DRY-ROT OF INCENSE CEDAR. 53 
fected tree possesses the potential capacity of sooner or later pro- 
ducing sporophores. 
Remembering the great percentage of dry-rot infections entering 
through wounds, trees with injuries must be treated accordingly. 
Trees with healed wounds are of less concern than those with open 
wounds, since the former, if not already infected, are immune except 
for the inevitable, though fortunately not frequent, attack through 
branch stubs, while the lattei are still open to infection. Then, too, 
the area of heartwood exposed by the injury is of grave consequence; 
the larger the area the greater the opportunity for infection. We 
already know the high percentage of infections through fire scars 
which so commonly expose large areas of heartwood; therefore 
fire-scarred trees, above all, should be marked as heavily as possible. 
Large lightning wounds are a serious danger, but small superficial 
injuries, especially if high up on the bole, can be almost disregarded. 
Frost cracks, though by virtue of the exceedingly small amount of 
heartwood they expose offering slight chance for infection, often 
aid in spreading infection established through some other agency, 
and trees with such wounds should be marked for cutting whenever 
possible. From the pathological viewpoint spiketops or stagheads 
may be almost disregarded except for then suppressing influence 
on the injured individual, but sound silviculture demands the re- 
moval of such trees from the stand. 
Even if the Utopian dream of a forest community without injured 
individuals could be attained, this in itself would not result in com- 
pletely controlling the destruction wrought by the dry-rot fungus, but 
only in minimizing it in a great measure. There would still be some 
loss from infections entering through knots. Then, too, no matter to 
what degree of intensive management a forest in this region may be 
brought in the future, some injuries will always occur, even from fire, 
while frost and lightning wounds are inevitable. The unavoidable 
injuries to a certain number of the seed trees during logging on any 
f ales area must not be overlooked. 
Therefore, all wounded trees must not only be eliminated on sales 
areas, but trees, even though unwounded and thrifty, must not be 
left with the expectation that they will be sound at the next cutting 
if by the time the cutting takes place they will have attained or 
passed beyond the age at which loss from dry-rot becomes of serious 
economic importance. It has been shown that the critical age occurs 
at 165 years and the age of decline at 210 years. Beyond the age of 
165 years suppressed trees become subject to extensive decay, while 
up to that age they may be expected, with rare exceptions, to remain 
relatively sound, the same being true for the dominant trees at an 
age of 210 years. 
