What Is A Healthy Forest?

I just received a notice from the Custer Gallatin National Forest CGNF) that they plan to do a Fuels and Forest Health Project in Cooke City, Montana.

Main Street in Cooke City, Montana, Photo George Wuerthner

The Forest Service says the project aims to mitigate wildland fire risks and enhance forest conditions surrounding Cooke City and Silver Gate, Montana. Among the usual claims, the project’s primary objective is to reduce fuels and thus reduce wildfires by “fortifying forest resilience against insects and disease.”

The 1988 Yellowstone Fire burned through this area a few miles from Cooke City. Obviously the fire did not “destroy” the vegetation. Photo George Wuerthner

 We continuously hear from the Forest Service and others that logging creates a healthy forest. The main parameters defining a “healthy” forest are low mortality from natural agents like drought, insects, and disease, high-severity blazes, and rapid tree growth.

Of course, foresters define what constitutes a healthy forest, and by happy coincidence, the Industrial Forest Industry supports all the above criteria.


Gardening the Forest–Thinning project on the Custer Gallatin National Forest. Logging has “sanitized” the site, removing snags, ground vegetation, and even reducing the potential for new snags and down wood by reducing density dependent ecological processes like insect, disese and drought that may kill some trees, but not all. Photo George Wuerthner

Such a definition demonstrates that most foresters and agency personnel fail to see the forest through the trees. They want green trees that grow fast because that is what the timber industry demands. But that is not what constitutes a healthy forest ecosystem.

The distinction between a “healthy forest” and a healthy forest ecosystem lies in the realization that an ecosystem is more than just green trees. Tree mortality and occasional episodic forest death are crucial components.

High Severity blazes create a unique habitat known as the snag forest which is essential habitat for numerous plants and wildlife species. It is even rarer than old growth forests since over time the snags fall down and forest regrows. IPhoto George Wuerthner

Dead trees serve as homes, food, and shelter for a myriad of species, from bacteria and fungi to insects and amphibians, for birds, and even for the largest mammals like bears. This understanding not only enlightens us about the complexity of forest health but also empowers us with a more holistic perspective.

Even after a fire, a significant amount of carbon remains on site both in snags and underground root systems. Photo George Wuerthner

However, when loggers cut down trees it disrupts the forest’s natural balance and significantly reduces carbon storage.

Logs removed during a thinning project on the Custer Gallatin National Forest. The FS never counts the trees killed by chainsaws as a “loss.” Only trees killed by natural agents like insects or wildfire are considered a “loss.” In many instances, more trees are killed by thinning projects than would die in a wildfire. Photo George Wuerthner

 When they suggest that this is protecting the trees from fire or other calamities, they never count the trees they have killed by thinning as a loss. This should be a cause for concern, as it directly impacts on our fight against climate change.

Logging roads become vectors for the spread of weeds (exotic species) which poses a major threat to native vegetation and wildlife. Photo George Wuerthner

Logging is not a benign activity. Logging often requires roads, a major vector for spreading exotic weeds like cheatgrass. Logging roads are a chronic source of sedimentation in streams.

Logging activities can disturb sensitive wildlife, forcing them into other areas where they may not have good habitat.

Logging roads provide human access that can disturb wildlife, often causing them to abandon an area. While a gate might keep out trucks and car, people can still access the area by walking, mountain biking or using an ATV. Photo George Wuerthner

Logging roads provide access to the forest for hunters, recreationalists, and other humans that can further disrupt or disturb wildlife. Logging removes the physical biomass of tree boles, thus reducing the potential habitat for hundreds of species that may depend on dead wood or snags.

Logging roads are a chronic source of sedimentation that never ends as long as the road exists. If this sediment flows into a stream, it can impact aquatic ecosystems. Photo George Wuerthner

While wildfire may increase sediment flows for a few years before soil cover reduces the erodion, Logging roads are chronic, never ending, source of sedimentation impacting aquatic ecosystems.

Snags that fall into rivers are important habitat for fish and aquatic life. Such input is episodic–meaning only once in a hundred years or more after a large fire do you get a major input of fallen trees. High severity fires are a major contributor of such snags to aquatic ecosystems. Photo George Wuerthner

Removing trees can even influence fisheries since logs falling into a stream provide a significant aquatic habitat for finny residents. But it can also impact more than fish. Studies have shown that more logs in a stream provide more habitat for aquatic insects, providing greater insect activity in the air above streams that birds and bats exploit.

A forester marking trees for a timber sale has no idea which trees have a genetic advantage in the face of challenging conditions created by insects, diseases, drought or wildlife. Logging may remove the very trees most likely to provide the key genetic traits that will allow the forest to adapt to things like changing climate. Photo George Wuerthner

 Removal of a significant portion of the trees may influence the forest’s genetic adaptations by removing individual trees with specific alleles that may provide long-term survival to the forest stand.

Sap on tree where bark beetles are extruded. Individual lodgepole pine have varying degrees of genetic adaptations to resist bark beetle attack. George Wuerthner

For instance, some trees may have a greater resistance to mortality factors like insects, drought, cold, wildfire, and disease.  These adaptations may only manifest if the stand experiences one of these agents. Since one can’t tell which trees have any particular genetic adaptation, logging may reduce the “resilience” of the forest.

Down wood is also critical to ecosystem function and a healthy forest ecosystem. Wildfire, insects, disease, drought, all contribute to this essential ecosystem component. Logging reduces such important elements of a healthy forest ecosystem. Photo George Wuerthner

Rajora et al. (2000) compared genetic diversity between pre-harvest pristine and post-harvest residual gene pools of two adjacent, old-growth stands of Eastern White Pine in Ontario. The conclusion was that logging reduced genetic diversity in the post-harvest residual gene pools of the two old-growth stands. Also, all of the genetic losses were low-frequency or rare alleles, which may compromise the integrity of locally adapted gene pools and the ability of Eastern White Pine to respond to changing environmental conditions.

After the 1988 Yellowstone Fires, the lodgepole forests naturally reseed without any assistance from humans. Yellowstone wasn’t destroyed, it was rejunvenitated by high severity blazes. Photo George Wuerthner

Such losses are seldom considered those advocating logging to promote forest “resistance.” Logging reduces the ability of a forest stand to survive.

Logging sanitizes a forest.  Rather than creating a “healthy forest ecosystem,” logging creates a degraded one.


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Comments

  1. Karl J. Findling Avatar

    George,

    I use your articles often; thank you!

    The Deschutes NF is most likely going to allow motorized Class-1 E-Bikes onto the Phi’s Complex (non-motorized trail system).
    With no NEPA to implement these trails, and no EIS for the allowance of Class-1 E-Bikes, this is not good.
    Oregon Chapter of Backcountry Hunters and Anglers is going to oppose this.
    Also, there is no enforcement of the rule now, so this can lead to Class-2 and # E-Bikes.

    I thought you’d want to know, if you didn’t already.
    Public Comments are due in a month.

    Thanks for your articles!

    Karl J.

    1. Jeff Hoffman Avatar
      Jeff Hoffman

      I strongly oppose even non-motorized bicycles on trails. Any type of cycle, motorized or not, is a VEHICLE and belongs solely on roads. Cycles are bad for wildlife and the ecosystems, but even supposed environmentalists have turned into a bunch of self-centered and self-righteous yuppies who give no consideration to anyone who’s not humans. A Sierra Clubber got elected to a board of directors of a local park system several years back, and implemented rules to allow bicycles on trails where they had been prohibited. Now you’re lucky if you’re not terrorized by some a-hole off road bicyclist while you’re hiking there.

  2. Wayne Tyson Avatar
    Wayne Tyson

    As always, a great writing job! It needs proofing, however.

    It also needs wider dissemination, such as Op-Ed pieces (edited to about 750 words) for major media outlets. Email me if you would like any help.

  3. Ida Lupine Avatar
    Ida Lupine

    Is this alarming to anyone or is it just me? Doing everything but the right thing it seems:

    https://grist.org/solutions/wood-vaulting-carbon-storage-solution/

Author

George Wuerthner is an ecologist and writer who has published 38 books on various topics related to environmental and natural history. He has visited over 400 designated wilderness areas and over 200 national park units.

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