Fire and soils

Discover how fire impacts soils and what factors influence these effects.

Debris flow after fire and rain in Warrumbungle National ParkFire has been an important part of many Australian landscapes for thousands or even millions of years. But fire has significant effects on soils, and fire-management practices must take these into account.

Impacts

Fire can:

  • increase soil erosion
  • increase the sediment load in streams
  • change the availability and cycling of nutrients and carbon in the soil
  • change the quantity and quality of water from burnt catchments
  • damage aquatic ecosystems, fauna habitats and roads and other infrastructure
  • increase flooding.

The type and extent of these changes depends on many factors, including:

  • fire frequency
  • fire severity
  • burn season
  • weather conditions
  • the spatial pattern of the burn.

High-intensity wildfire has very different effects from low-intensity fires such as hazard-reduction burns. High-intensity wildfire can cause massive soil erosion, major siltation of streams, nutrient losses and long-term impacts on catchments.

Fire and soils (PDF 1.6MB) summarises the current state of knowledge about the impacts of fire on soils, particularly in Australia. The report outlines the potential impacts of different fire regimes on soil erosion and sedimentation, nutrient and carbon cycling, and water quantity and quality.