Biotic pollination mechanisms in the Australian flora — a review

Abstract

Various aspects of pollination biology in Australia are examined and the relevant literature is reviewed in detail. The history of Australian pollination studies is briefly discussed and particular emphasis given to the contributions made by some of the more outstanding workers in this field. The enormous diversity of the pollen-vector fauna is documented and emphasis given to the adaptations of particular vector types and of the blossoms that they visit. The pollination role of the Australian invertebrate fauna is discussed and an assessment made of the proportion of anthophilous (i.e., flower-frequenting) taxa in various insect groups. Critical examination of recorded feeding habits of the Australian coleopteran and dipteran faunas reveals that at least 28 of the 121 coleopteran families (i.e., 23%) and 44 of the 87 dipteran families (i.e., 51%) contain anthophilous species. The Australian bee fauna, consisting of c. 3000 species, is exclusively anthophilous and constitutes the most important group of invertebrate pollinators; a comprehensive table listing those bee taxa that have been recorded visiting the blossoms of native plant genera, is provided. Two vertebrate pollination systems are important in the Australian context: ornithophily, involving flower-visiting birds as the pollen vectors, and therophily whereby flying or non-flying mammals act as the pollen transporters. Mammal pollination (therophily) is discussed at length, and several new terms introduced to describe the syndromes of marsupial (metatherophily), placental (eutherophily), and rodent (sminthophily) pollination respectively; comprehensive tables listing the anthophilous chiropteran and marsupial taxa of Australia are also provided. The role of various types of pollen vectors in promoting convergent and divergent floral evolution in the Australian flora is illustrated with examples from selected plant taxa. New information on the pollination biology of the tribe Boronieae (Rutaceae) is presented, and some of the more unusual floral adaptations noted. The review concludes by emphasising those areas where future research is needed and where broad co-operative studies would be most productive.