About Weeds

Weeds cost the Australian economy at least $8 billion annually in lost production, reduced biodiversity and money spent directly on weed control (Jones, 2009).

The definition of a weed is both time and site specific and fundamentally involves a plant being out of place. Most plants are intentionally planted because of some benefit to humans. They are not a problem if their population remains within the confines of its original planting location. However, many deliberately introduced plants ‘escape’ and become invasive species that cause substantial damage to agriculture, the environment or human / animal health.

Economics effects
Loss of primary production and expense of weed management activities incurred by landowners and managers is great.

In Australia weeds have traditionally been classified into two broad groups depending on their implied impacts.
These recognised nominal groupings are:

1. Non-classified weeds
2. Noxious weeds 

Non-classified weeds
Non-classified weeds represent an increasing threat to many ecosystems due to the inability to legally restrict their spread in private land. Many species are horticultural escapes that have sat dormant in the landscape before “suddenly” becoming weeds, e.g. Morning Glory, and Asparagus species. They invade native plant communities and reduce biodiversity. They may also restrict access, impinge on recreation activities, impact on human health and reduce the aesthetic value of an area.

Noxious weeds
Some serious weeds are legally required to be controlled or restricted. These are known as noxious weeds and the law that controls these in NSW is the Noxious Weeds Act 1993. Noxious weeds have the potential to negatively impact on the economy, community and / or environment. In New South Wales, the administration of noxious weed control is the responsibility of the Minister for Industry and Investment.

Many weed species are classified in more than one of these groups. For example, while Blackberry is classed as a noxious weed it is also considered an environmental or agricultural weed depending on the location. Additionally, Blackberry is listed as a weed of both national and regional significance due to its high invasive ability, impact on biodiversity and ecological integrity of the landscape, economic burden and potential control feasibility.

Certain plants have been declared as noxious under the Noxious Weeds Act 1993. This act makes it an offence to grow, propagate or sell plants and stipulates how they should be controlled. Local Councils are the Local Control Authorities and have the responsibility to enforce the Noxious Weeds Act (For a complete list of plants declared in your area contact your local Council, or go to http://www.dpi.nsw.gov.au/agriculture/pests-weeds/weeds/noxweed

Class 1 noxious weeds such as Chinese Violet and some undeclared species such as Glory Lily may be relatively rare. These plants have a high possibility of spreading into native bushland and their presence is considered a serious issue. If infestations are found they must be reported to the Local Control Authority or NSW Agriculture.



 

Jones, C. (2009). Green Agriculture Stewardship Scheme (GASS): Submission to House of Representatives Standing Committee on Primary, Inquiry into the role of government in assisting Australian farmers to adapt to the impacts of climate change. Armidale NSW: Australian Soil Carbon Accreditation Scheme.

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