in pure stands or mixed with balsam fir, tamarack, and 
white-cedar. 
Tamarack Swamp.—Very similar to the spruce-swamp type 
in characteristic associates and site, tamarack predominating. 
“Cedar” > Swamp.—Occurring on shallow peat, having fair 
drainage, the common associates being the spruces, balsam 
fir, tamarack, and paper birch. (A mixture of white-cedar 
and other conifers on upland sites was classified under the 
spruce-fir type.) 
Nonproductive Swamp.—Scrubby spruces or tamarack on 
deep, poorly drained peat, usually less than 5 inches d. b. h. 
at 100 years of age. This type does not include peat lands 
that are deforested but potentially productive. 
Scrub Forest—Stands of any species or mixture that are 
of such poor form as to be totally unmerchantable except for 
fuel wood and show no promise of becoming merchantable. 
VOLUMES 
Merchantable Timber—Timber of the size and quality 
usually accepted in commercial operations. It does not 
have an economic meaning such as saleable or accessible. 
Saw-timber Volume.—Saw-timber or board-foot volume is 
recorded by International (14-inch kerf) scale, which closely 
approximates the green-chain tally of the logs. Board-foot 
volume was estimated for all trees in the 10-inch diameter 
class (9.0-10.9 inches d. b. h.) or higher containing at least 
one 10-foot log of good quality or a 16-foot log of poor 
quality. Minimum top diameter for sawlogs was 6 inches 
d. i. b.6 for softwoods and aspen; 8 inches for other hard- 
woods. For most trees the top diameter was greater than 
8 inches because of the limitation of merchantability. 
Cordwood Volume.—Cords were compiled on the basis of 
75 cubic feet of wood per cord, which, for the average size 
and shape of cordwood, will make a stack of standard size, 
4 by 4 by 8 feet, when piled with bark on. 
High-grade Pulpwood—The pulpwood volume estimates 
included wood in trees below saw-timber size from which at 
least two 8-foot sticks could be cut and in tops of sawlog 
trees from which at least one 8-foot stick could be cut. A 
few small logs of pulpwood species were also estimated as 
pulpwood rather than sawlogs. In the case of aspen and 
hemlock, no wood smaller than 5 inches d. i. b. was esti- 
mated as pulpwood. For other species the minimum 
diameter was 4 inches. 
“Cedar” Products—White-cedar was estimated in terms of 
poles and posts. The standards for poles conformed to the 
specifications of the Northern White Cedar Association; 
lengths ranged from 16 feet to 45 feet, and minimum and 
maximum top diameters varied with the length of the pole, 
from 4.5 to 9 inches. White-cedar posts were 7 feet long, 
with a minimum top diameter of 4 inches. 
Total Volume.—Total volume is expressed in cubic feet of 
wood (excluding bark). It includes the volume between 
stump and a 4-inch top. In the case of hardwoods it 
5 Northern white-cedar (Thuja occidentalis) is not a true 
cedar (Cedrus) and ‘‘cedar”’ is therefore a misnomer for this 
species, although in common usage. 
6 D. i. b.=diameter inside bark. 
VII 
includes the volume of large limbs to a 4-inch minimum 
diameter. 
LOG GRADES 
Hardwood saw timber was graded according to the fol- 
lowing specifications: 
No. 7 Logs.—At least 12 feet long and 12 inches d. i. b. at 
the small end, the following defects being allowed, the 
variation depending on log diameter: Up to three standard 
defects or sound bright knots, each with a diameter of not 
more than 3 inches, or their equivalent in damage to the 
product of the log; up to 20 percent deduction from the 
gross scale for rot or similar defects. No. 1 logs were expected 
to saw out 60 percent or more of No. 1 common or better 
lumber. 
No. 2 Logs.—Generally at least 10 feet long and 8 inches 
d. i. b. at the small end, including, however, the better- 
quality 8-foot logs, 10 inches d. b. h. or more; but these— 
and likewise all longer logs less than 10 inches d. i. b.—to 
be surface clear, straight, and sound. Logs more than 10 
inches d. b. h. were permitted as many as three standard 
defects. No. 2 logs were expected to saw out 75 percent 
sound lumber, of which 30 percent would be No. 1 common 
or better. 
No. 3 Logs.—Including all logs suitable for ties, timbers, 
or low-grade lumber. For most species the minimum size 
requirements were 8-foot length and 8-inch diameter. 
These logs would generally saw out 50 percent sound. 
Cull.—Culls included large trees (18 inches d. b. h. or 
more) which did not contain one 16-foot No. 1 or No. 2 
grade log, or two 16-foot No. 3 grade logs; smaller sawlog- 
size trees (10 to 16 inches in diameter), if they did not 
contain one 10-foot No. 2 log or one 16-foot No. 3 log; 
defective small trees; white-cedar trees, too crooked or 
decayed to produce at least one 16-foot pole or two 7-foot 
posts. Also deductions were made in the volume of mer- 
chantable sawlog trees for rot, crook, fork, shake, and other 
defects. 
GROWTH AND YIELD 
Current Annual Growth—Current annual growth figures 
purport to show what the present forest areas are likely to 
produce annually during the decade 1935-44, if no radical 
changes occur in their acreage or composition. Technically, 
this is known as periodic annual growth. 
Allowable Annual Drain.—Allowable annual drain is the 
average volume of mature merchantable timber that will be 
ready for cutting each year during the next few decades 
under a conservative form of management. In old-growth 
slow-growing stands, the allowable drain exceeds annual 
growth, but in young stands it is less because most of the 
growth there is on immature trees. 
Normal Actual Drain —The term “normal actual drain” 
refers to prospective use of wood during the next decade, 
providing general economic conditions are reasonably 
stable. It is based upon a compilation of estimates of 
individual operators, reinforced in some places by actual 
averages for the preceding 5 or 10 years. Where actual 
production or consumption figures are presented in connec- 
