Environmental ‘tragedy’ as fires burn through one-fifth of Northern Territory national park

Large fires west of Alice Springs have burnt through 20% of the Tjoritja/West MacDonnell national park in what conservationists say is a nationally significant environmental “tragedy”.

The fires have been fuelled by a hot March, which followed three years of above average rainfall that has increased fuel loads in the semi-arid region.

In the past three weeks, more than 100,000 hectares have burned across the MacDonnell Ranges area, which the federal government has declared a priority place under the national threatened species strategy.

The affected area includes sections of the Tjoritja/West MacDonnell national park that the Arid Lands Environment Centre (ALEC) said were close to habitat for the main remaining strongholds of the critically endangered central rock rat.

Related: More than half NSW forests lost since 1750 and logging ‘locking in’ species extinction, study finds

“The Tjoritja/West MacDonnell Ranges wildfire is a tragedy,” said Alex Vaughan, a policy officer at ALEC.

“This is a place that [federal environment minister] Tanya Plibersek just last year recognised as one of the most important places nationally for threatened species conservation.”

Vaughan said the fires were an example of the devastation that could occur when the threats of climate change and invasive species intersected.

He said the fuel build-up caused by three wet years included “rampant” growth of invasive buffel grass, an introduced species used for pasture improvement that has spread across central Australia and become particularly problematic in national parks.

Buffel grass, in addition to altering a landscape, exacerbates fire danger because it burns hotter and causes more frequent fires.

In South Australia it has been declared a weed but no such declaration has been made in any other Australian jurisdiction, including the Northern Territory.

Under national environmental laws, it is one of several invasive species that were listed in 2013 under the key threatening process known as “novel biota”.

Abatement advice was developed but Vaughan said actions had not been resourced and the territory and federal governments had “completely failed” to manage the problem of buffel grass and other fire-promoting weeds.

He said national coordination was necessary to fund management of buffel grass.

“In central Australia, it is the greatest invasive species threat to environment and culture, yet buffel is not a declared weed in the NT, nor is it listed as a weed of national significance,” he said.

“The consequences of this wildfire are devastating and, unfortunately, we are in for a long and tough fire season over the next 12 months.”

Christine Schlesinger, a desert ecologist at Charles Darwin University’s Alice Springs campus, said fires in the region had previously mostly been managed in areas dominated by spinifex.

She said buffel grass had promoted hotter and more frequent fires that were affecting the forest canopies by burning long-lived trees.

“What we’ve seen over the past couple of decades is a loss of a huge number of hundreds-of-years old trees from buffel-fuelled fires,” she said.

“Areas that were previously less prone to fire are now a major source of fire-spread through the landscape.”

The NT environment minister, Lauren Moss, acknowledged community concern about buffel grass and said the government was establishing a technical working group to assess its impacts in central Australia and consider management approaches.

She said this would included consideration of declaring buffel grass a weed under territory laws. The working group will report back to the government later this year.

Related: Decline of more than 500 species of marine life on Australian reefs ‘the tip of the iceberg’, study finds

“While buffel grass has provided valuable fodder as well as dust suppression and erosion control in desert areas since the 1960s, there is increasing concern about its role in heightening wildfire intensity, and associated impacts on biodiversity,” she said.

A spokesperson for the federal environment department said the government was in close contact with NT officials about the impacts of the fires on biodiversity.

“Our changing climate is increasing the risk of catastrophic bushfire events which have a massive impact on our native wildlife,” they said. “The increasing frequency and intensity of fires in the MacDonnell Ranges is an example of this.”

They said the on-ground management of established weeds was primarily the responsibility of state and territory governments but the federal government was funding development of a new national framework that aimed to “revitalise the long term, strategic approach to managing established weeds”.