•112 Forestry Quarterly. 



great variety of opinion as to what to count to main or inter- 

 mediary stand, and to likely underestimates. 



The increment, however, is to be ascertained on both final and 

 intermediary yield; namely a total average increment for the 

 rotation under normal stock conditions, and a current increment 

 for the first decade. Also the average felling age increment for 

 each management class is to be ascertained by use of the tables 

 checked by sample areas. These latter are to be kept permanent, 

 so that the progress of increment can be studied. 



Age class conditions according to area and volume, and com- 

 parison with normality are to be specially looked after, but the 

 normal stock is to be figured from the yield tables, not as hitherto 

 according to formula. 



The forest capital is to be ascertained for comparison with the 

 annual net yield according to most modern valuation methods. 

 Stands up to 40 years of age are to be calculated at actual cost 

 value, older stands at sale values ; soil values as soilrent values 

 checked by actual sale values. The prescribed interest rate is 

 2.5%. While — quite properly — the management is not to be 

 based upon a strict soilrent calculation, the principle is laid down, 

 that the aim of the management is to be to secure the highest 

 forest net yield possible under sustained yield management be- 

 sides at the same time attempting to secure an adequate interest 

 rate on the capital involved in the management. 



Hence, stands are to be considered ripe, when the periodic 

 increment of the forest net yield begins to decline considerably, 

 and to determine this rotation, forest net yields and average in- 

 terest calculations are to be made, also soil expectancy values with 

 interest rates of 1.5 and 3% are to be calculated to exhibit the 

 time of culmination. 



If then the rotation based on the forest rent and the financial 

 rotation based on an "adequate" (if, no special considerations, 

 2.5%) interest rate coincide, it is accepted. If not, then an in- 

 vestigation is to be made to see by what changes in management 

 coincidence can be secured. 



In this way, for the first time, at least a financial check is in- 

 troduced. 



Where the determination of the rotation in this way leaves 

 uncertainty, the index per cent., or with very valuable stands only 

 the value increment per cent., is to be used for judging ripeness. 



