Recruitment of the invasive ornamental, Schinus terebinthifolius, is dependent upon frugivores

Generalist avian frugivores often play an important role in the processes of naturalization and invasion for plants introduced for ornamental and landscaping purposes. We investigated the potential role of Australian birds in the current invasion of riparian habitats and coastal wetlands by the ornamental Schinus terebinthifolius Raddi. Feeding trials in captivity predicted silvereyes (Zosterops lateralis Latham) as dispersal vectors for this weed. There were no differences in either total germination or germination rate between seeds voided by caged silvereyes and those from which exocarps had been removed manually. Germination of seeds incubated within entire fruits was minimal, as was emergence from intact fruits in a held experiment. Seed banks of S. terebinthifolius were relatively transient under field conditions, with no seeds surviving for 9 months. Since fewer than 5% of the seeds in sown whole fruits gave rise to seedlings (cf. 20-42% for sown bare seeds), we conclude that recruitment potential of S. terebinthifolius is highly dependent upon the consumption of its fruits by frugivores.