70 



A PRIMER OF FORESTRY. 



being eateu, or broadleaf trees, and so more likely to 

 be devoured, they should be protected from pasturing 

 auimals uutil they are large enough to be out of danger. 



GRAZING AND FIRE. 



Grazing in the forest does harm in three ways. First, 

 it is a fertile cause of forest fires. (See figs. G4-(3G and 

 PI. XXXV.) Burning the soil cover of grass and other 



Fig. 65. — A forest of Lodgepole Pine in a region used for grazing. Bighorn 



Forest Reserve, "Wyoming. 



]dants improves the grazing, either permanently, by 

 destroying the forest and so extending the area of pas- 

 turage, or temporarily, by improving the quality of the 

 feed. For one or the other of these objects, but chiefly 

 for the latter, vast areas are annually burned over in 

 nearly every part of the United States where trees grow. 

 The great majority of these fires do not kill the old 

 trees, but the harm they do the forest and, eventually. 



