Tree Classification 
SOUND SAW-TIMBER TREES — Softwood trees at least 
9.0 inches d.b.h. and hardwood trees at least 11.0 inches 
d.b.h., with not less than one merchantable butt log 
12 feet long, or with 50 percent of the gross volume 
of the tree in sound saw timber. 
SOUND POLE-TIMBER TREES — Straight-boled trees 
between 5.0 inches d.b.h, and saw-timber size. 
SOUND SAPLINGS — Straight-boled trees between 1.0 
and 4.9 inches d.b.h. 
CULL TREES — Trees that fail to qualify as sound saw 
timber or pole timber because of poor form, excessive 
limbiness, rot, or other defect. Volumes shown for cull 
trees include also the limbs, in sections 4 feet long and 
at least 4.0 inches in diameter inside bark, of saw- 
timber-size hardwoods. 
Species Groups 
SorTwoops — All of the pines, eastern redcedar, 
pond cypress, baldcypress, and hemlock. 
SOFT HARDWOODs — Black and water tupelos, sweet- 
gum, soft maple, yellow-poplar. The other soft hard- 
woods include sweetbay, cottonwood, willow, and 
southern magnolia. 
HARD HARDWOODs — AIl of the oaks, hickories, and 
ash. Volumes shown for sycamore and birch also include 
river birch, beech, elm, honeylocust, and sycamore. 
Volume Estimates 
BOARD-FOOT VOLUME — The volume in board feet, 
measured by the International 14-inch rule, exclusive 
of defect in that portion of saw-timber trees between 
the stump and the upper limit of merchantability for 
sawlogs. 
VOLUME IN CoRDs — For sound trees the volume in 
standard cords (including bark) of the sound portion of 
trees 5.0 inches d.b.h. and larger, between stump and 
a minimum top-stem diameter of 4.0 inches inside bark. 
For cull trees similar volumes are included plus the 
volume in limbs, in sections 4 feet long and at least 
4.0 inches in diameter inside bark, of saw-timber-size 
hardwoods. 
VOLUME IN CUBIC FEET — Same as volume shown in 
cords except bark is not included. 
INTERNATIONAL 14-INCH LOG RULE—A tule for 
estimating the board-foot volume of 4-foot log sections, 
according to the formula V = .905 (0.22D? — 0.71D). 
The taper allowance for computing the volume in log 
lengths greater than 4 feet is 0.5 inch per 4-foot section. 
Allowance for saw kerf is 14 inch. 
STANDARD CORD — A stacked pile, 4 by 4 by 8 feet, of 
round or split bolts, estimated to contain, on the average, 
90 cubic feet of softwoods (wood and bark) or 80 
cubic feet of hardwoods (wood and bark). 
Growth and Drain 
GROWING STOCK: 
Saw timber —The sawlog volume of all sound 
saw-timber-size trees. 
All timber —The cord or cubic-foot volume of 
the entire stem from stump to a minimum 4-inch 
diameter inside bark, of all sound trees 5.0 inches 
d.b.h. or larger. No limbs or cull trees included. 
NET GROWTH: 
Board foot — The change during the calendar year 
in the saw-timber growing stock resulting from tree 
growth and mortality losses. Includes the gains accru- 
ing from the growth of small trees into saw-timber 
sizes during the year. 
Cord or cubic foot—The change during the 
calendar year in the stem volume of all sound trees 
5.0 inches and larger resulting from tree growth and 
mortality losses. Includes the gains accruing from the 
growth of saplings into pole sizes during the year. 
MORTALITY: 
Board foot — The net volume lost from the saw- 
timber growing stock during the calendar year by the 
death of individual trees through the normal action 
of fire, tree competition, disease, insects, drought, 
and wind. Catastrophic losses did not occur during 
the growth period. 
Cord or cubic foot—The net volume lost from 
the all-timber growing stock during the calendar 
year by the death of individual trees through natural 
causes. 
COMMODITY DRAIN: 
Board foot— The net volume removed from the 
saw-timber growing stock through cutting of timber 
products and logging waste during the calendar year. 
Cord or cubic foot — The net volume removed from 
the all-timber growing stock through cutting of timber 
products and logging waste during the calendar year. 
62 Forest Resource Report No. 3, U. S. Department of Agricnlture 


