A NATIONAL PLAN FOR AMERICAN FORESTRY 907 



Within the past decade the application of production engineering 

 technic to the study of logging and sawmilling practice has revealed 

 that cutting operations in this country have been removing vast 

 numbers of small trees, not alone to the severe impairment of the 

 future productivity of the forest but also at a very heavy present loss. 

 Table 4 shows results of such studies in six widely separated localities 

 and in stands of different species. These studies were carried on 

 entirely independently by different investigators, but all the results 

 agree in principle. For each species cut for the general lumber 

 industry there is a diameter limit below which cutting results in definite 

 loss. Since stumpage is not charged as a cost in these studies, the 

 data in the table mean that the trees below this diameter limit not 

 only yielded no stumpage return from cutting but also caused a 

 definite cash operating loss. All tree diameters above the upper 

 heavy line drawn horizontally through the table are in this losing 

 category. It is a mistake to cut trees even to this limit, for the rea- 

 son that most of the sound growing trees capable of yielding only 

 low returns from cutting now are more valuable for holding. It can 

 be recommended then that as a general rule only trees of the sizes 

 shown below the lower heavy line should be cut. The exceptions 

 to this rule are trees of all sizes that are not of form and condition to 

 grow further in value but on which something can be realized if they 

 are cut at once. The trees of the sizes shown above the lower heavy 

 line constitute the forest capital left after each cutting, which is 

 responsible for the future earnings of the forest. 



APPLICATION OF THE SELECTIVE CUTTING SYSTEM IN THE UNITED STATES 



For more than a century European foresters have carried on cut- 

 tings on the principle of so selecting the trees to be cut that the 

 residual stand will consist of trees capable of further growth in volume 

 and value. In other words, they have managed cuttings in a manner 

 to improve the stands. American foresters have advised a similar 

 practice, but this procedure has seldom been followed on private lands 

 in the United States. 



