484 APPENDIX 



wise to only 0.5 per cent the stands, if they remain uncut, increase in value in a larger 



39 000 

 ratio than is indicated by the increase in age. The numerator of the fraction ' , 



which represents the mean annual value increment, at that per cent increases in the 

 ratio of 100 to 101, while the denomination becomes larger only in the ratio of 210 to 211. 

 From the standpoint of the greatest net forest revenue the stands under consideration 

 have been properly managed; if the standard for their management, however, is to be 

 the greatest mean value increment, they should not be cut yet but should be retained 

 as capital until the per cent of volume and value increments correspond approximately 

 to the ratio between the annual increase in age and the present age. 



Of course, as soon as it is demanded in forestry that the remaining growing stock shall 

 yield interest, even at only a moderate per cent, the factors concerned in the economical 

 production of stands are entirely changed. From the standpoint of the theory of net 

 profits on the land which this suggestion is equivalent to, it would have been impossible 

 to grow such stands as the mature oak we are discussing, or even the French fir stands in 

 the Vosges. Accurate citations as to the time and severity of thinnings, the amount of 

 growing stock, and the length of the rotation cannot be made without detailed computa- 

 tions and voluminous material. The opinion presented can, however, readily be proved 

 as one of general acceptance. 



In connection with the determination of the results of applying the theory of net in- 

 come to oak high forest with long rotation period it should be mentioned that for this 

 only moderate rates of interest (2.5 to 3 per cent) are to be used. It should be borne in 

 mind, in addition, that under permanent management, the forest and its contained 

 growing stock constitute a uniform entity. A part of the growing stock is also embraced 

 within the younger and the middle-aged stands; hence the rate of interest on the growing 

 stock may be sufficient even though that of the oldest age classes of a given working 

 unit have fallen below that required on the entire capital. But even by applying this 

 conservative supposition the stands under discussion would be unable to satisfy the 

 demands for payment of interest. In contrast to management for the greatest mean 

 value increment which would leave those stands to grow for a yet longer period, the 

 theory of net income from the land requires that they be thinned and opened up earlier 

 and more heavily. The number of trees per hectare must be reduced to a greater extent 

 in the course of gradual thinnings so that at the age of 200 years only about half (40 

 instead of 80 per acre) shall be present. As a result of such management the working 

 capital will be diminished, the increment of individual trees is increased, and the interest 

 influenced favorably by both. Under such conditions and with the favorable site 

 factors present the miscellaneous stock, upon the production of which such importance is 

 rightly attached in administering the French State forests, could be raised with rotation 

 periods of 160 to 180 years. 



(d) OWNERSHIP OF THE LAND 



The conditions of property ownership have hitherto had a great influence in France 

 in deciding upon the age of maturity and the characteristic form of forest which shall be 

 regarded as normal and whose establishment shall be sought. Nowhere are the differ- 

 ences in the character of the forest, according to the ownership of the land, more clearly 

 emphasized than in France. Even in the literature this is stated definitely, though not 

 without exaggeration. Tassy says in reference to this: "It is not to be hoped that pri- 

 vate owners will ever find it to their interests to manage their forests as high forest. For 

 in such a case not only will the rate of interest on the money fall off considerably, but 

 which are conditions far more difficult of attainment, the impossibility of predicting 

 future conditions, immediate needs, the uncertainty of the immediate future, would all 



