have the opposite effect. Fire is the most potent 
factor in causing understocking and preventing 
satisfactory growth after logging. 
Every managed forest having normal distribu- 
tion of age classes, whether composed of even-aged 
stands or of uneven-aged stands, would probably 
produce about the same volume of wood per acre, 
site for site, under a selective-cutting as under a 
clear-cutting system of management, except as 
standards of utilization or the practicability of 
thinnings might vary. Under selective cutting the 
product would, however, average higher in quality. 
For example, the supply of high-quality old growth 
would be exhausted much less quickly and more of 
such timber would be produced. ‘This should re- 
sult in better utilization and therefore in greater 
Selective cutting might 
also result in utilization, through thinnings, of 
much material that would otherwise be lost. On 
the other hand, it might result in a higher per- 
centage of tolerant species in the stand. 
It may be concluded that widespread substitu- 
tion of selective cutting for clear cutting would 
affect the volume and value increment on some 
net utilizable growth. 
areas favorably, on others unfavorably, and on 
others not at all. For the region as a whole, the 
effect of the change would depend on what type of 
selection predominated. 
a controlling factor, the change would probably not 
If liquidation remained 
65 
alter materially the growth estimates herein pre- 
sented. If large areas were carefully selectively 
logged under a system of light cuts at frequent 
intervals, realizable growth measured in board feet 
during the next few decades should substantially 
exceed the estimates presented. 
Summary 
Under prevailing methods of management the 
forests are being depleted of high-quality volume, 
the comparatively small volume being added by 
growth is of relatively poor quality, and no ma- 
terial improvement in quality of forest growth can 
be anticipated. Such increase in volume incre- 
ment as may be expected without change in forest 
practice is small in comparison with that needed 
to support forest industries continuously at present 
levels. Although at the present time and for the 
region as a whole the relation of cut to permanent 
production capacity is apparently fairly rational 
it decidedly is not so for individual units. Cutting 
has been irregularly distributed, the best-quality 
stands and the most accessible stands being taken 
first. In several units, notably the Grays Harbor, 
Puget Sound, and Columbia River units, the 
present rate of cutting exceeds that allowable under 
sustained-yield management, while in Oregon 
outside of the Columbia River unit an increased 
cut could be sustained. 
