How prescribed burns can prevent wildfires and renew ecosystems

Plumes of black smoke rising ominously over the horizon. Bright orange flames licking up from the forest floor with dizzying speed. A canvas of black and white scorched earth left behind.

The destructive images from the wake of a catastrophic wildfire are easy to remember. But it’s just as easy to forget the renewal and growth that smaller fires can bring.

From our coastal prairielands to forests in eastern Washington, many habitats in our state depend on a cycle of low-intensity fire. For more than a century, however, the power of fire was stifled by well-intentioned wildfire fighting efforts. This fire suppression resulted in the overgrown, unbalanced ecosystems we see today in prairies and many of our central and eastern Washington forests.

Historically, low severity fires would burn periodically, reducing litter build up and paving the way for new life. Flora and fauna within these habitats evolved, adapting to the wildfire cycle and, in many cases, became dependent on their occurrence.

The Washington State Department of Natural Resources (DNR) is working to bring the wilderness back to its original splendor through prescribed burning – controlled burns for forest maintenance or habitat restoration. These controlled burns are designed to mimic low-intensity wildfires that would naturally occur.

“Prescribed fire can play a major role in the natural world by creating healthy ecosystems for plants and animals to flourish,” said Commissioner of Public Lands Hilary Franz, who leads the DNR. “With proper planning and oversight, we can put fire to work for us and reduce the fuels that contribute to dangerous, severe wildfires.”

DNR is focused on two general types of habitats: The agency’s Natural Areas Program has been burning in prairies for years, and DNR’s Forest Health and Resiliency Division is launching a Prescribed Fire Program to restore the dry ponderosa-dominated forests of central and eastern Washington.

Prairie restoration burning

In prairies, without frequent fires to clear moss and deep thatch accumulation, native plants suffocate. There has been a substantial loss of habitat from encroaching trees and shrubs from surrounding forests; the native prairies of today are thought to be limited to only 3 percent of their former extent.

On a mild, sunny day in October, DNR conducted a controlled burn at the Mima Mounds Natural Area Preserve.

“Mima Mounds is one of the largest remnants of the native prairies that occurred in this region historically,” said David Wilderman, Natural Areas ecologist for DNR. “Fire is a key component in maintaining prairies.”

This particular burn was long-awaited, and nearly didn’t happen thanks to soggy western Washington weather. Conditions have to be just right to conduct an effective, safe prairie burn, Wilderman said. And, it’s not just the weather that can halt a prescribed burn – fire crews have to pay particular attention to wind conditions.

One way this burn will renew the prairie is through the elimination of some fire-intolerant invasive species, like Scotch broom. Mima Mounds is dotted with areas of this green, brushy nuisance. The plant reproduces by seed, which can stay viable for nearly 80 years, Wilderman said.

“(Fire) also helps rejuvenate native prairie plants and wildflowers,” he said, citing camas as an example. “Camas is an important native food plant for Native Americans and an important nectar plant for butterflies in the spring.”

Even the smoke from controlled burns can have a positive effect on the landscape. Wilderman said for some native species, contact with smoke can result in more effective seed germination.


Forest restoration burning

Many forests can also reap benefits from a controlled burn. Frequent, low-intensity burns clear built-up woody debris, diminishing the types of fuels that lead to high-severity fires, which are difficult for forests to recover from and put our communities at risk.

A controlled burn can help manage invasive species and weeds, as the majority of native plants are adapted to the wildfire cycle whereas many invasives are not. In addition, controlled forest burns can prevent plant diseases, cycle nutrients in the soil and increase habitat for grazing wildlife.

The forests of central and eastern Washington have grown too dense and homogenized over time, resulting in a loss of varied habitat. A truly healthy forest is ever-changing, alternating with sections of fresh burns, young growth and established old growths. Several animal species, such as the Canada Lynx, depend on a morphing forest for survival as they use different habitats for hunting, raising babies and mating.

Read more about the state’s 20-Year Forest Health Strategic Plan to restore forest health and reduce wildfire risk here.