81 



advanced age, than in simple coppice, as this pTOcedurQ 

 tends to lengthen the stems of tbe reserves and has other 

 advantaiges^ The possibility is prescribed, as in simple 

 coppice, by area, but with the addition of a rule regulating 

 the constitution of the reserve of standards : 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. 



3. Reservation of .standards.— The characteristic of the 

 method lies in the reservation of the standards, and the value 

 and exact constitution of this reserve niust be deterfnihed 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 

 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 

 area 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 "standards the 

 better ; as this reserve enormously increases both the capital 

 value and the revenue. Tbe value of the coppice, as com- 

 pared with that of a fully established reserve of standards, is 

 insignificant. 



The folloning example ezhibitg the method by which the number of standards 

 can be arrived at, and the influence of the reserTation on the revenue and capital Tains 

 of the foreat. It will be assumed that the lengtb of tbe rotation.is 20 years ; that tbe 

 masimnm 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 difierent ages is as follows ;— 



Sqnare feet. 



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



„ two rotations 40 „ . . • . ISO 



„ three „ 60 „ . • . . 400 



„ four „ 80 „ .... 600 



The nnmber of pqnara feet in one acre is 43,560 ; and as -^55-= 72, a crop of 



that number of trees of 80 years old would form a complete crop on one acre. Let us 

 suppose th»t, in view of this and from observation on the spot, it is decided that the 

 total number of standards per acre should not exceed about 40 trees, and that trees of 

 from 60 to 80 jears old hare attained the most useful dimensions they can reach 

 while snund; aUo that it has been estimated that only about a third of the stems 

 firAi reserved can be again reserved with advantage at the second rotation, and so as 

 regards these again. There shoald, therefore, be reserved at each exploitation— 



27 standards of one rotation. 

 9 „ „ two rotations. 



3 „ „ three „ 



