As devastating as they often are, forest fires help ecosystems and forests to flourish and continue playing their role in the ever-changing symphony of nature. Without the aid of the fires, a forest would become an overgrown tangle of dead-fall with only the most persistent vines remaining and thousands of species would become extinct for lack of habitat.
Nature sets the stage for forest fires to occur by first allowing drought to kill the weakest vegetation. Then the storms come with lightening, which sparks the dry tinder into a blaze that spreads like…well, like wildfire.
The fire moves through the dry tangle of the forest floor swiftly and burns only the top layer of the soil. As the fire burns the dry vegetation, it reduces them to ash and releases their nutrients more quickly than the process of decomposition would. In a very short time, this will give an added boost to the unburned seeds buried in the forest soil and life will return to the forest.
Larger, healthy trees may be scorched on their lower trunks but the tops are safe, far above in the forest canopy and the scorched trunks will heal in time. Many of these trees are conifers that rely on the heat of the fires to burst open their cones and allow seeds to germinate.
Smaller trees and those that are past their prime will succumb to the fire and leave openings in the canopy that allows sunlight to reach the forest floor. This encourages the growth of new plants and trees and raises the temperature of the forest’s understory, which slows the growth, and spread of pathogens.
As the fire passes through the forest, it kills the insects that have found a home here and may be wreaking havoc because of their numbers. The fire also destroys pathogens such as Phytophthora ramorum, which is responsible for the death of thousands of oak trees, and Scirrhia acicola, which kills long-leaf pines.
Forest fires are the largest factor in keeping open grasslands, prairies and meadows from becoming overgrown with trees. These grasslands provide habitat for many species of wildlife such as grazers, ground nesting birds, burrowing animals and helpful insects.
Healthy forests don’t just happen and though the ways of nature often seem destructive and counter-productive, we have learned that the fires play a very important role in keeping a forest healthy. As with any ecosystem, there are many things at work, which make up the forest’s ecosystem and forest fires are only one of them.
Sources
http://ec.europa.eu/environment/integration/research/newsalert/pdf/107na2.pdf
http://www.na.fs.fed.us/spfo/pubs/fidls/br_spot_pines/brown-spot.htm
