Weeds are plants growing where they are not wanted. Weeds cause high economic, social and environmental costs in many parts of Australia. Some weed species are so widespread and insidious that they have become of national significance.

I have no formal training in this area and so to me the selection process is quite complex and so for a more accurate explanation of this process you should look at the document "The Determination of Weeds of National Significance" on the Weeds Australia Web site.

73 plants including specific willow taxa under one heading of willows, were initally nominated by State Governments and these were condensed to 71 that went through the ranking process.

The ranking process was based on four major criteria:

•  
• invasiveness;
• impacts;
• potential for spread, which included analysis of the current and potential distribution of the weed
• socioeconomic and environmental values which included
• Economic data for agricultural and forestry weeds (primary industries)
  Environmental values
• Biodiversity indicators refering to Threatened species data and the numbers of threatened conservation areas
• Conservation indicators including the impacct of the weeds in Interim Biogeographic Regionalisation of Australia (IBRA) regions and the monoculture potential of the weed
• Social values
The following factors and attributes for which data was not available were not included in the ranking process:.
• feasibility of control;
• level of control currently available for the weed;
• previous and likely future success in controlling the weed;
• a weed’s susceptibility to disease, insect and/or vertebrate attack;
• ecological considerations such as the length of the vegetative and flowering periods;
• current integrated weed management research;
• State/Territory history in controlling the weed;
• the weed’s current priority and funding commitments within State/Territory programs; and

• valuing land uses.

Whilst Willow Warriors did not contribute to the assessment process we hope to contribute to future reviews by contribution mapping data by willow taxa to show the changes in current distribution of willow taxa