THE RED SPRUCE. 15 
areas on steep, rocky mountain slopes or wet bottom lands. Com- 
petition with the hardwoods is reduced both by their inability to adapt 
their root systems to the shallow soil and by excessive moisture con- 
ditions. Thus spruce is found most abundantly, not where the best 
conditions for its own growth exist, but where its competitors are 
not readily able to grow. 
On the more favorable soils such agencies as fire, windfall, and 
fungous or insect attacks may prove a means by which the extension 
of spruce is made possible, provided a sufficient number of spruce 
seed trees remain to seed up quickly the ground formerly occupied by 
its competitors. 
LIGHT REQUIREMENTS. 
Spruce is one of the most tolerant of shade of our forest trees. Of 
the associates, only hemlock, and possibly sugar maple and beech, 
are more tolerant. 1 Spruce also possesses to a remarkable degree the 
power to recover and grow in a thrifty and normal manner follow- 
ing its release from long periods of suppression. Having once gained 
a foothold in the selection forest, the young spruce grips life tena- 
ciously, struggles along for many years under the shade of the forest, 
and gradually forces its way upward as natural thinning reduces the 
number of its overtopping competitors. It is hi fact to these quali- 
ties more than any others that spruce owes its ability to persist as a 
factor in the mixed selection forest of the Adirondacks, in the North- 
east, and throughout its range. 
Strangely enough these tolerant and recuperative qualities are 
most characteristically displayed by spruce in the selection forest. 
In the dense, even-aged pure stands, root competition and mechan- 
ical interference due to overcrowding enter in to complicate the situ- 
ation. Trees which are suppressed under these conditions recuper- 
ate very slowly, if at all. Most often, when the stand is opened up 
sufficiently to afford the requisite amount of light and growing space, 
the suppressed crown is so reduced in size and vitality as to make 
recuperation imperceptible for a period of years. Such suppressed 
trees when released from overcrowding often succumb to windthrow 
or sun-scald. 
Balsam although moderately tolerant is less so than spruce, the 
keen rivalry between the two species being due to other qualities in 
which balsam surpasses spruce. 
WINDFIRMNESS. 
Unlike most hardwoods and some of the conifers, notably the yel- 
low pine and Douglas fir of the West, spruce develops a very super- 
ficial root system. On account of the intimate relation between the 
root and the crown of a tree and the active competition of root sys- 
i Under the keenly competitive conditions which prevail in even-aged second-growth stands, spruce is 
able readily to suppress and kill out even these species. 
