Periodical Literature. 329 



might be attempted. The economic utilization of stands at the 

 proper moment overrules the narrow sustained yield principle. A 

 broader view is to prevail. 



Since only rarely normal forest is in question, the yearly felling 

 areas are to be so adjusted as to avoid overmature stands to be 

 left or unripe ones to be cut. 



The sustained yield principle of volume and value production is 

 to find expression in regeneration at proper time and in more in- 

 tensive care for increment by thinnings. 



The aim to secure a normal forest condition by proper distri- 

 bution of age classes is to be fostered only as far as it can be done 

 without great economic sacrifices. The maturity of the stand 

 carefully ascertained is to decide primarily whether it is to be cut 

 or not. The budget allotment for the future if age classes are 

 very abnormal, is to give merely an approximate idea of the 

 progress of felling without being binding for the future. Graphic 

 methods of giving insight into the actual status and changes are to 

 be used. 



Freedom is left to determine even the annual budgets from year 

 on the basis but independently of the periodic felling plan, leaving 

 it in the discretion of the administration to anticipate or delay 

 fellings according to market conditions. 



The economic principle finds clearest expression in the motives 

 by which the rotation and the maturity of the single stand are 

 determined. 



While formerly the maximum volume production alone was the 

 basis of the rotation, now, without giving up the desire to produce 

 most desired wood quality, the maximum forest rent with reason- 

 able interest on the invested capital, soil and stock, is to be also 

 in part determining, as far as other interests or protective func- 

 tions do not interfere. 



Extensive investigations into growth relations and value pro- 

 duction of younger as well as old stands are to be the basis, and 

 various rotations are to be figured and chosen from. 



The time of the minimum forest rent is to be the upper limit of 

 the rotation while saleability of the produced grades or sizes is 

 the lowest limit; an investigation into the production of various 

 assortments or sizes at different ages must therefore precede. 

 The progress of the quality increment is another criterion, mak- 

 ing a difference between such species as spruce and fir where the 



