A National Chainsaw Epidemic

Slash piles in a clearcut, Gifford Pinchot National Forest, in the Washington Cascade Range. Photo: Jeffrey St. Clair.

A national chainsaw epidemic exists in America’s woodlands. A recent article in the New York Times titled “Plans for an Ailing Forest Include Logging” exemplifies this trend.

In the article, officials in Oregon say that we must cut down the forests—including green trees to arrest the forest health crisis. Conveniently, precisely what constitutes a forest “health” crisis is defined by the timber industry, forestry schools and public management agencies like the Forest Service and BLM.

According to officials interviewed in the article, the problem is that trees are dying from natural causes—drought, beetles, wildfire, and disease. However, officials have a solution—kill the trees with chainsaws before any natural source of mortality can occur.

The article states that trees are dying at alarming rates and blames the same cause—decades of fire suppression have exacerbated problems by increasing the density of trees.” However, some contest this interpretationand suggest decade-long climate variation has more to do with changes in forest density than fire suppression.

Nevertheless from the Forest Service perspective,  natural mortality events like drought, disease, high temperatures, and other processes are an unacceptable way to thin the forest. They assert we need chainsaw medicine to cure what “ails” the forest.

But here’s the issue. First, foresters define the problem. To most foresters, trees dying from anything other than a chainsaw is a forest ‘health” problem.

I do not dispute that more trees may be dying than in the past—this is to be expected given we are experiencing some of the worst droughts and highest temperatures in over a thousand years.

Drought, wildfires, disease, higher temperatures, and insects are nature’s way of adjusting forest growth to match today’s climate regime.

In all these cases, natural thinning agents can reduce tree density more efficiently than logging for several reasons.

First, dead trees are critical to “healthy forest ecosystems.” Most foresters cannot see the proverbial forest for the trees.

Numerous studies have demonstrated that dead trees are critical components of the forest used by everything from insects to fungi to fish, birds, mammals, and even geological processes—for example, dead trees falling into a river creates the aquatic habitat for salmon and trout. Many species live in “mortal fear” of green trees for their very existence depends on a generous supply of snags, down wood, and the gradual physical decay of tree boles and litter.

A second issue is that no forester with a paint gun marking trees knows which individual trees have a genetic adaptation for tolerating drought that can kick out bark beetles or are even more resistant to wildfire.

We know these genetic differences do exist and confer greater survivorship. For instance, among some lodgepole pine, individual trees that are better adapted to drought are also more resistant to bark beetles. The reason has to do with how a tree responds to bark beetle attacks. When a beetle tries to find its way into the tree bole, the trees respond by flooding the site with sap that pushes the beetle and its eggs out. Trees better adapted to drought also have more sap reserves. But not all pine has this ability.

When loggers use chainsaws to cut out, say, half of the trees on a site to “reduce” the density, they may be removing the very trees with these kinds of adaptations or other traits that permit survival of high temperatures, wildfires, diseases, and so forth.

When trees are cut and removed from the forests, they release more carbon into the atmosphere exacerbating climate change, remove biomass, and, in essence, destroy the home and food for countless species.

This is no different than how wolves and other predators affect elk or deer herds. Predators can sense which deer or elk are vulnerable. By removing the weaker animals, the overall health of the deer or elk herd is increased. Studies have repeatedly demonstrated that hunters with guns tend to kill the healthier animals in a herd, so they have the exact opposite effect on herd health

Foresters in the NYT article suggested that dead trees will increase fire risk, however, that is a false conclusion. First, green trees under drought, temperature and other trees are more likely to burn due to the abundance of fine fuels like needles, cones, and small branches on living trees. Plus they contain flammable resins in their needles. By contrast, dead trees over time lose needles, and other fine fuels and are more resistance to fire.

The other issue is that the probability that a fire will actually occur in an area with dead trees is very low. The majority of all wildfires burn in green forests.

Chainsaw medicine decreases the forest stand’s overall natural resistance and degrades forest health.

Natural mortality agents maintain overall forest ecosystem health, while the chainsaw epidemic is the biggest threat to our ecosystem’s resistance and stability.

George Wuerthner has published 36 books including Wildfire: A Century of Failed Forest Policy