26 



BULLETIN 139, IT. 8. DEPARTMENT OF AGRICULTURE. 



diameter takes on the average Norway pine soil from 132 to 173 

 years. The average annual growth culminates at about 140 years on 

 all sites, and consequently the rotation which would give the greatest 

 volume production would be one of 140 years. If timber is cut when 

 too young or too old the full productive capacity of the soil is not 

 utilized, especially if the timber is cut clear. When natural repro- 

 duction is sought, particularly with the shelterwood system or from 

 clear cutting, the -stand should be felled if possible while the trees are 

 producing seed prolifically, i. e., between 80 and 130 years. 



Financial returns. — A long rotation means a larger growing stock 

 or forest capital; and in compound interest calculations the interest 

 on this standing timber more than counterbalances the sale value 

 of the additional lumber produced. To illustrate this principle, 

 according to Table 11 a Norway pine stand on Quality II soil 1 yields 

 10,200 board feet after 60 years, 18,600 after 80, 27,400 after 100, and 

 36,700 after 120 years. Table 16 shows the estimated returns on 

 money invested in Norway pine stands when cut after 60, 80, 100, and 

 120 years. Compound interest has been figured at 4 per cent on an 

 initial cost of $15 for land and young growth; taxes and fire protection 

 at 4 cents per acre per year; and stumpage at $20, a very conservative 

 figure, for the years 1973, 1993, and 2017. 



Table 16. — Revenue derived from the conservative management of Norway pine. 



Length 

 rotation 

 (years). 



Yield from thinnings. 



Final yield 

 per acre. 



S15 capital 



at 4 per cent 



compound 



interest. 



Approxima- 

 tion of final 



yield per 

 cent on orig- 

 inal invest- 

 ment. 



60 

 80 

 100 

 120 



1 Estimated thinnings will pay cost of taxes and fire 

 [ protection 



f S204. 00 

 J 372. 00 

 1 548.00 

 I 734. 00 



S157. 79 



345. 74 



757. 57 



1,659.94 



4J- 

 4 + 

 3h+ 

 3i 



Any forecast of future returns necessarily involves some elements 

 of uncertainty. What will be the taxes, fire loss, or unforeseen 

 injuries? Will natural reproduction be wholly or partially success- 

 ful, or a total failure ? What will be the stumpage price ? At what 

 figure should the land and timber be capitalized ? It is certain that 

 in 1950 Norway pine in the United States will bring at least as high 

 a stumpage price as good Scotch pine in France and Germany brings 

 now — from $12 to $24 per thousand board feet — probably 30 to 100 

 per cent more, since it now nets from $10 to $12 on the stump. But 

 even with such an increase, the returns from forest investments ex- 

 tending over long periods of time are certain to be small as com- 

 pared with returns from short-term investments. 



1 All calculations are based on Norway pine growing on sandy soil, because this is the soil to which the tree 

 is naturally adapted. 



