The main push behind forest thinning is driven by "fire mitigation" yet there is no evidence proving that thinning the forests actually decreases fires or fire severity. Research based on actual fire history has shown that in some cases, thinning forests actually increases fire severity by eliminating wind breaks, increasing the temperature of the soil and leaving behind kindling from the thinning process.
Through passing the Healthy Forest Restoration Act, Congress promotes the false assumption that the severity of forest fires in all forests are conclusively linked to ladder fuel loads. This conclusion was made in studying southwest low elevation ponderosa pine forests that are naturally park like as a result of frequent fires. These conditions are not indicative of most of the forest types in our nation. The major problem with presenting a national policy that prescribes the same treatment across all of the forests in the nation is that each forest has a unique ecology and fire history. To make a general policy that promotes thinning as an indisputable way to help restore all forests to their natural state is disingenuous to say the least. Fire history in our National Forests vary considerably between forests. In Colorado, a large percentage of forests have a mixed fire severity history and fires are largely determined by moisture content in the forests, not by ladder fuels. The Hayman fire is a good example of this and represents the largely mid-elevation mixed conifer forest. When looking at the Hayman Fire Case Study conducted by the Forest Service after this fire, prescribed burns and thinning treatments that were implemented throughout the fire area did very little to change fire behavior. The weather exclusively drove the flames, not ladder fuels.
Fire research shows that when a hot catastrophic fire begins, there is no altering its course. Fires do not avoid forest lands because of thinning. Once a catastrophic fire is underway in our forests, there is little to nothing that can be done to divert that fire, yet these are the kinds of fires the Forest Service refers to when trying to convince individuals and the public that thinning would be a preventative measure for fire. The goal of thinning, according to proponents, is to reduce ladder fuels which will theoretically slow down fires by keeping them on the ground, reducing the chances of a canopy burn. The problem with this assessment is that a catastrophic fire will not lay down on the ground once it reaches a thinned area unless weather conditions cooperate. At the ignition sites of a fire, firefighters might be able to get the fire under control if the forests have been treated for ladder fuels, however, we will never know where fires are going to ignite. The impracticability of thinning the entire forests of the nation should be obvious and so should the adverse affects this policy would have on the forests. It is impossible to fireproof the forests, and fire is also absolutely necessary for ecological forest health.
Throughout history all of our attempts at "managing" forests have ended in disaster. Why are we allowing an agency responsible for making disastrous decisions throughout its history convince us otherwise?
Wind and Climate Determine Fire Severity
Fires are driven by wind and climate so when droughts occur accompanied by high winds, low humidity, and high temperatures, fire danger increases dramatically and no amount of fuel reduction will change fire behavior, as is seen in the research conducted on fires after they have occurred. When climatic conditions are right, fires will burn through the forests no matter what the fuel load is. The Forest Service tries to convince land owners and the general public that if they eliminate ladder fuels, the forest surrounding them will be less likely to experience a catastrophic canopy burn by increasing the likelihood that fires will be able to be contained by lessening the severity. Research conducted on several fires, such as the Hayman and Biscuit fires, show that in some areas that were thinned, the fires actually killed more trees than areas that were untreated. Further, the fires in some of the treated areas burned with more severity because of the masticated mess left on the ground from the treatment and also because the canopy was opened up which decreased wind breaks, heated the forest floor and introduced fire prone plants, grasses and shrubs, all of which increase fire intensity. The recent Black Forest fire area in Colorado was heavily mitigated, yet was one of the most disastrous fires in the state in terms of loss of homes and structures. Fires are driven by weather, not by ladder fuels, and are therefore impossible to predict and control.
Managing The Forests is NOT the Solution to Fire Prevention
Deforestation of old growth forests in the United States Since 1620
The Forest Service policies over the past century have focused on fire suppression and as a result those policies have increased the amount of ladder fuels in some areas which has damaged the overall health in these forests. Logging has done more damage than fire prevention. Heavily logging the forests, and almost all of our forests have been logged at some point, eliminated the previously fire resistant older trees, leaving slash behind and created dense young growth forests with invasive weeds and non-native fire prone grasses leaving behind an ecological nightmare. Every attempt that we have made to "manage forests" has created extreme damage to the land in treasured forest areas.
The main drive behind these policies has always been to increase the profits for the timber industry. It was undesirable to allow profits to go "up in smoke" in forested areas and because of this, and the money generated through "fighting fire" with government subsidies, the Forest Service adopted a policy of putting out every forest fire before 10am. All of the past policies of managing forests have ended up with far more devastating consequences then if the forests were left in their natural state. Today, the U.S. has eliminated 95% of old growth forests due to governmental programs aimed at managing the forests for the timber industry. The remaining forests are fragmented and increasingly damaged by the flawed assumption that people have the wisdom to manage them. With the last fragment of remaining forests, it is increasingly important that we insist on taking a step back from this type of management and begin to respect the complex relationships in forested areas and recognize that the forests know best what to do with their health and that our scientific approach to forest health is clearly not benefiting the land or our future. Instead of being worried about the accumulation of ladder fuels, we might want to start worrying about the forests themselves and the fact that most of them no longer exist as a result of human encroachment and greed management.
Thinning Report Concludes that Results Are Ineffective
Research has consistently shown that treatments cannot reduce fire severity if the fire does not affect treated areas while fuels are reduced. For thinning to be effective, treatments would need to take place every 10-20 years since fuel levels rebound relatively quickly after treatments. Further, in one report entitled "Fire Probability, Fuel Treatment Effectiveness and Ecological Tradeoffs in Western U.S. Pubic Forests", 40,000 fires were analyzed and the research showed that the likelihood of a fire going through the treated areas when the fuels were reduced was between 2-4% during the time in which the treatments would be effective. The report further showed that the money and incentives that would go into forest thinning would need to occur every twenty years over the course of 720 years in order for the treatments to be 50% effective while those fuels were reduced. Further, the report states that "potentially adverse treatment effects on watersheds are not counterbalanced by benefits from reduced fires severity" (pg. 3). This report is important to take into consideration when analyzing the effectiveness of forest thinning because the research clearly shows that thinning for reduced fire severity is unlikely to reduce catastrophic fires and is far more likely to harm the forest ecosystem.
Research points to the fact that the best action individual land owners can take is to fire wise their homes by clearing up to 200 feet around their homes, installing metal roofs and building fire safe decks around their homes. Thinning countless acres of forests around properties and throughout our forests will not decrease fire risk. Making homes defensible and fire wise makes sense and does not damage forest ecology in any way close to the thinning projects that are proposed throughout our country.