For well over a century, man has been doing everything possible to squelch and put out fires, particularly in national parks. An example is Yellowstone. For a very long time, fires were routinely put out there. Though the intentions were good, this was leading up to an ecological disaster.
The trees in Yellowstone national park are primarily pines and firs. These trees produce a large quantity of dead branches and needles each year. In turn, this deadfall coats the forest floors. Normally small forest fires burn the debris, which keeps the forest clean of flammable fuels.
However, because man stepped in and put the fires out each time they started, the surplus wood and needles accumulated for decades, producing a thick mat often many feet deep. When we add to this that both firs and pines, and many of the bushes that grow in the park, are highly resinous, a problem was caused just begging for a trigger for something major to happen.
The trigger was provided by natural wildfires. The real problem was that it was decided at that time to simply let them burn themselves out. That isn't much of a problem, if the fires have been allowed to do this in the first place. This hadn't been done in Yellowstone, however.
The direct consequence was that with so much fuel, the fires merged and burned out of control. They didn't just burn through the bushes and trees, they burned down through the debris on the forest floor, making it almost impossible to put them out since they could start up again at a distance from the original fire.
By the time people realized they'd made a mistake in the decision to let the fires burn, it was too late to do anything about it. Ultimately, a huge area burned. Old growth forest died, as did many wild animals found in few other places anywhere, in the wild. The amount of wood burned was so great that the smoke blanketed many neighboring states.
Resources were brought to bear to help contain the blaze, but by that time, it was more of a holding situation rather than a matter of putting out the forest fire. The fire was too extensive.
When the fire was finally out, the ecological damage was tremendous. Many thousands of acres of forest had burned, deer, elk, buffalo, and bear populations as well as many other animals had been decimated, and most of the park looked like a wasteland. Remember that this is a huge park, so the amount of devastation was not small.
The impact wasn't only negative, however. Burning the forest floor made it possible for new growth to grow, which may not have been able to otherwise. This produced more food for recovering animal populations. Both plants and animals rebounded surprisingly fast. Traces of the fire can still be seen to this day, yet the forest and the fauna of it have surpassed the extent of what it was before.
Is it recommended that we let such a disaster to happen again? Not at all, however from the ashes comes new life. This is also a great ecological impact, and a positive one. The Yellowstone forest fire caused huge loss of life, yet not all of it is negative. Forest fire can be a bringer of life, not always death.
One would hope though that man learns from the mistakes of the past. It really makes no sense to keep repeating them.