50 BULLETIN 871, U. S. DEPARTMENT OP AGRICULTURE. 
On the Xational Forests a great deal can be accomplished in the 
way of control of mechanical injuries resulting in wounds through 
which the dry-rot fungus can enter. As has been shown, fire is by 
far the most important factor in promoting dry-rot, with knots, the 
nearest competitor, of relatively far less importance both in regard 
to the number and seriousness of resulting infections. 
Fire can be, in a great measure, directly controlled. The ever- 
increasing efficiency of the fire-protection methods on the Xational 
Forests, with the continual reduction in the number of damaging 
fires, speaks for itself. Certain private holdings are also protected 
from fire, either incidentally by falling within the boundaries of a 
Xational Forest or through a protection system handled on a coop- 
erative basis by the United States Forest Service. Knots, of course, 
can not be controlled. Xatural pruning, with the continual produc- 
tion of dead branches, which later break off, is inevitable in any 
forest. However, it may be expected that infections through this 
source will become increasingly fewer as time goes on, in proportion 
to the reduction in the number of fire-wounded trees. All other 
factors, whether controllable or uncontrollable, and this includes frost 
and lightning, are of so little importance that they may be neglected 
in any consideration of mechanical injuries in the future stand. 
But fire protection works for the future welfare of the stand alone. 
It can not affect the huge number of individuals in the forest with 
healed or open wounds through which dry-rot has already entered 
or those -uninfected individuals with open wounds still exposing them 
to attack by heartwood-destroying fungi; nor can it have any influ- 
ence on all the other injured, diseased, or distorted members of the for- 
est community. These have no place in the stand, are in most cases a 
direct menace to the sound trees, and should be removed as soon as 
possible. Unfortunately, we have not been able to attain the highly 
desirable intensive practice of eradicating such undesirable individuals 
by means of improvement thinnings applied at will wherever needed 
in the forest. 
Under present conditions this can only be done in the main through 
timber sales, with free-use permits playing a limited part. But the 
Government is far from able to sell the timber where cutting is most 
needed from a silvicultural point of view. Economic factors, espe- 
cially transportation, and in some cases the degree of soundness of 
the stand play the chief role in determ in ing the exact location of a 
sale area. In fact, a mature or overmature stand badly in need of 
cutting may have to be left untouched, owing to the refusal of pros- 
pective purchasers to handle the high representation of inferior 
species. 
In the case of incense cedar, this prejudice on the part of the lum- 
berman does not arise from any inherent qualities or characteristics 
