74 



is applied in exactly the same way as simple coppice, the 

 difference between the two methods— a very great one- 

 being in the selection and reservation of the standards. 

 The exploitable age is calculated for the underwood only 

 and in the same way as in the case of simple coppice. Gene- 

 rally, however, the underwood is felled at a more advanced 

 age, as this procedure tends to lengthen the stems of the re- 

 serves and has other advantages. The possibility is pre- 

 scribed, as in simple coppice, by area, but with the addition 

 of a rule regulating the constitution of the reserve of stand- 

 ards : that is to say, prescribing the number of stems of each 

 species and of one rotation which must be reserved at each 

 exploitation, and specifying the number of older stems to be 

 felled. 



Reservation of standards. — The characteristic of the 

 method lies in the reservation of the standards, and the 

 value and exact constitution of this reserve must be deter- 

 mined with great care. The number and proportion of each 

 class of standards have therefore to be decided. The total 

 number of all classes that can be retained is limited by 

 the fact that the standards should remain isolated after they 

 are first marked and until they are felled. The maximum 

 number per acre is, therefore, the area of one acre divided 

 by the average ai'ea covered by the crown of one mature 

 standard ; but the number that is reserved in practice depends 

 on the species both in the reserve and in the coppice. As 

 regeneration is principally obtained by means of coppice, the 

 cover of the standard trees must not be of a kind to unduly 

 interfere with the development of the stool shoots. Provided 

 no such interference occurs, the greater the number of stand- 

 ards the better ; as this reserve enormously increases both the 

 capital value and the revenue. The value of the coppice, 

 as compared with that of a fully established reserve of stand- 

 ards, is insignificant. 



The following example exhibits the method by which the number of standards 

 can be arrived at, and the influence of the reservation on the revenue and capital value 

 of the forest. It will be assumed that the length of the rotation is 20 years ; that the 

 maximum age up to which the standards can be preserved is 80 years ; and that it has 

 been found by experiment that the cover of the trees of different ages is as follows : — 



Square feet. 

 Trees of one rotation or 20 years, each .... 30 



„ two „ 40 „ 150 



„ three „ 60 „ 400 



,. four „ 80 „ . . . , ,600 



