SIZE OF THE AGE CLASSES. 215 



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, 

 if any, = ^ X n. 



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 cuttings, 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 

 left standing, to form the youngest age gradation of the over- 

 wood. That portion should occupy an area = ^, assuming, 



that each age gradation of the overwood occupies the same 

 extent of ground. The area occupied by each age class of 



overwood comes to = y, X r = —. 

 1\ t 



Assuming now, that the youngest overwood class, 1 to /• years 

 old, though still forming part of the underwood, is already 

 counted as belonging to the overwood, then there are t over- 

 wood classes. The latter are not separated according to area, 

 as in the case of clear cutting or coppice, but t gradations are 

 standing mixed on each annual coupe, so that each of the 



latter contains -th part of each overwood class. 



