest. Approximately 80% of the smaller tree and shrub species observed were flowering. Twelve species which had flowered and fruited prior to the cyclone flowered again. Some species which normally flower following periods of partial or complete deciduousness in the drier months of the year flowered after being defoliated by the cyclone. Widespread defoliation of the rainforests, together with the hot, dry weather which followed the cyclone, exposed the understorey layers to abrupt increases in temperature, insolation, and water stress. It is postulated that these environmental changes may have effected the synchronization of flowering of a larger number of species than would normally occur. It is suggested that longterm changes in the species composition of the damaged forests as a result of coincidences of seed availability and regenerative space may occur.