Facts About Wildfires

Basic Facts About Wildfire

Wildland fire is one of nature's oldest phenomena.  Evidence of free-burning fires has been found in petrified wood and coal deposits formed as early as the Paleozoic Era, about 350 million years ago. Wildland fire is any fire burning in wildlands, including wildfires and all prescribed (controlled or managed) fires.

Wildfires are a powerful force of nature, and as natural as rain, wind, snow, or lightning. In fact, lightning is the spark that sets many natural wildfires.  Summer tends to be the high season for wildfires, as heat and drought make vegetation dry and more likely to burn.

A wildfire is one that is out of control and generally viewed as undesirable by land managers.  It needs to be put out or suppressed.  Examples of a wildfire would be:

 

1. A fire burning the habitat of an endangered animal like the sagegrouse as has been the case in Southern Idaho the past few years.
   
   
2. The nearly annual fires that are “sparked” in areas having dense vegetation, drought and high winds condition.

 

Forestry or Firefighting Managers would call for fire fighters to suppress (extinguish) this fire.

 

A prescribed fire is one that is considered to desirable by managers because it meets some management objective.

 

Small fires are routinely “prescribed” by forest or other land management managers/professionals in order to keep ecosystems healthy and to prevent more serious fires.  They can be naturally ignited, such as those that are started by lightning, or they can by lit and managed (controlled) by land managers to accomplish a specific task.

 

Burning logging debris following a logging operation would be one example of a time that managers might ignite a fire.  Allowing a lightning-caused fire to burn because it is clearing out dead branches and needles on the forest floor of a Ponderosa Pine Forest would be an example of a prescribed natural fire.

 

How Wildfires Start 

On a hot summer day, when drought conditions peak, something as small as a spark from a train car's wheel striking the track can ignite a raging wildfire. Sometimes, fires occur naturally, ignited by heat from the sun or a lightning
strike. However, the majority of wildfires are the result of human carelessness or actions.  

Up until the mid-1940s, more than 20 million acres of forest would burn annually. Advances in fighting fires and controlling the forest structure has significantly reduced the ferocity of forest and brush fires and limited the amount of U.S. wilderness that burns every year to around 4 million acres.  Improvements in equipment, advanced safety measures and forced evacuations have saved thousands of lives - of both residents and firefighters.

Other Specific Facts About Wildfires

In 2000, 7.5 million acres burned in the U.S. This is an area roughly equal to the size of Massachusetts, Rhode Island and Delaware combined. (Source: Nature Conservancy magazine, May/June 2001).

Wildfires affect most areas of the U.S. with wildlands.  Some of the most significant fires have taken place in: Arizona, California, Colorado, Florida, Idaho, Montana, Nevada, New Mexico, Utah, Washington and Wyoming, and areas such as Yellowstone, Mesa Verde National Park and Los Alamos.

At least 860 structures, mostly family homes, were destroyed in fires during the 2000 season. There is a lot that homeowners can do to help save their homes from wildfires, such as constructing the roof and exterior structure of a dwelling with non-combustible or fire resistant materials such as tile, slate, sheet iron, aluminum, brick or stone.

The fires of 1988 marched through Yellowstone National Park in June, leaving much of the park in ashes and the debate over man and nature continues.  In keeping with its natural burning policy, the National Park Service allowed the lightning-caused fires to burn until July 14, when the lack of moisture and high winds began turning small fires into raging firestorms.  Eventually 800,000 acres burned in the park.    

In 1997, Indonesia was blanketed by a choking, thick brown haze.  Hundreds of fires, many deliberately lit to clear land, continued to burn for months, and resulted in blackening more than 740,000 acres and polluting the air.  Meteorologists say El Nino, an unusual weather pattern over the Pacific Ocean, has produced the worst drought in a half-century and delayed monsoon rains needed to extinguish the flames and clear the air in this area of the world.

 

Other Wildfire Statistics

1. An average of 1.2 million acres of U.S. woodland burn every year.
   
   
2. More than four out of every five wildfires are caused by people.
   
   
3. Negligent human behavior such as smoking in forested areas and improperly extinguishing campfires are common causes of forest fires.
   
   
4. Weather conditions can directly contribute to the occurrence of wildfires such as through lightning strikes, or indirectly such as by an extended dry spell or drought that contributes to the availability of fuel.
    
5. A large wildfire, or conflagration, is often capable of modifying the local weather conditions or producing "its own weather." 
   
   

Related Terms

Listed below are some terms often used in describing wildfires and their “signs” or effects.

Surface fires -- The most common type of wildfires, surface fires move slowly and burn along the forest floor, killing and damaging vegetation.

Ground fires -- Usually started by lightning, ground fires burn on or below the forest floor through the root system.

Crown fires -- Crown fires spread by wind moving quickly along the tops of trees.

Santa Ana winds -- "Santa Ana" is the name given to the gusty northeast or east wind that occurs in Southern California during the fall and winter months.  Santa Ana Winds are often hot and very dry, greatly aggravating the fire danger in forests and bush lands.

Conflagration -- A large and destructive fire, typically aggravated by strong winds that carry burning debris over natural or artificial barriers.

Dry thunderstorm -- Typically a thunderstorm with a high altitude base in which thunder and lightning are observed, but little or no rain reaches the ground.