land and probably considerable portions of such 
land will be shifted from forest to farm use in the 
future. Consequently, in the growth phase the 
hardwood stands were considered only in the cur- 
Results of the periodic 
erowth calculation, made in order to estimate 
board-foot timber inventories as of the years 1943, 
1953, and 1963, are not discussed here but are 
included on page 150. 
In the growth phase as in the inventory phase, 
rent growth calculation. 
volume estimates were made in cubic feet and in 
board feet (for detailed specifications see p. 7). 
Periodic growth was computed on the basis 
of the current board-foot utilization standard 
only, as a means of estimating future board-foot 
In anticipation of more intensive 
in the future, realizable and 
inventories. 
forest utilization 
potential annual growth were also computed 
according to another standard, board feet for all 
trees 11.1 inches d. b. h. or more estimated in 
16-foot logs to 8-inch top, Scribner rule. Board- 
foot growth rates were reduced 5 percent for 
breakage and defect. 
Current Annual Growth 
Estimates of current annual growth, the annual 
increment of stands in their present condition, were 
based on acreages of growing types as found in 
1933. ‘This is the only one of the four kinds of 
growth calculation that does not involve estimates 
of future changes in condition and extent of forests. 
An estimate of current annual growth should not 
be used as a basis for any estimate of volume at a 
future time; it cannot remain valid for more than a 
short period. It does not show the potential 
productivity of the land, and it does not show the 
growth realizable over long periods such as are 
involved in management plans for large forest 
areas. 
Current annual growth in the region totals 917 
million cubic feet, or 2.4 billion board feet, Scribner 
log scale, of which 886 million cubic feet or 2.3 
billion board feet is occurring in conifer stands 
(table 22). 
Immature conifer stands occupy 9.9 million acres, 
or 38 percent of the commercial conifer forest land 
of the region. In cubic feet their annual increment 
Ol 
amounts to only 0.66 percent of the region’s total 
conifer timber stand; in board feet, only 0.42 
percent. 
Western Oregon, having a greater acreage of 
rapid-growing stands than western 
Washington, is producing 56 percent of the 
region’s cubic-foot growth and 62 percent of its 
board-foot growth. 
The three Puget Sound units contain 30 percent 
by area of the conifer second growth in the region 
and have 22 percent of the region’s annual conifer 
board-foot growth and 28 percent of its cubic-foot 
growth. The two Oregon coast units, though con- 
taining only 14 percent of the region’s conifer 
second-growth area and having approximately a 
commensurate amount of its current cubic-foot 
growth (16 percent), have 25 percent of its board- 
foot growth. This is due to the relatively large 
proportion of sawlog-size stands among the grow- 
ing forests on the Oregon coast, there being great 
areas of advance second-growth timber now about 
80 years old. 
Table 23 shows the species distribution of cur- 
For the 
region as a whole, approximately three-quarters 
of the growth is of Douglas-fir and about one-fifth 
is of the pulpwood species. Notable departures 
from the regional averages are found in the Grays 
Harbor unit, where nearly two-thirds of the growth 
is of pulpwood species and less than one-third is of 
Douglas-fir. In the Rogue River unit, other 
species (in this instance principally ponderosa 
pine) are making more than one-third of the total 
current growth, both in cubic feet and in board 
feet. 
The growing stands as a whole compare favorably 
in physical accessibility with the virgin stands of 
immature 
rent annual growth in conifer stands. 
the region that are now being logged; but because 
their quality is, in general, much poorer, they are 
lower in current economic availability. However, 
the immature stands are growing rapidly in volume 
and in value and should not be logged at this time. 
Of greater import than their current economic 
availability is their potential availability. It is es- 
timated that approximately 90 percent of such 
stands as a whole is either economically or poten- 
tially available. 
Very little of the current net increment is being 
added to the large or clear stems that provide the 
ee 
