Australia
March 26, 2009
Climate change will cause some of
Australia’s potential weeds to move south by up to 1000km,
according to a report by scientists at
CSIRO’s Climate Adaptation
Flagship.
Weeds cost Australia more than A$4 billion a year either in
control or lost production and cause serious damage to the
environment.
In an address today in Perth to the GREENHOUSE 09 conference on
climate change, CSIRO researcher, Dr John Scott, said, however,
that those cost estimates were only based on the damage caused
by weeds known to be active in Australia.
“Out there, throughout the nation, are many weed species lying
low but with the potential to take off and add to the economic
and social burden of weed control,” Dr Scott said.
“One critical unknown is what these lurking weeds will do under
climate change. Will their distributions change? Will they
spread north or south, east or west, and will these movements
change them into full-blown pest species?”
A recent CSIRO report for the Australian Government’s Land and
Water Australia looked at what effects climate changes
anticipated for 2030 and 2070 might have on the distribution of
41 weeds that pose a threat to agriculture (“sleeper” species)
and the natural environment (“alert” species).
“We found that climate change will cause most of these weeds to
shift south, with wet tropical species making the greatest move
– over 1000km,” Dr Scott said.
“The regions most at threat from alert and sleeper weeds, both
under the current climate and under climate change, are south
east Australia, followed by the south west.”
Karroo thorn (Acacia karroo), rosewood (Tipuana tipu) and kochia
(Bassia scoparia) were found to pose the greatest threat under
climate change while white weeping broom (Retama raetam) and
fringed dodder (Cuscuta suaveolens) were predicted to have the
highest risk of establishing in new areas.
“The predicted move south by both native and introduced plants
would produce a ‘vacuum’ in northern Australia so, to prevent
lurking species from invading, a new list of alert and sleeper
weeds for this region needs to be developed,” Dr Scott said.
The report also found that while the area currently infested by
the most widespread weeds will decrease under climate change,
the area of high risk would still be large.
National
Research Flagships
CSIRO initiated the National Research Flagships to provide
science-based solutions in response to Australia’s major
research challenges and opportunities. The nine Flagships form
multidisciplinary teams with industry and the research community
to deliver impact and benefits for Australia. |
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