While terrible to behold, forest fires are a part of nature and like all parts of nature, serve their purpose. Wood in order to ignite must be heated to a temperature of 572o F. In nature there are several ways to perform this task; the most common occurrences are lightning strikes. Other ways include drought, volcano eruption, sparks caused by falling rocks, and finally even from the energy release of decomposition.
There are several ways to control forest fires, the most common way would be to create a fire line, or a perimeter around the blaze devoid of fuel in an attempt to preserve the area outside of the perimeter. If the blaze is too intense then planes and helicopters can use chemicals in tandem with the fire lines to suppress the fire more efficiently. Finally the most effective way is to reduce the chance of a forest fire through prevention. This involves a process caused controlled burning. This simply means that excess forest is burned away on days in which the conditions are optimal.
Humans have another role that relates to forest fires, their creation. Every year fires are started by arson. There is no need for intent to be there, instead all it takes is someone flinging a cigarette out the window as they drive by and the butt can start a whole forest ablaze. Of course there are camping accidents that cause problems (I set a field on fire once), but unfortunately there are people with no moral standards who start these fires for their own perverted pleasure.
As was mentioned in the opening paragraph forest fires do have their uses. Fires enrich the soil; kill off the organisms that are no longer able to survive, creating niches for new organisms to take over. Finally there are several species of trees that use fires as a way of furthering their own species. The seeds of these trees do not allow germination until a fire has cleared the way for them. These seeds may remain viable for decades.