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 beeome accustomed to the greater 
force of the wind and send their roots deeper into the 
earth to withstand the heavy buffets. 
Tee 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 inpossible 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. 
