64 BULLETIN 544, TJ. S. DEPARTMENT OF AGRICTJLTtjKE. 
The burniiig should not be under taken until the trees are suffi- 
ciently large to have developed a suitable thickness of corky bark to 
afford the necessary protection from injury, and are sufficiently 
cleared of their lower branches to afford opportunity for the fire 
tenders to get about easily and to control the fire. 
In the absence of roads or other cleared areas which might be used 
for fire control, ground-cleared fire lines should be provided around 
the border and possibly at intervals within the stand, particularly 
if a hillside is to be burned. 
Burning should be restricted to a time, preferably early spring, 
when the loose top litter is dry but the under layers and soil are 
damp. The burning must not be allowed to reach to mineral soil. 
A sufficient force of men properly equipped for fire fighting should 
be in attendance to check a too deep burning and prevent the fire 
getting beyond control. 
The plan of burning in strips along a well-defined and protected 
front with gradual progress away from it should be followed. All 
other precautions mentioned elsewhere should be carefully observed. 
light burning is not advisable in selection stands where the repro- 
duction and young growth form a distinct asset, since they would 
inevitably be injured or destroyed. It has a place where dense, 
even-aged stands are to be cut clean and reproduced by natural regen- 
eration methods, although too much emphasis can not be laid on the 
danger of fire escaping and the taking of every precaution necessary 
to prevent it. 
SOWING AND PLANTING. 
It is highly probable that it will eventually be found profitable to 
plant many of the spruce areas when they are cut over, rather than 
to wait for the slower and less certain restocking by natural means. 
This will come first on those areas at present covered with even-aged 
stands and such of the selection stands as are understocked with young 
growth or chiefly cut for pulp wood. 
A comparison of yields will suffice to show the advantages to be 
attained by planting over cutting under the selection system. Thus 
the average yield per acre of spruce in Maine at the present time 
cutting to a 12-inch diameter limit, is placed by lumbermen at abou 
2,000 board feet. With a diameter limit of 12 inches, a period of 4 
years must elapse before a similar amount can again be harvested. 
It is obvious that a cut to 8 inches would still yield material of a size 
suitable for pulp wood and would increase the present cut per acre 
to about 3,000 feet board measure * (5 cords) and reduce proportion- 
ately the cost of logging. But with an 8-inch diameter limit it is 
1 The approximate correctness of this figure is borne out by a yield table prepared for the " Lower 
spruce and hardwood lands" in Maine, by Hosmer, appearing in the report of the forest commissioner, 
Maine, 1902. 
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