Fires in Nature Flashcards
What is the nature of a wildfire dependent on?
The types of plants involved
The strength of the winds
Topography of the area
The behaviour of the fire
What are retardants?
Chemicals sprayed on to fires to slow them down (nitrates, ammonia, phosphates, sulphates and thickening agents)
What are pyrophytic vegetation?
Plants adapted to tolerate fire, methods of survival include thick bark, tissue with high moisture content and underground storage structure
What are the conditions needed for a wildfire?
Ignition source and fuel
What are natural ignition sources of wildfires?
Lightning is the main cause - particularly electrical storms that have hardly any rainfall
What are the human ignition sources of wildfires?
Falling power lines Discarded cigarettes Children playing with matches Camp fires Agricultural fires
Where are wildfires likely to happen?
Areas that are susceptible to drought, dry vegetation and lightening strikes, such as;
Australia
USA and Canada (particularly California and Florida)
Southern Europe (such as southern France, Italy, Greece, Turkey and Mediterranean Islands)
How do wildfires benefit some ecosystems?
In Mediterranean climate and savannas, they;
Clear vegetation
Aid new seed germination
Simulate the growth of certain plants
Rid an area of insects and parasites
e.g. Pyrophytic vegetation like the banksia plant in Australia need fire to open their woody fruit
Why are wildfires a threat for LA?
Much of the area is covered by drought resistant chaparral which is a scrub vegetation as the area is too dry for tree growth - after a summer drought this vegetation can become tinder dry
A dry wind called Santa Ana descends from the local mountains which increases dryness of vegetation and allows easy spread of fire
Low density buildings where between have been vegetation growth which allows fire to spread
What are the direct effects of a wildfire?
Loss of crops, timber and livestock Loss of life Loss of property Release of toxic gases Loss of wildlife Damage to soil structure
What are the secondary effects of wildfires?
Evacuation - Large amounts of emergency shelter/food will need to be found and people will not be allowed back into area for significant time period
Increased flood risk - Loss of vegetation decreases interception
Give an example of a loss of wildlife in a wildfire.
In Indonesia, the fires of 1997 destroyed the Wein River orangutan sanctuary on Kalimantan
Give an example of a loss of wildlife in a wildfire.
In Indonesia, the fires of 1997 destroyed the Wein River orangutan sanctuary on Kalimantan
How can we manage a wildfire before it occurs?
Managing vegetation
Managing the built environment (fire resistant materials such as stone and brick and building materials
Modelling (computer simulations to see the behaviour of fire)
Education
Warning systems
Community action
Insurance
Give an example of how community action can manage a wildfire before it occurs
Victoria, Australia 1983 - 47 people died and over 2000 homes were destroyed
A community education programme was established in response known as ‘Community Fireguard’ - assists people on developing their own fire survival strategies.
