Land, bird, smoke and man

Prescribed burns on Pilungah and Ethabuka reserves, Wangkamadla Country, prepare the landscape for bushfire season and enhance biodiversity.

The night sky begins to sparkle, and a deep purple absorbs the day’s glowing orange. A resident Magpie Lark calls piercing the vast quiet on Wangkamadla Country at Pilungah Reserve in south-west Queensland. Anticipation hangs in the cool July air.

Tomorrow – after much preparation – the Bush Heritage team will give parts of this Country the opportunity to burn. The following day, they will travel 65km south to Ethabuka Reserve and repeat the practice.

Gathered around the dinner table is Alistair Hartley, National Fire Program Officer, and Corinna Clark and Ingo Schomaker, Pilungah’s reserve managers. Together, they discuss safety protocols and the plans for the prescribed burns, consult maps of the reserves and keep a close eye on the predicted weather conditions

A prescribed burn involves the planned use of fire to manage land. A burn’s outcome will depend on the varied conservation and cultural goals, weather conditions and make-up of a landscape. So too, will the burning techniques, which are devised through consultation with Traditional Custodians and deep analysis of a region’s unique flora, fauna, soil, climate, hydrological health, topography, burn history and accessibility.

Fire is a natural part of our landscape. Fire is required for the improved health of Country and now can play a role in asset management in the catastrophic events leading to bushfire,” explains Vikki Parsley, Yuin Wiradjuri woman and Aboriginal and Torres Strait Islander Partnerships Managers, who works closely with the Fire team.

“Fire has been used by Aboriginal and Torres Strait Islander people to manage and shape the continent for over 60,000 years.”

In partnership with Traditional Custodians, we share knowledge about best fire practices to inform our approach to prescribed burns, and our support of partners’ culturally led burns.

Located south-west of Mount Isa, Pilungah and Ethabuka border the Northern Territory. This is desert country, where Spinifex Hopping Mice bounce between grassy hummocks, belts of iron ore emerge from red sand and the seemingly never-ending dune’s ecosystems thrive on less than 300mm of average annual rainfall. Both burns will target spinifex grasses; however, the intended outcome for each reserve is different.

“Pilungah already has a good variety of age classes through the spinifex – age class refers to the time since vegetation was last burnt. At this reserve, we will burn to enhance the mosaic of age classes. In 2011, a bushfire moved through 90 percent of Ethabuka, reducing much of the vegetation to one age class. Here, we're trying to establish the mosaic of different age classes and break up the 12-year-old fuel, which will help reduce the ability of bushfires to move through the landscape,” says Alistair.

Spinifex is fire prone and burns with intensity due to its structure and resinous nature. Connectivity between hummocks increases when a single age class area of spinifex matures. Following rain events, this connection is emphasised by the growth of other annual grasses. If left unmanaged, this poses a significant threat during the late dry season, when sparks from lightning storms combine with dry, south-west winds to meet a tinder box of connected spinifex: one susceptible to large and destructive fire.

“When working with spinifex, one of the key things you want to do is reduce the intensity of the fire. To do this, you try and burn at the coldest time of year and when the soil temperature is at its lowest. This takes the heat out of the fire and protects the rootstock of any spinifex around, or other grasses that you want to come back post-fire.”

“We’re also looking for the right winds. Now, we look for cool, southerly winds from the Antarctic. These will help the fire go out at night once we lose the heat from the sun. So, we’ll have low intensity fires that won’t go on for days.”

It’s not just a reduction in the risks imposed by large bushfire that these burns help to achieve. Spinifex grasslands thrive in arid areas and are notoriously competitive with their neighbours. As a faster-to-burn species, other plants such as mallee and acacia will capitalise on the scarce resources available during the post-fire period to grow and reproduce – adding greater diversity to the desert.

Over the following days, patches of white smoke rise from between the sand dune swales as strategically lit, small fires creep across the landscape. Black Kites circle above and dive bomb on the reptiles and insects that are making their escapes from the fire to close, unaffected refuges. The chirps of Zebra finches and other seed-eating birds return shortly after the flames cease and smoke lifts.

These burns are part of each reserve’s long-term fire management plan designed to: provide refuge for the diversity of life by establishing a pattern of different vegetation age and structure, protect key cultural values, and build climate change resilience into our landscapes. Alistair reflects after the burns:

“As the Paul Kelly song goes ‘from little things, big things grow’. We’re focused on the bigger picture, and we are just at the start. So, we plan to be back yearly, and progressively increase those patterns of different age classes through the landscape.”

It’s been busy period for the team. Optimal conditions across the country throughout June, July and August meant they were able to conduct a number of prescribed burns, and support cultural burns on partners’ lands. Now, bushfire season has arrived, and with the shift in cyclical weather patterns from the wetter La Niña to drier El Niño, they are continuing the work necessary to prevent and manage the threat of destructive, uncontrolled fire.