by Mitch Lansky
A thousand-year forest management plan. Am I joking? After all, the United States is only a little over two centuries old. We live in a world of rapidly changing technologies where, in just a decade or so, people have started using personal computers and cell phones on a wide scale. It is difficult to imagine what life will be like 10 years from now, let alone 100 or 1,000.
Because life is changing so fast, most people focus on the relatively short term, rather than the very long term. With wars, terrorism, economic downturns, energy crunches and climate change commanding our attention in the short term, thinking about how to manage forests for the next thousand years might seem out of touch. Maybe this is a problem.
The Shakers said that we should act as if we were going to die tomorrow and live for a thousand years. If we were going to die tomorrow, we would want to do what is most important to us. If we were going to live for a thousand years, however, we would make sure that whatever we do (to use the words of the Brundtland Commission) “meets the needs of the present without compromising the ability of future generations to meet their own needs.”
Forestry requires a longer-term perspective than most enterprises. Unlike agriculture, you cannot start from bare ground and expect to have a crop at the end of one or two years. Red spruce, the premier species of most of Maine’s forests, can reach a marketable size for pulpwood in 40 or 50 years, but does not start putting on mature wood, suitable for better fiber or lumber, for 60 years. The trees, however, can live for a very long time. Some red spruce in Baxter State Park, on North Turner Mountain, are over 400 years old.
For forestry to be considered “sustainable,” one would hope that productivity could be maintained for three rotations of trees. Given that red spruce seemed to have no problem living for more than 333 years in pre-settlement Maine, 1,000 years is a reasonable length of time to test the sustainability of a management regime.
Other cultures have been able to manage their forests, farms and fisheries for more than 1,000 years without depletion. Farmers in China, for example, grew crops on the same land for over 4,000 years. Native people in Maine lived with and used their forests without depleting them for many thousands of years. Indeed, even as people inhabited the land, the forest was recovering from the retreat of glaciers 10,000 years ago. Sustainable management has been done, so it can be done.
The Presettlement Forest
In the presettlement forest of Maine, native peoples and their cultures were a dot in the circle of the forest. The forest was the environment in which they lived. They used trees and forests for many purposes – from food and herbs to firewood, tools and buildings – but their impact on forest structure was relatively small. They had low populations and stone-age technology.
Reconstructions of Maine’s presettlement forest, based on early surveys and on studies of existing old growth, found that the forests of much of Maine had relatively long cycles of catastrophic disturbance. The average time between major fires and hurricanes at a given location might be around 1,000 years. This does not mean that trees lived to be 1,000 years old – smaller-scale disturbances, such as pests and smaller wind throw, were more the rule. In some regions of Maine, such as the blueberry barrens, native peoples may have used fire to manage for favored crops, but in most of Maine they did not.
The impact of such disturbance cycles is that most of the forest was of uneven age, with larger old trees, dead standing trees, dead downed trees and gaps of various sizes with young trees. Most of the land was in later successional stages. In northeastern Maine, one study estimated that only 16% of the forest was in stands under 75 years old. Now, two-thirds of the forest is in stands where the dominant trees are not big enough to qualify for saw timber.
The Age of Exploitation
Early settlers from Europe began a different relationship with the forest: It was a resource to be mined. Wood was essential for economic development and trade. Land was cleared for pasture and agriculture. White pine was used for ship masts and lumber. Hemlock trees were cut down just for the bark to tan leather. Huge swaths of land were cut to make charcoal to smelt metal. The human dot grew, and the forest circle shrank.
The management model was high grading – cut the best and leave the rest. No one worried (in the beginning) about running out – there seemed to be an endless supply. And anyway, you cut down trees and more grow back.
After a while, high value trees were no longer easily accessible, and the quality of easily accessible trees was not so high. Technological advances, however, helped increase wood supply. This increase was not by improving management, but by opening up access to more trees and creating uses and markets for trees lacking quality, which were previously left behind.
Eventually the big white pines started to run out. By 1860, more red spruce than white pine was going down the Penobscot River to Bangor mills. By the end of the 19th century, after the market for wood pulp for paper became established, even those in industry became concerned that increased consumption could deplete red spruce. Some citizens started demanding diameter limits and the creation of reserves. Those demands were ignored.
Forest species, forest structure and disturbance cycles started to change. Massive fires followed logging. In 1825, the Miramichi fire burned 800,000 acres in Maine and two million in New Brunswick. Fires in 1903 were so severe that Maine became the first state in the nation to set up forest fire towers and actively fight fires.
With the cutting of white pine and red spruce, forest gaps began filling with balsam fir, a favored food source for the spruce budworm. As with fires, spruce budworm outbreaks increased in frequency, severity and extent. From 1911 to 1919, Maine and eastern Canada experienced a spruce budworm outbreak that killed most of the fir and much of the spruce. Forrest Colby, head of the Maine Forest Service in 1919, admitted, “It is a fact not to be disputed that we are cutting off our forests today much faster than they are being reproduced, and we have been doing this for years… That we have wasted our forest is a matter of common knowledge.”
Clearly, high grading was not a good long-term approach and seemed to be meeting with limits a century ago, yet we are cutting more wood today than then. What changed? The first big factor was transportation. As the best trees were cut here, loggers moved to the Lake States and the Pacific Northwest and found even better trees. Railroads and canals opened shipping and markets from these places to the population centers in the East.
The transportation networks also enabled farmers to leave the thin, rocky, glacial soils of Maine for the richer Midwest soils. Abandoned farmland in Maine and abandoned pastureland (as animal power was replaced by machines) reverted to forests. Maine now has millions more acres of forest than it did a century ago.
A second factor was changes in technology and substitution of other products for timber products. Substitutes for wood in buildings (concrete and steel), smelting (coal) and other products (chemicals and plastics) reduced demands.
The most important factor for the recovery of Maine’s forest, however, was the Great Depression. The timber industry in Maine started to shrink even before the Depression, but the Depression kept down demand for timber products until after WWII.
The combination of reforestation of abandoned farm and pastureland, regrowth of land hit by fires and spruce budworm, and reduced demand for Maine forest products helped Maine’s forest bounce back. The species composition and age structure of the older Maine forest was changed, but more wood was available, and new demands for it arose – primarily for wood pulp for paper. The demand for lumber did not start to spring back until the 1980s.
After WWII, a new style of forestry arose – industrial management. The forest was no longer the life support system in which people lived; it was a resource for mills, a dot in the circle of industrial society.
Industrial society had new tools to manage forests – machinery to cut and move trees and chemicals to control pests. The new model was the forest as factory farm. If computers projected shortfalls of timber for mills in a few decades, the Maine Forest Service called for more intensive management – more herbicides, more planting, more pre-commercial thinning (using Central American guestworkers). Industrial management allowed landowners to simplify the landscape to grow more of what society needed, rather than for the extraneous needs of forest ecosystems.
Late in the 20th century, industrial landowners, who owned both mills and timberlands, controlled more than 40% of the forest of Maine. At the beginning of the 21st century, however, most industrial landowners sold their lands, so intensive management declined, somewhat.
The new landowners, timber investment management organizations, have been managing for shorter time horizons. They cut enough for annual dividends and then sell the land for capital gains. Various degrees of high grading are still popular, but now, with markets for everything, even trees lacking quality are harvested – for biomass boilers or conversion to chips. Rather than clearcut and plant, such companies favor “shelterwood” with “overstory removals,” where all large trees are cut, leaving just saplings and seedlings.
Forest ownership is a business investment, so the primary goal of forest management is to get the best return on that investment. Ecological and social goals can be pursued only if they do not interfere with the primary goal.
Limits to Growth
Even if industrial practices of planting, thinning and herbicide spraying could increase yields, a problem remains: Our whole economy is based on perpetual geometric growth, but the forest appears to have limits. Indeed, the latest U.S. Forest Service inventories seem to show that limits to growth in harvesting have already been met in much of Maine. All Maine counties (except Hancock) that have most of their land under Tree Growth Tax, indicating a dominance of commercial forestry, are cutting more than is growing.
Global markets for wood products mask the limits to growth, just as national markets masked regional shortages a century ago. Cutting that exceeds growth in a given country is apparently not a problem. If we run out of wood in one place, we can get more from Brazil, Siberia or someplace else.
Even with a global timber base, limits to perpetual growth in demand exist. Economists consider 3% to be a barely adequate growth rate for our economy. Anything less has experts worrying about the need for more “stimulation” to increase growth rates. In the short term, industrial foresters can, with a straight face, plan to increase growth rates to meet projected increased demands. Genetically engineered trees, high-powered fertilizers, more thinning … and maybe we can keep the mills going in the next few decades. But can this go on for 1,000 years?
To illustrate the power of compound interest over much longer periods, consider a tree that is 1 foot tall and growing taller at a rate of 3% per year. (We’ll ignore trunk diameter and root systems here for simplicity.) In a thousand years, the height of this tree will be 14.5 times the distance of the earth to the sun. At 4% (considered “healthier” or “more robust” by economists), the tree would be 3.5 light years tall!
Obviously, physiology limits tree growth to more earthly maxima, and one can no more sustain such endless growth on a planet with limits than sustain the growth of a soap bubble. At some point, both will pop. Global industrial growth is limited because we live in a world with limited water, forests, fisheries, farmland and nonrenewable resources. Do we want to ignore these limits until we run out of options, or do we want to start living within limits now, while options still exist?
Living within Income
Since we do not know what societies will need hundreds of years from now, our best strategy for managing for the future is to keep as many options open as possible – which we are not doing when we allow essential habitats to diminish and species to disappear. The first ecological rule of thumb is to manage within the range of variability to which species have adapted for the past few thousand years. If there is not enough early successional habitat, that can be fixed in a few days. If there is not enough late-successional habitat, it will take more than a century to fix. The ecological starting point, therefore, is to manage conservatively and retain as much natural structure as possible, but also to have large reserves with little or no management.
The second ecological rule of thumb is to live within our biological income. Our society confuses income with capital depletion. Forests have ecological capital – such as soil nutrients, organic matter, large old trees, dead standing and downed trees, mycorrhizal fungi, decomposers, predator and parasite complexes, and forest structure. Just as with a bank account, you cannot perpetually take out more than you are getting in interest and expect to have the same amount of wealth in the future.
We cannot predict what markets will exist centuries from now, but to keep options open for the future, we should plan to grow large, quality trees. If future generations want such trees for making violin soundboards or for building post and beam homes, they will be available. If not, they can always be chipped – or left to grow. Big trees put on more volume per acre per year than small trees, so nothing will be lost in productivity for growing them.
While natural forests are self-regulating, forest management is an interaction between human society and forests. If the human society is not sustainable, the forest management will not be sustainable. Rather than find ways to continually increase supply to meet ever increasing, and eventually, impossible-to-meet demands, a better approach would be to find ways to reduce demands to reasonable, sustainable levels, within biological and physical limits.
For forestry to persist for a thousand years implies the need for cultural continuity. While laws and regulations might be useful, even more important is having a society that values the forest so highly that it could not imagine severely damaging it. A conservation ethic must be passed from generation to generation.
Continuing to allow the mining, high grading and simplification of forests without concern for future generations reflects poorly on our ethics as a society. The logic of short-term economics seems to favor destroying what we depend on, but a higher logic refutes this. Our technological, economic and political systems are supposed to serve, not enslave, people. If these systems cannot foster healthy forests, stable communities and biological wealth for future generations, then something is wrong with these systems. Rather than degrade forests and communities to adjust to the needs of these systems, we should adjust these systems to the needs of forests and communities.