Traditional burning
Traditional burning. Photo © Parks and Wildlife

Before Aboriginal people populated the Australian continent some 40,000 to 60,000 years ago, the major cause of fires would have been lightning. Aboriginal people learnt to harness the naturally recurring fire caused by lightning and other sources to their advantage, which resulted in skilful burning of landscapes for many different purposes.

Fire was used to:

  • make access easier through thick and prickly vegetation
  • maintain a pattern of vegetation to encourage new growth and attract game for hunting
  • encourage the development of useful food plants, for cooking, warmth, signalling and spiritual reasons.

Early European explorers and settlers commented on the Aboriginal people’s familiarity with fire, and the presence of fire in the landscape continually throughout the year. Most of the fires were relatively low intensity and did not burn large areas.

This constant use of fire by Aboriginal people as they went about their daily lives most likely resulted in a fine grained mosaic of different vegetation and fuel ages across the landscape. As a result, large intense bushfires were uncommon.

Fire is a significant part of Aboriginal culture and the knowledge of its use has been retained by many Aboriginal families as their culture and values are shared between generations. Karla Wongi – Fire Talk is an interesting article that provides additional information.

The plants and animals themselves provide clues to the ubiquitous presence of fire.

Fire fact

Fossil records and charcoal deposits indicate that fire has been present for at least 30 million years in the Australian landscape in response to periods of aridity.

Dating fire from balga stems

Low intensity fire pattern which leaves patches unburnt for food and habitat.
Dating from grasstree fire rings. Photo © Parks and Wildlife

Western Australian grass tree or balga (Xanthorrhoea preissii) occurs across the south-west of WA in forests, heaths and woodlands. Balga grow up to five metres high and are long lived - 200 year old specimens are common. A one metre tall balga can be 50 to 100 years old.

As the needle-like leaves die, they are laid down as a highly flammable thatch around the stem. Under the charcoal on the stems, the old leaf remnants lie in repetitive coloured rings. Light and dark brown rings represent annual growth. Studies suggest that black rings represent green needles that have been killed by fire and can provide a record of fire occurrence dating back several centuries. Scientific opinions differ as to the accuracy of this technique for reconstructing fire history (refer to reading list below).

Fire histories inferred from balga stems are consistent with other sources of evidence suggesting that burning by Aboriginal people in the south-west of WA was quite frequent. Understorey plants in the northern jarrah forests reach flowering age three to four years after fire, and most native animals recover to pre-fire levels within three or four years of a low intensity fire.

Further reading:

  • Abbott I and Burrows (2003) Fire in Ecosystems of South West Western Australia: Impacts and Management. Backhuys Publishers, Leyden, The Netherlands.
  • Miller BP, Walshe T, Enright NJ and Lamont BB (2007) Error in the inference of fire history from grasstrees. Austral Ecology, 32: 908-916.
  • Ward DJ (2009) Bushfire history from grasstrees at Eneabba, Western Australia. Journal of the Royal Society of Western Australia 92: 261-268