Reposted from The Wildlife News
IS SUSTAINABLE FORESTRY SUSTAINABLE?
In WILDLIFE NEWS by George Wuerthner on May 4. 2014.
There has been a lot of positive talk about sustainable forestry by the timber industry, politicians, and even among many environmental groups. Everyone is looking for a way to exploit the Earth and pretend they are not impacting anything. 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. It has been my experience, if someone is exploiting natural landscapes in a manner that is commercially viable; the activity is typically not ecologically sustainable. In nearly all instances that I have seen, the so called “sustainable” logging, grazing, farming or 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. It’s the free lunch syndrome.
Today with a growing awareness of our global environmental impact, finding ways to sustain ourselves while sustaining the planet is imperative. The question for me is whether so called “sustainable” practices really exist or is it just another piece of propaganda used to sell more to unwitting consumers to assuage their guilt. With public outrage growing over the butchery of forests that used to be passed off by timber companies as “scientific forest management”, many timber companies are finding it necessary to earn certification as sustainable forestry operations to appease consumers and reduce criticism of their operations.
What I have observed when I go on tours of so called “sustainable resource extraction” whether it is “sustainable grazing”, “sustainable farming” or “sustainable forestry” is a failure to ask a fundamental question. How does a wild ecosystem function and how closely does the sustainable activity emulate it and preserve natural ecological processes? Rather what I find among promoters of “sustainable” exploitation is a tendency to view things from the exploitation perspective and then attempting to make the land fit the needs of the industry. So sustainable grazing is about avoiding overgrazing. That’s an admirable goal in its own right, but that’s completely different from asking what it takes to have a sustainable grassland ecosystem. The same for sustainable forestry—what is required to maintain a forest ecosystem, and is there any way to extract some wood from the forest without seriously disrupting ecosystem processes and function.
A couple of weeks ago I toured a highly touted “sustainable” forestry site in California. The company whose property we viewed was certified as a sustainable forestry wood producer by the Forest Stewardship Council. 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.
In general I find what is touted as “sustainable forestry” is usually more of an economic definition than an ecological one. By sustainable, timber companies and their supporters in the “sustainable forestry” movement are engaged in practices that ensures a continual long-term timber supply. For instance the company lands I visited had been selectively logged at least three times in the past 100 years and it still had trees on it. So from their perspective they were practicing “sustainable” forestry.
The land still had trees, but did it still have a fully functioning forest ecosystem? 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.
I don’t want to imply by the following critique that we should abandon forest certification or the goal of sustainability. The forestry procedures I saw on the tour were a vast improvement over the cut and run practices of the past. The company practiced selective cutting of trees over clearcuts. They maintained buffers of unlogged strips along streams. They typically did not cut existing old growth trees. However, whether they are truly ecologically sustainable as is often implied is questionable.
The company owners and foresters who led the tour were definitely 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 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 rings were close and tight. Then he showed us a segment of a tree 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.
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.
The company does not clearcut its land, and does not remove more than 50% of the trees in any single cutting. There are always trees growing on the sites. Thus the site does provide a sustainable supply of fodder for the mill. But is it not providing a sustainable ecosystem.
For instance, the company forest management plans call for the eventual cutting of all trees on any particular area. However, since the logging is done over a period of years—not all trees are removed 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—except for the small percentage of existing old growth that is scattered about its lands.
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. Over time on the company lands the existing old growth will die and will not be replaced because all non-old growth trees will eventually be cut—just not all at once. 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—over time the wild forest will again have 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 was considerably less than what I observed in the wild forest.
Dissimilarity 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 stream, despite the fact that the company did maintain some narrow buffers of unlogged land along all creeks. Again because there was still some salmon spawning in the waterway, the company used that to prove its practices were benign. Perhaps they were, but I would love to know how many salmon the creek used to support in the pre logging days. I’m willing to bet it was higher than what occurs today.
Because thinning the forest opened up the canopy permitting more light to reach the forest floor, the “sustainable” forest had more shrubs and small trees growing in the understory. These shrubs and small trees were natural “ladders” for fires to carry the flames of any fire that should occur into the canopy of the trees. By contrast the understory of the old growth wild forest was open and had much less ladder fuels.
In addition to these physical differences, there were other potentially important 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, and clean the forest. Disease and insect outbreaks are also equally unwelcome, though these are important ecological processes in most forest ecosystems.
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.
Thus if enough time between cuttings, there may be a semblance of recovery to the causal viewer, however, one study comparing logged forests with virgin forests in North Carolina found that even 80 years after the last log was removed from the forest, nearly half of the forest floor plant species were still absence from the logged forest. Another study in Ontario found that selective logging removed half of the genetic diversity—mostly be removing the rare alleles. But it is these rarer genes that may sustain the forest in times of adversary—sustained drought, new insect attacks or whatever.
Suffice to say 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. After all on most forest lands we have only gone through 2-3 rotations (cuttings) and like a corn field, we can get a few harvests from the land before the soil productivity is depleted. Whether we can cut trees indefinitely on timber company lands, even those managed for “sustainable” cutting, remains to be seen. My guess is that far too many ecological impacts are externalized and uncounted—and just plain invisible to even the most practiced eye.
As Aldo Leopold admonished years ago the first precaution of intelligent tinkering is to keep every cog and wheel. Unfortunately you cannot be removing a significant amount of biomass from a forest and be saving the parts—the logs removed are the cogs and wheels needed for a functioning ecosystem.
About the author
George Wuerthner is an ecologist and former hunting guide with a degree in wildlife biology
