Wetlands burnt to enhance habitat
From the Spring 2007 edition of Bush Telegraph Magazine.
Forests NSW staff use drip torches to
light up giant rush during an ecological
burn of Moira Lake. Unusually dry
conditions have allowed access to the
wetlands to establish control lines
and carry out the burns safely.
Photo courtesy Gary Miller
Extremely dry conditions in the Murray River catchment have provided a rare opportunity for Forests NSW to treat areas of the Moira Lake and Reed Beds wetlands with fire in order to reduce the coverage of giant rush (Juncus ingens).
Forests NSW regional ecologist/hydrologist, Gary Miller, said that giant rush while native, had become locally invasive.
“Historical records of these areas show that giant rush would have occupied only a small amount of these wetlands,” he said. “Changes to the wetting and drying cycle have upset the balance within the lake and led to a reduction in other wetland species such as Moira grass and common reed.
“Burning is one of a range of tools we use to rehabilitate these wetland areas, increase plant diversity and increase the foraging habitat for a range of waterbird species.
“The unusually dry conditions have allowed us to gain access to the wetlands in order to establish control lines and carry out the burns safely.”
Giant rush is the largest of the rush species, which inhabits shallow areas of wetlands and favours areas subject to frequent inundation.
It is used as nesting habitat for colonial nesting waterbirds such as ibis.
Forests NSW staff from Mathoura and Deniliquin carried out the burns in specific areas throughout Moira Lake and Reed Beds wetlands during June and July.
Operations forester, Mick Lalor, said that the burns had to be contained within isolated patches in order to protect sensitive bird breeding areas and fringing red gums.
“The giant rush beds form contiguous stands of heavy elevated fuels and controlling the burns requires good planning, coordinated teamwork and keeping a keen eye on the local weather conditions.
“The burning needs to take place during winter in order to restrict the burning to specific areas,” he said.
Local Rural Fire Service volunteers assisted with the burning operation. Staff from the Victorian Department of Sustainability and Environment observed the burning with a view to carrying out similar work in Victorian State forests.
The Moira Lake and Reed Beds wetlands are within the Barmah-Millewa Forests Icon Site, which is part of ‘The Living Murray’ program.
As part of ‘The Living Murray’ program, other substantial infrastructure works are also being planned to provide a more natural wetting and drying cycle to these wetlands, including a drainage channel for Moira Lake. Read more on pages 10-11.
Giant rush
Scientific name: Juncus ingens
Common name: Juncus rush
The giant rush is a native aquatic plant that is the largest rush in the world – growing up to five metres tall.
It grows along the River Murray in areas that experience shallow but prolonged flooding, like billabongs, lakes, marshes and drainage channels. The flooding may last six to eleven months. The giant rush grows in heavy, soggy soil and will germinate its seeds in wet mud, but not when flooding.
The giant rush may grow around river red gum communities but there are not usually many other reed species present. It provides nesting sites for some bird species, such as ibises.
The changed pattern of water flow in the River Murray (due to water management) is believed to have created a greater number of giant rush populations which have grown in place of other plant species.
Source: Murray Darling Basin Commission
Public Affairs & Media, Albury
