Weeds can be significant at a property, local, regional, state and/or national level based on their impact or potential impact. There are a number of recognised 'lists' of weeds of national interest. The nature of the weeds, and the resulting national actions required, determine on which lists a species may appear.
Weeds of National Significance
Thirty two Weeds of National Significance (WoNS) have been identified by Australian governments based on their invasiveness, potential for spread and environmental, social and economic impacts.
National Environmental Alert List
The National Environmental Alert List (the Alert List) for environmental weeds identifies 28 plant species that are in the early stages of establishment and have the potential to become a significant threat to biodiversity if they are not managed.
Sleeper weeds are plants from overseas that have currently established only small wild populations but have the potential to spread widely and affect agricultural or natural environments. Huge environmental damage and control costs can be prevented if these weeds are eradicated before they become widespread.
Species targeted for eradication
There are six species targeted for national eradication under the Natural Resource Management Ministerial Council's National Cost-sharing Eradication program.
Species permitted entry into Australia
There are also lists that identify what plant species are permitted entry into Australia. More information is available at Lists of databases of plants or plant material prohibited from import into Australia.
Species targeted for biological control
Successful biological control is the most effective way to control most weeds in the long term. Weeds are listed as target species for biological control through a cross-jurisdictional government process that allows for research on biological control for that weed.
The introduction of a potential biological control agent is separately assessed under the Quarantine Act 1908 and the Environment Protection and Biodiversity Conservation Act 1999. The assessment involves comprehensive host testing (testing what plants the biological control agent will attack) before release.
State and territory noxious weed lists
In addition to the national lists above, state and territory governments have their own lists of noxious weeds. The Weeds Australia website contains a summary of the state and territory noxious weed legislation and associated lists.