190 THE THEORY AND PRACTICE OF WORKING PLANS 



cutting area those areas for the cutting in the ensuing decade 

 which he deems most expedient for reasons of silviculture, 

 cutting sequence (cutting series), administration, and maturity. 



If the sum of the stands so chosen greatly exceeds the 

 allowed ten-year cutting area, those stands are to be excluded 

 and saved for a future decade whose growth is the most thrifty 

 and valuable. 



By dividing the entire periodic cutting area into the mer- 

 chantable volume thereon, the cut per acre is obtained. This 

 multiphed by the annual cutting area gives the allowed annual 

 cut in volume. 



In coppice with preponderating standards and in selection 

 forest regulation by area is not desirable, since it does not do 

 justice to the complicated and varying needs of the tree in such 

 uneven-aged stands.* In such stands the cut for the ensuing 

 working period consists of all trees above a fixed diameter 

 (determined as stated above), in addition the volume of those 

 trees which during the next ten years will reach this diameter 

 and such as have to be removed for silvicultural reasons (" wolf- 

 trees," " snobs," etc.). In the case of coppice with standards 

 there is, also, of course, the A'olume of the coppice. A tenth of 

 the total amount for the next decade is the allowed annual 

 cut, this is checked by the current annual increment per cent — 

 the sum of the current annual increment per cents of each diam- 

 eter class, and by the result of past cuttings. Order and prog- 

 ress of the cuttings are insured by the observance of a cutting 

 cycle. 



The pro^'isions for renewal of the working plan are as fol- 

 lows: Each plan is drawm up for a period of twenty years, but 

 at the end of the first decade an intermediate revision — or 

 review — is had; at the end of the twenty years a complete 

 revision is had resulting in a new plan. Exceptional circum- 

 stances may necessitate a complete revision before that time, 

 as when unforeseen changes have occurred in the very founda- 



* Where the undergrowth is too dense to permit calipering, it may be neces- 

 sary to regulate the cut, even of coppice with standards, by area. 



