A SENIOR ecologist has disputed the claim that environmental watering contributes to the spread of Paterson’s curse.
The invasive annual weed, which flowers in spring and early summer, is flourishing in the Gunbower Forest and much of southern Australia, thanks to warm and the wet conditions of recent months.
It is reported to be thriving around the region, including at Murrabit, Mount Hope and Guttrum State Forest.
Last week the Gannawarra Times reported the concerns of Gunbower Island resident Geoff Wakeman that the weed’s presence in creek runners in the forest meant its spread would likely dramatically increase once water flows down the creeks.
Mr Wakeman also believes environmental water being left for long periods in the forest has killed off native plants that would protect the area from Paterson’s curse.
However Damien Cook, an expert in wetland, riparian and terrestrial ecology who does contract work for the North Central Catchment Management Authority, has dismissed the claim as “a furphy”.
“Paterson’s curse is a terrestrial plant which grows on high land, so saying environmental watering makes it worse is a furphy,” he said.
“Water will drown it; it can’t stand water.
“If the plants are in the creek runners at the moment, they’ll drown when the water goes in.”
Mr Cook said Paterson’s curse grows in areas that have been “very disturbed”.
“Paterson’s curse is bad in Gunbower Forest because it was over-grazed in the past,” he said.
While land managers acknowledge that the European weed is best sprayed before it flowers, the Department of Land, Environment, Water and Planning (DELWP) said spraying had not been done this year.
“Parks Victoria and Department of Land, Water and Planning staff have cut and slashed the weeds at high visitation and camping areas to reduce the impact on visitors,” acting district Manager James Marshall told the Gannawarra Times.
“DELWP crews have also recently undertaken some roadside spraying of weeds on the island to reduce the dispersion of seeds during other land management works such as grading roads and slashing verges.”
It is understood that DELWP and Parks Victoria have limited funding for weed control on public land and prioritise attempts to control invasive species.
Spokesman for voluntary-based conservation group the Victoria National Parks Association Phil Ingamells said Parks Victoria needed more funding to manage weeds.
“Parks Victoria’s budget for managing a very large area of the state is less than half of 1 per cent of the state’s budget,” Mr Ingamells said.
“We’ve been asking for Parks Victoria’s funding to be doubled to at least 1 per cent of the budget.”
The weed, which is poisonous to grazing animals, particularly horses and pigs, is also an issue for farmers and landowners.
Agriculture Victoria described it as impossible to eradicate.
“Throughout Victoria, Paterson’s curse is common and cannot be eradicated,” an Agriculture Victoria spokesperson said.
“Land managers are encouraged to use an integrated approach to manage Paterson’s curse, including pasture establishment, registered herbicide control and physical removal.”
Paterson’s curse
· Paterson’s curse is poisonous to grazing animals. The plant contains pyrrolizidine alkaloids that cause cumulative chronic liver damage, loss of condition and sometimes death. Pigs and horses are most susceptible. Ruminants such as sheep, cattle and goats are less affected.
· Historically, numerous biological control agents have been tested in Australia and many of these are now widely distributed throughout Victoria, such as the leaf mining moth, crown and root boring weevils and taproot flea beetle. Biological controls play a complementary role in the management of Paterson’s curse.
· Paterson’s curse is primarily spread by seed. Biosecurity practices including people movement and vehicle wash down are important to prevent further spread.
Source: Agriculture Victoria
