Teacher background information

This elaboration describes opportunities for students to investigate the interactions between the biosphere and the atmosphere in the context of bushfire management. Students will learn how the traditional fire management practices of the Aboriginal and Torres Strait Islander peoples of tropical northern Australia are being recognised by contemporary science for effectively reducing greenhouse gas emissions. Additionally, these practices result in healthier ecosystems compared to former practices in fire management informed by Western science. Students have opportunities to appreciate how the traditional ecological knowledge and experience of Aboriginal and Torres Strait Islander Australians are informing and enriching modern scientific understanding of tropical savanna ecosystems and how the reinstatement of traditional fire management regimes is contributing to more sustainable land management practices and a reduction of atmospheric pollution.

Wildfires form a major component of the global carbon cycle. During this natural phenomenon the carbon stored in the biosphere (in the form of organic matter in plants and animals) is converted to carbon dioxide and released into the atmosphere. Fire also plays an important role in other global system cycles when it returns vital nutrient elements such as nitrogen and phosphorus from the biosphere back to the lithosphere, thus making them available once more for the regrowth of plants and the rejuvenation of the whole ecosystem. 

Carbon dioxide is a naturally occurring atmospheric gas with heat-trapping properties which play a vital role in the stability of global climate patterns. However, the burning of fossil fuels, such as coal, mineral oil and natural gas, has led to a dramatic increase of carbon dioxide levels in the atmosphere since the beginning of the Industrial Revolution. This by-product of modern-day lifestyles has been identified as the major cause of an enhanced greenhouse effect. This is leading to a gradual warming of the Earth’s systems and an associated change in climate patterns, which has sparked global efforts to reduce the emission of carbon dioxide into the atmosphere. 

Over millennia, Aboriginal and Torres Strait Islander peoples living in the tropical savanna woodlands of northern Australia have amassed a wealth of ecological knowledge, and have developed strictly controlled fire regimes. Controlled fires were purposefully designed to burn at low intensity in the early dry season and only in carefully selected patches of bushland. This practice results in a landscape that consists of a ‘mosaic’ of patches in different stages of regrowth. Recently burned patches act as effective fire breaks against the spread of large-scale and high-intensity fires. Since the beginning of European colonisation, Western land management practices have disrupted this carefully designed fire management regime leading to more frequent out-of-control wildfires that are extremely destructive, highly polluting and emitting significantly larger quantities of greenhouse gases than the controlled burns prescribed by traditional practice.  

Students could investigate the West Arnhem Land Fire Abatement (WALFA) project. This project has adopted a new fire management regime with support from local communities, the Northern Land Council, and Aboriginal traditional owners and organisations from the West Arnhem Land region. Defining factors such as fire timing, frequency and the size and pattern of patches to be burnt are informed by the experience and knowledge of the Aboriginal peoples of this region. Similarly, the traditional fire management practices of Torres Strait Islander peoples are being recognised and reinstated on the islands of Moa, Badu and Mabuiag. These projects use traditional ecological knowledge, together with modern scientific practices, to better control the timing and intensity of savanna fires and to monitor the effectiveness of the new measures in reducing greenhouse gas emissions.