Chapter 1000 - Glossary of Terminology

Internal Revenue Manual
Specialized Industry Guidelines - Timber
Section (10)10, General
Last amended: 6-26-1978

General

(1) The Glossary of Terms reflects the words and terms frequently used by Timber Industry.

(2) The Glossary is not intended to include all of the terms used in the text. Words not shown in the Glossary that are found in the text will carry the general definition of the words usage.
Glossary of terminology

Acre

A unit of land area, comprising 43,560 square feet or 10 square chains. A square acre is 208.7 ft. on the side.

Age, Rotation

The age at which the stand is considered ready for harvesting under the adopted plan of management.

Annual Ring

The growth layer of one year as viewed on the cross section of the tree bole, stem, or branch.

B.F.

The abbreviation for "board foot" (also B.M., board measure).

B.M.

Abbreviation for "board measure" meaning board foot or feet.

Board Foot

A unit of measurement represented by a board I foot long, I foot wide and I inch thick. Abbr. Ft. b.m.; bd. ft. In finished or surfaced lumber, the board-foot measure is based on the measurement before surfacing or other finishing. In practice the working unit is 1,000 board feet. Abbr. M bd. ft.; M B. M.; M B. F.

Board Foot, Green Chain Tally

The unit of measurement of unfinished lumber as it comes out of the sawmill proper.

Board Foot, Log Scale

Unit of measure of content of a log or run of logs, determined by means of a log rule.

Bole

The stem or trunk of a tree, usually the lower, useable or merchantable portion of the tree trunk.

Bolts

Short logs or sections of large logs that have been split. A bolt is usually less than 41/@ feet long.

Buck

To saw felled trees into logs or bolts.

Butt

Base of tree or larger end of logs.

C.F.I.-Continuous Forest Inventory. A system for the periodic monitoring of the growth, volume, composition, and mortality in the forest stand by means of a series of permanent sample plots.

Carriage

A frame on which are mounted the head blocks, set works, and other mechanisms for holding a log while it is being sawed, and also for advancing the log towards the saw line after a cut has been made. The carriage frame is mounted on trucks which travel on tracks, the carriage being actuated by a steam feed, cable or rack-and-pinion de- vice, which propels it back and forth past the head saw.

Clear Cutting

A system of harvesting timber that removes all merchantable trees on the area in one logging operation.

Conifer

A tree belonging to the order Coniferae, usually evergreen, bearing cones and needle-shaped leaves, and producing wood known commercially as softwood.

Cord

A volume measure of stacked wood. A standard cord is 4 x 4 x 8 ft. or 128 cu. ft. of space. A long cord (unit) contains 160 cu. ft. of space and is 4x5x8 ft. Since round wood cannot be stacked to give solid volume, actual wood volume varies between 70 and 90 cu. ft. per cord.

Core

1. The inner layer or layers of plywood or coreboard, usually of low quality material. 2. The portion of a veneer bolt left in the lathe after rotary-cutting veneer.

Crown

The upper part of a tree, including the branches with their foliage.

Cruise

A survey of forest lands to locate and estimate volumes and grades of standing timber; also, the estimate obtained in such a survey.

Cycle, Cutting

The planned interval between major harvesting operations in the same stand. D.B.H.-Diameter (of a tree) at breast height, or 4'h ft. above the ground.

Deciduous

A term applied to trees that lose their leaves in the fall.

Deck, Log
  1. The platform upon a loading jack.
  2. A pile of logs.
  3. A rollway (California).
  4. The platform in a sawmill upon which logs are held just before sawing.

Syn. Mill deck.

Ecology

The science which deals with the relation of plants and animals to their environment and to the site factors that operate in con- trolling their distribution and growth.

Even-Aged

A term applied to a stand in which relatively small age differences exist between individual trees.

Firebreak

A natural or constructed barrier utilized to stop or Internal Revenue Manual check fires that may occur or to provide a control line from which to work. Sometimes called a firelane.

Girdle

To encircle the stem of a living tree with cuts that completely sever bark and cambium, and often are carried well into the outer sap- wood, for the purpose of killing the tree by preventing the passage of nutrients or by admitting toxic materials.

Hardwood

Generally, one of the botanical group of trees that have broad leaves, in contrast to the needle-bearing conifers; also wood produced by broadleaved trees, regardless of texture or density.

Head Saw

The main log cutting saw in a sawmill.

Heartwood

The inner core of a woody stem, wholly composed of nonliving cells and usually differentiated from the outer enveloping layer (sapwood) by its darker color.

Increment Borer

An auger-like instrument with a hollow bit, used to extract cores from trees for growth and age determination. Used also to extract wood cores for other purposes.

Intolerance

The incapacity of a tree to develop and grow in the shade of and in competition with other trees.

Kiln-Dry

The seasoning of lumber in a Un.

Log
  1. To cut and deliver logs.
  2. Tree segment suitable for lumber and other products.
Log Rule

A table showing the estimated or calculated amount of lumber which can be sawed from logs of given length and diameter; commonly divided into four groups upon the basis of derivation: (1) diagram rules, (2) formula rules, (3) rules based on actual output, and (4) hybrid rules. Common rules are:

  1. Doyle rule. A simple formula rule used in the eastern and southern United States; it underestimates small logs and overestimates large logs.

  2. Doyle-Scribner rule. A combination rule derived by using Doyle rule values for logs up to 28 inches in diameter and Scribner rule for logs larger than 28 inches. This rule is extensively used by private operators in the South.

  3. International rule. A formula rule allowing ½ inch taper for each 4 feet of length and 1/8 inch shrinkage for each one-inch board; closely approximating the green-chain lumber tally, in one form it assumes a 1/8 inch kerf; in modified form in which it assumes a V4-inch kerf, it is an official rule of the U.S. Forest Service.

  4. Scribner rule. A diagram rule, one of the oldest in existence. It assumes 1-inch boards and V4-inch kerf, and makes a liberal allowance for slabs and disregards taper. Official rule in many parts of the United States.

  5. Scribner Decimal C rule. The Scribner rule modified by rounding off the last digit to the nearest 10 and dropping the cypher. An official rule of the U.S. Forest Service.

  6. Spaulding rule. A diagram rule, disregarding taper and allowing for an 11/32-inch saw kerf with size of slab varying with size of log. It is the statute rule for California and is widely used elsewhere on the Pacific Coast.

Old Growth

Forests in which little or no cutting has been done. synonyms: first-growth timber, vir- gin timber.

Overcut

The excess of the log scale actually cut from a tract over the amount estimated before cut- ting.

Overrun

The excess of the amount of lumber actually sawn from logs over the estimated volume or log scale, usually expressed in percent of the log scale volume.

Overstory

Upper crown canopy of a forest.

Peeler

A log used in the manufacture of rotary-cut veneer.

Pulpwood

Wood cut or pre- pared primarily for manufacture into wood pulp, for subsequent manufacture into paper, fiber, board, or other products, depending largely on the species cut and the pulping process. Also, cordwood.

Reforestation

The natural or artificial restocking of an area with forest trees; most commonly used in reference to the latter.

Release Cutting

A cutting of larger individual trees that are over-topping young trees, for the purpose of freeing the young trees to permit them to make better growth.

Reproduction

The process by which a forest or range is renewed, including (1) artificial: renewal by direct seeding or planting (reforestation); and (2) natural: renewal by self-sown seeds, sprouts, rhizomes, etc. (regeneration). Also seedling or saplings of any origin (young growth), the result of reproduction.

Restocking

Applied to an area on which the forest is being reestablished by natural means.

Rosin

The solid residue obtained after distilling off the turpentine from oeorsin. Syn. Colophony. Gum rosin is obtained from slash and longleaf pine trees. Wood rosin is obtained from highly resinous slash and longleaf pine wood (especially stumpwood) by a steam and solvent process.

Rot, Heart

A decay found in standing timber, characteristically confined to the heartwood.

Sapling

A young tree less than 4 in. d.b.h. The minimum size of saplings is usually, though not invariably, placed at 2 in. d.b.h.

Sapwood

The light-colored ring of wood which appears on the outer cross-section of a log. The sapwood is composed of living cells and serves to conduct water and minerals to the tree crown.

Sawtimber

Timber stands in which trees of sawlog size make up most of the volume.

Sawyer

One who controls the carriage and other machinery in sawing logs into lumber.

Scaler

One who determines the volume of logs.

Second-Growth

Timber growth which comes up after removal of the old stand by cutting, fire, or other cause. Typical second-growth conditions may come about in a forest that is untouched so far as lumbering is concerned.

Section

A unit of land measurement, 640 acres or one mile square.

Seedling

A tree grown from seed. The term is restricted to trees smaller than saplings.

Seed Tree

A tree that produces seed; usually trees reserved in a harvesting operation to supply seed for natural reforestation.

Selective Logging or Cutting

The removal of selected mature, large, or diseased trees as single, scattered trees or in small groups of trees. Young trees start in the opening thus made; the result of this type of cutting is an uneven-aged forest.

Site

An area, considered as to its ecological factors with reference to capacity to produce forests or other vegetation: the combination of Internal Revenue Manual biotic, climatic, and soil condition of an area.

Skid

To pull logs from the stump to the skidway, landing, or min.

Slash

Branches, bark, tops, chunks, cull logs, uprooted stumps, and broken or uprooted trees left on the ground after logging; also, large accumulation of debris after wind storm or fire.

Softwood

One of the botanical group of trees that generally have needle or scalelike leaves-the conifers; also, the wood produced by such trees, regardless of texture or density.

Stand

An aggregation of trees or other growth occupying a specific area and sufficiently uniform in composition (species), age, arrangement, and conditions as to be distinguishable from the forest or other growth on adjoining areas.

Stand, Mixed

A stand in which less than 75 percent of the trees in the main crown canopy are of a single species.

Stand, Pure

A stand in which at least 75 percent of the trees in the main crown canopy are of a single species.

Stock, Growing

The sum (in number and volume) of all the trees in a forest.

Stumpage

Standing timber as viewed by an exploiter. Also, the value of the stumpage.

Stump

Wood-Resinous stump (and root) of longleaf or slash pine used for extraction of turpentine and rosin. Syn. Lightwood.

Thinning-Cutting in an immature stand to increase its rate of growth, to foster quality growth, to improve composition, to promote sanitation, to aid in litter decomposition, to obtain greater total yield, and to recover and use material that would be lost otherwise.

T.S.I.

Timber stand improvement-usually applied to inter- mediate cutting.

Underrun -The amount by which the mill cut of merchantable lumber is less than the estimated volume of log scale; usually expressed in per- cent of log scale.

Understory

Trees growing under the overstory.

Uneven-Aged

A term applied to a stand in which there are consider- able differences in age of trees and in which three or more age classes are represented.

Weed Tree

A tree of a species having little or no value.

Yield, Sustained

As applied to a policy, method, or plan of management the term implies continuous production, with the aim of achieving, at the earliest practicable time, an approximate balance between net growth and harvest, either by annual or somewhat longer periods.