When Steve Dwyer returned to Mary River National Park after years away, he was shocked at how the landscape had changed.
"I could see the fire damage to the savanna woodlands and the monsoon forests on the edge of the flood plain," the NT Parks ranger said.
In a matter of years, parts of the Top End national park had come to resemble an African grassland, with thick tussocks of gamba grass displacing native plants.
Since gamba grass was introduced to the Northern Territory as cattle feed in 1931, the invasive weed has become widespread in parts of the Top End.
Growing up to 4 metres tall, the African grass outcompetes native flora and fauna and can burn at eight times the intensity of native grasses, posing a significant threat to the environment, homes, and lives.
Election pledge a potential 'game changer'
Despite being recognised as a weed of national significance in 2012, no federal funding has been committed to tackling the spread of gamba grass in the NT — until now.
Labor and the Coalition have announced election promises to fund programs to combat the weed.
The Coalition has pledged $450,000 over three years to support Territory NRM, which coordinates the Gamba Army, a task force dedicated to managing gamba in the Top End.
Meanwhile, Labor is promising $9.8 million over four years for around 30 additional positions to boost the Gamba Army's efforts and prevent the weed from spreading to Kakadu National Park.
The Invasive Species Council has welcomed Labor's pledge and called on other parties to match its commitment.
Mr Cox said the pledge had "the potential to be a real game changer in tackling gamba in the NT, ensuring enough resources and boots on the ground to start to see the year-on-year reduction in gamba's spread".
'You've got to break that cycle'
When Steve Dwyer started working at Mary River National Park in the early 2000s, gamba was already posing a threat to the park's environment and wildlife.
At the time, the rangers would spray the weed with herbicide and later burn the leftover chaff to reduce its bushfire risk.
"We'd try to burn it early after the wet season to protect our neighbours and areas of bushland from really intense late dry season fires, which were always a threat."
It was not until later that Mr Dwyer realised these burns — a common practice for managing the environment in Northern Australia's tropical savannas — were helping the weed to prosper.
"Early burning is still really intense in a gamba fire, and it damages the vegetation far more than a native spear grass fire," he said.
"You've got to break that cycle."
New ways to manage gamba
Returning to Mary River National Park in 2014 — this time as head ranger — Mr Dwyer knew something needed to change.
"If gamba burns intensely, it kills all the trees and gets all the sun and resources for itself," he said.
"And if you spray the gamba, and don't burn the thrash that's on the ground, the seeds only last for a couple of years. So the ability is there to break the cycle."
Working with researchers at the National Environmental Science Program, Mr Dwyer said they have documented a 90 per cent reduction in gamba grass in parts of Mary River National Park.
"The native vegetation is recovering because it's hugely resilient. And if you can give it a rest, you'll see it bounce back," he said.
Mr Dwyer said it could be difficult to exclude fire from areas prone to burning, but stressed it was an important practice to use where possible.
"In most of the areas where we tried fire exclusion, it worked really well because we put the time in to upgrading our fire breaks and doing everything we could to keep fire out of those areas," he said.
"Why use fire to control something, when it's probably the most important facet for its healthy growth?"
Mr Dwyer said gamba would continue to present a "huge problem", but said it was "great to see a huge effort and a foundation shift in the way we look at it and the way we're managing it."
"The amount of resources that are going into gamba is astronomical, but it needs to be — we've got a lot to undo," he said.
