522 



APPENDIX 



If the volume of old wood and that of average wood are to each other as 5 is to 3 

 it is a normal proportion, and if not it is possible to decrease or even the difference by 

 approximate transfers. Then the final volume of old wood plus its growth is divided by 

 one-third the number of years in the rotation. The trees have been calipered by 2-inch 

 diameter classes, commencing with 8 inches, and the volumes figured with the volume 

 table made by M. Algan (No. 11 for the fir and spruce and No. 5 for the pine and broad- 

 leaved trees). 



The following table gives the division by groups and diameter classes: 



The normal proportion should be: 



Old wood 4,557.2 X 5/8 = 2,848.31 . -„ , 

 Average wood 4,557.2 X 3/8 = 1,708.9 J*'*'^'-''- 



For the transfer as prescribed by the method the only change which is justified is 

 by the abundance of overmature timber in the lower diameter classes which means that 

 the yield would be: 



n 2,848.3 „ , . , 

 P = -'-rs — = 59 cubic meters. 

 48 



But on the other hand in this forest the growth cannot be overlooked (see table 

 of growth per cent in the Appendix) and we intend to count that of the old wood during 

 half of the period (conservative estimate of growth at 1 per cent per year). The jdeld 

 will thus become: 



P = 



2,848.3 + jJT, X 24 X 2,848.2 

 48 



= 73.58 or 74 in round figures. 



This yield, which corresponds to 1.62 per cent of the calipered material and is 1.6 

 cubic meters per hectare per year for the forested area, is not too large but fully provides 

 for the small growing stock (and the consequent necessity for economy). 



B.-AREA FELLINGS 



The area to be cut over by improvement cuttings being 43.97 hectares, the yield 

 will be: 



P = —^ = 2.75 hectares. 



10 



