Focal Point

From the President

Your NPA 

Environmental News

Features

Marine Scene

Western News

Biodiversity

Your Parks

On The Track

Letters
To The Editor

Reviews

Feature: Invasive Species

Eyes wide shut
Funding the bitou bashers
The Great Grose Weed Walk
Saving the natives
Bullies invading the corridors

Eyes wide shut

ANDREAS GLANZNIG, Senior Policy Adviser, WWF-Australia, talks about getting smart on weeds invading national parks Take a walk through the World Heritage listed Barrington Tops National Park in spring and you will be met by a rain of yellow-flowering shrubs. They are not wattles but invasive Scotch broom plants. Even wilderness areas are not safe from weed damage - invasive orange hawkweed was discovered on the slopes of Mount Jargangal in Kosciuszko National Park, possibly brought in on the boots of a bushwalker.

Cytisus scoparius (Scotch Broom) in Barrington Tops National Park. Photo: Mel Schroder, NPWS.

Most national park weeds are escaped invasive garden plants
A quick flick through the 2004 NSW State of the Parks report highlights that the NSW government recognises that 'weeds pose one of the most significant threats to biodiversity after land clearing and habitat destruction'. The report highlights that major park control programs are in place for bitou bush, lantana, blackberry, perennial grasses, Scotch broom, gorse, exotic vines, willows, aquatic weeds, asparagus species, African boxthorn, camphor laurel, glory lily, groundsel bush, olives, ochna, privet and St John's wort. What is most telling from this list is that most are escaped invasive garden plants.
Escaped invasive garden plants are the major source of weeds in Australia.
In fact, seven out of every ten environmental and agricultural weeds in Australia is an invasive garden plant that has jumped the back fence. According to the Weeds CRC, Australia's premier weed research institution, the garden industry has imported over 5,500 known weed species into Australia over the years, of which over 1,800 have already naturalised. A number of these contribute to Australia's annual weed bill of $4 billion a year, and just six invasive weeds have degraded over 20 million hectares of Australia's environment - an area equivalent in size to Victoria. This includes lantana, which degrades four million hectares.
But the real sting is that over 3,700 garden plant species that are known weeds may yet jump the back fence. In fact, your garden probably has a number of invasive garden plants that could endanger Australia's environment and, that given the right conditions, will spread into bushland and ultimately move into many national parks. This presents a huge risk to Australia's environment and the national parks you hold dear.
To put a stronger spotlight on this problem, in early 2005 WWF released a CSIRO report, Jumping the Garden Fence, the most detailed analysis to date of Australia's invasive garden plant problem. The report shows that governments still permit the sale of many of the world's and Australia's worst weeds. These include Weeds of National Significance and Alert List weeds. Three examples provide a snapshot of this clear and present risk:
The Australian Government is spending hundreds of thousands of dollars on community awareness and a reporting hotline for 28 national Alert List environmental weeds, yet six of these weeds can still be bought from local garden centres.
The World Conservation Union (IUCN) identified 36 plants as part of their 100 World's Worst Invasive Alien Species List. The majority (20) of them are escaped invasive garden plants and a quarter are still for sale. Despite histories of causing major harm to the environment in other countries, three are still for sale in NSW. This includes a really nasty weed, Kahili ginger (Hedychium gardnerianum ) which is a major invader of forests in New Zealand and a problem in South Africa. It is already naturalised in NSW but surprisingly it is not a declared noxious weed.
Farmers lose over $4 billion annually to weed control costs and lost production - one in every seven dollars of agricultural income is lost to weeds, but over half of the weeds identified in a grazing industry report are escaped invasive garden plants and a third of them are still for sale.
Clearly, governments are doing far too little to deal with a major cause of Australia's weed problem - the trade and wide distribution of high-risk invasive garden plants. The last survey in the late 1990s found that over 1,000 known weed species (or 12% of total traded species) were advertised for sale by the garden industry.
The CSIRO report shows that the NSW Government only stops the sale of a relatively small number of environmental weeds. Only 18% of naturalised escaped invasive garden plants are prohibited for sale in NSW. This failure to ban the sale of all high-risk invasive garden plant species is the reason why weed problems in NSW national parks can only get worse.
Jumping the Garden Fence identified the 10 most serious invasive garden plants still for sale in NSW.
The lack of a statewide ban on the sale of Lippia epitomises the urgent need to review and expand the State's noxious weed list. For example, the Macquarie Marshes are reeling in the face of the aggressive invasion by Lippia (Phyla canescens). The total estimated annual environmental cost is $1.8 billion, with graziers facing an annual cost of $38 million. The report shows that because this very serious environmental and grazing weed has only been declared as a noxious weed locally, it continues to be sold in NSW and thus has the potential to be spread to new catchments where it can cause even more damage.
A large number of high-risk environmental weeds continue to be sold in NSW. One example is Ceylon hill cherry (Rhodomyrtus tomentosa), which is a prohibited import into Australia, targeted by the Australian Quarantine Inspection Service for eradication as a quarantine weed. It is a serious weed in Hawaii and Florida, but not prohibited for sale in NSW and advertised for sale from at least one NSW garden centre. Will the NSW government wait until this quarantine weed becomes a major problem in the State's sub-tropical national parks before it bans its sale?

Most of tomorrow’s weeds are growing in gardens right now.

The 10 most serious invasive garden plants still for sale in New South Wales (CSIRO 2005)

Causes and sources
It costs NSW taxpayers more than $7 million each year to control weeds in national parks, mostly escaped invasive garden plants. But this necessary, though reactive, policy response is not focussed on stopping the causes of the growing weed problem in NSW.
It defies common sense that in the face of the large and growing weed threat, the NSW government currently allows the sale of so many high-risk weed species. A far stronger policy response is needed.
Amendments to the NSW Noxious Weed Act will commence in early 2006. The act introduces a new five-class system for noxious weed control, and importantly contains a new class (Class 5) that enables the government to prohibit the sale of invasive plants statewide without putting a broader impost on farmers and other land managers.
As part of the review to the NSW noxious weed list, WWF is strongly of the view that all plant species that pose a high risk to the environment or primary industries should at least be listed as a Class 5 noxious weed. But to ensure that all high-risk environmental weeds get onto at least the Class 5 list - particularly those that are not yet naturalised or are still invading new areas - a far stronger push is required by the Department of Environment and Conservation and its Minister to secure this result. The high-cost alternative is to wait until high-risk weeds escape from gardens and invade national parks before acting.
This leaves medium-risk invasive garden plants. It is simply not realistic to ban the sale of all the more than 5,500 known weed species brought into Australia by the garden industry, particularly as these plants cover a broad spectrum in terms of their weed risk and impact on the environment and primary industries.
WWF believes that it should still be possible to sell weeds that pose a lesser risk, but they should be clearly labelled as invasive species. The label should provide information on how to plant, maintain, and dispose of the plant to minimise the risk of it escaping and becoming a weed. This should be complemented by community education programs that encourage people to buy safer non-invasive plants. A good example is the Nursery and Garden Industry Australia program called 'Grow Me Instead'.
Conclusion
Australia needs a better way to deal with its growing weed problems, one that focuses on the causes and sources. Governments are now reworking the National Weeds Strategy, and this provides another opportunity to put this better way in place. But we will need to write to Federal and State agricultural and environment ministers, and talk to our local members about the issue. Keeping our eyes wide shut will see our national parks increasingly swamped by weeds.
Further information
WWF has released a range of reports on this issue.
They can be accessed at: http://wwf.org.au/ourwork/invasives/

1. Groves R, Boden R and Lonsdale WM, 2005.
Jumping the Garden Fence:
Invasive garden plants in Australia and their environmental and agricultural impacts. CSIRO report prepared for WWF-Australia, WWF-Australia, Sydney.
http://wwf.org.au/publications/jumping_the_garden_fence/

2. Glanznig A, 2005.
Making State Weed Laws Work.
Issues Paper. WWF-Australia, Sydney.
http://wwf.org.au/publications/makingstateweedlawswork/

3. Martin P, Verbeek M, Thomson S and Martin M, 2005.
The Costs and Benefits of a Proposed Mandatory Invasive Species Labelling Scheme.
Discussion Paper. WWF-Australia, Sydney.
http://wwf.org.au/publications/InvasivesMandatoryLabelling/