Resource Development Council

Transition to young-growth

timber is far off in the Tongass

By Owen Graham

There has been a lot of talk lately about the need for the timber industry in Southeast Alaska to transition to young-growth timber harvesting. This transition concept is being promoted like it is some new idea and that it can be completed quickly. The transition is not a new concept and it will not be complete any time soon. The forestry profession has always been about growing young trees and transitioning out of the old-growth timber. Young-growth timber is much more uniform than old-growth, young-growth is essentially defect free and young-growth stands will have double the volume of timber per acre that exists in most old-growth stands.

Early foresters spoke in terms of sustained yield and the acreage of timberland needed to sustain manufacturing facilities in perpetuity. In 1909 shortly after the Tongass National Forest was established, government foresters completed an initial assessment of the commercial timberland and by the 1930s researchers (RF Taylor - 1934 and Meyer - 1937) had completed the first growth and yield tables which were indexed by site conditions for the Tongass. These yield tables allowed foresters to calculate the harvest age that captures the maximum growth potential for stands of timber on various growing sites.

Trees grow like people, slowly at first, then rapidly for a period of time, then slowly again. The peak growth is referred to as the Culmination of Mean Annual Increment. The Forest Service is obligated by the National Forest Management Act to defer rotational harvest until a stand achieves this culmination. If the trees are harvested too soon the growth potential of the land will not be maximized. Growing the trees beyond the optimum date would result in larger, more valuable trees but again, the maximum growth potential of the land would not be achieved and additional acres would have to be managed for growing and harvesting timber in order to compensate for harvesting the timber before the fast-growth period had ended.

In addition to optimizing the growth potential of the land, the economic value of the young trees must be considered. 96% of the young-growth available under the current forest plan is less than 50-years old. At age 50, most of the trees in a typical stand of timber are less than eight inches in diameter and their value is much less than the cost of harvesting. In contrast, the same trees will be about sixteen inches in diameter and will be much more valuable at the optimum harvest age of around 100 years.

The Tongass National Forest covers more than 90% of Southeast Alaska and, according to the 1989 Forest Service Benchmarks publication, the commercial timberland on the Tongass that is not set aside in congressional reserves would sustain an annual harvest level of nearly two billion board feet of saw timber. However, only a small percentage of the forest is needed or scheduled for harvest. In 1966, the maximum allowable harvest level was 825 million board feet, in 1980 the level was dropped to 450 million board feet and in 1997 the level was dropped once again to the current level - about 230 million board feet of saw timber (267 million board feet including utility/pulp logs). It is unlikely that the timber industry will have sufficient economy of scale to be cost competitive at the 230 million board foot harvest level, but for now that is irrelevant because, with the current availability of timber sales at less than 50 million board feet per year, the industry is struggling just to survive.

In a 2004 young-growth management paper (Barbour – 2004), the Forest Service explains that “Under the current plan future harvests from federal land will ensure that the land base available for young-growth management increases in each decade until harvest of young-growth timber replaces old-growth harvests about 50-60 years from now.” The authors of that paper are correct; the last thing we need right now is a premature transition to harvesting our young-growth timber.

Owen Graham is Executive Director of the Alaska Forest Association.

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