106 THE BOOK OF FORESTRY 



a belt or "wind mantle" of stout strong trees around 

 a forest of shallow-rooted individuals which serves to 

 break the force of the wind. If they find it necessary 

 to remove trees from the interior of such a piece of 

 woodland they remove only a few at a time in order 

 that the others may become accustomed to the greater 

 force of the wind and send their roots deeper into the 

 earth to withstand the heavy buffets. 



Ice and snow often injure forests by collecting upon 

 the trunks of branches, and weighting them down until 

 they break. Young growth of any kind or hardwoods 

 before shedding their leaves are especially subject to 

 damage during such storms. These injuries are practi- 

 cally impossible to avoid but are fortunately quite rare. 



From the above description it will be seen that the 

 life of a tree in a forest community is not free from 

 peril. Where children in a town or city run the risk 

 of measles or chickenpox, the little trees die in large 

 numbers from lack of food, moisture and light. The 

 death rate in the forest is very high in youth just as 

 with babies in large cities. During middle age the 

 forest appears quite healthy with only an occasional 

 loss from lightning or from injury of some sort. As 

 old age approaches the trees again die quite rapidly and 

 the fungi and bacteria decompose them into humus 

 which enriches the ground for the young forest which 

 has started beneath the old one. 



Only by close study and careful watching can the 

 death rate of the forest be kept within bounds and 

 the protection of the forest against harmful agencies 

 is an important part of the forester's work. 



