548 JOURNAL OF FORESTRY 



''fellings." If the cut equals, for example, 4 per cent of the stand, with 

 a cutting cycle of five years, one will have to remove 20 per cent of the 

 volume ; with a cutting cycle of 10 years, 40 per cent must be removed, 

 and with a cutting cycle of 15 years 60 per cent, which certainly would 

 be far too much from the cultural viewpoint. A short cutting cycle 

 permits (on the other hand) the removal of diseased and dying trees 

 before they have lost too much in value. We cannot do better (in 

 treating this subject) than to quote M. H. Biollet, forest inspector at 

 Couvet, Switzerland : 



"Who will contend," he said, "that light and frequent cuttings are 

 more in conformity with physiological laws and are better for the forest 

 or for the soil than operations at long intervals and, moreover, of more 

 moment than the intervals wider apart? If it is desired to have trees 

 well formed, with homogeneous wood, with regular texture, avoid cut- 

 ting for (rapid) growth; it is necessary that the transformation should 

 be slow and evenly graduated." 



REVISIONS 



The forest is continually changing and growing. In its evolution 

 . . . the forester . . . must make new stock estimates of the 

 entire volume. This stock survey, compared with former ones, will 

 permit the determination of the increment and a check on the regula- 

 tion, a revision of all the calculations enumerated in this study and the 

 establishment, if necessary, from new management data, of a new 

 yield. In selection forests an inventory may profitably be made before 

 each felling, or every five or six years. 



CONCLUSIONS 



As has been seen, the method proposed is based on the normal spac- 

 ing of the boles ; it does not imply in itself any particular form of stand. 

 It can be applied equally well to a fir stand, whether selection or even- 

 aged. In the regular fir stand the trees of each age class, figuring from 

 a normal-yield table, will be grouped together. In the selection fir 

 forest, these trees will be mixed irregularly. 



In both cases it is clear the aim to follow is to have such a condition 

 that the largest volume will be produced with the smallest possible 

 growing stock; it is known that the means of arriving at this condition 

 and of keeping it so is by normal spacing of the boles. The method 

 gives up completely the idea of rotation, even as a means of fixing the 

 yield. It tends to an assuredly intensive silviculture and responds to 



