336 DETERMINATION OF THE YIELD. 



a proper arrangement of the age gradations, more especially 

 the requirements of transport. 



If a coppice forest is so extensive that it is desirable to cut 

 in several places in each year, while the rotation remains the 

 same throughout equal to r, it is first divided into a corre- 

 sponding number of working sections, and then each of the 

 latter into r annual coupes. 



If these several working sections are treated under different 

 rotations, a separate account must be kept for each ; for 

 instance, oak coppice worked for bark alongside of coppice of 

 an entirely different nature, such as alder coppice. 



In order to obtain as far as practicable equal annual returns, 

 the calculations should be made with reduced areas, though 

 it is not necessary to go into very minute calculations. The 

 different coupes should be marked on the ground. 



The final yield is ascertained by estimating the returns 

 which may be expected from the areas to be cut over during 

 the working plan period. 



Intermediate returns consist of all cuttings made on areas 

 not put down for cutting over during the working plan period. 

 As a rule they are not of much importance. Their amount 

 should be estimated according to local average figures. 



1). Coppice with Standards. 



The first step is to lay down a division into annual coupes 

 in the same way as for simple coppice ; this division regulates 

 the yield of the underwood. 



The normal yield in overwood, as given on page 243, can 

 only serve as a very general guide ; in reality, the management 

 of the overwood partakes of the character of forest gardening 

 or selection fellings. Hence this sylvicultural system offers 

 considerable difficulties if the areas are extensive. Any but 

 a very elastic method of fixing the yield would be out of 

 place. 



The determination of the final yield in overwood is effected 

 by estimating, on the areas to be dealt with during the working 



