THE FOREST 5 
tolerant of shade to a considerable degree. As a con- 
sequence, the forest is composed of trees of all ages and 
sizes, for the younger trees are able to survive beneath 
the shade of the older ones. Such a forest is said to 
have the selection form. 
A selection forest is usually composed of species 
tolerant of shade. This does not mean, however, that 
intolerant species are wanting, for these maintain their 
existence by prolific reproduction, rapid growth, and 
the ability to live on poor soil, rather than by overcom- 
ing their rivals in the struggle on the ground. Thus 
where openings are made by windfall or fire, such 
species often take possession of the land, coming up in 
fairly even-aged bodies, sometimes of very considerable 
size. On fire slashes in the Adirondacks, for example, 
the Poplar, a tree very intolerant of shade, but with very 
light seed easily carried by the wind, rapidly takes pos- 
session of the soil. White Pine comes up in openings 
after fire. Tamarack, the most intolerant of all, grows 
rapidly in height, and so maintains its place. It starts 
in openings, and, by growing faster than Spruce or 
Balsam, forms an upper story above them. In the long 
run, other things being equal, the tolerant species will 
win, and the intolerant will be forced to retire to the 
openings caused by fire, wind, insects or disease. 
The species which occur in Ne-Ha-Sa-Ne Park are 
Spruce, Birch, Hard Maple, Soft Maple, Beech, Balsam, 
Hemlock, White Pine, Tamarack, Cherry, Black Ash, 
White Ash, two Poplars (distinguished as the Aspen 
and the Largetooth Aspen), and Bird Cherry. Of these, 
