Skip to Navigation

Pathway risk analysis for weed spread within Australia


This project is designed to ascertain the ways in which weeds spread once in Australia and to assess the relative risks or threats from different pathways of weed spread. This will enable better targeting of efforts to reduce the movement of high risk weeds around Australia.


The purpose of this research is to:

  • assess the relative risks of sources and pathways of weed ingress within Australia; and
  • identify ways to reduce these risks.


Twenty four sources (sites or areas of land where weeds are actively growing and from which new invasions may emerge) and 17 pathways (the means by which weed propagules are moved) were identifies for weed spread in Australia through the review of literature. The most important sources of weed proagules, according to survey respondents, were Transport sites such as roads, railways, ports, airports and water transport sites. Other important sources of weeds were Land in transition, Pasture/ rangelands, Horticulture – ornamental and private gardens, and Rivers.

While every effort must be made to prioritise high risk pathways of weed spread for management and regulation, the number and wide diversity of potential sources and pathways ( in reality anything that moves or is moved) shows the difficulty of the task of preventing weed spread altogether.


There has been considerable effort to elucidate the means by which weeds and potential weeds enter Australia and to assess the risks associated with importation of plants, but no comprehensive studies have been undertaken to ascertain the way that weeds spread once present within Australia or to assess the relative threats or risks (likelihood and potential magnitude) of different sources and pathways due to species, quantity of propagules, distance, and sensitivity of the invaded environment. Most recently naturalised taxa are still only locally distributed, and so it is critical to identify the primary pathways for the spread of these, as well as more widespread weeds, so as to be able to prevent movement to un-infested areas. The approach and methods taken in this project will on the whole result in the maximum amount of information in weed ingress being obtained in a timely and cost efficient way.

Publications and Resources

None listed


Land & Water Australia. 2008. Pathway risk analysis for weed spread within Australia. [Online] (Updated April 28th, 2009)
Available at: [Accessed Wednesday 23rd of October 2013 09:51:56 PM ].


State & NRM Region(s)

Related Topics

id: 2566 / created: 18 August, 2008 / last updated: 28 April, 2009