304 FORESTRY INVESTIGATIONS U. S. DEPARTMENT OF AGRICULTURE. 



I 



The total amount of wood standing iu such a forest at the time of entering upon the work 

 would represent the normal stock the wood capital which must be maintained in order to insure 

 an equal annual yield. The average difference of the amounts of wood standing in any two 

 compartments would represent the normal annual accretion the amount of wood which we are 

 entitled to harvest if we desire to secure a continuous revenue in equal annual amounts. 



If, for example, on our 100 acres managed with a 100-year rotation we found the average 

 annual accretion per acre to be 50 cubic feet, the normal stock the wood capital which must be 

 maintained on the acre would be found by the addition of the contents of all compartments, 



100 x 50 

 as ., ' - x 100 = 250,000 cubic feet. The total normal yield which we are entitled to harvest 



would be represented by the oldest 100 year-old compartment, containing, naturally, 50 x 100 = 

 5,000 cubic feet, or 2 per cent of the normal stock. 



If we were to cut more than this normal yield in any year, we would be trenching on the 

 capital stock and disturb the attempted equalization of income. If we were to cut less, we would 

 unnecessarily accumulate capital in the wood, which would be lying idle and bo for the time 

 unremunerative. 



The conception of a normal forest, with normal stock, normal accretion, normal distribution 

 of age classes, and normal yield, first taught in 1788, is a most useful one, representing au ideal 

 or standard which, although in practice never attained and hardly fully attempted, serves 

 nevertheless as a guide in calculation and working plans. 



In practice the growths of different age may be distributed in compartments of separate 

 areas or they may be distributed iu single trees over the entire area or in groups of trees, and 

 thus many variations of the method may occur, but they are all based on the same principle of 

 maintaining a wood capital distributed over a uumber of age classes in such amounts that the 

 oldest classes always represent what may be cut as the annual or periodic revenue which has 

 accumulated on the entire capital. 



Before even an approach to such ideal and systematic condition can be secured in our virgin 

 woods a long time must elapse the period during which the regulation is gradually perfected, 

 the length of which depends upon the condition of the forest area. If begun with a well stocked 

 virgin forest composed of old and young timber of varying age, the conditions are most favorable, 

 and a systematic management can be instituted in a comparatively short time and with a revenue 

 from the start. 



In any case it requires a strong mind and persistent effort on the part of the owner to 

 accumulate the wood capital, to forego, if need be, present revenue for future profits and to keep 

 capital and interest account iu the growing crop clearly separate, and to abstain from cutting 

 into the wood capital before it has done its full duty when tempting opportunity arises for 

 liquidating it. 



This fact, namely, that a differentiation into fixed capital and interest as represented in the 

 growing timber and the harvest is not readily recognizable that the choice of when to harvest 

 the growth is not based on natural conditions so much as on the opinion and pecuniary interest 

 of the owner, and in addition that there is a long time during which he could if he chose turn the 

 accumulated fixed capital into cash may sometimes, to be sure, appear as an advantage from the 

 standpoint of private industry, but from that of national economy it is fraught with danger, as it 

 is apt to lead to uneconomical use of the forest resource whenever the owner finds himself in 

 dilticulties or sees a temporary advantage in reducing this capital, which can be restituted only 

 by the expenditure of a long time. 



If a farmer sells his cattle, horses, plows, etc., and leaves the, ground to fallow, he may suffer 

 loss individually, but the community does not, or at least only to a slight degree; for while, to 

 be sure, the land docs not produce, it accumulates iu the fallow conditions the elements of 

 fertility, and as a rule is not long allowed to remain unused and can in a season's time be made 

 to produce again. 



On the other hand, if a forest growth is removed without reference to the requirements of a 

 regulated management, namely, without leaving a wood capital of useful kinds upon which a new 

 growth can accumulate, not only is the area of wood production reduced, but in the new spon- 

 taneous growth of undesirable kinds which, as a rule, come iu, an impediment to useful occupation 



