98 Forestry Quarterly. 



jected to statical calculations. When a sale value has arrived, 

 the main question is : Does the stand by its annual increment in 

 volume and value make good the annual expense of administration 

 and interest on its capital value? Is it ripe or not? Any com- 

 pound interest calculations with 3%, the author declares, can 

 give favorable results only as long as the stands are young; in 

 old ones, no art will make the customary 100 year rotation profit- 

 able (except through unusual rise of prices. — Rev.) 



The important point is made that the complicated calculations 

 can be obviated, if, instead, merely the volume increment per 

 cent, is ascertained. If this is found considerably under 3%, the 

 stand is ripe, for the value increment can always (in stands near 

 ripeness) be only a fraction of the volume increment per cent., 

 since value rises only with increase of diameter, and that for a 

 long time in direct relation, in old stands not even to that extent, 

 so that, if the volume per cent, is small, it is nevertheless larger 

 than the value per cent., for the volume depends on the annual 

 ring area. Without volume increment no value increment need 

 be expected. 



Referring to Pressler's index per cent, which "to him who can- 

 not see the forest for the stands" is a convenient means of cal- 



r 



culating value increment [(p= — ; — (a-j-b+c)], the author points 



r 1 1 



out that, if a-f-b+c is to be at least equal to 3% as the expected 

 business per cent., a stand would rarely be able to bring it when 

 over 70 years old. 



But the interest yield of a stand is an entirely different matter 

 from the interest yield from a whole forest, which has other stands 

 following in age class gradations, and is considerably higher than 

 the single stand by itself. Here, in the statics of the forest quite 

 special considerations enter. A forest, managed for sustained 

 (not necessarily annual) yield, has to pay interest on soil value, 

 (s) and value of normal stock (11s), and the latter should be put 

 into the calculation at its real value, which can be secured by sale, 

 (its wrecking value), while usually by forest financiers expec- 

 tation values are introduced. 



What uproar there would be, if in any other business at the an- 

 nual stock taking, raw materials on hand were valued at what 

 might be expected they were worth when placed into manufacture. 

 On the contrary, depreciation is charged, while we foresters in 



