88 FOREST VAI,UATION 



pound interest discussions into the business of raising timber, on 

 the other, have prevented the two schools from coming together. 



Of late there is a better understanding, it is evident to all that 

 the forest must produce good marketable stuff, and that if the for- 

 est can not make more than 3% in doing this, there is little use of 

 introducing 5% in the formulae. On the other hand it is clear that 

 the planting of small saplings at $50 per acre and holding old stands 

 which have not earned 1% for a quarter of a century are mistakes 

 to be avoided. 



With an interest rate of 2%, the rotation of highest Se, the 

 financial rotation coincides closely with the technical rotation or 

 that producing the timber most in demand and now in actual use. 



A few figures may serve to ilhistrate this : 



Ordinary rotations for regular timber forest in central Europe 

 run about as follows : 



Pine and spruce 80 to 100 years 



Balsam and beech 100 to 120 years 



Oak ISO to 200 years 



For spruce in Germany as seen from the tables under discussion 

 of Se, the maximum Se, and therfore p,, for site I-IV, on a basis 

 of 2% comes at 70-80 years, at a 3% basis in 60-70 years. 



For pine in Germany on sites I-IV, on a basis of 2% as well as 

 3% the maximum Se comes at 60-70 years. 



For balsam in Germany according to Lorey, maximum Se for 

 sites II-III on a basis of 2^4% comes at lOO-iTO years, which ac- 

 cording to Lorey is also the preferable age from the standpoint of 

 silviculture. 



For oak in Germany, according to Schwappach, a rate of 2% 

 puts the maximum Se at 120- 130 years, but here the modem tech- 

 nical requirements demand a rotation of 160 or over. 



For beech in Germany the maximum Se on 2% basis for sites 

 I-IV comes at about 80 years, a rotation which does not produce 

 satisfactory saw timber and similar goods. 



Poor sites such as poor sands in the pinen,' of north Germany 

 are unable with any rotation to make a 3% income under the ordi- 

 nary conditions of German management, and barely work out 2% 

 for land and costs. That the rotation can be shortened by planting 

 good transplants and by an energetic practice of thinning is evi- 

 dent. In addition, the modern means of manufacture have made it 

 possible to use smaller sizes and so work toward shorter rotations 

 in the forest. 



