By Dr John Kanowski, Chief Science Officer and Dr David Roshier, Senior Ecologist (Research)
For AWC’s hard-working Operations team, effectively managing habitats is core business: our sanctuary-based operations staff are front-line land managers, responsible for AWC’s programs across a national network covering more than 6.5 million hectares. No other private conservation organisation in Australia operates on the ground at this scale or deploys such a large proportion (around 80 per cent) of its team in the field.
The objective of this program is to manage landscapes in a way that promotes ecological health and regulates the key threats of destructive fire, weeds and feral animals. These threats are pervasive across Australia and programs to mitigate their impacts need to work in synergy. For example, targeted prescribed burning at the right time helps control some weed species, but at the wrong time can enhance the growth of others. Wildlife sees the strongest recovery in destocked areas with appropriate fire management.
Getting fire management right is arguably the most important part of AWC’s conservation land management program, particularly in tropical northern Australia where changed fire regimes and wildfires can wreak destruction across vast areas. For millennia, the use of fire by Indigenous Australians led to nuanced, regular fire regimes that became an integral part of long-term ecological cycles. Disruption to traditional burning led to an unravelling of those processes.
AWC’s land managers use fire as a landscape management tool throughout the year –techniques and timing are dependent on location and landscape, and fire is applied in order to achieve the best ecological outcomes. This includes planning and delivering low intensity burns (both aerial and ground-based) in the early dry season, measuring and reporting on the results, fire-fighting to protect ecological assets in the late dry season, and in some regions, wet season ‘storm burning’ is used to maintain open grassy landscapes. AWC’s prescribed burning programs are carefully designed to reduce the threat of major wildfires that impact large areas of habitat, while at the same time protecting unburnt patches of habitat and refuge for animals.
Guided by science-informed strategies, AWC’s land managers assess the fuel loads on the ground, incorporating satellite data as well as input from AWC’s ecologists, Traditional Owners, partners and stakeholders. Detailed fire plans are developed that target specific vegetation communities and age-classes to achieve just the right extent of burning at just the right time. We work hand-in-hand with our partners to deliver the largest non-government fire management program in Australia, involving multiple tenures (including AWC, Indigenous and pastoral lands) across more than 6.5 million hectares of the Kimberley – an area approaching the size of Tasmania – and across almost 8 million hectares of northern Australia.
The enormous scale of AWC’s fire program is unique. In 2020 AWC conducted helicopter aerial burning over 35,000 kilometres nationally, and a further 1,000 kilometres on foot and from vehicles.
AWC’s land managers and ecologists work together to develop fire management strategies for AWC properties. In the Kimberley, for example, information on the response of fauna to early- and late-dry season fires, obtained from AWC’s long-term ecological monitoring and research programs, has helped refine targets for the fire regimes we are establishing in the landscape. In 2021, AWC is collaborating with fire ecologist Dr Brett Murphy from Charles Darwin University to quantify the optimal extent of prescribed burning to effectively limit the spread of wildfire and achieve preferred fire regimes.
Predation by feral cats and foxes continues to propel Australia’s decline in biodiversity. To combat the ongoing threat these introduced predators pose, AWC’s land management team manages and maintains mainland Australia’s largest network of feral-free areas and undertakes targeted feral predator control outside of fenced areas. In 2020 for example, during the establishment of the Western River Refuge, AWC removed 78 feral cats on Kangaroo Island alone. For reference, a single feral cat is estimated to kill 246 native mammals every year (Murphy et al. 2019).
Feral herbivores (such as cattle, camels and pigs), range widely across the regions where AWC works. They consume and trample vegetation, remove ground cover and devastate wetlands, thereby removing shelter (increasing exposure to feral predators) and food for native animals. Today, AWC fights an ongoing annual battle to remove vast numbers of feral animals from
sanctuaries and partnership areas. Where economically viable, feral cattle are mustered off properties. Using strategic fencing, AWC has created Australia’s largest functionally feral herbivore-free ecosystems on the mainland at Wongalara (100,000 hectares), Pungalina-Seven Emu (80,000 hectares) and Mornington-Marion Downs-Tableland (600,000 hectares) Wildlife Sanctuaries. In 2020, despite the impacts of COVID-19, we removed an astonishing 8,398 feral herbivores from our properties.
Weed control is another important part of AWC’s land management program. Over 3,200 introduced plants have naturalised in Australia. About 10 per cent of these are considered ‘transformer’ weeds, capable of substantially modifying the environment. Weeds have a range of impacts on vegetation and ecological processes – some, especially the fast-growing grasses, can greatly increase fire hazards. All compete with native plants and can significantly degrade habitat. Control mechanisms for weeds can vary from laborious handson removal, use of appropriate herbicides, selective burning and aerial spraying. AWC land managers and ecologists are working together to develop and refine a National Weed Management Strategy and, at each of our properties, site-specific control efforts are focused on weeds that have most serious impact on the environment. Across the 6.5-million-hectare estate, AWC treated a mammoth 162,130 weeds in 2020.
With your support, AWC’s field team is controlling key threats that impact the survival of Australia’s wildlife, including fire, feral animals and weeds, and effectively restoring habitats on a vast scale. Together we are increasing the chances of survival for Australia’s rarest and most threatened species.
Murphy, B.P., Woolley, L-A., Geyle, H.M., Legge, S.M., Palmer, R., Dickman, C.R., Augusteyn, J., Brown, S.C., Comer, S., Doherty, T.S., Eager, C., Edwards, G., Fordham, D.A., Harley, D., McDonald, P.J., McGregor, H., Moseby, K.E., Myers, C., Read, J., Riley, J., … and Woinarski, J.C.Z. 2019. Introduced cats (Felis catus) eating a continental fauna: the number of mammals killed in Australia. Biological Conservation 237: 28-40.
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