344 Forestry Quarterly 



that if then the annual increment (volume or value) is used, the 

 stock remains unchanged, and the age classes establish themselves 

 (Heyer's method?). 



If the question were to be discussed, what changes in existing 

 condition or management of a given forest might be immediately 

 (not in future) desirable in order to secure a larger and more 

 valuable increment, it must not be overlooked that the owner is 

 rarely in position practically to undertake anything affecting pres- 

 ent conditions to radically change the stock. Every owner must 

 organize his forest under the given stock conditions, and with 

 present market conditions in view : speculations for the future 

 will bring mostly disappointments. 



An ordinary yield table, giving contents of main and side stand 

 and the mean periodic increment, furnishes all necessary basis 

 for regulating a forest. From this, for various rotations, the 

 annual yields for the working block and the corresponding nor- 

 mal stock are figured, and finally the age of economic maturity 

 as defined above ascertained. If x is the chosen rotation, I ^ 

 the corresponding total increment per acre, and 5„ the normal 



stock per acre, then the equation c —l^ holds, and any stand, 



" 2 

 the yield of which shows this amount, has attained maturity. All 

 older stands of a working section to which the rotation x is to 

 apply are also to be considered ready for the axe, since their 

 yield exceeds the minimum ; all younger stands remaining below 



the minimum -^ are immature. These stands are also not to 

 2 



be placed in calculation with their present yield, but with the 

 product of the mean annual total increment of the ripe stand 

 into their age (Heyer's method?). 



If instead of the mean annual total increment, the mean 

 felling age increment is used, the age of maturity coincides with 

 the age of half the rotation, while with the mean annual total 

 increment, the age of maturity lies mostly 10 and more years 

 above half the rotation. 



The above regulation may, of course, be based on volumes or 

 values. 



[We leave to our readers to discover the flaws in the radical 



position taken by the author. — Rev.] 



Uber die Beziehungen zwischen Waldwertrechnung und Waldertragsregelung. 

 Zeitschrift fiir Forst-und Jagdwesen, December 1915, pp. 756-62. 



