[Stephen Cauchi, The Age, May 17 2009] CONSERVATIONISTS are calling for a crackdown on garden plants — and the sale of their seeds in nurseries — in an effort to stop the devastation of native flora in national parks.The Invasive Species Council says escaped garden plants are overwhelmingly the source of the weeds that choke many national parks. It called on home owners to destroy invasive species in their gardens, for national park bodies to destroy them in the wild, and for governments and nurseries to identify and ban their sale on a municipality-by-municipality basis.The environment group, to speak on Friday before the United Nations International Day for Biological Diversity, cites invasive species, alongside habitat loss and climate change, as the world's, and Australia's, main threat to biodiversity.
"A typical weed is an escaped garden plant," said the group's project officer Tim Low. "About two-thirds of weeds in Australia are plants that have escaped from cultivation. Nearly all of these are garden plants."
Some of the worst garden offenders are prickly pear, gorse, thistles, lantana, athel pine and blackberries. Mr Low said: "Particularly during times of drought, when there isn't much fruit in the forest, birds will fly into gardens out of adjoining forests, grab a bellyful of fruit, and then fly back into the forest."
The problem was acute where forests adjoined urban areas, such as in the Dandenong Ranges. However, birds, cars, wind, rivers and floods could spread seeds far beyond the confines of a garden, he said. Even the outback could be affected, as country properties often had garden plants. And people often dumped garden waste in rubbish tips, from where it spread further.
Mr Low said home owners should be educated to identify and remove weeds from their gardens, especially those close to national parks. He urged home owners to plant species that did not spread, including roses, hydrangeas and petunias.
Geoff Carr, a botanist with consultant Botany Australia, said not all weeds were exotic species. Some were Australian plants brought from interstate or species from another part of the same state. "Government should identify the species that pose the greatest threat and prohibit their cultivation. If they need to compensate owners, so be it," he said.
But, Mr Carr said, governments, councils and nurseries had shown little interest in combating the problem. The Dandenong Ranges, Otways and Grampians were areas worst affected. Some parts of national forest were beyond repair.
Article: WeedsNews40 (permalink) Date: 19 May 2009; 12:22:42 PM AEST