The Beneficial Effects of Forest Fires

Forest fires are undoubtedly a threat. In the mid-1900s, all forest burns were considered     1    , and firefighters responded to all of these fires whether or not they were burning close to where humans lived. This     2     to forest fires was both expensive and risky. However, more     3     forest managers began to see that forest fires did have benefits. Foresters saw that forest fires were beneficial for trees and soil.

Previously, people believed that forest fires caused     4     damage to trees, however, now forest managers know that trees are the major     5     of fires. Many     6     occurring forest fires, often caused by lightning strikes, are surface fires that burn the understory — the shrubs and herbs from the forest — without damaging the trees in the overstory. In this way, the fire     7     competition from the smaller trees, allowing the larger trees to flourish. Once the understory has been burned away, the forest is less likely to burn from high-temperature fires that can do real damage to the tall trees.

In the past, it was not obvious how forest fires enriched the soil. Today, foresters understand that forest fires improve soil quality by changing the ‘litter’ — dead leaves and branches on the forest floor — to nutrient-rich soil. Normally, litter decomposes very slowly. However, fire releases the     8     in the litter immediately. This creates an increase in the amount of phosphorus and potassium which are key elements that promote tree growth.

As forest managers have leared more about the long-term effects of forest fires, they have realized that forest fires can have beneficial effects and have changed their forest management     9     to reflect this new opinion. It is now recognized that forest fires, are a natural part of forest ecosystems and are beneficial to the trees and soil. As long as fires are no     10     to homes and communities, foresters now often choose to do nothing to stop the fires.