12 BULLETIN -344, TJ. S. DEPARTMENT OF AGRICULTURE. 
The relative importance of the four types varies according to the 
locality. In the mountainous portions of central Maine the mixed 
hardwood lands and spruce slopes are of greatest importance, while 
in the northern part of the State the spruce flat is the more prevalent. 
The spruce slope is the characteristic type in the White Mountain 
region. In the Adirondacks the mixed hardwood type is the most 
common, followed by the spruce swamp and the spruce slope. In 
the southern portion of its range spruce is only sparingly associated 
with hardwoods, the spruce slope type being more prevalent. 
SPRUCE SWAMPS. 
The spruce swamp type dominates the low-lying, poorly-drained 
areas, whose soil is a muck or peat, spongy in texture, and acid. The 
characteristic species are red spruce, black spruce, balsam, tamarack, 
cedar, soft maples, black ash, and other moisture-loving trees. 
Sphagnum moss and low water-loving herbaceous plants commonly 
form the undergrowth. Spruce usually makes a slow growth in such 
situations, and is short and scraggly in appearance. It is particu- 
larly susceptible to windthrow on these soils, which prevents its at- 
taining as large size or as great age as when growing on the better 
types of soil. Even-aged stands are not at all uncommon. Numer- 
ous small islands of drier and firmer soil texture are scattered through- 
out this type of soil. They support a somewhat better growth of 
spruce, mixed with hemiock, white pine, birch, and some beech and 
sugar maple. Balsam, tamarack, or arborvitse will not infrequently be 
found predominating in the wetter portions; and black spruce is 
largely confined to such places. 
SPRUCE FLATS. 
The level and rolling flats bordering the swamps, lakes, and water- 
courses, are occupied by the spruce flat type. The soil is variable 
in composition, moderately deep where sandy or gravelly in texture, 
and shallow where stones and bowlders predominate. While the 
percentage of moisture may be high, the drainage is free and a favor- 
able condition is afforded for thrifty tree development. The flat type 
is in large measure a transition between the swamp type and the tyv>c 
of the mixed hardwood lands, and in many respects exhibits the 
characteristics of each. Spruce, birch, soft maples, white pine, hem- 
lock, and balsam are the characteristics trees in mixture. The 
presence of black ash, which is usually accompanied by considerable 
balsam, denotes conditions bordering on the swamp type. The 
presence of sugar maple, on the other hand, denotes a transition to the 
hardwood lands. White pine of good quality formerly occurred in 
abundance in this type in both Maine and the Adirondacks, par- 
ticularly where a sandy soil predominated. Spruce attains an inter- 
