Tom Power - January 23, 2006
Post-Fire Logging, Forest Recovery, and Hazardous Fuel Reduction
The debate over the use of commercial logging to treat forests burned by wildfire has been rekindled by an article published recently in Science magazine , the nation’s leading scientific journal. The study analyzed the impact of logging on forest recovery and forest fuel reduction following the 2002 half-million acre Biscuit Fire in southwest Oregon.
There has been an intense national debate over the appropriateness of logging burned-over forested areas, typified by the debate over the Biscuit Fire. Timber interests and the US Forest Service have argued that logging is “necessary” in order to clear the remnants of the fire and plant new trees. If that is not done, the fear is that the burned areas will remain deforested for decades, leading to erosion and the loss of most of the biological values associated with forests. In addition, there was the fear that the remaining woody material would become fuel for new wildfires, further damaging the burned areas. Of course, there was also the attraction of harvesting and processing large volumes of commercially valuable trees.
Soon after the Biscuit Fire, a team of 17 Forest Service scientists analyzed the fire area and proposed harvesting up to 100 million board feet from the burned area, primarily from areas already served by roads and committed to plantation forestry. In those areas the value of the timber would pay for the costs of extracting it and there would be minimal additional environmental damage. Their superiors in Oregon and Washington, however, rejected that proposal as too modest and ordered the team to develop a plan to harvest ten times as much, up to a billion board feet. That set off an emotional debate. The Forest Service finally authorized the harvest of 372 million board feet and the logging commenced.
The study recently published in Science magazine compared similar logged and un-logged burned areas of the Biscuit Fire. It found that natural regeneration of trees had been quite successful, with the burned acres meeting local standards for being fully stocked with young trees. Unfortunately, however, in the logged-over areas of the burn almost three-quarters of those young trees had been killed, leaving those areas significantly under-stocked. Apparently the logging activity, through soil disturbance and the accumulation of logging waste materials, had buried most of the new young trees.
The felled trees that had no commercial value along with the branches and needles from the logging dramatically increased the quantity of both fine and coarse woody fuels that were left on the ground by loggers in the burned over areas. The density of fuels on the burned-over forest floor was three to six times higher in the logged areas. Although the wildfire had killed 95 percent of the trees, it consumed less than 10 percent of the woody biomass. Instead of that remaining woody material standing above the forest floor and only slowly falling to the ground, the logging brought it all down and left much of it on the ground because it was not commercially valuable and would have cost too much to remove from the forest.
In short, the logging of the burned-over forest retarded reforestation and increased the volume of hazardous fuels, just the opposite of what the Forest Service had promised. In addition, because much of the logging was carried out in roadless and old growth areas far from the existing transportation network, it did not pay for itself. The American taxpayer had to subsidize logging that appears to have damaged the forest and increased the danger of additional wildfires. The logging was both economically and environmentally irrational.
This study, of course, was for a particular large fire area in southwest Oregon and the particular approach to logging taken there. Only further analysis in other areas will tell us if those results are more generally applicable. But these particular results do raise an important question about U. S. Forest Service activities that has been with us for a long time: Why does the Forest Service regularly under-estimate the costs of its activities, financial and environmental, and over-estimate the expected benefits. That common Forest Service planning posture is what one author called a “conspiracy of optimism.” The U.S. Forest Service loses money on almost all of its commercial timber programs, which means they are not really “commercial” timber programs at all. In the process, those programs tend to have serious negative environmental impacts. The obvious question is why in the early 21st century this pattern is continuing as seen with the logging of the Biscuit Fire?
Part of the answer is a century-old frame of mind towards nature that many of us, not just the Forest Service, still carry with us. We see trees dying in the forest as an “economic” waste. All of that standing dead timber after a fire will ultimately rot, fall over, and rot some more. Those towering old growth trees are at the end of their life cycle and will ultimately become litter on the forest floor. Shouldn’t we harvest them instead and turn them into something useful? The biological sciences, of course, tell us a quite different story about the value and benefits of natural processes renewing themselves. But many of us still see the forest as a warehouse of commercially valuable trees to be extracted, not as a living system that supports us in numerous other important ways. Until that changes, we will continue to do economically irrational things to our natural landscapes while imagining that we are pursuing economic value. That frame of mind unavoidably impoverishes us.