2IO ECONOMICS OF FORESTRY. 



misjudges the value of the limitation as far as 

 silvicultural results, the perpetuation of a valuable 

 forest, are concerned. In fact, from this last and 

 most important point of view it might be wiser, 

 under certain conditions, to impose upon the owner 

 the cutting out of everything below a given diam- 

 eter. For, as we have seen in nature's mixed 

 forest, valuable timber and weed trees are growing 

 side by side ; the diameter restriction indiscrimi- 

 nately applied might prevent the removal of the 

 objectionable portion, the weed growth, putting a 

 premium upon the decimation of the more valuable 

 portion. Without silviculture, i.e. attention to sys- 

 tematic reproduction, a diameter restriction is of 

 little value. With silviculture it is not necessary, for 

 even the entire removal of the whole crop — denu- 

 dation — and its replacement by planting or sowing 

 would accomplish the object sought, namely, the 

 continuity of the forest, and in many cases might 

 be preferable to other methods. Arbitrary diameter 

 restriction is merely a device to prevent a too 

 rapid reduction of a valuable species before the 

 time when its reestablishment by silvicultural 

 methods becomes practicable. Otherwise a diam- 

 eter limitation has justification only when it can 

 be shown that it is more profitable and in the 

 owner's interest to leave trees below the diameter 

 limit uncut for a longer time. 



In other words, the determination of the rotation 

 or felling age, or of the felling size, is largely a 



