Fire in the Western Australian rangelands

Page last updated: Friday, 6 April 2018 - 10:26am

Fire is integral to many ecosystems in the Western Australian rangelands. Rangeland fires affect more than just pastoralists and the businesses they run: these fires affect community safety and health, regional economies, societal and cultural values of landscape, biodiversity and tourism.

We provide the pastoral industry with information on the interaction of fire and grazing pressure on the productivity of rangeland pastures and animals to improve sustainable resource use.

Fire in the rangelands plays a major role

Fire and grazing pressure are the main drivers of productivity over which rangeland managers have some influence. Managed fire can reduce the risk of wildfires, benefit pasture productivity, be used to influence grazing pressure, and contribute positively to biodiversity values in fire-prone ecosystems. Wildfires, on the other hand, are a threat to safety and the business viability of pastoral enterprises, and threaten rangeland biodiversity and productivity.

Fire is never a gentle master (proverb)

Burning will not improve land that is already in poor pasture condition.

Fire affects land systems and pasture types in different ways, and importantly, have cumulative effects over time. There is no single ‘fire recipe’ that can be applied across vegetation types, regions or the whole state.

Content

Principles for managing rangeland pastures with fire

Match any planned burn to the paddock conditions

Paddock conditions include pasture type, land system and rainfall zone (timing, intensity, size, distribution, frequency). We provide detailed information for each rangeland region:

Manage total grazing pressure after a fire

Fresh regrowth after fire is attractive to grazing animals and susceptible to overgrazing.

Principles are:

  • Match the stocking rate to the amount of feed available after fire.
  • Prevent overgrazing near water, preferred pasture types and sensitive areas after fire: total grazing pressure includes all grazing animals.
  • Do not burn immediately adjacent to the most recent burn because this can lead to overgrazing along the 'edges'.

Plan for fire well ahead of time

  • Have the equipment, training and fire behaviour information needed for successful fire management.
  • Burn only a limited proportion of a property in any one season.

The relevant government agencies provide advice on aspects of fire management. The legislated hazard management authority is the Department of Fire and Emergency Services (DFES).

DPIRD, Parks and Wildlife Service (within Department of Biodiversity, Conservation and Attractions) and local government also provide advice on certain aspects of fire management relevant to rangeland managers.

Reduce wildfire risk

Important steps to manage wildfire risk:

  • use aerial or ground burns early in the dry season to produce areas of relatively low fuel
  • use natural barriers and changes in vegetation type to limit the spread of fire
  • grade fence lines and access tracks
  • clear fuel from around assets, such as buildings, yards and bores
  • have the right equipment ready
  • get training and develop the skills needed for managing wildfires.

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Benefits from using planned fire in rangeland pastures

Planned and managed fires can:

Improve pasture utilisation with planned fire

Planned fire can improve pasture utilisation by influencing livestock grazing behaviour:

  • Animals prefer to graze the fresh 'green pick' produced when soil moisture is present after burning.
  • Livestock will tend to move to the fresh green pick on burnt patches, and this reduces overgrazing of unburnt preferentially grazed patches.
  • The result is that a greater percentage of the pasture is consumed by livestock and converted to livestock growth.

Avoid damage to burnt, regrowing pasture:

  • Prevent overgrazing and loss of desirable plants on vulnerable, newly burnt country.
  • Reduce grazing pressure on burnt country by either burning a patch of country large enough to spread the grazing pressure, or reducing livestock numbers on the burnt country; managers can calculate suitable stock numbers on burnt country by using a forage budget.
  • Manage grazing pressure and post-fire livestock trampling to maintain sufficient groundcover to reduce potential wind and water erosion risk on bare ground after fire.
  • Reduce grazing pressure from feral animals and native herbivores.

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Reduce potential damage from wildfires

To reduce the risks associated with wildfires in high rainfall areas:

  • Reduce fuel over the property early in the dry season, while maintaining adequate reserves of feed for at least the remainder of the dry season.
  • Use cool dry-season fires to create patches with relatively low fuel loads in preparation for the more intense fires of the late dry (or summer) season. Under some circumstances, these patches may form an effective firebreak or provide a lower fire intensity haven for animals.
  • Use strategic fuel reduction as the first step in a rotational burning program for extensive areas of rank pasture without existing internal barriers.
  • Maintain an effective network of firebreaks and tracks. Vehicle-width firebreaks are generally insufficient to stop a wind-driven fire; they provide access to allow personnel on the ground to safely light fires during planned burning or access for wildfire mitigation and mop-up. Note that low wind conditions are no guarantee that fires can be contained. Willy-willys (dust devils) are frequently generated when the atmosphere is unstable even when the fuel load is patchy. These can pick up burning material and carry it over most tracks or graded firebreaks. Guidelines on the construction and maintenance of firebreaks (PDF 2MB) are provided by DFES. 
  • Protect fences from high intensity fire. High intensity fire will weaken high tensile wire fencing, may accelerate corrosion rates, and it destroys wooden, fibreglass, plastic or ceramic fence components. Limit damage by grading heavy plant growth away from fences.

Improve safety around infrastructure, habitation and tourist areas

Safety of people is the primary concern, and this means that pasture productivity may be sacrificed in the buffer areas around infrastructure and wherever people gather. Fire and grazing can be used to keep fuel loads low. Consult DFES for guidance.

Reduce woody plants in grassland

Hot burns can reduce woody weeds or woody thickening of native plants in grasslands. The fine fuel load in the target area needs to be high enough to carry a fire of sufficient intensity to kill juvenile trees and shrubs. Hot burns are risky, and therefore firebreaks and other control methods must be good enough to prevent wildfires spreading. Contact DFES for advice on hot-burn planning and risk for the target area.

A cautionary note: burning can increase or decrease the incidence of native woody species and exotic weeds, depending on the situation. We can provide advice to managers on likely outcomes for a target area or plant species of concern when planning a burning regime or a forage budget.

Maintain biodiversity and conservation values

Early dry-season fires are relatively cool and slow moving compared with wildfires. Creating a burning mosaic across the landscape can have significant benefits for biodiversity, particularly for native fauna that require areas with differing fire histories to persist.

In the northern rangelands, biodiversity depends on a mixture of early-burnt, late-burnt and unburnt country with vegetation at varying stages of maturity since the last fire. This is known as a 'mosaic' or 'fine-scale mosaic' burning regime. Biodiversity maintenance over the long term in some low rainfall or high value conservation areas depends on the absence of fire for very long periods.

Damaging fires should be kept out of environmentally, socially and culturally sensitive areas. Such areas may be the focus of on-station tourism activities contributing to enterprise income.

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Reduce greenhouse gas emissions from rangeland fires

Reduce greenhouse gas emissions from managed rangeland fires by reducing the total amount of tropical, subtropical and semi-arid savanna country burned in any year, and shifting the seasonality of burns from intense wildfires late in the dry season to earlier, cooler fires. More information is provided on the Carbon farming and reducing emissions through savanna fire management web page.

These management options are covered by the savanna fire abatement methodology under the Carbon Farming Initiative. Carbon farming presents an opportunity for land managers to financially benefit from providing the ecosystem service of mitigating carbon pollution.

Early dry-season fires release less greenhouse gas

Late dry-season fires in savanna woodlands emit 52% (on average) more emissions per unit area than earlier, cooler fires (Russell-Smith et al. 2009). Shifting the fire regime from predominantly late, extensive fires to a system dominated by earlier fires can be achieved through developing a mosaic of burned patches from early cool fires, developing a system of firebreaks, and tactical fire suppression.

Early burning using the Commonwealth Clean Energy Regulator approved methods can potentially reduce rates of rainfall run-off and improve water use efficiency on managed country. This scheme may be available to producers with savanna country receiving an average annual rainfall of 600 millimetres or more. Assistance for leases under indigenous management developing a carbon farming or fire abatement project may be available through the North Australian Indigenous Land and Sea Management Alliance (NAILSMA).

For savanna burning projects or carbon farming projects:

  • Contact local government, the Department of Biodiversity, Conservation and Attractions, and the Office of Bushfire Risk Management within DFES for specific advice on wildfire regulations.
  • Seek independent technical, financial and legal advice about your particular circumstances.
  • Check the lease conditions on leased Crown land; you may need consent from the Minister for Lands.

Note: frequent early dry-season fires are likely to reduce pasture growth in tropical savannas, especially if grazed soon after burning. See the regional fire management pages for more detail (links on the right-hand side of this page).

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Risk factors in rangeland fires

The main risks from using fire to manage rangeland pastures are:

  • more erosion and pasture condition decline, particularly if combined with grazing during early growth
  • burning sensitive areas that are already preferred by livestock can lead to excessive grazing after burning
  • burning more country than planned
  • feed shortage during drought or below-average rainfall.

These risks can be reduced through good planning and execution of fires. DFES can assist with general fire management planning and aerial burning programs to reduce wildfire risk on pastoral leases.

Planning for rangeland fires

Fire management is an important aspect of the overall property management plan, and includes prescribed burning and wildfire mitigation.

We recommend planning onto a laminated station map, marking:

  • critical assets and infrastructure: graded tracks, water-filling points, fence lines, buildings, tourist areas
  • areas where fire protection is a high priority
  • where there are low-fuel areas resulting from previous burning
  • grazing values
  • land systems, soils, pasture types, topography.

Managers can update the map during the season to help staff and visitors understand management needs.

In most cases a permit will be required from the local shire Bush Fire Control Officer prior to burning.

Consultation and cooperation with neighbours and nearby communities is essential. Regional fire management planning bodies and groups require and value input from pastoral lessees and managers.

Planning support

Biophysical and infrastructure mapping services and assistance with developing or updating an overall property management plan are available from local DPIRD officers. Free property management planning assistance is also available through Rangelands NRM (Ecologically Sustainable Rangeland Management planning). 

Assistance with fire management planning for pastoral lessees is available from DFES (Guidelines for the development of Pastoral Station Bush Fire Management Planning). There is also a subsidised (often free) annual aerial burning program to reduce wildfire risk that pastoral lessees can take part in.

Department of Fire and Emergency Services and fire management plans

DFES encourages all interested lessees to develop fire management plans and will assist lessees to develop a plan. Fire management planning is a free service that provides a map-based product for individual pastoral stations. Producing these plans does not constrain pastoralists in any way.

Funding for this service is separate from the aerial burning budget and assistance to lessees and managers for this activity is available all year round.

DFES fire management planning resources:

You can find other information from your local Land Conservation District Committee, NAILSMA and the Australian Wildlife Conservancy.

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Fire mapping and predicting fire behaviour

Satellite information

There are fire mapping services available to rangeland managers:

The satellite mapping services can provide information on:

  • degree of fuel ‘curing’
  • location of active fires (hotspots)
  • fire scars.

Satellite-derived information is used by DFES to plan aerial control burning and to assist rangeland managers responding to wildfire emergencies.

Weather forecasts

Sources include:

Visual curing and fuel load guides

Curing is a measure of pasture ‘greenness’ and is defined as the percentage of material in the pasture that is dead. The degree of curing has an important effect on fire behaviour. Fuel load is the amount of fuel or biomass that has accumulated in the pasture, measured as tonnes of dry matter per hectare (cut, then dried until fully cured). DFES has produced a visual grass curing guide and a series of regional visual fuel load guides to assist land managers to estimate and communicate the degree of curing and amount of fuel in the pasture.

Fire meters

The fire danger meter and index gives a measure of how difficult a fire will be to control based on curing, temperature, humidity and wind speed measured in the field. Note: do not rely on grassland models for spinifex fires.

  • Landgate has a very handy set of fire behaviour calculators that include spinifex, semi-arid mallee heath and other fuel types.
  • Amicus is a new multiplatform computer application developed by CSIRO that enables the calculation of expected fire behaviour from burning conditions that you enter.

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Training

Managers and employees can get training in fire safety and bushfire fighting from DFES if they join or form the local volunteer bushfire brigade.

Equipment

Relevant equipment including graders, water tanks and portable pumping equipment needs to be identified in the fire management plan and maintained in a good state of readiness. The local DFES office can provide technical advice on important items, such as drip torches, slip-on fire units, protective clothing and communications equipment.

Early dry-season aerial burning program

DFES has offered an early dry-season aerial burning program service to Kimberley pastoral lessees for more than 10 years.

The aerial burning program is a service within the annual DFES budget for the Kimberley, and supplemented by grant application funding when required. Fire management plans for each lease are not an essential prerequisite for accessing the aerial burning service.

The process for applying is:

  • work out how to fit early dry-season burning into your schedule
  • contact DFES to obtain the intent form and any other paperwork required
  • return a predicted flight line path for your property as well as a signed intent form.

A representative of the lessee must be present in the aircraft during the aerial burning flight runs on their lease or leases.

Note that the signed form is an indication of intent only, not a contractual commitment. Withdrawal from the program due to unforeseen circumstances will have less impact than late indications of interest.

DFES will attempt to ‘cluster’ aerial burning flight runs if possible to save resources. Therefore, the earlier you contact them to discuss availability, the more likely it is that your requirements can be accommodated within the schedule.

The lead time required to arrange to get the helicopter to your lease is at least 1 week. The lead time may be longer at the peak of demand.

Aerial burning programs for wildfire hazard reduction in pastoral areas other than the Kimberley can be organised if sufficient interest is indicated.

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For more information

For information on the aerial burning program contact DFES.

For enquiries on all aspects of bushfire risk management, contact the Office of Bushfire Risk Management (DFES) on (08) 9395 9538. 

Reading

Burrows, N,  Ward, B & Robinson, A 2009, 'Fuel dynamics and fire spread in Spinifex grasslands of the Western desert', Proceedings of the Royal Society of Queensland, vol. 115, pp. 69–76, viewed 14 November 2017 www.researchgate.net/publication/285820542_Fuel_dynamics_and_fire_spread_in_Spinifex_grasslands_of_the_Western_desert

Department of Agriculture and Food, Western Australia [DAFWA] 2006a, Fire management guidelines for Kimberley pastoral rangelands, best management practice guidelines, DAFWA, Perth, http://researchlibrary.agric.wa.gov.au/lr_best/2

DAFWA 2006b, Fire management guidelines for southern shrubland and Pilbara pastoral rangelands, best management practice guidelines, DAFWA, Perth, http://researchlibrary.agric.wa.gov.au/lr_best/1/

DAFWA 2012, 'Early dry season aerial burning program', in Rangelands Memo, March, DAFWA, Perth.

Fire and Emergency Services Authority [FESA] 2007, Kimberley bushfire burning guidelines and firebreak location, construction and maintenance guidelines, FESA, Perth, www.dfes.wa.gov.au/safetyinformation/fire/bushfire/BushfireProtectionPlanningPublications/Kimberley_Bush_Fire_Burning_and_Firebreak_Booklet_2007.pdf 

FESA 2010, Guidelines for the development of pastoral station bush fire management planning, FESA, Perth, www.dfes.wa.gov.au/safetyinformation/fire/bushfire/BushfireProtectionPlanningPublications/FESA-Guidelines_for_Pastoral_Station_Fire_Management_Plans.pdf

FESA nd, Firebreak location, construction and maintenance guidelines, FESA, Perth, www.dfes.wa.gov.au/safetyinformation/fire/bushfire/BushfireProtectionPlanningPublications/FESA%20Firebreak%20Guidelines_std.pdf

Russell-Smith, J, Whitehead, P & Cooke, P (eds.) 2009, Culture, ecology and economy of fire management in North Australian savannas: rekindling the Wurrk tradition, CSIRO Publishing, Melbourne.

Stretch, J 1996, 'Fire management of spinifex pastures in the coastal and west Pilbara', Miscellaneous publication 23/96, Department of Agriculture and Food, Western Australia, Perth, http://researchlibrary.agric.wa.gov.au/misc_pbns/35/.

Suijdendorp, H 1955, 'Changes in pastoral revegetation can provide a guide to management', Journal of Agriculture, Western Australia, 3rd series, vol. 4, pp. 683-687.

Tropical Savannas Cooperative Research Centre 2001, Savanna burning: understanding and using fire in northern Australia, Tropical Savannas Cooperative Research Centre, Darwin, http://savanna.cdu.edu.au/publications/savanna_burning.html

Rangeland surveys:

Contact information

Kathryn Ryan
+61 (0)8 9166 4015
Wayne Fletcher
+61 (0)8 9690 2135