6. Reduced timber growth. The future as described by 
the assumptions in chapter 3, modified by reducing by 25 
percent the net annual growth on pine plantations, natural 
pine, and mixed pine—hardwood stands shown in the 
empirical yield tables used in developing the base 
projections. 
7. Reduced national forest harvest. The future as 
described by the assumptions in chapter 3, modified by 
reducing timber harvests on the national forests to 8.1 
billion board feet in 1990 and maintaining this level through 
2030. 
8. Natural regeneration on marginal cropland and 
pasture. The future as described by the assumptions in 
chapter 3, modified by assuming that all marginal cropland 
and pasture in the South would naturally revert to timber- 
land by 2000 (70 percent natural pine, 30 percent hardwoods 
in the Southeast; 40 percent natural pine, 60 percent 
hardwoods in the South Central). 
9. Planted pine on marginal cropland and pasture. The 
future as described by the assumptions in chapter 3, 
modified by assuming that all the marginal cropland and 
pasture in the South would be planted to pine. 
10. Economic opportunities on private timberlands. The 
future as described by the assumptions in chapter 3, 
modified by assuming the utilization of all the economic 
opportunities (except those involving intermediate stand 
treatment and those not involving area changes in manage- 
ment types) for increasing timber supplies on timberland in 
private ownerships that yield 4 percent or more net of 
inflation or deflation. 
11. All economic opportunities on private land. The future 
as described by the assumptions in chapter 3, modified by 
assuming that (1) all the economic opportunities (except 
those involving intermediate stand treatment and those not 
involving area change in management types) for increasing 
timber supplies on timberland in private ownership that 
would yield 4 percent or more net of inflation or deflation 
would be utilized, and (2) all the marginal cropland and 
pasture would be planted to pine. 
12. Increased management intensity on forest industry 
timberlands in the Douglas-fir region. The future as 
described by the assumptions in chapter 3, modified by 
assuming that all the economic opportunities to increase 
timber supplies on forest industry timberlands in the 
Douglas-fir region would be utilized. 
The implications of each of these selected futures are dis- 
cussed below. The discussion is directed at the important 
differences in the resource changes and economic and 
environmental effects from those shown in the base pro- 
jections. Most of the data on resource changes are shown 
only for the private ownerships—forest industry and other 
private. Most of the selected futures would not have 
significant impacts on the resources in national forests and 
other public ownerships. 
Improved Processing Efficiency 
The limited historical data that are available show that 
lumber and plywood outputs per cubic unit of log input have 
been increasing in most major producing sections. Past 
assessments and the base simulation in this study have 
assumed that such improvements in utilization would in the 
future increase at 2 percent per decade. Noting that rising 
stumpage costs will provide an incentive for more efficient 
utilization and that the technology is currently available, 
some observers argue that recovery improvement in the 
future should average closer to 5 percent per decade. 
In response to such views, it was assumed for this simu- 
lation that the increase in softwood lumber and plywood 
yields would be 25 percent over the projection period, 
rather than the 10 percent increase included in the base 
Improvements in utilization that increase the 
output of lumber and plywood per unit of 
log input can have a substantial impact on 
the economy. They can reduce the demand 
on domestic timber resources, constrain 
price increases, and increase both the 
production and consumption of lumber and 
plywood. 
