C I N T R A F O R
Special Paper Abstract
Future Prospects for Western Washington's Timber Supply
Darius Adams, Ralph Alig, David Anderson, James Stevens, John Chmelik. 1992 (200 pp) SP12 $16.50
The Washington Timber Supply Study was commissioned by the Washington Legislature to secure more detailed data on Western Washington's forest resource base and to update earlier studies of prospective timber supplies for the State's mills. Its objectives were to: (i) identify the potential range of future harvests in Western Washington, highlighting those aspects of owner behavior and the resource base most important in establishing the variance of harvest over time, and (ii) translate harvest projections into impacts on forest industry employment and wildlife habitat.
The initial conditions projections suggest that total Westside harvest levels roughly equivalent to the average of the 1980's could be maintained for several decades. This would involve a shift in the ownership composition of harvest toward private and Department of Natural Resource (DNR) lands and a near-term increase in the hardwood proportion of harvest. Timberland area would decline by about 950,000 acres or 10 percent between 1990 and 2090, with nonindustrial private ownerships the principal source of this loss.
Average forest industry harvest levels observed during the 1980's could be maintained, with an increased share of hardwoods in the near-term. Nonindustrial timberlands also appear to have the physical potential to maintain average harvest levels of the 1980's, but with no associated increase in the hardwood share. Using Forest Service estimates of DNR inventory, projected harvests from DNR lands would be substantially higher than historical averages. With DNR estimates, projected harvests are well within the historical. range. Harvest projections on both private and. DNR lands are sensitive to the intensity of timber management, land base changes and restrictions on the minimum age of timber harvestable. Because industry lands have limited volumes of older timber, changes restricting timber available for current harvest have larger percentage impacts on industrial lands than on nonindustrial or DNR; ownerships. National forest harvests are assumed to follow projections from the preferred alternative of the Forest Service's 1992 northern spotted owl EIS. This would entail a decline in the national forest share of Westside harvest from an average of 13 percent over the last decade to around 8 percent in the future. Other government lands could readily maintain the average harvest of the past 25 years.
Projected near-term cut from industrial private lands is extremely sensitive to any change that limits current available stock. A 10-year increase in minimum harvest age reduces average cut in the first is years of the projection by 17 percent, a land base reduction of 15 percent reduces near-term cut by 24 percent, and a combination of the 'two changes lowers cut by 51 percent. Long-term softwood harvest levels depend heavily on trends in management intensity. Nonindustrial private ownerships are the principal source of timberland lost to non-forest uses; Eliminating this loss could increase long-term nonindustrial cut levels by 15 percent for these ownerships.
Relative to 1989 levels, forest industry employment under' initial conditions would fall by approximately 6,600 person-years or 11 percent by the year 2005. The composition of employment by sector (logging, milling, secondary manufacturing, etc.) would not be appreciably changed. The initial conditions projections portray a future forest land base in which the area of stands in the grass-forb, open sapling-pole, and closed sapling-pole--sawtimber classes decline, while areas of large sawtimber and old-growth increase. As a result, projected habitat suitability ratings fall for species with strong preferences in early successional stages and for those with "mixed" preferences across a range of early and late stages. Species with preferences in the large sawtimber and old-growth classes would appear to benefit, though the projected habitat suitability ratings do not account for the existence of specialized habitat characteristics or the effects of habitat fragmentation/aggregation.
Under the initial conditions and all other scenarios, the average age and volum6 of growing stock on timberland would decline and inventories would be increasingly concentrated near minimum harvest age boundaries. Because private and DNR lands have only limited volumes above minimum harvest ages, projected harvests are sensitive to changes in the timberland base, minimum harvest ages, and inventory levels. Limited volume in older ages also restricts the projected harvest impacts of pooling lands across timbersheds and (non-federal) ownerships, with positive near-term effects in the range of 6-10 percent and negligible long-term changes. Under the initial conditions, timberland area losses of some 950,000 acres (10 percent of the 1990 base) are anticipated from private; and DNR ownerships over the projection period, with nonindustrial private ownerships the principal source of this loss. If this loss could be eliminated, near term softwood harvest could rise by 3 percent and long-term cut by 8 percent.