Plant reproductive phenology and floral resources of an Australian subtropical rainforest

Abstract

A survey of the reproductive features of the rainforest flora of Lamington National Park, based on herbarium records and published floras, is presented to provide a community-wide description of floral morphology and flowering phenology. The flora is predominantly composed of shrubs and trees, but also supports a large diversity of vine species. The majority of species (73.5%) have flowers less than 10 mm in diameter of which 80% are white or green in colour. The greatest number of species are in flower from September through to February, although a number of species flower during the cooler, drier winter months. The data compiled on floral features and phenology for individual plant species were assigned to the species lists derived from the IBISCA-Queensland (Qld) altitudinal gradient in Lamington National Park, Australia. No statistically significant changes in flower colour or size were detected with increasing altitude from 300 m to 1100 m a.s.l., but decreasing trends in the proportions of colourful flowers, flowers less than 5 mm in diameter and unisexual flowers were observed. No pollination studies conducted in Lamington National Park have been published although subtropical forests in general are believed to be predominantly generalist pollinated. Data on the morphology of flowers and timing of flowering provide some support for this idea. Determining the prevalence and species turnover of such generalist pollination systems along altitudinal gradients, such as the IBISCA-Qld gradient, could help determine the reproductive resilience of subtropical rainforest plant species under climate change.