Response to Boone and Crockett on wildfire and forest health

In a recent commentary “Working to Improve Forest Health” posted by James Cummings of the Boone and Crockett Club mistakenly assumes that current wildfires are somehow “abnormal” and a sign of unhealthy forests.  Then, since he creates a problem where none exist, he prescribes more active management in the form of logging/thinning as the means of “fixing” the problem. http://wildlife.org/working-to-improve-forest-health/?platform=hootsuite

Mr. Cummings can be forgiven for his misunderstanding as we all are continuously bombarded with misinformation about wildfire and forest health.

Mr. Cumming’s perspective lacks context and is skewed by a short temporal scale. Episodic and periodic natural events from beetle outbreaks to large wildfires are not signs of “unhealthy” forests. Instead, they are like predators that maintain the long-term health ungulates and our ecosystems.  These natural processes operate at a different time scale than humans, and the proper temporal and spatial scales are necessary to appreciate their role in ecosystem health.

If you merely compare the acreage burned by wildfire during the past few decades to say the previous mid-century burned area, you would indeed see a substantial increase in acres charred. However, that is a misleading comparison and insufficient time to really draw conclusions about wildfire. Attributing current wildfires to “fuel buildup” as a result of “fire suppression” or lower timber harvest is misleading.

It ignores the enormous role that climate/weather plays in all wildfires.

The entire middle of the last century between the late 1930s and late 1980s (when Yellowstone burned) were much cooler and moister than the present. Indeed, some scientists worried we were headed towards another ice age.

What happens when it’s cooler and moister; you get fewer ignitions and the ignitions you do get, don’t spread. The fewer fires and overall limited acreage burned during these moister decades are frequently used by management advocates to suggest that fire “suppression” was successful. But in reality, humans had little influence on wildfires—Nature was great at suppressing fires.

If you go back to the beginning of the last century, you will find that tens of millions of acres burned. There is the famous 1910 Burn which raced across 3.5 million acres of Idaho and Montana, but that fire was only one of many that charred our forests in the early part of the last century. During the 1920s and 1930s, as much as 50 million acres burned across the West in some years. Today when we have 10 million acres burn, and we call it a “bad” year for fires.

Some fire ecologists believe we have a fire deficit. In other words, compared to the past century, we are seeing less wildfire across the landscape then was common just a century ago.

What drives large fires are climate/weather conditions almost irrespective of “fuels.” If fuels were the reason for large wildfires, we would expect the largest fires to occur in the coastal forests of Oregon, Washington, and Alaska where there is more biomass per acre than a hundred acres in places where fires are occurring from chaparral to lodgepole pine forests. Indeed, some of the largest fires are burning in ecosystems that are generally considered to be “low” on fuel like sagebrush, chaparral, and some pine forests.

A second problem with Mr. Cummings assumptions is that he, like many folks, conflates fire regimes in ponderosa pine forests where frequent blazes with short fire rotations were common with all other plant communities where much longer fire rotations are the norm.

Indeed, everything from chaparral to juniper to sagebrush to lodgepole pine, higher elevation fir forests, among other ecosystem types, typically experienced many decades to centuries between wildfire. They only burn when the climate/weather of extensive drought, high temperatures, low humidity, and high winds can push fire through these communities.

In these ecosystems, it is entirely “natural” for fuel to accumulate over the decades and centuries until released by wildfire.

Furthermore, most of the acreage burning across the West are occurring in these ecosystems, not ponderosa pine forests. So, characterizing the blazes we see as “abnormal” or in need of “active management” to “fix” them is incorrect.

The reason we see more and more large blazes is due to changes in our climate. Climate heating is creating conditions more conducive to large wildfires. In fact, there is both anecdotal as well as scientific evidence that suggests that logging/thinning forests can exacerbate fire spread.

Suggestions that “active management” read logging can reduce wildfires ignores much of the fire science that concludes that under extreme fire weather conditions we cannot stop wildfires.

This past year, more than 200 scientists sent a letter to Congress that asserted … “as the climate changes, most of our fires will occur during extreme fire-weather (high winds and temperatures, low humidity, low vegetation moisture). These fires, like the ones burning in the West this summer, will affect large landscapes, regardless of thinning, and, in some cases, burn hundreds or thousands of acres in just a few days. Thinning large trees, including overstory trees in a stand, can increase the rate of fire spread by opening up the forest to increased wind velocity, damage soils, introduce invasive species that increase flammable understory vegetation, and impact wildlife habitat.”

The letter went on to explain: “For instance, scientists recently examined the severity of 1,500 forest fires affecting over 23 million acres during the past four decades in 11 western states. They found fires burned more severely in previously logged areas, while fires burned in natural fire mosaic patterns of low, moderate and high severity, in wilderness, parks, and roadless areas, thereby, maintaining resilient forests.”

Although it may seem counter-intuitive, the snag forests that result from large high severity blazes is among the rarest habitat in the West and contains the second highest biodiversity after old growth forests. Knowing this, we ought to be careful about assuming such blazes are “destroying” our ecosystems.

Finally, the overwhelming conclusion of most fire ecologists is that large wildfires are inevitable given global heating. But the loss of homes and communities is not. Thinning and other active management more than a few hundred feet from homes confers no additional benefits. In fact, it is the flammability of homes that determines whether structures survive a blaze. The focus should be on reducing home ignitability rather than active forest management.

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