Understanding the Role of Fire in the Forest

Alamogordo, NM – July 24, 2020 – Prescribed fire has been used for decades as a forest management tool to remove excessive amounts of logs, branches and forest debris, (aka fuel) that can accumulate leading to large, high-intensity wildfires.  Over this same time the population in rural areas has decreased, causing prescribed fire to remain an enigma to most urban dwellers who only visit the forest occasionally. 

“As kids we’re taught fire is a negative thing. Smokey Bear for decades recited “Only you can prevent forest fires, but in actuality, it is more nuanced,” said Dave Bales, Acting Fire Staff for the Lincoln National Forest. “It’s true, high-intensity, high-temperature fires cause irreparable damage to the forest, but the forest actually needs low-intensity fires to thrive.

Understanding Fire on the Landscape

Fire was present on the landscape long before humans decided to live here. Throughout most of the 1900s and even today, many fires must be quickly suppressed to protect homes and infrastructure that now dot the terrain. Still, certain ecosystems like the pine forests and grassy areas of the Lincoln National Forest, benefit from fire. That’s where prescribed burns, like the 16 Springs Prescribed Burn that took place last week, and strategic use of wildfire, like the recent Cherry Fire, come in.

Plants and animals in the Southwest are adapted to co-exist with fire. Some species, like Aspen and NM Locust even require fire to germinate. Without it these tree species will die off entirely. The adaptation to fire means that burned areas regrow quickly. Plant regrowth after a fire is typically healthier because the ash left behind contains high levels of phosphorus and nitrogen that acts as a natural fertilizer. Nutrient rich trees and grasses equates to better forage for wildlife resulting in healthier herds of elk and deer. In short, fire plays a critical role in maintaining a healthy ecosystem. 

After many years of fire exclusion, an ecosystem that needs periodic fire becomes unhealthy. Trees are stressed by overcrowding, fire-dependent species disappear, disease and insect infestations are more prevalent and flammable fuels build up and become hazardous.

Throughout history the Lincoln National Forest experienced fires every 10-35 years. That fire return interval has jumped seven-fold to 150 years as man began extinguishing most fires, allowing for seven times the amount of dead and down debris to accumulate on the forest than would have historically been present.  

“The presences of the extra woody material can lead to catastrophic wildfire, which is why it’s so important we take every opportunity to prescribe burn when conditions allow,” explained Lincoln National Forest Fuel Specialist Wes Hall.  

Wildfires that burn into areas where fuels have been reduced by prescribed burning cause less damage and are much easier to control.

Understanding the Role of Fire

Photo Caption: This photo from the Deschutes National Forest in Oregon demonstrates the difference in how a wildfire will act in treated and untreated areas. The left side of this road is untreated, while the right side was treated with thinning & prescribed fire three years ago. The high-intensity crown fire dropped from the canopy (aka treetops) to the forest floor once it reached the treated area. The results are the trees in the treated area lived, while almost all the trees in the untreated area died.

 

Few, if any, other treatments have been developed that can compete with prescribed fire for its effectiveness and affordability. Chemical and mechanical treatments can cost the Forest Service, and therefore the taxpayers, 10 to 20 times more money than prescribed burning.

“There is no other tool that can remove fuel from the forest floor without removing vital nutrients from the soil,” said Hall.   “If we haul off excess fuels, we’ve also removed the nutrients that would have eventually ended up back in the soil. Without fire the ecosystem slowly loses its ability to support itself, either through a lack of nutrients or the inability of plants to regenerate.”

Prescribed Fire

Prescribed fire (aka a controlled burn) can take place any time of the year if conditions are right. Fire personnel, foresters, wildlife biologists and other natural resources professionals evaluate the area and come up with a plan that specifies what the weather should be like the day of the burn, how hot or intense the fire should be and how fast or slow the flames should move. Prescribed fire specialists compare conditions on the ground to those outlined in burn plans before deciding whether to burn on a given day.

A prescribed fire that does not achieve the desired results is a loss of both time and money. A careful balance must be struck where conditions on the ground are dry enough to carry fire so the fire doesn’t just go out; but wet enough that fire activity is within an acceptable level. These types of burn windows are short on the Lincoln National Forest, usually happening in the spring, fall and directly before the summer monsoons arrive.  Regardless, the fact remains, more prescribed fire means fewer extreme wildfires in the future.

Recent Examples of Positive Fire Effects on the Lincoln National Forest

16 Springs Prescribed Burn

Last week the Lincoln National Forest was able to successfully treat 143 acres in the 16 Springs Area through prescribed burning. Conditions were perfect because the area received light rain just a few days before, moderating fire activity during the burn. Fire managers chose to treat along Road 5583 because it is a popular camping spot and therefore, has an increased risk of escaped campfires. The prescribed fire perfectly achieved the results and new bright green grass growth is already being seen just one week later.

16 Springs Rx Burn

Photo Caption: This photo was taken one week after the 16 Springs Prescribed burn. Green grass has already begun to sprout because ash from the prescribed fire provides nutrients in the soil that acts as a natural fertilizer causing rapid regeneration of plant species like bunchy grasses.

 

“Our goal was not to remove all the vegetation or wood on the ground. We want to leave some because it prevents erosion and provides wildlife habitat for insects, rodents and birds and that is exactly what ended up happening,” Hall said. “We hope to be able to do more prescribed burning the future so we can restore forest health. The use of low-intensity fire now, can prevent a high-intensity fire in the future.”    

Understanding the role of fire

Photo Caption: The 16 Springs Prescribed Fire did not move into the meadow pictured here. Conditions were too wet in the fine fuels to burn. The fire did however consume drier, larger dead and down material in the understory of the pine trees.

 

Had the fire staff waited just one week they would have lost their opportunity because the monsoon season has officially started and the vegetation in 16 Springs is too wet to burn now.

The Cherry Fire

The Cherry Fire started from lightning on July 16, 2020 in an area of the Sacramento Ranger District with no homes or infrastructure. Fire managers develop a plan for every fire, which includes tactical decisions specific to each incident. They decided on a confine and contain full-suppression fire tactic, meaning fire personnel hold fire growth to a defined area.

“Natural fire starts can offer us unique opportunities to see positive fire effects if the conditions are right,” said Assistant Fire Management Officer Caleb Finch. “In the case of the Cherry Fire, we had high humidity levels that we knew would keep fire behavior minimal and the monsoons were right around the corner.”   

Throughout the incident’s duration firefighters reported similar fire results to those of a prescribed burn. The low-intensity fire consumed the dead and down woody debris on the forest floor but did not get up into the tops of the trees which would have caused permeant damage to the vegetation. The fire was eventually put out by a combination of control lines and consecutive days of rain.

It’s important to understand the role fire plays on our planet. The last 100 years has taught us how important fire is to the ecosystem and how we must learn to live with it if we want a healthy resilient forest to enjoy.

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https://www.fs.usda.gov/detail/lincoln/news-events/?cid=FSEPRD770049