BALSAM FIE. 
29 
where balsam fir occurs scatteringly, the number of seedlings per 
acre is small, often only 700 to 1,000, though occasionally, if there 
are a number of large balsams, the number may reach 50,000. The 
number of seedlings is, of course, largest in pure stands of balsam, 
where they may be 300,000 and more to the acre. In mixture with 
spruce in the swamps and flats the number of balsam seedlings will 
vary from several thousand to 200,000 and more, according to the 
number of large seed-bearing balsams in the stand. 
TOLERANCE. 
Balsam fir requires less light than tamarack, white pine, and white 
cedar, but more light than either red spruce or hemlock. It will, 
however, endure more shade on deep, moist soils than on poor, shallow 
ones. In mixture with spruce, mature healthy balsam invariably 
towers above the former. Similarly, in a mixed hardwood forest, 
balsam fir, when fully developed, is the dominant tree. For the 
first five or six years of its life, balsam will grow in dense shade, but 
as it develops it demands more and more light. On moist soils, how- 
ever, it may thrive without being in the top story of the forest, and 
beneath white birch and poplar, also, it often remains apparently 
healthy and vigorous. But where it comes in under a hardwood 
forest already established, its leader is usually stunted or killed 
when it enters the hardwood foliage. A broken limb or leader often 
affords the means of entrance for rot, and though balsam, especially 
on deep, moist soil, is capable of recovery after a long period of 
suppression, it is apt in such cases to be unsound. Many trees 
were found to be rotten in the middle at the point of suppression, 
with no visible point of entrance for the rot. Others were found 
100 years old, with a height of 18 feet and a diameter of 3 inches, 
which, after 66 years of suppression, retained sufficient vitality to 
grow rapidly after again receiving the light. 
SOIL AND MOISTURE REQUIREMENTS. 
Though their demands upon soil are very similar, balsam fir 
requires for its best development a richer and moister soil than 
does spruce. With its more northern distribution it seeks the cool 
and moist north and east slopes in preference to other exposures. 
In the Adirondacks it is hardly ever found on the abrupt, rocky, 
southwest slopes, with thin soil, on which spruce often forms a pure 
stand and reaches a good development. Balsam fir attains its 
best growth and largest sizes on the flats, the soil of which is usually 
a moderately moist, deep, sand loam. In the wet swamps with 
acid soils, as well as on pure sand, it thrives but poorly. 
