DEFINITION OF TERMS USED IN 
FORESTRY AND LOGGING 
Taken from Bulletin 61, U. 8. Forest Service 
Accretion. Increase in diameter or height; distinguished from 
increment, increase in volume. 
Advance Growth. Young trees which have sprung up in acci- 
dental openings in the forest or under the forest cover before 
reproduction cuttings are begun. 
After Growth. Young trees which have sprung up as the result 
of reproduction cuttings. 
i Angle Morror. An instrument for turning angles in subdividing 
and. 
Annual Ring. The layer of wood produced by the diameter 
growth of a tree in one year, as seen on 4 cross section. 
Arboriculture. ‘The growing of trees for any purpose. 
Aspect. The direction toward which a slope faces. The eight 
main points of the compass, N., N.E., E., S.E.,8., S.W., W., N.W. 
are distinguished in forest description. 
Assimilation. In plants the production of organic matter from 
inorganic matter. 
Back Fire. A fire started purposely some distance ahead of a 
fire which is to be fought. The back fire is Intended to burn 
against the wind, so that when the two fires meet, both must go out 
for lack of fuel. 
Ball Planting. A method of transplanting young trees with 
balls or lumps of earth around the roots. 
Basal Area. The area of a cross-section of a tree or the sum of 
such areas. 
Barn Boss. One who has charge of the stables in a logging 
camp. 
Birl. Tocause a floating log to rotate rapidly by treading upon it. 
Blank. An opening in the forest where, from any cause, very 
few or no trees are growing. 
Blaze. To mark, by cutting into trees, the course of a boundary, 
road, trail, etc. 
Board Foot. The contents of a board one foot square and one 
inch thick. The common unit of measure for logs and lumber in 
the United States. 
Board Measure. The standard of lumber measurement, the unit 
of which is the board foot. 
Board Rule. A graduated stick for determining the contents 
of boards. The number of board feet in boards of given widths 
and lengths is shown upon the stick. Often called scale stick. 
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