One of the frustrations I face as an advocate for forest protection is the continuous stream of misinformation from government agencies such as the Forest Service and state forestry, as well as from many conservation organizations like the Nature Conservancy.
For example, I received an article from the Forest Service titled “Multiple treatments are key to resilient Western Forests. In the opening paragraph, the article asserts: “Forests in the West used to be a lot more open, so wildfires were much less severe.”
The problem with this characterization is that only about 10% of western conifer forests were historically “park-like”, dominated by frequent low-severity blazes.
The primary tree that fits this model is ponderosa pine. However, even in these pine forests, high-severity blazes occurred, leaving many trees dead.
Most western forest types (and most non-forested areas like chaparral) tend to have much longer fire intervals, often many decades to hundreds of years between significant ignitions.
These trees include fir and spruce, hemlock, cedar, Douglas fir, western larch, some pines like lodgepole pine, whitebark, Bishop pine, Monterey pine, and white pine, as well as aspen. None of these trees fit the high-frequency-low-severity model. When these forests burn, they exhibit significant high-severity mortality.
In addition, most non-forest plant communities, like sagebrush and chaparral, are burned at long intervals and are not adapted to frequent fires.
In between these major fires, down logs, snags, and ground litter accumulate. However, this is all within the natural historical conditions, not some aberration as often suggested by the Forest Service.
And many national forests had few, if any, ponderosa pine. In the Northern Region of the Forest Service, which includes northern Idaho and all of Montana, only 4% of the forest type is ponderosa pine and other “dry conifer” forests.
For instance, ponderosa pine occurs only in the most eastern low-elevation portion of the Custer Gallatin NF (CGNF) in Montana. The CGNF typically characterizes all of its forest types as high-frequency, low-severity stands to justify logging.
A further problem, right up front in the opening paragraph, goes on to say, “We can actually see scars from old wildfires in cross-sections like this one. By cross-dating fire scars from multiple trees, scientists can reconstruct what past forests looked like, including how dense forests were.”
The problem ignored by pro-deforestation agencies to justify thinning and logging the forest is that there are serious methodological issues with such fire-scar studies that tend to exaggerate fire frequency.
For instance, the main way scientists obtain fire scars is by wandering through the forest in search of scarred trees. But this is not a random selection, which biases the studies from the very beginning.
For instance, if all your scarred trees are on a dry south-facing slope and more prone to burning, they may not represent the general forest condition.
It is analogous to going into a bar on a Saturday night, asking the crowd how many people like to drink alcohol, and getting nearly 100% agreement from the patrons that alcohol is good—then extrapolating that percentage to the community’s overall population.
Many fire-scar studies use a very small sample of trees to characterize entire national forests. One study of ponderosa pine found that nearly half of the fire-scar research examined only 1–2 trees, yet used these to characterize the landscape’s fire history. There are other problems that you can read about here.
By contrast, the use of other methods to determine past forest stand composition and fire frequency, including photo interpretation, sediment flow studies, pollen studies, charcoal studies, and government land office reports, nearly all report longer fire intervals and high-severity blazes as natural events rather than aberrations.
A study of “Spatially extensive reconstructions show variable-severity fire and heterogeneous structure in historical western United States dry forests” concluded that: “Park-like stands of large trees maintained by low-severity fire predominated only in parts of the study landscapes.” The main conclusions were: “forests were structurally variable, including areas of dense forests and understory trees and shrubs, and fires varied in severity, including 15–65% high severity fire.”
The typical justification given for the alleged departure from open forest is fire suppression and lack of Indian burning. However, neither of those explanations applies to most Western landscapes.
Native American burning was primarily localized and did not have a major landscape-scale influence, and fire suppression was only successful when climate/weather permitted it.
During the middle of the last century, the overall climate was cooler and moister, permitting glaciers to grow in the western mountains. At the same time, there were fewer ignitions and far less acreage charred by wildfires. In contrast, throughout the early part of the century, including 1910, we had the 3.5 million acres burn, and the dry 1920s, when as much as 50 million acres burned—all due to climate conditions. More recently, since the 1980s, as climate change has promoted more wildfires, fire suppression effectiveness has been overwhelmed.
In short, the idea that most western ecosystems frequently burnt, were characterized by open, park-like stands, and were “healthy” ignores both evolutionary and ecological realities. It is a narrative promoted to support more logging of our forests.
The way to protect homes and communities is to reduce the flammability of structures through home hardening. Home hardening is by far the most cost-effective means of reducing wildfire risk and has the fewest ecological and environmental impacts.
The post The “Most Western Forests Were Open and Park-like” Myth appeared first on CounterPunch.org.
This content originally appeared on CounterPunch.org and was authored by George Wuerthner.