What is Sustainable Forestry?

This past week, the Trust for Public Lands announced that it had secured a conservation easement for 13,000 acres in Northwest Montana as part of the Lost Trail Conservation Area. The easement precludes subdivision of the land for housing tracts and allows the landowner, Green Diamond, to continue its forestry operations.  

Advocates of this proposal note that the easement prescribes “sustainable” forestry to “ensure a continued timber supply to the wood products industry.”

One representative definition suggests sustainable foresters: “Rather than leave forest ecosystems completely untouched, it’s about maintaining or enhancing their productivity, diversity, and resilience.”

Ultimately, this definition and others like it believe that enhancing productivity is a “good thing” or that logging creates “resilience,” which usually means limiting natural mortality agents.

While I believe this easement is better than strip malls and exurban subdivisions, one can still question whether this agreement and others like it preserve ecosystem health.

Funding for the conservation easement was made possible through the bipartisan Great American Outdoors Act, which permanently funded the critically important Land and Water Conservation Fund.

Given the public financial contribution, I think it is reasonable to ask whether the public is getting its money’s worth. I do not know the details of this easement, but I do know that, in all likelihood, the continued logging of this land will diminish its ecological integrity.

The problem is that “sustainable” forestry is seldom defined.

I have visited seven certified “sustainable” forestry operations over the years. None of these “sustainable” operations were ecologically sustainable. In nearly all cases, what is considered “sustainable” is a continuous supply of wood for the mills.

Although sustainable forestry operations are generally better than more traditional logging, they still degrade the forest ecosystem, just more slowly than in the past.

Nearly all sustainable forestry operations I’ve visited are sanitized landscapes. There is a paucity of downwood, snags, and often a lack of age-class diversity. Shrub layers may be removed. Pesticides and herbicides may still be applied. Typical forestry practices like selection for specific tree species, size, and other features interrupt and often negate evolutionary selective pressures.

 The “sustainable” forestry sites I have visited sometimes allowed trees to grow slightly older before they were cut on a planned logging rotation, but none allowed for significant the creation of old-growth conditions nor mortality from natural agents.

The general principle of sustainable forestry operation is to maintain green and “healthy” trees. Of course, what is considered “healthy” is defined by the timber industry and forestry schools.

A truly healthy forest ecosystem has a significant amount of natural mortality.

How a tree dies often dictates how it is recycled. For example, because charred wood inhibits some fungi and bacteria, burnt trees tend to rot more slowly and thus physically last longer in the ecosystem, providing habitat for birds, fungi, insects, small mammals, and other plants. Trees attacked by insect-like bark beetles rot more quickly because the boreholes created by beetles allow bacteria, fungi, and other elements to assess the tree’s interior.

When, for example, foresters mark trees to reduce density to preclude bark beetle infestations, they are short-changing natural selection. When suppressing wildfire and thus snag creation, they eliminate a significant agent for creating wildlife habitat.

At least 15 species of birds in the northern Rockies are more abundant in snag forest for their foraging and nest habitat. Some lichens are more abundant in natural forests than in managed forests on older mature trees. Some lichens are dead tree obligates, meaning they are only found in areas with significant tree mortality. A considerable number of mushrooms are associated with high-severity burns.

Some trees are genetically better adapted to dealing with cold, drought, or heat. However, a forester marking trees for logging has no idea which trees possess such genetic features. Ironically, I have heard repeatedly from foresters and agencies like the Forest Service that they are logging tree stands to increase their resilience. However, the net effect of their logging efforts is to reduce the overall genetic diversity that contributes to a sustainable forest ecosystem.

A few other issues to consider is that private interests are often paid nearly the total price per acre for a conservation easement as an outright purchase. Public ownership may result in better management.

Furthermore, many states have reduced tax rates for Ag or timber lands that are less than what the federal government pays in Payment in Lieu of Taxes (PILT). For instance, Flathead County, where the easement is located, the federal government paid $3,407,950. By comparison, the timber industry across the entire state of Montana paid only $2.6 million in property taxes. So keeping the land in private hands often means less finances for local governments.

So next time you hear that the timber industry practices “sustainable” forestry, ask precisely what that means. In my experience, it simply means they take a smaller percentage of the trees with each logging operation to maintain a long-term wood supply for the mills. They are not preserving ecological and evolutionary processes that support healthy forest ecosystems.