WIND IN THE FOREST. 



75 



is a strong reason why all wounds, such as those made 

 in pruning, should be covered with some substance like 

 paint or tar to exclude the air and the spores it carries. 



WIND IN THE FOREST. 



The effect of wind in the virgin forest is not wholly 

 injurious. Although in many regions it overthrows 

 great numbers of old trees, their removal is usually fol- 



FlG. 69. A windfall in the Olympic FIG. 70. In the same windfall. Olympic 

 Forest Reserve, Washington. Forest Reserve, Washington. 



lowed by a vigorous young growth where the old trees 

 stood. (See PI. XXXIX.) In this way the wind helps to 

 keep the forest full of young and healthy trees. But it 

 also breaks and blows down great numbers of useful 

 growing members of the forest. Much of this windfall 

 occurs among shallow -rooted trees, or where the ground 

 is soft because soaked with water, or where the trees 

 have been weakened by un soundness or fire. Some 



