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Yellowstone Forest Fires
Forest Fires
I. How They Work
II. Fire Management
I. Map of Yellowstone
II. Yellowstone Fire
III. One Year After
IV. Six Years After

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Forest Fires

Fire: Man's friend, foe, ... or god?
Beginning when the earliest humans first rubbed two sticks together, or hit flint against stone, or grasped a burning limb and captured flickering yellow flames, fire has fascinated mankind. Fire was deemed so important to some early civilizations that they worshiped it as a god. The Greek philosophers of long ago considered it one of the four essential elements, along with water, earth, and air. By controlling fire, we could see in the darkness, cook food, keep warm in winter, and clear forests to plant crops and keep the marauding animals at bay. But fire is also dangerous. It rages when out of control, it can destroy our homes, our communities, the crops and forests we depend upon for survival, recreation, and knowledge.

Which came first, the lightning or the forest?
Lightning. From the time our planet came into existence, lightning has sparked the landscape. Lightning continues to dance upon the surface of the Earth. It is the natural source of forest fires. Today, humans give lightning a lot of help. More than half (50%+) of all the forest fires in the United States and Canada are caused, directly or indirectly, by people.

Smokey the Bear is right.
Smokey the Bear, sporting his forest ranger hat, has warned millions of visitors to national parks and forests, "Only YOU can prevent forest fires!" In more than half the cases of forest fires, he is right. More than 50% of fires are man-made. Some are purposely set for reasons of livelihood — to clear ground for farming, grazing, or development, to get rid of unwanted underbrush, even to fertilize the soil.

Other fires are set accidentally by careless campers who don't know how to put out a campfire correctly, or by smokers who toss away their burning cigarette butts, or by litterbugs whose discarded glass bottle may act as a magnifying glass and ignite the dry tinder on the forest floor. And some forest fires are the result of criminal arson.

Lightning strikes.
Lightning causes an average of 20 forest fires a day in the U.S. alone. Fortunately, most of these fires go out on their own.

Definition, please
A forest fire is an unenclosed and freely spreading combustion that consumes the natural fuels of a forest. Combustion is another word for fire, and natural fuels can be fallen litter, ground-hugging grasses, shrubs, trunks, branches, and leaves — in short, any vegetable matter in the forest that can burn. When a fire burns out of control, it is called a wildfire.

As far as fire is concerned, are all forests created equal?
Definitely not. Tropical rain forests — cloaked in fog and continually drenched by mists and downpours — have virtually no fire worries. Even in the deciduous, broad-leaved forests of the temperate zone, the rainfall, general dampness, and relatively high humidity play a big role in limiting fires. But this is not true of coniferous forests (those with cone-bearing trees), where highly flammable, resin-coated needles blanket the forest floor. Nor is it true of the forests of evergreen, broadleaf trees found in hot, dry zones. These two types of forests frequently develop natural conditions ideally suited to the spread of fire.

Review Questions

  1. Explain the difference between a forest fire and a wildfire by providing a definition for each.
  2. People are a cause of about ____________ % of forest fires.
  3. What types of forests have the highest risk for fire? Why?