MAINTENANCE OF A SUSTAINED ANNUAL YIELD. 17 
land 1s kept stocked with trees and is producing valuable material to 
its utmost capacity, whether an equal return is obtained every year 
or not. 
In Kurope a constant, approximately equal, annual income from the 
forest is deemed of first importance, especially on large tracts. There 
is always in such places a steady market which has to be supplied with 
timber. Moreover, a large force of expert foresters and woodsmen is 
employed to care for the forest, and it is extremely desirable that they 
find steady employment. It is desirable also that there be an annual 
income to cover the taxes and interest on the invested capital. 
In order to secure this income the merchantable timber, which could 
be taken out without injuring the forest, is not removed in one year, 
but the cuttings are distributed so that an approximately equal amount 
is cut annually. Thus, if a tract of 100,000 acres were stocked with 
Pine, ripe at 100 years of age, an amount equivalent to the yield of 
1,000 acres would be cut each year. 
The forests in which this provision is most strenuously observed are 
owned by the Government, but it frequently happens that a private 
owner, requiring a large sum of money or a certain quantity of wood at 
once, cuts so heavily into the forest capital that no further income can 
be realized for a considerable length of time. By so doing he does not 
necessarily injure the productive power of the forest, but instead of 
spreading his cuttings over a large number of years, cuts the whole or 
a considerable portion of the area at one time. 
In this country the forests owned by States or the Federal Govern- 
ment should, in very many cases, be managed so as to yield a constant 
annual return just as in Kurope; and the same applies to many large 
lumber or paper companies which own extensive tracts of land and 
which require a certain amount of timber every year to supply their 
mills. But for most private owners the only practical system of man- 
agement is one in which the returns are obtained periodically. 
The two preserves considered in this report are covered with virgin 
forest, in which much of the timber is very old and on the decline. Here, 
as in any original forest, the growth of the trees is just about equalized by 
the loss through decay and wind or other destructive natural agencies. 
The forest is therefore virtually at a standstill, or, in other words, is 
accumulated capital which is producing no interest. If the old trees 
are cut and utilized before they decay and are replaced by young, 
thrifty, growing specimens, the forest becomes at once productive capi- 
tal. It is obvious that it should be placed on this basis as quickly as 
possible, or, in other words, that the old timber should be removed as 
rapidly as it can be marketed. To illustrate the proposition more con- 
eretely, the growth obtained under a system of annual sustained yield 
may be compared with that under the method of intermittent sustained 
yield. If the timber on the tracts discussed in this report were cut to 
10 inches in diameter, it has been calculated that the same returns 
4364—No. 26 z} 
