We hear praise for sustainable forestry from the timber industry, politicians, and even among many environmental groups. While sustainability is an admirable goal, most of what I have seen touted as sustainable practices are far from ecologically sustainable, especially when compared to wild landscapes. In nearly all instances that I have observed, the so called “sustainable” logging, grazing, farming– fill in the blank– is only sustainable by externalizing most of the real costs (ecological impacts) of production. That doesn’t prevent people from trying to claim that they have achieved the Holy Grail and found a way to exploit nature and protect it too. Everyone wants to think they can take from nature and somehow not have to pay the full cost. It’s the free lunch syndrome.
Sustainable forestry as practiced today is usually more of an economic definition than an ecological one. By sustainable, timber companies and their supporters in the “sustainable forestry” movement engage in practices that ensure a continual long term timber supply, not a sustainable forest.
A couple of weeks ago I toured a highly ballyhooed sustainable forestry site in California. The company whose property we viewed was certified by the Forest Stewardship Council as a sustainable forestry wood producer. Certification by FSC permits a company to sell its wood for a premium and supposedly gives consumers reassurance that the wood they are buying is environmentally benign or may even enhance ecosystem function.
The company land was, by the standards of the industry, well managed. They did no clearcutting. They left buffers along streams. They didn’t cut any remaining patches of old growth. In short, they were a model timber operation. Their land still had trees, but did it still have a forest? For many the mere presence of trees is taken as proof that logging on the site was sustainable. But a continuous supply of trees for the mill doesn’t necessarily mean you are preserving or sustaining a forest ecosystem.
The company owners and foresters who led the tour were proud of their efforts. I don’t want to denigrate their practices, which, on the whole, were much better than those followed by other timber companies. But that doesn’t mean their logging practices were perpetuating a forest ecosystem. For instance, the company owner showed the tour group growth rings of a tree that grew on the site before his company began to manage the area. Because of the competition with other trees, the tree had grown slowly and the rings were close and tight. Then he showed us a segment of a tree that had grown up after they had selectively cut some trees. The growth rings were wide and spaced far apart, demonstrating–in his mind–how thinning “improved” the forest. Now he was growing “more” wood on the land than when it was a “wild” forest. But my first thought when I saw the two tree segments was “what good are trees that grow under slow conditions”? Do trees with tight growth rings resist rot longer? If so would they remain as a biological legacy on the site far longer than a tree grown under “sustainable forestry practices?” While a fast growing tree may be good from the lumber company’s perspective, a fast growing tree is not necessarily good from a forest ecosystem perspective.
Company representatives believed they were “tidying up” the forest-much as a gardener weeds a flower bed-by selectively weeding out the “bad” or “damaged” trees, and leaving the fast growing “healthy” trees. This practice may seem like good forestry-especially from the prospective of creating more timber to cut–but it may not be what is needed in the long run to preserve forest genetic diversity. No one, including myself, has any idea what genetic properties are valuable to the forest ecosystem. Fast growth or any other trait we may select to preserve in the trees is not necessarily what is needed to preserve the forest ecosystem. It may be the trees we cull-the deformed trees, the slower growing trees, or trees that have other “defects”–that may hold the secret to the future. They may be the very trees, for instance, that might be best adapted to survive a warming climate. Who knows-but certainly not the forester marking such trees for removal believing he is “improving” the forest.
The company’s forest management plan called for the eventual cutting of all trees on its land-just not all trees at the same time as in a clearcut. You might call this a “rolling clearcut”. Because of this practice, no trees will ever again attain old growth dimensions or status before it is cut and hauled off to the mill. So how does this affect forest ecosystem sustainability? After the tour, I visited a nearby state park that had wild (unmanaged) forests. Though the differences might not be apparent to the causal visitor, I saw substantial physical differences between the managed company lands and the wild forest.
First, the wild forest had a much higher percentage of big, old trees. Furthermore, these disparities will grow ever greater the longer the company lands are managed for “sustainable” timber production. While on the wild forest, the percentage of old growth will vary over time depending on things like wildfire or insect attacks, but no matter what disturbs the forest-the wild forest will at least have the potential to grow significant amounts of old growth.
Given what we know about the value of older, bigger trees, this can’t help but affect the forest ecosystem. For example, big trees take longer to rot. They remain longer on the ground, in streams, and provide structural diversity to the forest floor and stream channels. One of the noticeable things about the managed forest we visited was the absence of big woody debris (logs) on the forest floor compared to the nearby wild forest. And though the company foresters had a prescription that left a few snags per acre, the number of large snags on their managed lands was considerably less than what I observed in the wild forest.
Another contrast between the so called “sustainable” forestry site and the wild forest were differences in the amount of wood in the streams. In the wild forest there was an abundance of logs that had fallen into the creek. These logs help to create fish habitat, and armor the banks against erosion. On the managed landscape, there were far fewer logs in the streambed, despite the fact that the company did maintain some narrow buffers of unlogged land along all creeks.
In addition to these physical differences, there were other potentially important ecological losses. Among other things, the timber company did not permit wildfires to burn through its “sustainable” forest tracts. Yet in this particular part of California, wildfire was an important ecological factor that on occasion would normally burn at least some of the forest stands. Typically such fires would create a mosaic of burned and unburned forests, release nutrients, kill smaller trees, create some snags of the larger trees as legacy logs, and cleanse the forest. In the managed forest, the company was doing everything it could to keep fire from burning up its profits. Without fire, it is doubtful this forest stand was really emulating a sustainable ecosystem.
In the “sustainable” forest, the company representatives admitted that the disturbed habitat created by logging roads and skid trails facilitated invasion by exotic weeds-but they handled it by spraying herbicides along roadways. In the nearby wild forest there were no roads and even few trails. Weeds were far less of a problem as a consequence. Soil erosion, particularly that from logging roads, was also an issue and one that never disappeared because once they constructed their main roads for timber management access, they did not remove them. Thus they remained as a long term source of sedimentation.
Do all these differences compromise ecological sustainability? I don’t know. But I am willing to assert it is premature to claim that such forestry practices are sustainable. While they may be an improvement over the kind of butchery that occurred in the past–and is still the dominant paradigm on many timber lands including public forests–I question whether such techniques are sustainable from a forest ecosystem perspective. And in the long run that is the only perspective that really counts. My guess is that far too many ecological costs are externalized and uncounted and the only thing we are sustaining are company profits.