Fires in Nature

• Wildfires

  Unwanted wild land fires, also known as bushfires in Australia and brushfires in America
• Wildfires


  • Tend to occur most frequently in hot areas where there is extended periods of drought
  • Strong winds cause fires to spread more quickly
• Causes of wildfires

  • Natural causes
  • Human causes
• Natural causes of wildfires


  • Lightning is the biggest natural cause
  • Spontaneous heating where leaves and branches on the ground are heated to the point at which it catches fire without a spark
  • Volcanic eruptions produce hot lava and ash which can ignite a fire, and steep slopes can then lead to the fire spreading quickly
• Human causes of wildfires


  • Arson where fires are started deliberately
  • Children playing with matches
  • Electricity pylons falling down in high winds
  • BBQ's and campfires that have not been extinguished properly
  • Broken bottles acting as a magnifying glass
  • Sparks from train wheels and machinery
  • Discarded cigarettes
  • Slash and burn farming techniques
• Primary effects of wildfires


  • Loss of life and injury to people and animals
  • Destruction of property and possessions
  • Loss of vegetation and crops
  • Smoke
• Secondary effects of wildfires


  • Homelessness
  • Health problems from the inhalation of smoke
  • Loss of animal habitats
  • Increased soil erosion as vegetation is no longer there to bind the soil together
  • Insurance premiums rise
  • Loss of jobs and income for agricultural workers who lose crops or livestock
  • Access to recreational areas is restricted
• Preventing wildfires


  • Remove dead leaves and branches in areas prone to wildfires
  • Organise controlled burning to remove fuel
  • Educate the public to reduce the human causes of wildfires
• Stopping wildfires once they have started

  1. Firefighters spray the fire with water and foam

  2. Organise air drops of water and fire retardant chemicals from planes to put out fires in inaccessible areas

  3. Spray ahead of wildfires to prevent the fire spreading

  4. Create fire breaks by removing a line of vegetation or digging a trench to stop the fire spreading

  5. Back burning is where areas ahead of the fire and deliberately burnt in a controlled way to remove the fires fuel supply
• Wildfire


  A large, uncontrolled fire that quickly spreads through vegetation
• Conditions favouring intense wildfires

  • Vegetation type: Thick, close together vegetation allows fires to spread quickly and easily. Trees and thick bushes lead to more intense wildfires; grasslands do not burn as intensely. Vegetation with flammable oils - like eucalyptus - causes more intense fires also.
  • Fuel characteristics: Vegetation should be dry to allow it to catch. Finer vegetation causes fires to spread quicker, but larger, thicker forms of vegetation burns for longer and more intensely.
  • Climate and recent weather: Wildfires can occur anywhere in the world, but the most common areas are located in areas with enough rainfall to have sufficient plant growth, but considerable dry spells and droughts to dry out the fuel. Areas with dry seasons such as California allow for intense wildfires. Wind also causes fires to spread quicker.
• Many climatic events can make wildfires grow more intense and extend wildfire seasons. The Santa Ana Winds and Diablo Winds in California, for example, cause more wildfire damage. El Niño (warm phase) and La Niña (cold phase) are also climatic events that are thought to affect wildfire prevalence.
• Recent temperature increases have caused an increase in the number of wildfires and an increase the length of wildfire seasons.
• Between 1998 and 2015 globally burned area declined about 24 percent. However, this may also be down to agricultural productivity and land use change as there are less areas that can be burned, i.e. less forestry.
• Types of wildfire burning


  • Crown fires - burn the entire tree from bottom to top, which is classed as the most dangerous and destructive type of fire
  • Surface fires - only burn the leaf litter, meaning they are easy to extinguish
  • Ground fires - burn at the dry peat or vegetation beneath the surface, and move slowly through the dried underground. Due to them being underground, they can be difficult to put out and can actually continue to burn throughout the year if the weather conditions allow it.
• Environmental effects of wildfires

  • Air pollution from ash
  • Water pollution
  • Habitats destroyed in fire
  • Toxic gases released in burning
• Economic effects of wildfires


  • Businesses destroyed
  • Agricultural land damaged
  • Cost of fighting fires (firefighters, helicopters, water)
• Social effects of wildfires

  • People killed or injured in fires
  • Homes destroyed
  • People go missing during evacuations
• Political effects of wildfires

  • Government buildings destroyed
  • Borrowing money for international aid
  • Pressure for government to do more about global warming due to increased frequency
• Risk management for wildfires


  • Fire risk assessment and mapping
  • Community education and awareness
  • Early warning systems
  • Firebreaks and fuel management
  • Meteorological monitoring
  • Fire behaviour modelling
  • Integrated fire management systems
  • Rapid response teams
  • Evacuation protocols
  • Interagency coordination
  • Assessment of burned areas
  • Infrastructure and property restoration
  • Community support and services
  • Regulations and building codes
  • Public land management
  • Research and policy development
• Wildfires are a natural phenomenon in many ecosystems, but they pose significant risks to life, property, and the environment, especially under conditions influenced by climate change and human activities.