The Truth About Forest Fires

By Doug Heiken

Oregon and its beloved forests have experienced some big fire years over the last few decades, and as the planet warms, more big fire years are on the horizon. It’s understandably difficult to see some of our favorite places changed by fire – the Columbia Gorge, the Chetco River watershed, the Three Sisters Wilderness, and the North Umpqua River watershed were all affected last year. After the smoke clears, many people often find a new kind of beauty in the changed landscape – newly opened vistas, blackened silhouettes of ancient trees, a flourish of wildflowers, bees, birds, and other wildlife that were hard to find in the shaded forest of yesterday. 

Fire mosaic in the Femont National Forest. Some trees die so that others may thrive.

It’s important to remember that all of our most cherished stands of old growth forest have their origins in a severe fire hundreds of years ago and may have experienced several less severe fires since then. All of our favorite forests have fire both in their past and in their future. Human views of forests are challenged by the fact that ecosystems change and persist across scales larger than a human lifetime.

Our forests are degraded not only by logging and roads, but also by treating fire as the enemy. Virtually all of Oregon’s forests are fire-dependent ecosystems that require periodic wildfire to enhance structural complexity and renew niches for diverse non-conifer plants and animals. While the news often reports that wildfire is “catastrophic” and “destroyed” the forest, in reality most wildfires create mosaics of mostly low and moderate fire severity.

After years of hand-wringing about the costs of fire-fighting, Congress recently passed the so-called “fire fix” that treats wildfire expenses, at least during the worst fire years, more like the costs of other federal emergencies such as hurricanes and earthquakes. Unfortunately, the “fire fix” is a half measure. Congress partially addressed the issue of funding the high cost of fire suppression, but Congress did not address the compelling need for funding and resources to actively restore natural fire regimes.

Part of the motivation for the fire fix was to stop borrowing from unrelated accounts within the Forest Service with the goal to free up resources for forest management such as logging for fuel reduction. This may sound good at first blush but unfortunately this may actually perpetuate problems with using logging as a flawed surrogate for fire. The Forest Service and BLM are trying to log our way out of the problem with unprecedented pace and scale of logging. Oregon Wild’s timber sale monitoring program is seeing 100,000 acre logging projects where virtually no acre is left untouched. 

We must do better before, during, and after fires. 

Before fire. A new study looked carefully at the behavior of a large fire in the western Cascades of Douglas County that burned through a checkerboard of public and private land with different approaches to logging and forest conservation. The findings strongly indicate that plantation forestry as practiced on private land (and to some extent on public land) makes fire hazard worse, while mature forests which tend to be more prevalent on public land, tend to be more resistant and resilient to fire. This is result is best explained by the fact that short-rotation tree farming maintains a high percentage of the landscape in a young stand condition with continuous high fuel loads close to the ground. Natural forests on the other hand have large trees with thick bark, tall trees with canopies held high above the flames, and much more complex fuel distribution that makes it harder for fire to move through, except during extreme weather.


Large Pine snag provides habitat and a variety of other ecosystem services.

Logging does not mimic fire. Some argue that logging is just doing what fire would do only it’s more surgical. Not so. For starters, logging requires logging roads that fragment habitat, disturb soil, spread weeds, limit carbon uptake, and cause erosion that pollutes streams. Fire does of course affect soil, but in ways that forest ecosystems and species are adapted to. In addition, logging targets large, commercially valuable trees for removal, while fire tends to retain large wood which then serves as long-lasting habitat for diverse wildlife.

Logging is not the answer. The Forest Service and BLM often claim that fuel reduction logging not only saves the forests but also saves spotted owl habitat from fire, and reduces carbon emissions from fire. The science says otherwise. “Forest fuels” is just another word for spotted owl habitat … and carbon. The agencies have models showing that fuel reduction reduces fire effects, models which may be accurate under ideal circumstances, but these models mistakenly assume a 100% chance that a forest fire will occur shortly after logging. This assumption is not grounded in the real-world. 

In the real world, no one can predict where or when fire will occur, or how severe it may be. The actual probability that fire will interact with fuel treatments is closer to 10%, so for every acre that is logged and burns favorably because of it, there are 9 acres that are logged and don’t burn, which means the habitat degradation and carbon emissions from the vast majority of logging are not offset by any beneficial fire effects. When all the probabilities are accounted for, much more damage is done by logging (plus unavoidable fire) than from fire alone. The agencies are extremely unwilling to accept this analysis, preferring instead of defend their flawed models and assumptions.

The analysis above gives the agency the benefit of the doubt and accepts that 10% of fuel reduction might interact favorably with fire, but even this might not hold true. The fire alone might have caused desired effects on the forest without any logging, or, logging itself might make fire worse by removing canopy trees which tends to increase fire hazard in several ways, such as: 

by moving the most hazardous small fuels from the canopy (where they are safely out of the way of surface fires) to the ground, where they are readily available for combustion; 

by allowing more light and heat into the stand which dries fuels and increases wind penetration; and 

by making more light, water, and nutrients available to stimulate the growth of ladder fuels.

Reduce fuels near homes, not in the back-country. To be fair, there is some fuel reduction work that makes sense, such as removal of small fuels in the home-ignition zone, within a few hundred feet of structures. The problem is that this work does not support timber sales which is the favorite way for the agencies to get anything done, even if logging is not the best way to do it. Also, most of this work to protect homes is needed on private lands. Recent analysis by economist Ernie Niemi shows that we could put a lot of people to work if Congress was willing to support it. Then, if our homes and communities were better prepared for fire, we could take a much more sane approach to fire management in the backcountry – actively encouraging fires to do good ecological work when weather is favorable.

During fire, the agency in charge typically conducts a para-military assault on ecosystems, replete with chainsaws, bulldozers, an air force, and destructive burn-out operations that put more fire on the landscape when weather conditions are least favorable. Fire crews are often from outside the area, so they often fail to recognize the special places where bulldozers and chainsaws do not belong.

Weak financial controls on spending during fires, has led to the development of the “fire industrial complex,” a dysfunctional response to fire that causes as much or more damage than it prevents. People have been making a lot of money from fires and the logging that follows, and where there is money there is corruption. 

When weather conditions are extreme, we throw money at fire with little-to-no effect. When weather conditions are favorable, we err by suppressing the eco-friendly fires that might burn with characteristic low and moderate severity. Things are changing but far too slowly. Sometimes the agency adopts a passive role and watches a fire if it is not threatening valuable resources, but fear creeps in. Will the weather turn dry and windy? How many calls is the local member-of-Congress getting about smoke? Will my career suffer if the wind shifts and the fire defies expectations? 

Old growth trees felled adjacent to Chuck Spring during the Tumblebug fire on the Willamette National Forest.

After fire, so-called salvage logging (let’s call it post-fire logging) is particularly harmful to the recovering forest. It removes large dead and dying trees that provide critically important habitat in the decades following fire. It disturbs soils that are already very sensitive as a result of the fire, it spreads weeds, and it slows forest recovery by killing newly emerging seedlings and sprouts. The overall result of post-fire logging is a simplified and impoverished plantation forest that most closely resembles a clearcut instead of the diverse and structurally rich conditions created by natural recovery after wildfire. Some argue that post-fire logging only affects a small fraction of the area burned, but this is misleading, because post-fire logging tends to have a disproportionate effect on areas with abundant large trees, that is, old growth stands that may have been protected before the fire, but become fair game after the fire. These big, old “snag forests” represent not just the most valuable opportunities for post-fire logging , but also the best habitat and the longest-lasting snag habitat. It may seem counter-intuitive, but fires actually cause a shortage of snags. By killing so many green trees, fires deplete the pool from which future snags must be recruited. (Note, this is also true of logging).

When it comes to global warming, logging is the problem, not fire. Logging advocates often suggest that wildfire is a significant source of greenhouse gas emissions, and logging will help prevent those emissions, but scientists have looked at this closely and the evidence says that fire is not a big source of greenhouse gases, and logging just makes things worse. Fire comes along infrequently, burns mostly the small fuels with the least carbon, while retaining the big trees with the most carbon. In the years between fires, forests are growing and absorbing far more carbon than they are emitting. Logging on the other hand, sends the branches and tops to the atmosphere in slash fires, and also targets the large trees and their carbon for conversion to sawdust and wood products. But only a small fraction of the carbon from a logged forest ends up in wood products. Most of the carbon takes an accelerated path to the atmosphere where it makes global warming worse. 

A better way. We log forests in ways that are not compatible with natural disturbance regimes. The Forest Service and BLM too often assume that fuel reduction will prevent or significantly limit extreme fire behavior, but science shows that fire is controlled by weather, much more than it is controlled by fuels, which means that most logging to reduce fuels is missing the mark. We may not be able to control the weather, but we can choose to let fires do their work when the weather is favorable.

Some have suggested a better approach is to develop brigades of well-trained fire managers who travel the region setting well-planned fires during favorable weather so they provide desired ecological benefits. These teams could be informed by traditional ecological knowledge (TEK) from native people who used fire as part of their way of life for millennia.

Photo Credits: 
Doug Heiken