[ASC-media] Media release: Australia's most unpopular exports

JCA Media jcamedia at starclass.com.au
Tue May 31 22:01:17 EST 2005

CRC for Australian Weed Management Media Release 05/21

For World Environment Day, June 5


Some of Australia's most beloved native trees and plants are causing mayhem in other people's environments.

The golden wattle, silver wattle, blackwood, broadleaf paper-bark, Cootamundra wattle, beach sheoak, silky hakea, coastal tea tree and tuart are becoming about as popular in some places overseas as blackberries, lantana, willows and alligator weed in Australia.

Casuarinas and paperbarks have invaded hundreds of thousands of hectares of beach and swamp country in Florida, while other Australian trees are causing fire and ecological problems in California and Hawaii.

In South Africa, eucalypts, wattles and tea trees have taken over huge tracts of landscape, pumping underground water dry, costing millions and forcing thousands of Africans to be employed on 'weed removal'.

Others, like the river red gum, Grevillea pteridifolia and Banksia ericifolia, are feared as the next big Aussie weed pests, based on their prodigious ability to produce seed.

"It's an irony, really," says the CEO of the Cooperative Research Centre for Australian Weed Management, Dr Rachel McFadyen. 

"We think of invasive plants as a $4 billion plague that is threatening Australia's precious ecosystems, wildlife and farming industries. But the truth is our natives are doing just as much damage overseas."

On World Environment Day, Dr McFadyen is asking all Australians not only to be alert to alien plants in the Australian environment but also to join world-wide efforts to stem plant invasions - including those by our own species.

"Australian trees and shrubs are naturally tough.  They do well in harsh, dry, salty conditions and in poor soils - and when they are without their natural predators and competitors, they can go wild and take over landscapes.

"Every Australian needs to be aware of the consequences of exporting native seeds or plant material overseas.  It could spell destruction to someone else's much-loved native landscape."

Dr McFadyen advises all Australians involved in sending seeds or cuttings abroad whether as gifts, for science, for landscaping or for trade, to do some checking up to see if the plant has the potential to become invasive.

The cost of plant invasions can be huge: the United States currently spends more than $A150 billion a year controlling infestations of non-native plants.  The Australian broad-leaf paperbark - Melaleuca quinquenervia - has invaded more than 500,000 acres of the Florida Everglades and is so bad it even has its own website (http://tame.ifas.ufl.edu/)! The US Government has banned it from sale.

In South Africa the list of Australian miscreants is even longer - eight varieties of wattle and three hakeas are currently listed as weeds, and another nine trees as potential weeds, part of a problem that has sapped almost a tenth of the nation's total water supply and costs 7 billion rand a year to tackle.

In the UK, half of whose 2900 plant and tree species come from somewhere else, the bill for controlling unwanted plants is also great. Over $A7.5 million is spent on controlling one Australian plant - swamp stonecrop - alone. It chokes ponds, threatening the survival of newts and frogs and is listed among Britain's worst weeds.

Australian eucalypts and acacias are also reported as growing out of control in countries bordering the Mediterranean, where many are still being promoted as solutions to problems such as erosion, dune stabilization and so on.

"Australian trees in particular are often advertised as "fast growing"," says Dr McFadyen.  "When you see those two words, you need to beware and think 'possibly invasive'."

Dr McFadyen says that ecosystems the world over are threatened by the movement of plants which people find attractive or useful, but which take over and dominate landscapes once they escape the controls on them in their native environments.

"Just as Australians a becoming more conscious of the need not to import invasive plants into our own country, it's up to us to be good global citizens and not export potential plant problems elsewhere," she says.

More information:
Dr Rachel McFadyen, Weeds CRC, 07 3362 9388 or 0409 263 817

Sally Vidler, Weeds CRC, 07 3362 9381 or 0419 184 153


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