In the United States, it had been common practice since the late 1960s not to suppress natural forest fires. The "let it burn" policy assumed that forest fires would burn themselves out quickly, without causing much damage. However, in the summer of 1988, forest fires in Yellowstone, the most famous national park in the country, burned for more than two months and spread over a huge area, encompassing more than 800,000 acres. Because of the large scale of the damage, many people called for replacing the "let it burn" policy with a policy of extinguishing forest fires as soon as they appeared. Three kinds of damage caused by the "let it burn" policy were emphasized by critics of the policy.
First, Yellowstone fires caused tremendous damage to the park's trees and other vegetation. When the fires finally died out, nearly one third of Yellowstone's land had been scorched. Trees were charred and blackened from flames and smoke. Smaller plants were entirely incinerated. What had been a national treasure now seemed like a devastated wasteland.
Second, the park wildlife was affected as well. Large animals like deer and elk were seen fleeing the fire. Many smaller species were probably unable to escape. There was also concern that the destruction of habitats and the disruption of food chains would make it impossible for the animals that survived the fire to return.
Third, the fires compromised the value of the park as a tourist attraction, which in turn had negative consequences for the local economy. With several thousand acres of the park engulfed in flames, the tourist season was cut short, and a large number of visitors decided to stay away. Of course, local businesses that depended on park visitors suffered as a result.
First, vegetation. As you might imagine, scorched areas were in time colonized by new plants. As a matter of fact, the plant life in Yellowstone became more diverse, because the fire created an opportunity for certain plants that could not grow otherwise. For example: areas where the trees had been destroyed by the fire could now be taken over by smaller plants that needed open, unshaded space to grow. And another example: seeds of certain plant species won't germinate unless they're exposed to very high levels of heat, so those plants started appearing after the fire as well.
It's a similar story with the animals. Not only did their populations recover, but the fire also created new opportunities. For instance, the small plants that replaced trees after the fire created an ideal habitat for certain small animals like rabbits or hares; and when the rabbits and hares started thriving, so did some predators that depended on them for food. So, certain food chains actually became stronger after the fire than they were before.
And last, fires like the '88 Yellowstone fire would be a problem for tourism if they happened every year; but they don't. It was a very unusual combination of factors that year—low rainfall, unusually strong winds, accumulation of dry undergrowth—that caused the fire to be so massive. This combination has not occurred since—and Yellowstone as not seen such fires since 1988. Visitors came back to the park the next year and each year after that.
Summarize the points in the lecture, being sure to explain how they address the specific concerns about forest fires described in the reading passage.
