DEFINITION OF TERMS 303 
wood harvested for any purpose; minor products include all forest 
products except wood. 
Forest Protection. The safeguarding of the forest against any 
damage caused by its own growth. 
Forestry. The raising (and utilization) of repeated crops of timber 
from non-agricultural soils. The main branches of forestry are 
forest policy, silviculture, forest management, forest protection and 
forest utilization. 
Forest Type. A forest or a part of a forest possessing distinctive 
characteristics of composition or habit of growth. 
Forest Utilization. ‘The most profitable use of forest products, 
including lumbering, the various wood-using industries such as the 
wood pulp, wood tannin, cooperage, veneer, excelsior, and similar 
industries and the uses to which our woods are put. 
Form Factor. Theratio, expressed decimally, between the volume 
of a tree, or portion of a tree, and of a cylinder or the same height 
and diameter. 
Germination. "The process by which a seed or spore gives rise 
to a new and independent plant. 
Girdling. The act of cutting through the inner bark and sapwood 
to cut off the circulation of the sap. Practiced in the Southern 
Appalachians as a means of quickly clearing agricultural land. 
ound Cover. All small plants growing in a forest, except 
young trees; such as ferns, mosses, grasses and weeds. 
Hardwood. A broadleafed, or dicotyledonous, tree. 
Haul. In logging, the distance and route over which teams 
must go between two given points, as between the yard or skidway 
and the landing. 
Head Driver. An expert river driver who during the drive is 
stationed at a point where a jam is feared. Head drivers usually 
work in pairs. 
Head Faller. The chicf of a crew of fallers. 
Heel In, To. To store young trees for planting by laying them 
against the side of a trench and covering the roots with earth. 
Height Growth. ‘The increase in heights of trees. 
Height Measure. An instrument for measuring the height of 
a, tree. 
Humus. Decomposed organic matter in and on the surface of 
the soil. 
Hypsometer. An instrument for taking heights of trees. 
Ice a Road, To. To sprinkle water on a logging road so that a 
coating of ice may form, thus facilitating the hauling of logs. 
Improvement Thinning. Usually the first thinning made when a 
forest is put under management, to prepare it for the application 
of a regular system. 
Increment. The volume or value of wood produced during a 
given period by the growth of a tree or of a stand. Three kinds 
of increment are distinguished: Volume increment is the increase 
in volume of a tree or stand; quality increment is the increase in 
value per unit of volume; price increment is the increase resulting 
from an increase in the price of forest products independent of 
aualitv increment. 
