The art of burning in the rain

On Yourka Reserve, Jirrbal and Warrungu Country, a method of aerial, controlled burning is helping to manage wildfire and safeguard the landscape.

“This country is designed to burn.”

That’s how Reserve Manager Paul Hales describes Yourka Reserve, Jirrbal and Warrungu Country, in far-north Queensland.

Yourka has a tropical climate that alternates between two extremes: the hot, dry season and the humid wet season. This is integral to how the landscape is managed.

For years now, Paul and, more recently, the National Fire Program Manager, Rhys Swain, have been building and implementing an effective fire plan for the reserve, including one method that could be mistaken for the title of a thriller novel: storm-burning.

Though, not as suspenseful as the literary genre, storm-burning is a technique specific to this climate, whereby fires are lit in between early wet season storms.

“After the first rain, and before the next bit of rain, you get the helicopter equipped with an incendiary device, which is a mounted device on the aircraft, and drop little capsules of Condy’s Crystals injected with glycol, which oxidise and create a small flame.” says Rhys.

One of the reasons for this is to control woody thickening, a common phenomenon in northern Queensland where an invasion of woody species is leading to a loss of grasslands. Over time, landscapes are tightening, turning open savannahs and woodlands into closed ones and less grass and shrubs means less of the species that rely on them, such as granivorous birds, rodents, small mammals and ants.

Controlled fire regenerates the landscape and keeps woody thickening under control, but how much fire is too much fire?

According to Rhys, it must be done according to the specific and varied needs of plants and animals.

“If hot, large-scale fires are burnt annually, the landscape would suffer. But if you go consecutive years without fire, grasslands can decline, woodlands become denser, and you are more exposed to dangerous late-season wildfires.”

To understand how fire experts like Rhys and Paul view the landscapes they manage, it’s useful to think of it from a bird’s eye view, where vast areas are managed like a grid.

To the untrained eye, a landscape like Yourka can seem bewilderingly complex: different topographic formations, significant changes in altitude and variations in vegetation, broken up by river systems, rocky outcrops and an infinite number of inhabitants that all rely on one another to survive. “From a bird’s-eye view, it can be broken down by establishing control lines and breaking up the landscape into 1km transects determined by ridge-tops, tree lines, creeks, rivers and gullies,” says Paul.

In the face of climate change and a national increase in high fire danger days, the window for prescribed burning is shortening and the risk of extreme fire events is increasing.

Yourka’s vicinity to the coastline, altitudinal range and variety of habitat mean that it is likely to be highly adaptable to climate change when factoring in projections of future rainfall, temperatures and refugia, but that doesn’t mean it’s safe from threat.

In December 2019, a major lightning-strike fire swept through Yourka, threatening a population of Mareeba Rock-wallabies and burning 43% of the reserve.

Paul, Bush Heritage staff and the Queensland Rural Fire Service spent 10 days containing the fire and despite a late wet season, the landscape recovered quickly. Due to the reduction in canopy cover of Tea Tree and Casuarina, grass and herbage appeared where it had never been seen before.

These events highlight the importance of having experienced people in the landscape. Paul has been reading and responding to this country for 14 years and burning to a calendar is not the answer.

“We use modern techniques like helicopters, incendiary machines, satellites and maps…but really, the effect of what we’re doing is well aligned with how Traditional Owners would’ve originally managed country for fire,” says Rhys.

Much of Rhys’s early education on fire management came from working with Traditional Owner groups in the Kimberley, and this is a type of knowledge sharing that he sees as critical to looking after country.

“It’s important to listen to and read country.

“We can learn from Traditional Owners by not getting stuck in western styles of fire suppression and instead be adaptive to what each landscape is telling us it needs.”