DEFINITION OF TERMS 305 
Merchantable Volume. The total volume of that portion of the 
tree which can be used under given conditions. 
Mixed Forest. Forest composed of two or more species. 
Monecious. Both male and female flowers borne on the same 
plant (e g., black walnut.) _ 
Mulch. Any loose material that protects the soil from frost 
or evaporation. 
Muskeg. A term commonly applied to sphagnum swamps by the 
Indians and woodsmen of the Northern States. 
Natronal Forest. A forest which is the property of the United 
States. In addition to recreation features, timber is sold from the 
N ational Forests, grazing is allowed, as well as agricultural settle- 
ment. 
National Park. A tract of Government land withdrawn by special 
act of Congress from settlement, occupancy or sale, under the laws 
of the United States, for the benefit and enjoyment of the people. 
Nurse. A tree which fosters the growth of another in youth. 
Nursery. An establishment for the raising of plants. 
Overmature Forest. Forest in which, as the result of age, growth 
has almost entirely ceased, and decay and deterioration have begun. 
Parasite. A plant or animal that lives upon and obtains its food 
from other living plants or animals. 
Patch Sowing. Sowing forest seed in spots. 
Pecky. A term applied to an unsoundness; most common in 
bald cypress. . 
Pike Pole. A piked pole, 12 to 20 feet long, used in river driving. 
Pitch Pocket. A cavity in wood filled with resin. 
Planting Site. An area which is to be artificially stocked with 
forest growth. 
Pole. <A tree from 4 to 12 inches in diameter, breasthigh. A 
small pole is a tree from 4 to 8 inches, breasthigh. <A large pole 
is a tree from 8 to 12 inches in diameter, breasthigh. 
Pollard. 'To invite the production of shoots at the top of a tree 
by cutting back the crown. ; ; 
_Present Yield. The amount of wood at present contained in 
given trees upon a given area. 
Protection Forest. A forest whose chief value is to regulate 
stream flow, prevent erosion, hold shifting sand or exert any other 
indirect beneficial effect. 
Pruning. The removal of branches from standing trees by 
natural or artificial means. The clearing of the stem through the 
death and fall of branches for want of light is known as natural 
pruning. When living branches are removed by cutting them close 
to the stem the operation is known as green pruning; when it Is 
confined to dead branches, as dry pruning. _ 
Puddle. To dip the roots of young trees in thin mud. Before 
heeling trees in the trench on a planting site their roots are usually 
* puddled.” ; 
Pure Forest. Forest composed of trees of one species. In prac- 
tice, a forest in which 80 per cent of the trees are of one species. 
Quarter Sawing. Origmally meant sawing along the radius of 
a log to expose the medullary rays and add to the beauty of the 
