Fire in the forest is a destructive process. It can occur in both temperate and tropical forests. Fire can be due to the lightening or the carelessness of human beings. Nearly 90 percent of the forest fires are caused because of human beings. Also some fires start in the hot and dry weather usually in Australia.
NATURAL CAUSES OF FOREST FIRES
1) Forests fires can occur due to lightening which burns the trees but rain after it extinguishes fire causing less damage to the trees.
2) Fire needs oxygen, fuel and heat to start. Oxygen is present all around in the air, wood of the trees act as fuel and heat does not allow the fire to extinguish. At a temperature of 572 degree wood releases a gas that reacts with oxygen present in air and triggers a flame which will give heat to the surrounding woods and the fire will start growing more and more strong. This can also happen in the cold days.
3) Earthquake is also responsible for the forest fires. In 1906 earthquake in San Francisco causes fire. Other reason for fire is volcanoes and drought.
4) High temperature and low humidity (dryness) provides favorable conditions to the fire and hence it can start in forests.
MAN MADE CAUSES
1) The most common cause for the forest fire is the negligence of the people. Any source of ignition like cigarette, naked fire which when comes in contact with inflammable things causes fire.
2) Smokers sometimes drop the lighted cigarettes and matches in the forest which can easily set nearby bushes on fire and further develops into huge forest fire.
3) Tourists, picnickers sometimes throw the lighted items in the bushes around or on the ground which causes fire.
4) Locomotives that are powered by wood and coal can set on the grass and trees to fire near the railway lines with just a spark.
5) Fire lighted by cultivators to burn a patch of forest can go out of control and burning more trees than required.
Only in U.S.A. nearly 100,000 forests experience fire per year which destroys a huge amount of valuable trees.