WESTERN WHITE PINE AND LARCH-FIR FORESTS 9 
prevent germination, will be likely at least to kill the seedlings in 
their first season. It is to avoid such failures that in most cuttings 
in the national forests seed trees are retained. 
EFFECT OF FIRE 
When a virgin forest of white pine is destroyed by fire a splendid 
stand of seedlings usually follows. This stand probably originates 
in part from seed in the duff and in part from seed in cones on the 
trees which the fire did not reach. The duff under a virgin stand 
is usually moist and is seldom destroyed entirely by a forest fire. 
When a slashing is burned, however, the result is likely to be less 
favorable. Reproduction after such a fire is by no means assured. 
In a spring fire the duff may be so moist that it is not consumed, and 
good reproduction will follow; but if the slash fire occurs in the 
summer or fall, the duff will have been dried out by the sun and 
wind and is apt to be entirely consumed along with the seed in it. 
’ If burning is delayed for a year or two after cutting, the seed will 
have already germinated, and all the seedlings will be killed. Any 
deliberate burning of slash as it lies, then, aside from other dangers, 
is very likely to result in little or no reproduction of white pine, 
although occasionally, if conditions are all favorable, excellent stands 
of young growth will follow, particularly if the burning is done in 
the spring immediately following logging. 
There is still a great deal about the laws of white pine reproduc- 
tion which foresters do not know, but it can be stated with a con- 
siderable degree of assurance that if the duff is not consumed good 
reproduction usually follows cutting, whereas if the duff is com- 
pletely consumed there will be little or no reproduction, unless seed 
trees are present. 
EFFECT OF SHADE 
White pine seedlings will not germinate and develop under too 
dense shade. Consequently if too much hemlock, white fir, Douglas 
fir, and cedar is left from a cutting the reproduction of white pine 
is hindered or may be entirely prevented. Since larch casts only a 
light shade and is less likely to have an unfavorable influence on the 
white pine, it may safely be left in greater quantities. On dry sites 
a moderate shade is favorable to white pine reproduction. The most 
favorable shelter will vary from 15 to 25 per cent crown cover on - 
yeep south slopes to 5 to 15 per cent on flats and no shade on north 
slopes. 
Under Forest Service practice, it is customary to cut all sound 
white fir and hemlock over 12 inches in diameter (breast high). 
Any considerable amount of defective hemlock or white fir is dis- 
posed of either by girdling or felling, and lopping and piling the 
brush. This is an expensive process and may cost up to $20 or $30 
per acre but is often the only way in which the productivity of the 
site can be maintained. : 
PRESENT LOGGING PRACTICE AND ITS RESULTS 
Most white pine logging employs horse skidding, chutes, and rail- 
road or river-drive transportation. Power logging is used in only 
two or three operations in the white pine region. 
54606°—27——2 
