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JOURNAL OF FORESTRY 



ditions, would more than pay for the operation. For simplicity all 

 species yielding saw timber were thrown together, but the per cent of 

 the total represented by white pine is shown in each case in parenthesis. 

 The figures show that the final yield of saw timber, at least on sandy 

 soil, can be nearly tripled by a release cutting made about the twentieth 

 year, and that thereafter the possibility of improving the final yield 

 grows rapidly less. The figures do not indicate, however, what may be 

 expected from proper cuttings made before the twentieth year, although 



Fig. 3. — Bven-aged sapling stand tivo years after second weeding 

 Species mainly white ash, red oak, and white pine. Forest weeds finally eliminated. 



the obvious presumption is that an earlier cutting would produce a still 

 better result, especially on the better soils. In stands less than twenty 

 years old, where the effect of competition in height growth has not so 

 completely declared itself, it is very difficult to make a crown classifica- 

 tion on which a specific calculation of yield can safely be based. Never- 

 theless, it is possible to get a definite idea of the possibilities of earlier 

 forest weeding by reference to operations and experiments carried out 

 in young growth less than ten years old. 



The destructive competition that takes place in a young mixed stand 

 is not solely a matter of worthless species against desirable species or 



