During most of the year, you will probably notice smoke curling into the sky as you approach Uluru. Early European explorers also noticed this. As Aboriginal people travelled on foot across the land they would carry a tjangi (fire stick) with them. They could use this to burn patches of old spinifex, cleaning the area for walking and making way for new growth. The new growth would provide bush tucker for Anangu and a patchwork of ideal habitats for animals and insects. Smoke from fires was a signal to other groups that people were travelling and in which direction. Fire was also used for hunting and cooking food.
Today most fires in the park are lit following land management patterns traditionally practiced by Anangu. These skills are vital for the preservation of the central Australian ecology. By burning in a mosaic pattern animals could shelter in the old spinifex and find new green feed in the burnt areas. Some animals such as the tarkawara (spinifex hopping-mouse) prefer the nyaru (recently burnt areas) to spinifex for foraging while others such as tjantjalka (military dragon) move away until the spinifex cover comes back.
Fires have shaped the landscape, habitats, survival of animals and patterns of vegetation. To understand how, it is important to understand the desert vegetation.
Anangu patch burning of spinifex
There are two main vegetation groups in the park: one dominated by spinifex and one dominated by mulga. The two types have adapted very differently to survive in the arid zone.
Tjanpi - Spinifex
The spinifex-dominated vegetation of the dunes and higher plains looks grassy with trees dotted about. Most of the plants here revegetate by sprouting either from under the ground, like spinifex, or above the ground, like the desert oaks. After fire, regrowth will be visible within weeks even without rain!
Vegetation with these resilient characteristics can survive frequent fires. Widespread fires in spinifex country can wipe out populations of birds, small mammals and lizards. Small patch burns are ideal for this type of landscape. Neighbouring patches of burnt, unburnt, recently burnt and aged spinifex create the best conditions for survival of a wide range of native animals, insects and plants. This practice of small managed burns has come to be known as patch burning or a fire mosaic of burnt and unburnt country.
Wanari - Mulga
Groves of trees on lower plains and in the dips between dunes (swales) make the mulga-dominated vegetation look quite different from the spinifex areas. Most of the plants in these areas regenerate from seeds.
Fire in mulga-dominated vegetation kills much of the flora. New growth comes mainly from seeds which often require the heat from the fire to crack the seed coat and encourage growth. It takes two good seasons of rain to germinate the seeds and get the seedlings underway.
Young mulga trees grow for around 10 to 20 years before they become mature enough to set seed. Fires in immature mulga forests can eliminate whole communities of the species. In the park at the moment you will notice large stands of mulga especially near Uluru. The seeds for these trees were germinated in the 1976 fires. Frequent fires would wipe out this type of vegetation. These areas can only afford to be burnt every 50 years or so.
It is therefore important to protect groves of mulga from frequent burning. Fire is used to create 'fire breaks' around young mulga groves. While fire can enhance the germination of mulga, adequate rainfall is the most important factor determining successful regeneration events.
As part of the central desert region Uluru receives around 280 - 310 mm of rain per year. This rain falls mainly in the late summer months. Rainfall is the key to increased fire danger in Uluru. The higher the rainfall, the greater the amount of plant growth, the more fuel there is for wildfire.
The two vegetation types, mulga and spinifex, produce fuel in different ways. In the mulga-dominated shrublands grasses and herbs make up the fuel. They grow after the rain and die off after only a short dry spell. Within six months they have blown away and there is too little ground cover to keep a fire burning. The fire danger period of mulga shrublands is therefore short and follows within six months of the rain.
Spinifex also grows following rainfall but, unlike other grasses it does not die off and then blow away. Instead it remains highly flammable. With rain, spinifex grows more and the amount of fuel builds up rapidly with each rain event.
The periods of highest fire danger occur after a few years without fire when the spinifex has built up and the growth of grasses in the mulga has peaked following heavy rain. When these factors coincide, uncontrolled fires will carry long distances through both vegetation types. These are the most devastating fires for plants and wildlife.
Natural fires mostly occur in the early summer months. They are usually started by the lightning strikes of dry electrical storms from the north west. When the storms arrive the weather is usually hot, dry and windy - conditions ideal for raging fires. Damage can be severe and widespread.
Traditional burning of the Uluru area stopped when Anangu were driven from the region during the 1930s. During the 1940s rainfall was good and vegetation flourished. The 1950 fire, fed by the fuel grown during the previous 20 years, wiped out about one third of Uluru-Kata Tjuta National Park's vegetation. The pattern repeated itself and in 1976 two fires burnt 76 percent of the park. Over the same period more species of medium sized mammals became extinct around Uluru and Kata Tjuta.