QO A MAXUAL OF FORESTRY 



product is produced. This shortening may be as great as twenty- 

 five per cent. For example, if an unthinned stand of pure 

 chestnut is merchantable for ties in forty years, a similar stand 

 which has been properly thinned should have trees of the same 

 size in thirty years. 



By permission of the Connecticut State Forester. 



Fig- 35- Portion of the same stand as shown in Fig. 33. Here a heavy D grade thinning 



was made and a large number of the trees were broken off by the wind. The trees were 



too slender for such a heavy thinning. 



Besides increasing the growth of the individual trees the total 

 yield of the stand is raised, by which is meant that in a single 

 rotation (or given number of years) more material is produced 

 by a thinned stand than by a similar one unthinned. There may 

 be as much as thirty per cent added volume produced by the 



