THE YIELD OF A FOEEST. 



17 



standing to mature. That time is found by studying 

 the rate of growth in diameter. 



This method of determining the yield by area is much 

 the most practicable of the three for the forests of the 

 United States, and in general it is the simplest and 

 most widely useful of all, because it does away with the 



FIG. 9. A forest from which more than the yield is being taken. Big Trees in 

 the Sierra Nevada Mountains, California. 



difficult task of determining the yearly increase in 

 wood. 



The objects in handling forests are so various that 

 sometimes no single one of these methods is satisfac- 

 tory, and then combinations of them are of great use. 



