BALSAM FIE, 
67 
ROTATION, 
The difference in the rate of growth of balsam fir and spruce has 
a direct bearing upon the choice of rotation or proper time of cutting 
the two species. From the tables it is evident that balsam fir, if 
its growth is to be utilized to the fullest advantage, should not be 
cut before it reaches an age of about 100 or 125 years, or a diameter 
of 12 to 14 inches breast high. Cutting balsam fir below 6 or 7 inches 
means utilization of trees which are still making a fair growth. 
Spruce, on the other hand, should not be cut before it is 175 or 200 
years old, since most of its growth is made at the age of from 100 to 
200 years. The rotation for balsam fir, therefore, should be about 
100 years, and for spruce at least 175 years. These rotations, of 
course, would be applicable only if balsam fir and spruce were grown 
separately. Since they usually grow together, the practical applica- 
tion of these different rotations would simply mean that in cutting 
over a virgin stand of spruce and balsam fir, the fir should be cut 
to a younger age, only the older spruce being removed. 
SUMMARY. 
1. Balsam fir forms, on an average, from 10 to 15 per cent of the 
entire red-spruce stand, or 5,355 million board feet. 
2. Under present methods of cutting, balsam fir is increasing at 
the expense of red spruce in the second growth throughout the entire 
range of the two species. 
3. Balsam-fir wood, while to some extent inferior to spruce for 
construction material, has a definite place in the pulp and lumber 
industries. 
4. Balsam fir grows much faster throughout its entire life than 
spruce, but is shorter lived and reaches maturity long before the 
latter. 
5. Balsam fir should be cut at an age of from 100 to 125 years, 
while spruce, as it grows at present in the wild wood, should be cut 
at an age of from 175 to 200 years. 
6. The annual increment per acre of balsam fir throughout its 
range varies from one-sixth to one-third of a cord, or 1 cord in from 
three to six years. 
7. The best silvicultural system of cutting is that of selection 
cutting in small groups. The natural reproduction of both spruce 
and balsam fir is assured under this system, with the possibility of 
increasing the proportion of spruce in the new stand. 
