Holding the line

The DCQ team on the road to erase Prickly Acacia.

Bruce Honeywill; Desert Channels Queensland

In 2019 floods wreaked havoc across northern Queensland.

Tens of thousands of cattle lost, businesses collapsed.

Nature and the Wet Season did its worst.

Yet once again, the resilience of the northern cattle producers and communities was an exemplar of the bush spirit.

The aftermath of an event such as the 2019 floods leaves tracks of tragedy across the landscape that can last for years.

As the floodwaters rushed south through the Desert Channels region so came biogenic material from invasive weeds such as Prickly Acacia, Parkinsonia, and Rubber Vine.

The challenge is the numerous seed pods that wash downstream to germinate along watercourses, flood plains, and Mitchel Grass Downs, so increasing the distribution and range of the weed from an estimated pre-flood 33,000,000 hectares in the northwestern and central-western areas of Queensland to further afield, potentially putting the entire Desert Channels region at risk.

Landholders and natural resource managers are still assessing the spread of these invasive weeds. The work to slow and stall the spread of weeds coming from the flood continues.

There has been significant government support for affected landholders and businesses.

This includes the Prickly Acacia Weed Management Program, Commonwealth Government grants contributing to identifying the extent of the spreading of weeds and reducing and mitigating the risk associated with Prickly Acacia following flooding.

Under the program, Desert Channels Queensland in partnership with landholders continues to survey and map Prickly Acacia to better understand the spread of the weed following the flooding and identify the extent of new infestation.

Originating in Africa and introduced to Australia as a potential shade and fodder species, Prickly Acacia quickly developed into a fast-spreading invasive weed without the natural control species of its native lands.

The threat in Australia is the reduction of biodiversity through the transformation of natural grasslands into thorny scrub and woodland.

The weed reduces available pasture for livestock.

The loss of ground cover causes erosion, makes access to watering points such as dams difficult, and increases the time and cost of mustering livestock.

Under the project, DCQ is assisting landholders with the development of on-farm weed management plans, building the capacity of landholders, and undertaking control methods.

Under the Commonwealth Government program, DCQ carries out surveillance and mapping of Prickly Acacia to understand the spread of the weed following the flooding, establishing the extent of new infestation, and the outcomes of management actions under the program.

During the course of the program, the battle has been joined by DCQ field teams working in partnership with landholders carrying out on-ground management activities such as mechanical control, the use of fire, controlled use of herbicides, and other control methods.

The field teams are the frontline in stalling the spread of the weeds as they assist landholders with the development of on-farm weed management plans and build the capacity of landholders and the community with management and control methods.

Significant success has been achieved to date.

In the assessment and mapping of new infestations coming from the floods, it has been found the properties that have carried out Prickly Acacia control programs are being affected less with the expansion of the weed, where it is spreading and clogging pasturelands.