The Department of Environment and Conservation (DEC) insists on burning at least 200,000ha of native forest every single year.
Despite government reports, both State and Federal, that question DEC's current burning regime, DEC continures to burn native forest despite the impacts on biodiversity, water and air quality, and the impacts on human health.
Fire in the natural environment
Burning bushland is seen as a remedy for many problems. Bush gets burnt to protect people and buildings from wildfires. It is burnt to get rid of unwanted plant material and to increase the flow of water into dams that are running dry. Burning the bush is proposed as a cure for the decline being seen in jarrah, tuart and wandoo forest and woodland. It also happens because some people think it is fun. Read on!
Introduction
Fire is a widely used land management tool. In Western Australia, it is often called ‘prescribed burning’. This has various objectives, such as getting rid of logging debris; regenerating specific plants; and reducing the amount of flammable vegetation to make wildfires less intense and easier to control. It is this last category of prescribed burning, also called ‘fuel reduction’ or ‘hazard reduction’ burning, that is the most controversial. If conducted too frequently ‘fuel reduction’ burning can actually increase the amount of flammable vegetation and make the environment more fire prone. Furthermore, in Western Australia, prescribed burn planning does not adequately take into account the recovery times of species, communities and ecosystems, for both flora and fauna.
Fire and flora
While some plants can recover quickly after being burnt, others need a long time to recover. For plants that can only reproduce from seed, a reasonable interval between fires is the time it takes the plant to grow and produce its seed, multiplied by two and a half. Some plants take 15 years before they even set seed. They would require fire-free periods of at least 35 years. Young or new growth on some plants may be fire sensitive for many years. Karri trees need 15 to 25 years before they can survive fire. If a fire occurs again before particular plant species have recovered from a previous fire, those species may eventually disappear from the ecosystem. Certain ecosystems such as peatland — areas that are very moist and contain a lot of organic matter — may never recover from burning. Furthermore, if fires occur too often, nutrients can be lost from the environment and not replaced from humus and decaying vegetation, so the health of the ecosystem will suffer.
Fire and fauna
The immediate impact of fire on all animals is disastrous. Fire kills them unless they are able to escape by moving faster than the fire-front (for example, kangaroos) or by having deep burrows (for example, some trapdoor spiders). The ability of animals to recover from fire depends firstly on the recovery of food sources and habitat and secondly on the presence of populations from which the burnt area can be recolonised. In the case of some rats and mice, recovery may occur within two years after a fire, but for Honey Possums it may be 30 years before their populations fully recover. Burning in spring, when a lot of prescribed burning is carried out, is bad for most birds. This is when they are raising their young, and fire reduces the amount of insects and nectar on which they feed as well as destroying their habitat. While some animals are present in larger numbers in recently burnt bush, no animal depends on fire for its survival. The example often used of a ‘fire-dependent’ species is the Tammar Wallaby, which requires dense thickets of vegetation for food and shelter from foxes. Such thickets need a fire-free interval of 25 to 30 years and can be rejuvenated by fire, but this does not mean that the Tammar needs fire for its survival. There is no evidence that the population of Tammars on Garden Island in Western Australia has decreased even though there hasn’t been a fire on the island for nearly 50 years.
Indigenous burning
It is sometimes said that we should burn the way Aboriginal people did. Even if we wanted to, it can’t be done. Firstly, in most parts of Australia, we don’t know how Aboriginal people used fire. Secondly, since European occupation, ecosystems have been changed so much that Aboriginal burning would no longer be possible. Much of the native vegetation has been removed and what is left is fragmented, and buildings, crops and stock that need protection from fire are scattered through it. Logging has left large amounts of debris in the forests and opened them up to more sun and rain and thus more plant growth in the understorey. Also, the native animals like tammars and woylies that ate and buried plant material have largely disappeared, so there is a lot more flammable vegetation in the bush now than there was before Europeans arrived. It has been claimed that in Western Australia the Noongar people burnt the jarrah forest every three to five years. This claim is strongly disputed and the evidence disproves it. If the Noongars had burnt the Jarrah forest every three to five years, all the plants and animals that need much longer between fires to survive would have disappeared.
A new approach to burning
By reducing the amount of flammable vegetation (the ‘fuel load’), prescribed burning may reduce the intensity of wildfires and make them easier to control, but it will not prevent them. Furthermore, controlling wildfires depends on many factors other than the fuel load, such as wind speed and direction, temperature, rain, and the response time, skill and equipment of fire-fighters. Ironically, prescribed burning as currently practised tends to make the whole environment more fire prone by promoting fire-loving plants and removing natural fire barriers such as peatlands, which are dried out and made more flammable. Instead of relying heavily on prescribed burning, there are many things that we should do to protect ourselves and the places and things we value from wildfires. First, we should plan towns so that we don’t build homes in places where there is a high risk of wildfires. If people insist on building in such places, they must be warned of the danger and encouraged to design fire-resistant houses and use fire-resistant materials. Their insurance premiums should reflect the higher risk. Second, we need to carry out proper risk assessment and risk management. Wildfire mitigation should focus on areas with a high likelihood of catching fire where the consequences would be most serious. Third, since we already have a lot of homes in high fire-risk areas, we need to develop a system of zones for classifying fuel management areas, with clear objectives for each zone. These should be applied across the landscape, and all land managers and the community should be involved. Fourth, we need to educate the community about wildfires so that everyone knows how to protect themselves, their homes and their environment from wildfires. If we do all these things, we can protect people, property and biodiversity from unwanted fires.
written by Beth Schultz