Fence jumping weeds kill NSW's natural biodiversity
28 Oct 2008
WWF-Australia has called on the New South Wales government to ban high risk plants from being sold in garden centres under the Noxious Weeds Act, after it was revealed that invasive plants are contributing to the near extinction of a significant number of Australia's rarest plant and animal species.
The call is part of WWF's recent submission to the NSW Scientific Committee, which highlights the need to control the spread of escaped exotic garden plants in New South Wales.
"We now have a situation where weeds are killing off our state's natural and unique biodiversity," said Gail Broadbent, WWF-Australia's Sustainable Development Program Co-ordinator.
"Take, as an example, two of Australia's rarest rainforest plants. There's the Coastal Fontainea, of which there are just 10 adult trees left near Lennox Head in NSW, and the Coxen's Double-Eyed Fig Parrot, of which there has only been 20 reliable sightings in NSW since 1970.
"Both are being pushed to the verge of extinction by out-of-control invasive weeds that were originally introduced to Australia as garden plants."
Garden plants that have escaped into the wild make up 69 per cent of Australia's population of threatening weeds. Of the 127 individual weed species identified as threatening NSW biodiversity, 82 were deliberately introduced as ornamental plants and 56 of these are still available for purchase in Australia.
"Research shows that banning the sale of high risk plants from garden centres gives Australia the best opportunity for potential weed infestations to nipped in the bud," said Mrs Broadbent.
"If we can ban the worst of these and clearly label those that may pose a threat in the future, then Australia's gardeners will have the knowledge to be in the front line of the fight against weed invasions.
"In taking an active role, they will not only preserve some of our endangered species, they will also help protect our agricultural industry from significant losses in the future."
WWF-Australia has also called for the creation of a state-wide early warning and rapid response program to target plants that have already escaped from gardens and pose a significant risk to the biodiversity of NSW and its agricultural enterprises. Ms Broadbent said the cost of setting up such a program would be far outweighed by the long-term benefits.
"Patterson's curse, an escaped ornamental plant, is estimated to cost the wool and meat industries alone $125 million a year according to the CSIRO," Ms Broadbent said.
"If we can attacks weeds before they get a foothold beyond the garden gate, it could save Australians, from the cocky at the farm gate to mums and dads at the supermarket, hundreds of millions of dollars."
Editor's notes
- The threat posed by weeds to Australia flora and fauna as a single factor is second only to land clearing.
- Weeds threaten 419 of NSW listed threatened species.
- Garden plants are the dominant source of Australia's population of weeds (69%)
- 82 of the 127 (65%) individual weed species identified as threatening NSW biodiversity are deliberately introduced ornamental plants.
- 56 of these 127 weeds are still available for purchase in Australia, 36 of these are available for purchase from NSW.
- There are 4065 plant species that have been imported into Australia for cultivation as garden plants that are referenced as weeds.
- Virtually all of Australia's major water-weed species were originally introduced for use in garden ponds or as ornamental aquarium plants.
- More than 20 types of willow are for sale in garden shops. Most are declared weeds of national significance and many infest waterways. The cost of removing them is considerable.
- Exotic vines including madeira vine, passionfruit, climbing asparagus, moth vine and climbing nightshade were introduced for ornamental and horticultural purposes. All have now been declared as key threatening processes under the Threatened Species Conservation Act.
- Approximately 35% of plants that have escaped from gardens threaten multiple species. As an example, Lantana camara L. threatens 96 biological entities in NSW, while kikuyu grass threatens another 16.
For more information
Alvin Stone, WWF-Australia Press Office. Phone: (02) 8202 1259 or mobile 0410 221 068
Mobile: 0410 221 068
