FOREST VEGETATION. 
Figure 15.-—Mature spruce forest. (Spruce-fir.) In its general aspect it is closely related to the 
alpine forest of the western mountains, with which it is connected by a more or less continuous 
belt at northern latitudes. It is best developed in Maine, New Hampshire, and northern New 
York, where it occurs both in swamps at low elevations and near the upper timber-line. In the 
Appalachian Mountains it occurs only at high elevations. Adirondack Mountains, N. Y. Photographed 
by A. Gaskill. 
Figure 16.—A mixed stand of Norway and jack pines. (White-Norway-jack pines.) This forest is 
characteristic of the Lake States. Its appearance is not markedly different from that of the pure lodgepole pine 
stands of the Rockies and of the scrub pine stands in the southeast. Its composition varies according 
to the soil. On poor sandy soil jack pine predominates; the heavier soils were originally occupied by white 
pine, while on the intermediate soils Norway pine forms the principal species. Cass County, Minn. 
Photographed by A. Gaskill. 
as on the Rainier National Forest, noble fir practically 
forms the timber-line tree. In the Cascades, at eleva¬ 
tions of from 4,500 to 7,000 feet, the forest consists of 
alpine fir, white-bark pine (Pinus aTbicaulis ), Lyall 
larch (Larix lyallii ), and mountain hemlock (Tsuga 
mertensiana ). In the Sierras this belt includes several 
types. Thus, on cool meadows, with plenty of mois¬ 
ture, varying in elevation from 5,500 to 6,500 feet, it is 
characterized by pure stands of lodgepole pine. From 
7,000 feet to timber line it is made up of alpine fir and 
mountain hemlock. On northerly and northeasterly 
slopes in the Sierras, at an elevation above 6,000 feet, it 
is largely of pure red fir, and at the same elevation, 
but on less moist and cool situations, it is usually red 
fir mixed with white fir. These various types all have 
the biological characteristics typified by the spruce and 
fir. In most of these stands there are open parks and 
stream-side meadows which provide excellent summer 
grazing. 
This belt is usually subject to heavy snowfall. The 
mean annual precipitation is over 30 inches and the 
temperature low both in summer and winter. The 
growing season is limited to the three months of 
June, July, and August, and near the timber line it is 
shortened to about eight weeks. Throughout the entire 
belt severe frosts are likely to occur every month in 
the year, although in Arizona studies have shown that 
the Fmgelmann spruce type is free from frost from 
June 15 to September 15. There has been little agricul¬ 
tural development in this type of forest. This is due 
chiefly to the unfavorable character of the land surface 
and to the cool climate and short growing season. 
Other Forest Divisions. 
Besides the main units, there are other forest com¬ 
munities which do not fit into any of these three large 
divisions, being remnants of some other forest units 
now extinct. Among these may be named the largest 
of these communities—the coast redwood—and such 
outstanding forest groves as Monterey pine and Mon¬ 
terey cypress which occupy very localized areas and 
all of which may be classed more or less with the 
cedar-hemlock series. 
The redwood belt (fig. 14),—The redwood belt, al¬ 
though confined to a narrow strip of the humid coast 
of California, is of great economic importance. It 
stretches in the form of a belt 400 miles in length 
and averaging 20 miles in width from the southwest 
corner of Oregon to near Santa Cruz, California, with 
an outlier in Monterey County. Within this belt the 
redwood, although commonly the dominant tree, is 
usually associated on the slopes with Douglas fir, low¬ 
land fir, western hemlock, and tan oak. On the flats 
or river benches it forms pure stands. In Humboldt 
and Del Norte Counties of California the redwood 
forms the heaviest stands of timber in the world. 
Figure 17.—Nearly pure stand of white pine. (White-Norway- 
jack pine.) About 120 years old; contains an admixture of white 
birch with an understory of balsam; on less sandy soils it is mixed 
with northern hardwoods. St. Louis County, Minn. Photographed 
by H. H. Chapman. 
There are records of 2£ million feet per acre and 
480,000 board feet to a single tree. The redwood 
belt is characterized by a heavy rainfall in the rainy 
season and heavy fogs in the dry season, with slight 
changes of temperature during each day and during 
the year. The main portion of the redwood belt re¬ 
ceives a seasonal average of over 50 inches of rain, but 
southward the average decreases rapidly, being about 
30 inches in the Santa Cruz and Monterey County 
forests. 
Practically the whole redwood belt, with the excep¬ 
tion of two public parks, is under private ownership. 
Until recently the owners sought to convert the logged- 
off land into agricultural use. The high cost of clear¬ 
ing the land, together with the rapid growth of the 
trees and their sprouting capacity, proved the land to 
be more valuable for forest growth than agriculture. 
Much of this land may, therefore, be kept in forest 
EASTERN FOREST REGION. 
In the East, because of the less mountainous sur¬ 
face, the natural divisions of the forest coincide 
chiefly with geographic regions rather than with alti¬ 
tudes, and therefore the line of demarcation between 
the several divisions into which the eastern forest may 
naturally be grouped is not as distinct as in the West. 
The nearest approach to altitudinal distribution of the 
several main divisions is found in the Appalachian 
Mountains. However, as in the West, the entire east¬ 
ern forest vegetation may be classified into a compara¬ 
tively few fundamental units. Seven main natural 
divisions are recognized: 
(1) Spruce-fir (northern coniferous forest). 
(2) White-Norway-jack pine (northeastern pine forest). 
(3) Birch-beech-maple-hemlock (northeastern hardwood 
forest). 
(4) Oak (southern hardwood forest). 
(5) Cypress-tupelo-red gum (southern river bottom 
forest). 
(6) Longleaf-loblolly-slash pine (southeastern pine 
forest). 
(7) Mangrove (subtropical forest). < 
Spruce-Fir Forest. (Fig. 15.) 
The spruce-fir forest is practically the same boreal 
coniferous forest which is characteristic of the high 
altitudes in the West, and which north of the fiftieth 
parallel merges with the eastern spruce-fir forests. 
This forest is found in the East both in swamps at low 
levels and at high altitudes in the mountains. In the 
low-lying, poorly drained areas, where soil is a muck 
or peat, spongy in texture, and often acid, the charac¬ 
teristic species are black spruce, balsam, tamarack, 
white cedar, and some red maple, giving rise to spruce- 
tamaracjk swamps, spruce-cedar swamps, or spruce- 
balsam swamps. At high altitudes it is composed 
largely of black spruce and balsam fir. On level or 
rolling flats bordering the swamps, lakes, and water- 
