HOW THE FOREST IS GUARDED 105 



vegetable, as man does to the animal, kingdom; the 

 highest, the most perfect of its type. 



Windy Ice and Snow. Of wind, ice, and frost much 

 could be said. Shallow-rooted species like spruce and 

 lodgepole pine of the Rockies are very subject to wind 

 throw. Snow or sleet storms may cause great damage 

 especially in young stands by bending and breaking 

 the leaders and branches, thus ruining the shape of the 

 tree or at least making fungus infection through broken 

 limbs quite probable. During frosty nights trees may 

 crack open owing to unequal contraction of wood and 

 bark and these ' 'frost ribs'* reduce the value of the 

 lumber. 



Wind, while a friend of the forest and a great help 

 in assisting trees to spread to and hold new areas of 

 land, nevertheless can inflict heavy damage upon the 

 forest communities. Shallow-rooted species like spruce 

 or the lodgepole pine are subject to severe damage 

 from windthrow and only by careful cuttings in such 

 forests can heavy losses be avoided. In the Southern 

 pine forests over which terrific tornadoes from the Gulf 

 of Mexico sweep from time to time, the loss is quite 

 heavy, especially if a forest of long-leaf pine has been 

 " boxed " for turpentine (see Chapter XI), for this box- 

 ing greatly weakens the trunk. Even though the trees 

 are not actually blown down, heavy gales may inflict 

 considerable damage, for if the bark of a tree, which 

 serves as a protective covering like our own skin, is 

 broken by a torn limb, the spores of some tree disease 

 may enter and ultimately cause the death of the tree. 



The method of preventing wind damage is easy to 

 state but often hard to secure. It consists in cutting 

 very lightly in dangerous situations or in forests subject 

 to windthrow. The German foresters sometimes plant 



