Keynote address: Research on bitou bush and boneseed - a work in progress
R.H. Groves, CSIRO Plant Industry, GPO Box 1600, Canberra, Australian Capital Territory 2601, Australia.
In this overview of research on the two environmental weeds bitou bush (Chrysanthemoides monilifera subsp. rotundata (DC.) T.Norl.) and boneseed (C.m. subsp. monilifera (L.) Norl.), I list some of the more significant milestones in previous research as I perceive them before assessing the effectiveness of some present research. Throughout, I emphasize the importance of understanding the ecology of these two subspecies in southern Africa (their region of origin), especially as it relates to their management in southern Australia using biological agents. Further quantification of the impacts of bitou bush and boneseed in reducing native biodiversity will be necessary information for the future, especially for boneseed. For more effective management of the weeds, it will be necessary to continue to exclude entry to Australia and New Zealand of the other four subspecies of Chrysanthemoides monilifera known from southern Africa. An optimal combination of agents for biological control of boneseed in southern Australia and New Zealand is also called for, as is the smarter re-vegetation of areas on which bitou bush and boneseed have been weakened by on-going management. The positive roles of bitou bush and boneseed in stabilizing dunes and in providing early winter food for some migrating native birds will become more significant as these re-vegetation programs progress. Other impacts, either positive or neutral, on different groups of species and ecological processes must also be addressed before an integrated management system can be formulated to further reduce the negative impacts on coastal ecosystems of these two weeds of Australasian significance.
Plant Protection Quarterly (2008) 23 (1) 15-19.