Bob Kintigh

During all my years as a professional forester, owner and manager of a small family owned forest, I always used the traditional approach to determine allowable timber cut: I chose the rotation age to which I wanted to carry the stand, determined the amount of timber the stand would produce, and divided by the anticipated rotation age.

However, important changes in the type of timber products the market has been asking for in recent years has caused me to take a radically different approach to determining sustainable cut. For 40 years I managed my timberland to produce large, high-quality trees that formerly brought premium prices in the marketplace. Technological changes and shifts in the world market have taken away this premium and small logs now bring just as much, and sometimes more, per MBF (thousand board feet) than larger high-quality logs. Several years ago, I made a decision to harvest the large trees before they got even larger and perhaps became even less desirable in the marketplace.

The Calculations

I began by making clearcuts from two to seven acres in size, and choosing portions of the stand with the largest trees. These were, of course, the portions of the stand with fewer trees per acre and the heaviest brush. Age of the trees was not considered. In fact, some cut areas were probably 10 years younger than some that remain. My plan is to continue making such clearcuts throughout our property ownership whenever log prices are reasonably good.

Using this method of harvesting, how do I calculate my allowable cut? We have about 220 acres of forestland. From this I subtracted 20 acres, the amount I estimate will be out of production because of steep, inoperable ground and/or areas set-aside permanently for wildlife habitat, roads and landings. This leaves 200 acres that can be devoted primarily to timber production, although this does not mean that other values are ignored or neglected in these areas. Under the intensive management we are now practicing, I believe that we can easily grow the logs that the market is calling for now in 40 to 45 years. Dividing 200 acres by the age at which I expect the trees to reach marketable size shows that I can cut four to five acres per year indefinitely. For those who have land that will not produce merchantable trees in this timeframe, the answer will be different, but the method could be the same. Landowners with smaller acreages that can not support an economical logging operation each year can still use this method, but would cut periodically rather then every year.

Application

In reality, the areas of higher site quality will probably be cut in 35 years, whereas areas of lower site quality may not be cut until they are 45 to 55 years old. Under this system, cutting every year is not a requirement, nor is there a prohibition that no more than four or five acres be harvested in one year as long as the average harvest over a time period does not exceed this acreage. For example, cutting 40 acres of our land in a decade would not violate the principle of sustained harvest. Family emergencies, college tuition or necessity to pay a death tax could be a reason for cutting a larger amount sometime.

Does this mean that I have a truck road to each clearcut? No. We do have at least one road in each 40 acres. Whenever a clearcut is harvested and replanted, skid trails are left unplanted so that the timber behind the clearcut can be skidded to the same landing. Little if any timber will need to be skidded more than 600 feet to the landing. Erosion prevention measures are carried out on skid trails where needed.

Management Practices

Practices that we carry out include excavator piling after logging. The goal is to pile only slash and brush that interferes with doing a good planting job. The operator does dig up large vine maple and other brush and put it on the piles. Broken chunks of logs and tops over four inches in diameter are not put in the pile, but are left lying on the ground to provide woody material and organic matter. Plug+1 planting stock of a good seed source (genetically improved when available) is used for reforestation. Western redcedar and Willamette Valley ponderosa pine are planted on micro sites where they are deemed a better choice than Douglas-fir. Vegetation is controlled by backpack spraying herbicides in a four-foot radius around each tree. Deer repellent is used the first year. Trees will be fertilized several times starting the first or second year. An aggressive program to eradicate Scotch broom is carried out and Himalayan blackberries are sprayed enough to keep them from taking over.

What about thinnings? I anticipate a thinning will be made at age 30 to 35 years. This does not change the size of the area that can be cut each year. It is simply an added bonus.

We do not have any streams that lend themselves to enhancement efforts beyond maintaining shade. Deer and elk abound, so we must provide sufficient cover and browse. We leave large trees (rough 3 Mill type that log buyers don't like) and girdle them for raptor roosts and future snags. We also leave small brush piles, which we have found to be frequented by wrens, kinglets, towhees and other birds.

Conclusion

The method of determining allowable harvest that I have described is simple and does not require extensive growth calculations. It can be used on any small or medium-size property. No one can argue that it is not sustainable.

Bob Kintigh is a forester, small woodland owner, a past president of OSWA and served 12 years in the Oregon State Senate. He is a recipient of OSWA's highest award, the Riggin' Slinger, and the Oregon Society of American Forester's lifetime achievement award. He can be reached at 541-741-9833.