71 



regeneration of the crops cannot be undertaken . Theoretically 

 the length of the preparatory period should be equal to tlie 

 exploitable age ; but, in practice, a shorter period is generally 

 adopted, and the attainment of the desired end is hastened 

 by judicious improvement fellings, etc. The object is to 

 obtain a crop normally constituted according to the method 

 of treatment adopted and containing a regularly graduated 

 series of age-classes. Such a forest growing stock can gener- 

 ally be secured in a shorter time than, that represented by 

 the exploitable age. 



Tbns, the irregularly crnstituted or ppice of 500 aorPB, already taken as an example, 

 wlicli it is wished to exploit at 20 years, ron!d only be ccnstitoted, according to 

 the normal type, by making dnriug the next 20 years 20 successive fellings of 25 

 acres in extent esch yesr. After the lapse of 20 years there would bo on the ground 

 twenty Bge-:!lafsei', each occupying the same area and differing in age by one year. 

 In practice, however, such a treatment is rot necessary, and it is merely sought to 

 properly constitute the capital as soon as possible. In the case of coppice exploited 

 at a low age, the pruvisioial pericd i-°, however, generally equal in duration to tho 

 exploitable age. 



e. Prescribing the fellinp.— The general working scheme is 

 merely an outline ; because detailed operations could not, in 

 most cases, be prescribed with any degree of certainty for 

 so long a time in advanca as the exploitable age or the 

 duration of the preparatory period. It is, therefore, neces- 

 sary to regulate in a special statement and for a shorter 

 time — 



(i) the duration of the operations ; 



(ii) the area to be operated on in. each year or period ; 

 (iii) the order to be followed in. the fellings ; 

 (iv) the nature of the fellings ; 



(v) "the material to be removed. 



(*) Period for which fellings are prescribed. — The 

 interval during which the fellings should be prescribed 

 depends on the general working ■ scheme, as provisionally 

 modified^ and on the nature of the plan. 'Ihe interval should 

 not be too long, as the longer the more likely is it that 

 unforeseen events'may necessitate its modification ; and this 

 may prove inconvenient. As a general rule, the term should 

 be long enough to enable the prescribed fellings to pass once 

 over the whole area to be worked, or to complete any definite 

 series of operatiors already undertaken. That is to say, the 

 fellings v»puld generally be prescribed for one whole felling 

 rotation in the case of coppice and selection -worked forests, 

 for one period in the method of successive fellings, etc. In 

 Europe longer periods than 10 or 15 years are seldom 



