The Times Australia
The Times World News

.
The Times Real Estate

.

Invasive grasses are worsening bushfires across Australia's drylands

  • Written by Andrew Edwards, Research Fellow Bushfires, Charles Darwin University

As the semi-arid Pilliga Scrub[1] burns in New South Wales, many of us are thinking about fire once again. It’s an El Niño summer in the hottest year on record. And there’s a remarkable amount of grass drying out and ready to burn.

Over the past few years, more rain than usual has fallen over vast regions of Australia’s rangelands, the arid and semi-arid regions that account for most of our land mass.

These rains have triggered an enormous boom in native grasses. But it’s also boom time for introduced species such as buffel grass (Cenchrus ciliaris) in the deserts, and Gamba grass (Andropogon Gayanus) in the savannas. These fast-growing grasses have outcompeted native grasses in many areas.

As they dry out, they become fuel for grass fires. Fuel loads have become extreme, especially in areas where invasive grasses are abundant. Already this fire season, enormous tracts of rangelands have burned, covering an area the size of Spain[2].

Our bushfire-mapping site[3] has captured the rangeland fire season so far. Fast-moving grassfires recently hit[4] South Australia. These grassfires can have fronts hundreds of kilometres wide. Yet this is only the beginning of the summer fire season.

Arid lands and buffel grass

When we think of fire in Australia, we often think of bushfires raging through a forest. But grassfires are very common once you leave the coast.

In Australia’s northern savannas, research has shown the direct link[5] between fires, dried grass fuel at the end of the dry season in October, and how much rain fell over the year. Put simply, more rain leads to more grass, which usually leads to more fire.

These past few La Niña years have dumped enough rain to trigger major grass growth in the deserts – producing enough fuel to carry very widespread fire.

Buffel grass has made the problem far worse. This tussock grass native to parts of Africa and Asia was introduced for pasture, as it grows fast, roots deeply, spreads easily and needs less rain than other grasses. But these traits have now made it the biggest risk to biodiversity in arid Australia. Buffel has been a declared weed in South Australia since 2015, and the Northern Territory is considering[6] whether to follow suit.

Management burns are needed to reduce the hazard but are increasingly difficult to implement. Buffel grass grows right up to trees and regrows quickly, promoting hotter and more frequent fires. Fire encourages buffel to regrow, which creates a grass-fire cycle. Native plants and fauna can’t adapt to this.

Read more: The buffel kerfuffle: how one species quietly destroys native wildlife and cultural sites in arid Australia[7]

Buffel also grows more evenly across a landscape, rather than in patches like many natives. At a fine scale, this means fire damage is worse, with more trees and shrubs killed. At a broader scale, areas invaded by buffel grass create links between flammable native plant communities previously separated by open patches.

The result? Fires can spread across larger tracts of land from a single ignition point, as we saw[8] in Tjoritja National Park (West MacDonnell) in 2019.

satellite image
The boom in buffel grass has led to very large grassfires this year. Copernicus/Charles Darwin University, Author provided (no reuse)

Because fires spread so easily, management burns become much more risky and also more damaging to native shrubs and trees – even in winter[9]. That’s a problem, because we need these burns to reduce fuel loads. More intense and wide-ranging fires are likely to injure or kill more native animals, both directly and from the loss of shelter and food after the fire.

Fires can start from lightning – or from simply driving through[10] long, dry grass. Historical weather and fire information indicates central Australia is in for a long hot summer.

How much fire might we see? In 2011, a year when we saw similar fuel loads, about 45% of arid and semi-arid lands had burned by the end of the summer.

Gamba grass on the savanna

In northern Australia’s tropical savannas, there’s a similar problem: fast-growing Gamba grass. This African tussock grass can grow up to four metres high. It’s invading new areas rapidly – government surveys show it increased from about 1,500 sites to more than 9,000 sites in six years in the Greater Darwin Region.

When Gamba dries out, the fuel loads it creates are many times greater[11] than native grasses. Gamba is now widespread throughout the greater Darwin rural area, including large areas of Litchfield National Park.

When Gamba grass burns, the fire runs so hot it can kill tall trees and devastate biodiversity. It’s also more dangerous for firefighters. The high fuel loads produce very high greenhouse gas emissions[12] and harmful pollutants such as particulate matter.

tall grass and car Gamba grass can grow up to four metres high. AAP

Unlike Buffel, Gamba is a declared weed in the NT. The territory government is putting in considerable effort[13] to reduce the damage it does through prescribed burning and requiring property owners to control Gamba.

Unfortunately, these control efforts have a cost. Days with very high levels of air pollution in Darwin are increasing each year, caused by the burning of Gamba to reduce fuel load and the chance of big fires later in the dry season. Polluted air is damaging human health[14].

To combat this, we need to use weather forecasting to advise volunteer firefighters (who do most of the prescribed burns) of the best time to burn.

As the heat of summer continues, we can expect to see more extensive grassfires in central and northern Australia. Highly flammable invasive grasses will make them worse still. We cannot ignore the changes they are making to central and northern fire regimes.

Read more: The summer bushfires you didn't hear about, and the invasive species fuelling them[15]

References

  1. ^ Pilliga Scrub (explorenarrabriregion.com.au)
  2. ^ size of Spain (www.theguardian.com)
  3. ^ bushfire-mapping site (www.firenorth.org.au)
  4. ^ recently hit (www.adelaidenow.com.au)
  5. ^ direct link (www.tandfonline.com)
  6. ^ is considering (www.abc.net.au)
  7. ^ The buffel kerfuffle: how one species quietly destroys native wildlife and cultural sites in arid Australia (theconversation.com)
  8. ^ as we saw (fireecology.springeropen.com)
  9. ^ even in winter (onlinelibrary.wiley.com)
  10. ^ simply driving through (www.abc.net.au)
  11. ^ many times greater (d1wqtxts1xzle7.cloudfront.net)
  12. ^ very high greenhouse gas emissions (link.springer.com)
  13. ^ considerable effort (depws.nt.gov.au)
  14. ^ human health (link.springer.com)
  15. ^ The summer bushfires you didn't hear about, and the invasive species fuelling them (theconversation.com)

Read more https://theconversation.com/invasive-grasses-are-worsening-bushfires-across-australias-drylands-215530

The Times Features

The Hidden Dangers of Blocked Drains and the Ultimate Solution for a Hassle-Free Home

Drain blockages are a big hassle to every homeowner and business owner alike. Whether it is a sink in the kitchen or bathroom, a clogged toilet, or a foul smell circulating aroun...

Understanding the Dangers of Ignoring a Gas Leak

Gas leaks are silent threats lurking within both homes and workplaces. A gas leak occurs when natural gas or any other gaseous substance escapes from a pipeline or containment. T...

Can You Sell Your House Privately in Queensland? Here’s How

Selling a house privately in Queensland is entirely possible and can be a cost-effective alternative to using a real estate agent. While agents provide valuable expertise, their co...

Itinerary to Maximize Your Two-Week Adventure in Vietnam and Cambodia

Two weeks may not seem like much, but it’s just the right time for travelers to explore the best of Vietnam and Cambodia. From the bustling streets of Hanoi to the magnificent te...

How to Protect Your Garden Trees from Wind Damage in Australia

In Australia's expansive landscape, garden trees hold noteworthy significance. They not only enhance the aesthetic appeal of our homes but also play an integral role in the local...

Brisbane Homeowners Warned: Non-Compliant Flexible Hoses Pose High Flood Risk

As a homeowner in Brisbane, when you think of the potential for flood damage to your home, you probably think of weather events. But you should know that there may be a tickin...

Times Magazine

"Eternal Nurture" by Cara Barilla: A Timeless Collection of Wisdom and Healing

Renowned Sydney-born author and educator Cara Barilla has released her latest book, Eternal Nurture, a profound collection of inspirational quotes designed to support mindfulness, emotional healing, and personal growth. With a deep commitment to ...

How AI-Driven SEO Enhancements Can Improve Headless CMS Content Visibility

Whereas SEO (search engine optimization) is critical in the digital landscape for making connections to content, much of it is still done manually keyword research, metatags, final tweaks at publication requiring a human element that takes extensiv...

Crypto Expert John Fenga Reveals How Blockchain is Revolutionising Charity

One of the most persistent challenges in the charity sector is trust. Donors often wonder whether their contributions are being used effectively or if overhead costs consume a significant portion. Traditional fundraising methods can be opaque, with...

Navigating Parenting Arrangements in Australia: A Legal Guide for Parents

Understanding Parenting Arrangements in Australia. Child custody disputes are often one of the most emotionally charged aspects of separation or divorce. Parents naturally want what is best for their children, but the legal process of determining ...

Blocky Adventures: A Minecraft Movie Celebration for Your Wrist

The Minecraft movie is almost here—and it’s time to get excited! With the film set to hit theaters on April 4, 2025, fans have a brand-new reason to celebrate. To honor the upcoming blockbuster, watchfaces.co has released a special Minecraft-inspir...

The Ultimate Guide to Apple Watch Faces & Trending Wallpapers

In today’s digital world, personalization is everything. Your smartwatch isn’t just a timepiece—it’s an extension of your style. Thanks to innovative third-party developers, customizing your Apple Watch has reached new heights with stunning designs...

LayBy Shopping