Wildfires

One continuously hears from the timber industry and its allies that the present occurrence of large wildfires is primarily the result of 100 years of ‘fire suppression’ and thus ‘abnormal’ fuel accumulations. We are told that forests were historically open and park-like, while today’s forests are ‘overgrown’.

The solution to large fires by proponents of the ‘fire suppression’ mantra is more logging, thinning, and prescribed burning to ‘reduce fuels’ and restore forests to their pre suppression condition.

There are several things wrong with this assessment, but the biggest error is its failure to incorporate historical fire data and climate influences these assertions.

First, there is debate about how dense historical forest conditions. Reviews of historical observations challenge the idea that all forest types were ‘park-like’ and open.

Second, it begs credibility to say that in the early part of the 1900s, men wielding shovels and axes wandering the mostly trailless mountain West on mules or horses were an effective control of fires. The fire statistics challenge this assertion. We should not forget that in 1910 more than 3.5 million acres burned the Northern Rockies in a single week. And during the 1920s-1930s, as much as 50 million acres burnt annually in the western US. Today, 10 million acres charred is a ‘record year’.

Most advocates of the ‘fire suppression’ paradigm ignore these early decades and point to what they assert was a successful fire control era during the 1940s-1980s when there were fewer blazes and a lot less acreage charred.

However, the West experienced a particularly cool and wet period driven by the Pacific Decadal Oscillation during this same period. Indeed, glaciers were growing in the Pacific Northwest during this era, and some climatologists were predicting a return to the Ice Age.

What happens when you have cool and wet climate/weather? You get fewer ignitions and fires that fail to spread. Hence, I would argue that Nature was pretty good at ‘suppressing’ fires, but human hubris always takes credit for something they had little to do with.

Fire suppression advocates like to suggest forest stands are denser due to the control of blazes. However, another consequence of cool, moist conditions is the higher survival of tree seedlings. These climate conditions would result in denser forest stands. The research suggests that more luxuriant forests actually are less likely to burn due to cooler temperatures, shade, and thus moisture.

Conversely, opening up the forest stand with logging/thinning increases aridity and wind penetration, leading to higher severity burns and more rapid-fire spread.

In a sense, the argument that fire suppression is responsible for large fires and denser forest stands ignores the considerable role of climate in wildfire occurrence.

Excerpted: ‘Drought and Wildfires’.

Courtesy: Counterpunch.org