Fire and flood: resilient landscapes, ecosystems and people

By Dr Hannah Sheppard Brennand, Science Writer

Australia is a land of harsh extremes, renowned for drought, flood, fire and cycles of boom and bust. Given this variation, Australia’s ecosystems have evolved a remarkable resilience to disturbance and many of these natural extremes play an essential role in the lifecycles of our plants and animals: Banksias need fire to germinate, bettongs rely on fire to keep the forest understorey open for grazing, burrowing frogs wait deep underground only to emerge during flooding and nomadic birds form huge flocks around transient lakes. However, in the face of pervasive threats such as feral cats and foxes and mismanaged fire these landscapes are not as resilient as they once were. Biodiversity is in decline, the climate is changing at an unprecedented rate and extreme events are becoming more frequent and intense. By undertaking conservation management and restoring biodiversity, AWC is building more resilient ecosystems that have the vital capacity to adapt.

Brad Leue/AWC

FIRE

Fire has shaped this continent for tens of thousands of years. First Nations people use deliberate fire management to create a patchwork of vegetation types and fire ages. The dispossession of First Nations people and disruption to these fire regimes has contributed to the rise of intense and extensive wildfire. In northern Australia these altered fire patterns burnt over 10 million hectares each year, on average, prior to the resumption of deliberate management. Wildfires like these increase the predation success of feral cats, that preferentially hunt on burn scars where native animals are exposed.

Effective fire management is crucial for resilient landscapes and is a core focus of AWC’s conservation land management actions. We work alongside our First Nations partners to incorporate traditional burning practices in a contemporary framework combined with technology and cutting-edge research, that is developed and delivered by AWC land managers, ecologists and our partners. The strategies are tailored to respond to diverse local systems – from desert to savanna to rainforest and eucalypt forests – with the overarching aims of conserving and promoting biodiversity, protecting life and property, and controlling invasive weeds at a landscape scale.

AWC’s annual burn programs account for forecast fire weather conditions. Australia is currently facing a significant and worsening fire weather forecast. This is concerning and is considered in programs and planning across the vast 7.5 million hectares where AWC and our partners implement effective fire management.

Brad Leue/AWC

Managing fire in the desert

The boom-and-bust cycles of central Australia mean that years of wet are followed by years of widespread fire. On Ngalia-Warlpiri and Luritja Country, AWC land managers and Newhaven Warlpiri Rangers deliver fire management across Newhaven Wildlife Sanctuary’s 262,000 hectares.

Fire management aims to shift landscape-scale fire patterns from intense, hot season wildfire to smaller, patchier, less severe fire patterns. Analysis collated by the Indigenous Desert Alliance-led 10 Deserts Project, in partnership with AWC, the Central Land Council, Kanyirninpa Jukurrpa, Bush Heritage and Desert Support Services, indicates that effective fire management is altering desert fire patterns, shifting fire seasonality towards the cooler months, reducing burnt-patch size and increasing fire age diversity. At Newhaven, AWC’s Fire Management Program has seen wildfire extent and severity reduced by 9% and 47% respectively since 2007.

These metrics deliver real-world biodiversity benefits such as increasing the persistence of fire-sensitive species and communities like the threatened Great Desert Skink. At Newhaven, effective fire management, coupled with targeted feral cat control, has seen a significant increase in activity and breeding success of the Great Desert Skink (Warrarna in the Warlpiri language) – a social lizard that builds and inhabits elaborate communal burrow systems.

At present, only a fraction of Australia’s central deserts are being effectively managed with fire, highlighting how much scope and urgency there is to scale up conservation land management. Lessons being learnt at Newhaven and other AWC properties are being incorporated into the actions being taken by Indigenous rangers and other land managers across the deserts. The Indigenous Desert Alliance, Central Land Council and other Indigenous organisations are actively collaborating to deliver outcomes based on these lessons. In 2022, Traditional Custodians, the Central Land Council and AWC partnered to deliver conservation outcomes at scale across Ngalurrtju Aboriginal Land Trust (320,000 hectares) – contiguous with Newhaven – and 2023 marks the first year of fire management. This partnership is a step in the right direction: ‘working two-ways to protect country and culture.’

FLOOD

For many parts of Australia there is a relationship between fire and flood. In northern Australia, wet season rains mark the end of the intense peak of the build-up and dry season. It also marks the start of wet and early dry season burning when AWC uses prescribed burning to reduce the impact of wildfires across the landscape, increase the mosaic of fuel ages and address weed infestations and woody encroachment into grasslands. As the climate continues to change, extreme rainfall events are expected to increase, particularly in northern and central Australia.

AWC land managers pay a significant amount of attention to the potential impacts of flood. One of the biggest challenges is the timing of programs, such as Ecohealth monitoring and feral predator management, to maximise efficiency and outcomes against investment. A range of measures are undertaken to manage operational infrastructure priorities including maintenance and residential resupply (in anticipation of sanctuary roads becoming impassable), and fence and road maintenance including flood-proofing and preparation for flood response.

Brad Leue/AWc

After the floods

The significant impacts of the 2023 Kimberley floods are still being felt. In January, record flooding inundated Mornington–Marion Downs and Charnley River–Artesian Range wildlife sanctuaries, with the waterline reaching the roof of the research office at Mornington. Despite the devastation, AWC staff were well prepared and everyone was kept safe.

The effects of the floods may take years to recover from, but AWC staff are back on the ground, repairing, restoring and future-proofing operations in northern Western Australia as best we can. Several staff members have returned to full-time life at Mornington (others are based out of Broome), Purple-crowned Fairywren researchers (from Monash University) are back on site and the program is in full swing.

At Charnley, upgrades to infrastructure continue as part of the critical Kimberley Conservation Hub. Great Bowerbirds are making the most of minimal humans on sanctuary and stealing roof screws, Green Tree Frog populations are booming and Endangered Purple-crowned Fairywren fledgling numbers are high. This year, Wilinggin Aboriginal Corporation‘s Darran.gu Wulagura (Strong Women) Rangers and AWC ecologists undertook population surveys of the threatened Golden Bandicoot for the first time on Wilinggin Country in the Artesian Range.

In August, the Ngarinyin People, the Traditional Custodians of Wilinggin Country, gifted a founding population of Golden Bandicoots to Newhaven’s mammal restoration project, restoring the threatened species to Australia’s arid interior.

Lyn Anderson/AWC Volunteer

Boom and Bust

During cycles of boom and bust the landscape fluctuates from periods of rain and abundance to periods of extreme dry. During ‘bust’ times, AWC’s vast Kalamurina Wildlife Sanctuary in South Australia is one of the driest properties in the country. During floods, water gushes in along the Warburton River turning the dusty, arid landscape into pools of shimmering wet. During boom times, rainfall closes all roads and tracks, isolating the sanctuary and the managers that call it home.

In July, Kalamurina Sanctuary Managers Luke Playford and Annemarie van Doorn were ‘flooded out’ and ‘flooded in’ after Luke nipped out to pick up their son from boarding school. ‘The landscape at Kalamurina changes significantly with the rain,’ says Annemarie. ‘Since we arrived two years ago, rainfall always seems to coincide with the school holidays and this time was no different. We received over 25 millimetres in 24 hours which turned a dusty sanctuary into a very wet one and resulted in Luke being away for two and a half weeks. Up north 25 millimetres is not a lot, but here in clay soil country it certainly is.’

BUILDING RESILIENCE

The impacts of climate change are already being felt around the world and Australia is experiencing more extreme fire seasons, floods and drought. These extremes are pushing our ecosystems beyond known limits. Through effective fire management and by restoring and protecting biodiversity, AWC aims to strengthen the capacity to adapt. The call to increase investment in the natural world and scale up our efforts to build more resilient ecosystems has never been louder.

Read or download this full issue of Wildlife Matters here.