Ecological benefits of wildfires

While a wildfire refers to an unintentional, uncontrolled fire, the term “wildland fire” is broader and includes fires purposefully set as part of prescribed burns. While all fires have the potential to become dangerous to property and life, prescribed, or controlled, burns are planned extensively and performed with tight safety parameters. Humans have been performing such burns for thousands of years and for multiple reasons, but, today, they are mainly used to promote ecological health and prevent larger, more damaging, uncontrolled fires.

It might seem counterintuitive that a fire, which burns plant life and endangers animals within an ecosystem, could promote ecological health. But fire is a natural phenomenon, and nature has evolved with its presence. Many ecosystems benefit from periodic fires, because they clear out dead organic material—and some plant and animal populations require the benefits fire brings to survive and reproduce.

For example, as dead or decaying plants begin to build up on the ground, they may prevent organisms within the soil from accessing nutrients or block animals on the land from accessing the soil. This coating of dead organic matter can also choke outgrowth of smaller or new plants. When humans perform a prescribed burn, the goal is to remove that layer of decay in a controlled manner, allowing the other, healthy parts of the ecosystem to thrive. Moreover, nutrients released from the burned material, which includes dead plants and animals, return more quickly into the soil than if they had slowly decayed over time. In this way, fire increases soil fertility—a benefit that has been exploited by farmers for centuries.

Several plants actually require fire to move along their life cycles. For example, seeds from many pine tree species are enclosed in pine cones that are covered in pitch, which must be melted by fire for the seeds to be released. Other trees, plants, and flowers, like certain types of lilies, also require fire for seed germination.

Even some animals depend on fire. The sole food source for the endangered Karner blue butterfly caterpillar (Lycaeides melissa samuelis) is a plant called wild lupine (Lupine perennis). Wild lupine requires fire to maintain an ecosystem balance in which it can thrive.

National Geographic