Common Definitions Used by the FIA
Removals: The net growing-stock volume
harvested or killed in logging, cultural operations (such as timber
stand improvement) or land clearing, and the net growing-stock volume
neither harvested nor killed but growing on land that was reclassified
from timberland to noncommercial forest land or nonforest land during
the period between surveys. This volume is divided by the number
of growing seasons to produce average annual removals.
Reserved productive forest land: Forest
land sufficiently productive to qualify as timberland but withdrawn
from timber utilization through statute or administrative designation;
land exclusively used for Christmas tree production.
Rights-of-way: Highways, pipelines,
Rotten tree: A live tree of commercial
species that does not contain at least one 12-foot sawlog or two
noncontiguous sawlogs, each 8 feet or longer, now or prospectively,
and does not meet regional specifications for freedom from defect
primarily because of rot; that is, more than 50 percent of the cull
volume in the tree is rotten.
- The same as a rotten tree except that a rough tree does not
meet regional specifications for freedom from defect primarily
because of roughness or poor form.
- a live tree of noncommercial species.
Salvable dead tree: A tree at least
5.0 inches d.b.h. that has died recently and still has intact bark;
may be standing, fallen, windthrown, knocked down, or broken off.
Sampling error (SE): A measure of the
reliability of an estimate, expressed as a percentage of the estimate.
The sampling errors given in this report correspond to one standard
deviation and are calculated as the square root of the variance,
divided by the estimate, and multiplied by 100. Indicated in statistical
tables as "SE".
Sapling: All live trees 1.0 inches
through 4.9 inches d.b.h. (see d.b.h.)
Sapling/seedling stand: A stand-size
class of forest land that is stocked with at least 10 percent of
minimum full stocking with live trees with half or more of such
stocking in saplings or seedlings or both.
Sawlog: A log meeting regional standards
of diameter, length, and freedom from defect, including a minimum
8-foot length and a minimum top diameter inside bark of 6 inches
for softwoods and 8 inches for hardwoods.
Sawlog portion: That part of the bole
of a sawtimber tree between the stump and the sawlog top.
Sawlog top: The point on the bole of
a sawtimber tree above which a sawlog cannot be produced. The minimum
sawlog top is 7.0 inches diameter outside bark (d.o.b.) for softwoods
and 9.0 inches d.o.b. for hardwoods.
Sawtimber stand: A stand-size class
of forest land that is stocked with at least 10 percent of minimum
full stocking with all live trees with half or more of such stocking
in poletimber or sawtimber trees or both, and in which the stocking
of sawtimber is at least equal to that of poletimber.
Sawtimber tree: A live tree of commercial
species at least 9.0 inches d.b.h. for softwoods or 11.0 inches
for hardwoods, containing at least one 12-foot sawlog or two noncontiguous
8-foot sawlogs, and meeting regional specifications for freedom
Sawtimber volume: Net volume in board
feet, by the International 1/4-inch rule, of sawlogs in sawtimber
trees. Net volume equals gross volume less deductions for rot, sweep,
and other defects that affect use for lumber.
SE: See Sampling error.
Seedling: A live tree less than 1.0
inch d.b.h. and at least 1 foot tall.
Single-family house: House sheltering
one family and immediately adjacent managed land.
Snag: Standing dead tree with most
or all of its bark missing that is at least 5.0 inches d.b.h. and
at least 4.5 feet tall (does not include salvable dead).
Soft hardwoods: Hardwood species with
an average specific gravity of 0.50 or less.
Softwoods: Coniferous trees, usually
evergreen and having needles or scalelike leaves.
Stand: A group of forest trees growing
on forest land.
A classification of forest land based on the size class (that
is, seedlings, saplings, poletimber, or sawtimber) of all live trees
in the area.
Standard cord: A unit of measure for
stacked bolts of wood, encompassing 128 cubic feet of wood, bark,
and air space. Fuelwood cord estimates can be derived from cubic-foot
estimates of growing stock by applying an average factor of 80 cubic
feet of solid wood per cord. For pulpwood, a conversion of 85 cubic
feet of solid wood per cord is used because pulpwood is more uniform.
State lands: Lands owned by the state
or leased to the state for 50 years or more.
- (for Maine) A relative measure
of stand density based on the "A line" of stocking guides
for appropriate species and forest types . The relationships between
the classes and the percentage of the stocking standard are: nonstocked
(0 to 9); poorly stocked (10 to 34); moderately stocked (35 to
59); fully stocked (60 to 100); and overstocked (101 and over).
- (States other than Maine) The
degree of occupancy of land by trees, measured by basal area and/or
number of trees in a stand compared with the basal area and/or
number of trees required to fully use the growth potential of
the land (or the stocking standard). In the Eastern United States
this standard is 75 square feet of basal area per acre for trees
5.0 inches d.b.h. and larger, or its equivalent in numbers of
trees per acre for seedlings and saplings. Two categories of stocking
are used in this report: all live trees and growing-stock trees.
The relationships between the classes and the percentage of the
stocking standard are: nonstocked (0 to 9); poorly stocked (10
to 59); moderately stocked (60 to 99); fully stocked (100 to 129);
and overstocked (130 to 160).
Strip mine: Area devoid of vegetation
due to current or recent general excavation.
Stump: The main stem of a tree from
ground level to 1 foot above ground level, including the wood and
Timberland: Forest land producing or
capable of producing crops of industrial wood (more than 20 cubic
feet per acre per year) and not withdrawn from timber utilization
(formerly known as commercial forest land).
Timber products: Roundwood (round timber)
products and manufacturing plant by-products harvested from growing-stock
trees on timberland; from other sources, such as cull trees, salvable
dead trees, limbs, tops, and saplings; and from trees on noncommercial
forest and nonforest lands.
Timber removals: The growing-stock
or sawtimber volume of trees removed from the inventory for roundwood
products, plus logging residues, volume destroyed during land clearing,
and volume of standing trees on land that was reclassified from
timberland to noncommercial forest land.
Tract/multiple family housing: Multiple
individual residential units or attached units (e.g., apartment
buildings and condominiums) and immediately adjacent managed land.
Transportation right-of-way: Land associated
with highways and railroads.
Tree class: A classification of the
quality or condition of trees for sawlog production. Tree class
for sawtimber trees is based on their current condition. Tree class
for poletimber trees is a prospective determination--a forecast
of their potential quality when they reach sawtimber size (11.0
inches d.b.h. for hardwoods, 9.0 inches d.b.h. for softwoods).
Tree grade: A classification of sawtimber
quality based on guidelines for tree grades for hardwoods, white
pine, and southern pine.
Trees: Woody plants that have well-developed
stems and that usually are more than 12 feet tall at maturity.
Unproductive forest land: See Other
Upper-stem portion: That part of the
main stem or fork of a sawtimber tree above the sawlog top to a
diameter of 4.0 inches outside bark, or to the point where the main
stem or fork breaks into limbs.
Urban forest land: Forest land sufficiently
productive to qualify as timberland that is completely surrounded
by or nearly surrounded by urban development (not parks), whether
commercial, industrial, or residential.
Utility right-of-way: Land associated
with pipeline or electric transmission lines; identified only if
vegetative cover differs from adjacent land use.
Veneer log or bolt: A roundwood product
from which veneer is sliced or sawn that usually meets certain minimum
standards of diameter, length, and defect.
Volume suitable for pulpwood: The sound
volume (only rotten cull excluded) of growing-stock and rough trees.