SPRUCE IN MIXTURE 23 
the other trees about them, as do Tamarack and Pine. 
Under average conditions on large areas, the propor- 
tionate numbers of different trees, equal in tolerance 
and other qualities, would be fairly evenly maintained. 
Allspecies, however, are not equal in their tolerance 
of shade, their resistance to storm and disease, in ten- 
acity of life and power of reproduction, so that an even 
mixture is seldom either achieved or maintained. 
We have already seen that Spruce grows in all situa- 
tions and soils. While in most portions of the Park it is 
mixed with other species, there are certain situations 
where Spruce occurs nearly pure. Thus, on south- 
western slopes the soil is frequently so stony and the 
slope so abrupt that such trees as Hard Maple and 
Beech find difficulty in obtaining a footing. In such 
places Spruce reproduces itself abundantly; Birch and 
Hemlock come up to some extent; but, in comparison 
with the forest on northern slopes and high flats, Spruce 
has almost undisputed sway. The same is true on 
certain ridges and knolls where the growth is almost 
entirely softwood, and on certain lowlands where its 
competitors are reduced to a few species with which 
the Spruce is abundantly able to cope. In such situa- 
tions, and wherever Spruce predominates, its future is 
assured. That 1s to say, under conservative treatment 
there is or there will be young growth enough to take 
the place of whatever merchantable timber may be cut, 
and hence the reproduction is sufficient to maintain the 
present proportion of Spruce. With proper care the 
latter could, on the whole, be increased. 
