April 20, 2016 Biodiversity 1 Comment
The Ecological Importance of Forest Fires

Forest fires can and do occur naturally and

play a number of important roles in ecosystems, and are commonly referred to as “wildfires.” These fires can start through natural disturbances such as lightning strikes.
 
Many types of forests have evolved to utilize fire disturbances to maintain ecosystem health and to regenerate. For example, many tree species actually require fire to germinate their seeds, and forest fires return important nutrients to the forest soil that was previously being stored in biomass. Wildfires help to clear out dead wood and other materials that would otherwise have taken much longer to break down and provide soil nutrition for the next generation of trees and plants living in that forest. This process helps to keep a forest ecosystem healthy.
 
Burned forests serve as important habitat for many species, such as the Black-backed Woodpecker, Picoides arcticus, that is specialized to live and thrive in forests that have experienced severe burning.
 
After a forest fire occurs, a process called ecological succession takes place, where the ecosystem goes through a series of changes and eventually develops into a mature forest again. Typically, the first species that recolonize a site after a fire are pioneer herbaceous species, such as fast-growing grasses and weeds. Next, slower-growing and taller types of plants come in. Later, early successional tree species, such as small pine trees come in, and then larger pine trees become established.
 
Eventually, long-lived hardwood tree species like oak and hickory become established, the forest canopy closes overhead, and you have a mature climax forest. This process can take a long time, ranging from several decades to even hundreds of years to move from early pioneer to climax stage habitat¹. At each stage of succession, the changing forest provides habitat for many types of species, including plants, animals, and birds.
 
At one time in the not-too-distant past, it was common forest management policy to suppress and control forest fires as much as possible due a general lack of understanding of fire’s important role in the ecological health of forest ecosystems. When forest fires are regularly suppressed, large amounts of dead biomass accumulates on the forest floor, increasing the risk for more frequent and much more intense wildfires than otherwise when they finally do occur. This puts human communities at an increased risk for damage from these more intense fires. Also, the trees that do grow in such forests are much more densely packed than they would otherwise have been.
 
With the current understanding of forest fires as a natural and healthy part of forest ecosystem ecology, forest management efforts typically are now focusing on a combination of containment where necessary to protect human communities, as well as periodic fires for the sustainability and health of forest ecosystems.

 


References

¹ http://enviroliteracy.org/land-use/forests/forest-fires/

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