Invasive grass with role in deadly Maui blaze ‘absolutely a threat’ to Australian lives

Invasive grass with role in deadly Maui blaze ‘absolutely a threat’ to Australian lives

A key ingredient in the deadly Maui fires — unmanaged invasive grasses, like buffel grass — is also spreading throughout vast areas of Australia, prompting a warning about the increased risk to people, houses and biodiversity on this side of the globe.

Buffel grass was introduced to Australia inadvertently by Afghan cameleers in the 1870s, and was later used deliberately to improve degraded rangelands in agriculture and suppress dust.

Buffel grass was introduced in the NT for dust suppression, and as a pasture for degraded lands.(Supplied: National Archives of Australia/William Pederson)

But it has now spread well beyond its planted areas and is present in every mainland state and territory, according to researchers.

The highly flammable grass is able to grow vigorously, even in comparison to native plants, building thick and highly flammable fuel loads throughout the landscape.

Buffel grass (pictured) and other introduced grasses cover a quarter of Hawaii.(Flickr: Forest and Kim Starr, CC BY 2.0)

South Australia state buffel grass coordinator Troy Bowman said without diligent, ongoing management, it posed a real threat to human life.

“There’s certainly a risk that at some point we may actually lose lives, due to buffel grass fires getting into the community and impacting on housing and associated safety,” he said.

He said this was especially true for remote communities in SA, and towns such as Port Augusta and Coober Pedy, where there had been a significant increase in buffel grass growth.

Fire, fuelled by buffel grass, came right to the doorstep of homes in Alice Springs earlier this year.(Supplied: Steven Schubert)

Homes have already been threatened this year in the Northern Territory, when a planned burn fuelled by the invasive grass escaped and came right to the doorstep of Alice Springs homes, after ripping through the Tjoritja/West MacDonnell National Park.

Hawaii fire fuel

In August, the spread of non-native grasses in Hawaii was put under the microscope, when the island of Maui ignited in one of the deadliest fires in US history.

The death toll stands at 97 people, with 31 still missing.

Dozens are still missing after the deadly wildfires in Lahaina, Hawaii.(Reuters: US Army National Guard/Staff Sgt Matthew A. Foster)

The devastating blaze was the result of a complex concoction of factors, fanned by extreme winds of over 100 kilometres per hour, and a hot, dry climate in a region in the grips of a flash drought, not well prepared for fire.

But experts have also pointed blame firmly at invasive grass species, which cover a quarter of Hawaii, according to scientists.

Charles Darwin University environmental scientist Christine Schlesinger said the situation in Australia was different in terms of where houses were situated and how they were constructed.

But she said the invasive grass was “absolutely a threat” to property and to people in Australia.

“Buffel grass just grows thicker, taller, and it’s much more continuous,” she said.

“And what we’re seeing is bigger fires, and hotter fires than what would have occurred in natural conditions.”

And it doesn’t just pose a risk to human lives and property.

Both Dr Schlesinger and Mr Bowman spoke of its increasing threat to biodiversity and its ability to “completely change the landscape”.

An expanse of buffel grass across the APY lands in South Australia.(Supplied: Alinytjara Wilurara Landscape Board)

In 2021, the APY Warru Rangers also presented the Umuwa Statement on buffel grass, saying it was “choking” their country.

“We can’t get bush foods where we used to — honey ant, malu [kangaroo], and our native plants are getting harder to find, our wildflowers are disappearing,” the rangers said in the statement.

“The buffel grows too fast and burns too often for our country. It’s the first plant that grows after rain and fire. While we didn’t bring it here, we live with the consequences.”

Spreading south

Australia is home to several invasive grasses.

But Dr Schlesinger said buffel grass was one of the most worrisome, due to its potential to spread across the country.

Research has shown the species has the ability to grow across 60 to 70 per cent of Australia.

Buffel grass (marked in green) has now spread through every mainland state and territory.(Supplied: Alinytjara Wilurara Landscape Board)

It mostly grows in Australia’s arid regions at present, with its largest distributions in Queensland, the Northern Territory, Western Australia, and South Australia.

But Dr Schlesinger said it was predicted to spread beyond these areas.

“It has already spread in many places throughout Australia, and … is predicted to increase with climate change as well,” she said.

“So it will spread further south.”

Tough to manage

The grass has been declared a weed in South Australia — the only state to have done so — in a move praised by Mr Bowman.

He said the listing helped control efforts by providing funding and investment opportunities.

“We’ve developed a strategic plan which guides buffel grass management through a zoning approach,” he said.

“The three zones range from areas where we aim to destroy the infestations or eradicate, to the next zone where we’re protecting sites, aiming for containment and reducing populations where possible.”

South Australia has declared buffel grass a weed.(Supplied: Alinytjara Wilurara Landscape Board)

Even so, he said the job was “labour intensive” and costly, due to the plant’s widespread distribution, often in remote areas.

The Northern Territory is also considering declaring buffel grass a weed.

Mr Bowman said efforts to raise the profile of buffel grass had gained “significant momentum”, including at a political level, but more awareness of its threat and funding for its management was vital.

Dr Schlesinger would like to see additional effort and resources put into developing more effective management techniques across the country.

“There are currently few methods available to actually prevent that spread or to control it in areas where it’s already really heavily invaded,” she said.

“So that’s one of the challenges … how to control the spread of it further, which really needs to be a massive priority.”

The issue of introduced grasses and their associated fire risk was raised by scientists at the first-ever global Invasive Alien Species Assessment Report launch, hosted by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services in September.

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