240 



WOOD AND FOREST. 



forests. They, together with goats and sheep, Figs. 87 and 88, deer 

 and cattle, work harm by trampling and browsing. Browsing destroys 

 the tender shoots, especially of deciduous trees, but trampling en- 

 tirely kills out the seedlings. The cutting up of the soil by the sharp 



cleft hoofs injures the forest 

 floor, by pulverizing it and al- 

 lowing it to be readily washed 

 away by storms until defores- 

 tation may result, as was the 

 case in France after the Eevo- 

 lution. It has cost the French 

 people from thirty to forty 

 million dollars to repair the 

 damage begun by the sheep. In 



New Mexico, u.s. Forest Service. this country, this matter has 



become a very serious one on 



the Pacific Coast, where there are enormous flocks of sheep, and there- 

 fore the government is trying to regulate the grazing on public lands 

 there, especially on steep slopes, where erosion takes place rapidly. 1 



The most destructive animal enemies of the forest are the insects. 

 The average annual loss of trees in the United States from this cause 

 alone has been estimated to be one hundred million dollars. 



Fig.88. Sheep Grazing- in Forest, Idaho. U. S. Forest Service. 



Insects have two objects in their attack on trees, one is to obtain 

 food, as when they are in the larval stage, and the other is to provide 

 for offspring, as do certain beetles. 



1 The evils of grazing are increased by the fact that fires are sometimes 

 started intentionally in order to increase the area of grazing land. 



