220 THE NORMAL AGE CLASSES. 



Example : 



Area = 200 acres 

 r = 20 

 n = 5 



The arrangement of age classes would be normal, if 



GI x 5 = 50 acres. 

 20 



r 200 - - n 



//= W " 



r _200 -_ - 



c ~ 



5= 50 " 



Total 200 acres. 



d. Coppice with Standards. 



Here each coupe contains coppice (underwood) and standards 

 (overwood). As far as the underwood is concerned, the 

 arrangement is exactly the same as in the case of simple 



coppice; the annual age gradation is = , and the age class 



= -x . 



r 



The distribution of the overwood, in its normal condition, 

 is somewhat peculiar, which may usefully be explained here, 

 though it is only of a theoretical value. 



In the first place it should be remembered that cutting in 

 both the under- and overwood on the same area must be made 

 at the same time, or rather those in the overwood must be 

 made immediately after the underwood has been cut over, and 

 before the new coppice shoots appear ; hence the rotation R of 

 the overwood must be a multiple of the rotation r of the under- 

 wood, say R = r x t. 



In each annual coupe, when cutting comes round to it, a 

 certain portion of the underwood (chiefly seedling trees), is 



