Skip to main content

Risk Assessment of Potential Biofuel Species: An Application for Trait-Based Models for Predicting Weediness?

  • Roger Cousens (a1)

To avoid major negative impacts of the widespread adoption of biofuel species, whether they are exotic species, natives, or novel constructs, we need a system for screening their weed potential. Australia is an important global center of biodiversity and also has major cropping industries to protect. Prevention of the entry of further weeds is therefore a major national priority. The Weed Risk Assessment (WRA) system was developed and implemented for importation decisions in 1997; it has since been introduced into other countries and is probably as good as any system currently in operation. However, we need to be aware of the limitations of any system, to address these, and to work toward improved or alternative systems. WRA is a very simple spreadsheet requiring answers to questions about a species' life-history traits, dispersal, habitat suitability, impacts on other species, and history overseas, which are then added together and compared with numerical decision criteria. Its predictive powers are limited by this simplicity and by the complexity of human attitudes toward risk and impact. Alternative risk-management methods are available but, even so, the capacity for improvement is limited. It is quite possible, therefore, that in using any trait-based system to assess the negative risks of importation or interstate translocation of biofuel species, we will wrongly reject a valuable species or approve a species that turns out to be a major weed. It is suggested that, rather than attempting to improve a single-tiered decision-support system (the quarantine “sieve”), a multitiered system (nested sieves) would lead to a more effective system and greater cost-effectiveness. The key to this would be a postentry screening process for those species that have successfully passed through the WRA system.

Corresponding author
Corresponding author's E-mail:
Hide All
Baker H.G. 1965. Characteristics and modes of origin of weeds. Pages 147172. in Baker H.G. and Stebbins G.L. The Genetics of Colonizing Species. New York Academic.
Baker H.G. 1974. The evolution of weeds. Annu. Rev. Ecol. Syst. 5:124.
Barlow B.A. 1994. Phytogeography of the Australian region. Pages 335. in Groves R.H. Australian Vegetation. 2nd ed. Cambridge, UK Cambridge University Press.
Caley P. and Kuhnert P.M. 2006. Application and evaluation of classification trees for screening unwanted plants. Austral Ecol. 31:647655.
Caley P., Lonsdale W.M., and Pheloung P.C. 2006. Quantifying uncertainty in predictions of invasiveness, with emphasis on weed risk assessment. Biological Invasions. 8:15951604.
Cook G.D. and Dias L. 2006. It was no accident: deliberate plant introductions by Australian government agencies during the 20th century. Aust. J. Bot. 54:601625.
Cooney R. 2005. Introduction. Pages 317. in Cooney R. and Dickson B. Biodiversity and the Precautionary Principle: Risk and Uncertainty in Conservation and Sustainable Use. London Earthscan.
Cousens R. 1985. A simple model relating yield loss to weed density. Ann. Appl. Biol. 107:239252.
Cousens R., Dytham C., and Law R. 2008. Dispersal in Plants: A Population Perspective. Oxford Oxford University Press.
Crawley M.J. 1997. Biodiversity. Pages 595632. in Crawley M.J. Plant Ecology. 2nd ed. Oxford Blackwell Science.
Crooks J.A. 2002. Characterizing ecosystem-level consequences of biological invasions: the role of ecosystem engineers. Oikos. 97:153166.
Daehler C.C., Denslow J.S., Ansari S., and Kuo H.C. 2004. A risk-assessment system for screening out invasive pest plants from Hawaii and other Pacific islands. Conserv. Biol. 18:360368.
Denslow J.S. and DeWalt S.J. 2008. Plant invasions in tropical forests: patterns and mechanisms. Pages 409426. in Carson W.P. and Schnitzer S.A. Tropical Forest Community Ecology. Oxford, UK Blackwell Scientific. In press.
Elith J., Graham C.H., Anderson R.P., et al. 2006. Novel methods improve prediction of species' distributions from occurrence data. Ecography. 29:129151.
Forcella F. 1985. Final distribution is related to rate of spread in alien weeds. Weed Res. 25:181191.
Gordon D.R., Onderdonk D.A., Fox A.M., and Stocker R.K. 2008. Consistent accuracy of the Australian weed risk assessment system across varied geographies. Divers. Distrib. 14:234242.
Groves R.H. 1991. A short history of biological invasions of Australia. Pages 5963. in Groves R.H. and Di Castri F. Biogeography of Mediterranean Invasions. Cambridge, UK Cambridge University Press.
Groves R.H. 2002. Robert Brown and the naturalized flora of Australia. Cunninghamia. 7:623629.
Groves R.H. and Hosking J.R. 1997. Recent incursions of weeds to Australia 1971–1995. Technical Series No. 3. Adelaide, Australia CRC for Weed Management Systems.
Groves R.H. and Willis A.J. 1999. Environmental weeds and loss of native plant biodiversity: some Australian examples. Aust. J. Environ. Manag. 6:164171.
Hazard W.H.L. 1988. Introducing crop, pasture and ornamental species into Australia—the risk of introducing new weeds. Austr. Plant Intro. Rev. 19:1936.
Holm L.G., Plunknett D.L., Pancho J.V., and Herberger H.P. 1977. The World's Worst Weeds: Distribution and Biology. Honolulu University Press of Hawaii.
Hughes G. and Madden L.V. 2003. Evaluating predictive models with application in regulatory policy for invasive weeds. Agric. Syst. 76:755774.
Keeler K.H. 1989. Can genetically engineered crops become weeds. Bio/Technology. 7:11341139.
Keller R.P., Lodge D.M., and Finnoff D.C. 2007. Risk assessment for invasive species produces net bioeconomic benefits. Proc. Natl. Acad. Sci. 104:203207.
Kot M., Lewis M.A., and van den Driessche P. 1996. Dispersal data and the spread of invading organisms. Ecology. 77:20272042.
Kriticos D.J. and Randall R.P. 2001. A comparison of systems to analyze potential weed distributions. Pages 6179. in Groves R.H., Panetta F.D., and Virtue J.G. Weed Risk Assessment. Collingwood, Australia CSIRO.
Lonsdale W.M. 1994. Inviting trouble: introduced pasture species in northern Australia. Aust. J. Ecol. 19:345354.
Low T. and Booth C. 2007. The Weedy Truth About Biofuels. Melbourne Invasive Species Council.
MacArthur R.H. and Wilson E.O. 1967. The Theory of Island Biogeography. Princeton, NJ Princeton University Press.
Mack R.N. 1996. Predicting the identity and fate of plant invaders: emergent and emerging approaches. Biological Conservation. 78:107121.
Maguire L.A. 2004. What can decision analysis do for invasive species management. Risk Analysis. 24:859868.
Maillet J. and Lopez-Garcia C. 2000. What criteria are relevant for predicting the invasive capacity of a new agricultural weed. The case of invasive American species in France. Weed Res. 40:1126.
Morfe T.A., Weiss J., and McLaren D.A. 2002. Economics of serrated tussock and Mexican feather grass in Victoria: Why we need to act now. Plant Prot. Q. 17:8694.
National Weed Risk Assessment System (NWRAS) 2006. Review of the National Weed Risk Assessment System. Canberra, Australia Natural Resource Management Standing Committee/Primary Industries Standing Committee Sub-Committee.
Nix N.H. 1986. A biogeographic analysis of Australian elapid snakes. Pages 415. in Longmore R. Atlas of the Australian Elapid Snakes. Canberra, Australia Bureau of Flora and Fauna.
Noble I.R. 1989. Attributes of invaders and the invading process: terrestrial and vascular plants. Pages 301313. in Drake J.A., Mooney H.A., do Castri F., Groves R.H., Kruger F.J., Rejmánek M., and Williamson M. Biological Invasions: A Global Perspective. New York Wiley.
Panetta F.D. 1993. A system of assessing proposed plant introductions for weed potential. Plant Prot. Q. 8:1014.
Panetta F.D., Mackey A.P., Virtue J.G., and Groves R.H. 2001. Weed risk assessment: core issues and future directions. Pages 231240. in Groves R.H., Panetta F.D., and Virtue J.G. Weed Risk Assessment. Collingwood, Australia CSIRO.
Parker I.M., Simberloff D., Lonsdale W.M., et al. 1999. Biol. Invasions. 1:319.
Parker P., Caton B.P., and Fowler L. 2007. Ranking nonendigenous weed species by their potential to invade the United States. Weed Sci. 55:386397.
Perrins J., Williamson M., and Fitter A. 1992. Do annual weeds have predictable characters. Acta Oecol. 13:517533.
Pheloung P.C. 2001. Weed risk assessment for plant introductions to Australia. Pages 8392. in Groves R.H., Panetta F.D., and Virtue J.G. Weed Risk Assessment. Collingwood, Australia CSIRO.
Pheloung P.C., Scott J.K., and Randall R.P. 1996. Predicting the distribution of Emex in Australia. Plant Prot. Q. 11:138140.
Pheloung P.C., Williams P.A., Halloy S.R., and S. R. 1999. A weed risk assessment model for use as a biosecurity tool evaluating plant introductions. Journal of Environmental Management. 57:239251.
Pianka E.R. 1970. On r- and K-selection. Am. Nat. 104:592597.
Radford I.J. and Cousens R.D. 2000. A comparative ecological study of Senecio madagascariensis (fireweed) and S. lautus (variable groundsel) (Asteraceae). Oecologia. 125:531542.
Raghu S., Anderson R.C., Daehler C.C., Davis A.S., Wiedenmann R.N., Simberloff D., and Mack R.N. 2006. Adding biofuels to the invasive species fire. Science. 313:1742.
Randall R.P. 2007. The introduced flora of Australia. Adelaide, Australia CRC for Australian Weed Management.
Regan H.M., Colyvan M., and Burgman M.A. 2002. A taxonomy and treatment of uncertainty for ecology and conservation biology. Ecol. Appl. 12:618628.
Reichard S.H. and Hamilton C.W. 1997. Predicting invasions of woody plants introduced into North America. Conservation Biology. 11:193203.
Rejmánek M. 1996. A theory of seed plant invasiveness: The first sketch. Biol. Conserv. 78:171181.
Rejmánek M. 2001. What tools do we have to detect invasive plant species. Pages 39. in Groves R.H., Panetta F.D., and Virtue J.G. Weed Risk Assessment. Collingwood, Australia CSIRO.
Rejmánek M. and Richardson D.M. 1996. What makes some plant species more invasive. Ecology. 77:16551661.
Roy J. 1990. In search of characteristics of plant invaders. Pages 335352. in di Castri J., Hansen A.J., and Debussche M. Biological Invasions in Europe and the Mediterranean Basin. Dordrecht Kluwer.
Scott J.K. and Panetta F.D. 1993. Predicting the Australian weed status of southern African plants. Journal of Biogeography. 20:8793.
van Kleunen M. and Johnson S.D. 2007. South African Iridaceae with rapid and profuse seedling emergence are more likely to become naturalized in other regions. J. Ecol. 95:675681.
Wainger L.A. and King D.M. 2001. Priorities for weed risk assessment: using a landscape context to assess indicators of functions, services and values. Pages 3451. in Groves R.H., Panetta F.D., and Virtue J.G. Weed Risk Assessment. Collingwood, Australia CSIRO.
Walton C.S. 2001. Implementation of a permitted list approach to plant introductions in Australia. Pages 9399. in Groves R.H., Panetta F.D., and Virtue J.G. Weed Risk Assessment. Collingwood, Australia CSIRO.
Weber J., Panetta F.D., Virtue J., and Pheloung P. In press. An evaluation of eight years' data from the Australian border weed risk assessment system. J. Environ. Manag.
Williams P.A. 2003. Guidelines for weed-risk assessment in developing countries. Pages 3759. in Labrada R. FAO Plant Production and Protection Paper 120 Addendum 1, Weed Management for Developing Countries. Rome Food and Agriculture Organization of the United Nations.
Williamson M. 1993. Invaders, weeds and the risk from genetically modified organisms. Experientia. 49:219224.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Weed Science
  • ISSN: 0043-1745
  • EISSN: 1550-2759
  • URL: /core/journals/weed-science
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 1 *
Loading metrics...

Abstract views

Total abstract views: 57 *
Loading metrics...

* Views captured on Cambridge Core between 20th January 2017 - 14th December 2017. This data will be updated every 24 hours.