will neglect other important areas where urgent change is also needed, such as population reduction, over consumption, and fossil fuel use.
Even though immediate change in all of these areas would be very desirable, I believe that gradual adaptation towards a sustainable lifestyle is preferable to revolution. We also need to admit the unpleasant fact that corporate control of our lives, of politics, the press, and even of the courts is so strong that the possibility for even gradual positive change is uncertain as long as people do not realize that it is absolutely necessary to involve themselves in public life and thereby resurrect a living democracy.
Because most of us are programmed to over-value money instead of concentrating on leading a responsible lifestyle and on valuing happiness, economic considerations will bear strongly on the success or failure of whatever changes we plan to bring about. Present political policy assumes that high monetary profits and good ecological protection are mutually exclusive. In my extensive work on creating policy to restore depleted private industrial forests, as well as that work presented here, I have come to the conclusion that this assumption is wrong.
Tree growth, in general, has three phases. It starts slowly, then accelerates, and finally slows down again. All trees continue to grow in the third phase, some more and longer than others; redwoods and cedars belong to the species that increase volume considerably for many hundreds of years after reaching culmination of average maximum volume growth (CMAI, culmination of mean annual increment). Also - and this is most important - all tree species show an increase in the quality of their wood during the slower, post CMAI phase of growth. This period is also the most important for sustaining high inventory and permanency of the biotope and for maintaining biodiversity. For the perpetuation of California's redwood forests this third phase of growth is especially important since it is needed to allow for natural regeneration and thus continued genetic adaptation to changing environmental conditions. Therefore, if native forests are to be used for perpetual lumber production, it is imperative, for reasons that include long-term extraction of maximum monetary profits, not to eliminate this lucrative component of all native forests.
However, with few exceptions, near elimination of this component is exactly what we humans have done and are still doing. Worse yet, not only are those older trees being systematically eradicated, but even the much younger ones, trees which are in their most active - pre CMAI - period of growth, are routinely eliminated under the regime of industrial forestry as it is practiced today. This trend is what has made the ongoing destruction of our native forests finally apparent to everyone who is concerned with our own and with other species' survival.
In order to restore these depleted forests we must do two things. We must harvest less than is growing and we must adjust the harvest rate so as to maintain high inventories of trees in the forests once they are restored. For those few remaining forests not yet damaged by unwise human interference, we only need to maintain high inventory, by harvesting not more than a certain percentage of inventory, as I will explain later.
To develop scenarios which would establish such conditions for our Northern California coastal redwood/Douglas fir forest, I applied the most appropriate scientific methods available using data based on most recent measurements of how this forest is actually growing. Unfortunately, we do not have sufficiently precise data on growth of second growth stands of trees 120 years and older and some values had to be derived from extrapolation or comparison with what other researchers assume to be close to reality.
Also I needed to account for the further decline in site quality and growth which is typical for third growth stands which represent the majority of our local forests today. Data for third growth were also derived from the recent large scale measurements conducted by the US Federal Inventory Assessment survey in 1985 for the local county. Taking all these factors into consideration, I then employed the same computer program, Harvest II, as I used to simulate growth, harvest and productivity trends described in detail in my book Maximizing Forest Productivity . The depleted industrial forests of our local county were "grown" for fourteen decades and were "harvested" at four different rates of percent of inventory (POI). In this way, values for inventory, age of oldest trees, productivity and annual harvest were obtained for each scenario. I also assigned a very much needed value for forest sustainability, which I equate with forest inventory: the higher the regulated inventory, the greater the forest's degree of sustainability. The accompanying three dimensional graph and the table summarizes the most important results of this analysis.
The major conclusions which can be drawn are:
1. Economic gain culminates at a harvest level of approximately 1% of inventory per year (1 POI).
2. Productivity measured in board feet culminates at a harvest level of approximately 2% per year (2 POI).
3. Forest sustainability at the levels investigated is highest at 1% of inventory harvest (1 POI).
4. The highest quality of timber, the most stable tax base, the highest degree of community stability and the most permanent and highest return for the landowner are achieved at the 1% harvest level (1 POI).
5. Industrial forestry, which is based on the principle of maximizing net present value, leads to harvest levels greater than 3%. The consequences of this practice are loss of the following: inventory, productive capacity, potential tax base, permanent jobs, timber quality, community stability, biodiversity and substantial long-term landowner income.
6. The requirements of Ecoforestry can only be fulfilled at the 1% harvest level. All other harvest levels reduce too much of the richness, biodiversity and sustainability of the forest.
In conclusion, one can see that high economic gain and good environmental protection are not diametrically opposed. On the contrary, up to the point of maximum economic return at approximately the 1 POI harvest level, both seemingly opposing goals of forest management actually improve in synchronous harmony. Harvesting 1% of inventory is the best long-term investment policy for the general public, the local community, the landowner and the forest, when that forest is to be used for timber production while maintaining its ecological integrity.
Therefore, we should gradually reduce harvests to approximately 1% of inventory per year. I suggest we move from slightly below the current rate to the 1% level over a period of 20 years: adapted to our local area this would translate into 3% for the first five years followed by 2% for the second half of the first decade and then declining at a rate of .1% per year throughout the second decade until the final harvest rate of 1% of inventory is reached in the twentieth year. To reach the goal of maximum economic gain and high forest sustainability, minor adjustments in the rate of harvest may be needed if actual growth and timber prices deviate from the anticipated values. However, the example of the Menemonee Indians' forest management on 200,000 acres in Wisconsin shows that an ideal working forest of the type arrived at in the modeling is actually in existence in the USA. This forest was harvested for 140 years at an average annual rate of approximately 1% of inventory. According to a public radio presentation as well as an article recently written by Wendel Berry, this level of harvest yields a forest in which lumber is of consistently high quality and quantity, forest inventory is high and non-declining, and associated plant, wildlife and natural systems are flourishing and healthy. Isn't this the kind of forest we all want?
[Hans Burkhardt, a former Ph.D. biologist with the California Institute of Technology in Pasadena and author of the book Maximizing Forest Productivity, was co-founder of the Mendocino County Forest Advisory Committee. He was the first member of the Committee to see the benefits of using percent of inventory harvest control as a means of ending forest depletion. He became the strongest advocate for that approach on the Committee. He lives among towering redwood trees on a small, self-sufficient ranch in Northern California.]
Copyright Mendocino Environmental Center 1995