Planning for prescribed burning

Article Index
Planning for prescribed burning
Master Burn Plan process
Prescribed Fire Plan
Proposed burn program

Page 4 of 4

Proposed burn program

Low intensity, patch burn designed to provide protection to natural and community assets are usually conducted in Spring and Autumn when weather is mild and fire behaviour is moderate and easier to manage.

In southern parts of Western Australia Spring burning is undertaken when fuels are still reasonably moist from winter rains. The moisture content of the fuels affects fire behaviour resulting in mild, slow moving fire with low flame height and low fire intensities. Flames are usually extinguished over night when the air gets cooler and the moisture in the air (relative humidity) increases. Burning under these conditions results in a patchy burn with some areas within the burn area left unburnt. These areas act as refuges for flora and fauna and provide reservoirs for recolinisation into the burnt areas. As the Spring progresses and the effect of sun and wind continue to dry the fuels it makes them more flammable, and the opportunity to undertake safe burns decreases.

Autumn burning is undertaken when ground fuels are beginning to wet up as a result of rains associated with the break of the season. The moisture content of the dry fuels from summer continue to increase with each rainfall event. The relatively dry fuels affect fire behaviour resulting in moderate intensity fire with low to moderate flame height. Bark and dead woody material above ground can catch alight and scorching of tree canopies is common. Larger fuels such as limbs and logs can catch fire and continue to smoulder for days. Burning under these conditions results in a more uniform burn with larger areas within the burn area being burnt and fewer, smaller areas remaining unburnt. These burns tend to result in regeneration and resprouting of vegetation, a release of nutrients and a reinvigoration of local habitats. As the autumn progresses, temperatures decrease and rainfall continues to wet the fuels making them less flammable. The opportunity to undertake effective burns decreases.

The Master Burn Planning process has been completed for planned burns during the next three years in the south-west forest region WA. An indicative prescribed burn program has now been developed for the autumn 2009 period and the six seasons for spring 2008 to autumn 2011. The proposed burns are designed to meet either a primary purpose, or a combination of purposes that include:

Community protection—protection of human life, property, public assets, parks, water catchments, timber values and plantations;
and silvicultural burns for regeneration of native forests following timber harvesting.

The extent of the indicative burn programs for the south-west regions for the six seasons for spring 2008 to autumn 2011 is shown on the maps below. These areas are based on coarse block boundaries only and are certain to be changed following internal consultation and field inspections and further input from the community engagement processes.

Maps of the intended burn program for all regions for Autumn/Winter 2009 (fifteen region maps, one forest regions map) are available for download below. Also available for download are the maps for the six seasons—spring 2008 to autumn 2011 (three region maps).

Public consultation maps are currently being prepared for the autumn 2009 burns, and will soon be available for public scrutiny at the relevant DEC District offices in south-west WA.