Land of the Great Forests
The forests of the Great Smokies are notable for the
large variety of native trees. How many kinds are there? It would be
difficult to find two botanists who would agree on the answer. The
difference between a shrub and a tree is, at best, rather
vaguesomewhat like the difference between a
pond and a lake, or a hill and a mountain. Where are we to draw the
line? A generally accepted definition is that a tree is a woody plant
with a well-defined stem and crown, has a diameter of 2 inches or more,
and attains a height of at least 8 feet. This will include a number of
plants which ordinarily are shrublike but which, on occasion, become
arborescent, or treelike; examples are mountain-laurel, witch-hazel,
staghorn sumac, the three kinds of native plums, mountain winterberry,
the various hawthorns, three species of Viburnum, mountain
stewartia, the tree sparkleberry, alder, devils-walkingstick, and
alternate-leaf dogwood. Counting these, there are more than 100 kinds
of native trees in the area.
The Chimney Tops as seen from the transmountain road. This most
photographed landmark towers above the head of the Sugarlands Valley.
Many species of trees make up the dense forests, here and throughout
the lower and middle altitudes. Courtesy, Tennessee Conservation
Department.
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Some of the trees, such as the red spruce and Fraser
fir, are found only in the colder and more moist situations at high
altitudes; others, such as scarlet and black oaks and most of the pines,
grow only on dry exposed slopes at low and middle elevations; still
others, notably yellow buckeye, basswood, and mountain silverbell, are
the "key" species in protected valleys below the usual
limits of spruce and fir. A few trees, such as the Allegheny
serviceberry, range over a wide variety of habitats, but all are limited
by combinations of such factors as temperature and length of growing
season (these two being correlated with altitude) and by moisture and
depth of soil (these being correlated with topographic position).
Along one of the trails in the park, a hiker admires the straight
trunk of a big yellow-poplar. Eastern hemlocks are in the
foreground. Courtesy, Tennessee Conservation Department.
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COVE HARDWOOD FORESTS
These forests occur in sheltered situations, at low
and middle altitudes (below 4,500 feet) where there is a considerable
depth of soil. Dominant trees are yellow buckeye, basswood,
yellow-poplar, mountain silverbell, eastern hemlock, white ash, sugar
maple, yellow birch, American beech, black cherry, northern red oak,
cucumber-tree, and, in former years, American chestnut. All these grow
to record or near-record proportions in the park. Wherever a number of
these are found together, and where the ropelike strands of the common
Dutchmanspipe make good growth, we find ourselves in the splendid
big-tree groves of the Great Smokies. It is largely due to the
occurrence of various unspoiled stands of these cove hardwood forests,
along with the stands of Canadian-zone spruce and fir at the higher
elevations, that Great Smoky Mountains National Park deserves its
reputation as an outstanding wilderness stronghold.
It may be difficult for some of us to realize that
the cucumber-tree grows to be greater than 18 feet in circumference,
yet such a tree stands in the Greenbrier area of the park. A yellow
buckeye is almost 16 feet in circumference, a yellow birch over 14 feet
a mountain silverbell almost 12 feet, a sugar maple over 13 feet, and a
yellow-poplar over 24 feetthese are circumference measurements
taken at 4-1/2 feet from the ground. All are cove hardwood species
in the park.
Fraser magnolia, one of the many smaller trees in
these forests, also reaches record proportions here; specimens are
known to attain a height of over 75 feet and a trunk diameter of more
than 2 feet. A number of shrubs, one of the most prevalent of
which is the rosebay rhododendron, and a long list of
spring-blooming herbs are to be found in the cove hardwood forests.
HEMLOCK FORESTS
The eastern hemlock is a common tree along streams
and lower slopes up to an altitude of 3,500 to 4,000 feet. It also
occurs on exposed slopes and ridges at middle altitudes and up to almost
5,000 feet, where it stops rather abruptly, there being practically
no hemlocks above 5,500 feet. Associated with the
hemlock are such trees as the red and sugar maples, American beech,
yellow and sweet birches, black and pin cherries, American holly,
yellow-poplar, and mountain silverbell. Both the rosebay and catawba
rhododendrons are common shrubs in hemlock forests, the former being an
abundant streamside understory while the latter occurs in heath "balds"
on the higher exposed ridges. Drooping leucothoe, smooth hydrangea,
scarlet elder, thornless blackberry, mountain-laurel, and hobblebush
are the other shrubs one might expect here. The variety of
spring-blooming herbs is not nearly as extensive as in the cove hardwood
forests.
Naturalists measure the largest known eastern
hemlock, which has a trunk circumference of 19 feet, 10 inches.
Courtesy, Dr. William Hutson.
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NORTHERN HARDWOOD FORESTS
These forests, largely dominated by yellow birch and
American beech, occur mostly above 4,500 feet. Often they are almost
surrounded by red spruce and Fraser fir. Such trees as sugar maple, black
cherry, and eastern hemlockall a part of the northern hardwood
forestsreach their uppermost limits at, or near, the 5,000-foot
elevation. Red maple, striped maple, American beech, yellow buckeye, and
Allegheny serviceberry drop out before, or at, the 6,000-foot elevation.
Yellow birch, pin cherry, and mountain maple may reach the summits of
the higher mountains where, normally, spruce and fir are dominant. The
variety of shrubs in these forests is limited mostly to smooth
hydrangea, drooping leucothoe, catawba and rosebay rhododendrons,
thornless blackberry, and hobblebush. Herbaceous plants, especially
those which bloom in the spring, are of considerable variety; some of
the most abundant of these include the Virginia springbeauty, common
fawnlily, creeping bluet, American woodsorrel, fringed phacelia, great
starwort, trilliums, violets, crinkleroot, and yellow beadlily.
SPRUCE-FIR FORESTS
Along the high State-line ridge which runs the length
of the park, a forest of spruce and fir extends in an almost unbroken
stand from the western slope of Clingmans Dome to near Cosby Knob, close
to the park's northeastern corneran air-line distance of
approximately 25 miles. Only in the vicinity of Charlies Bunion, swept by
the great fire of 1925, is there an appreciable break in the evergreen
chain. On the Tennessee side of the park, the finest growth is on Mount
Le Conte, third-highest peak in the Smokies; on the North Carolina side,
the area southward from Mount Guyot (second-highest peak), between
Hughes Ridge and Balsam Mountain, contains the most extensive
spruce-fir stand. Above the 6,000-foot altitude, the only trees occasionally associated
with the red spruce and Fraser fir are yellow birch, pin cherry,
American mountain-ash, and mountain maple.
Fraser fir and red spruce (right). These
high-altitude trees in the Great Smoky Mountains are symbolic of the Canadian
zone.
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So dense does the growth of trees become that shrubs
and other plants may be practically absent over wide areas. However, in
places the following shrubs may be found: catawba and Carolina
rhododendrons, southern bush-honeysuckle, Allegheny menziesia, scarlet
elder, dingleberry, thornless blackberry, roundleaf gooseberry,
hobblebush, witherod, and Blueridge blueberry. Ferns prevailing at these
high altitudes include the toothed woodfern and hayscented, lady, and
common polypody ferns. Most conspicuous of the spring-blooming herbs
include creeping bluet, Virginia springbeauty, American woodsorrel,
pallid violet, painted trillium, erect trillium (white and purple forms)
and yellow beadlily; the summer-blooming herbs that you are most likely
to see include acuminate aster, white wood aster, cluster goldenrod,
pink turtlehead, Indianpipe, and Rugel's groundsel.
CLOSED OAK FORESTS
On intermediate to dry slopes, at low and middle
altitudes, the forests are dominated by four kinds of oaks (white,
chestnut, northern red, and black), three hickories (pignut, red, and
mockernut), and by red maple, sweet birch, sourwood, yellow-poplar,
blackgum, black locust, and mountain silverbell. Formerly, the ill-fated
American chestnut was a very important component of this forest. Small
trees, especially flowering dogwood and witch-hazel, and such shrubs as
mountain-laurel, rosebay rhododendron, smooth hydrangea, flame azalea,
oil-nut, buckberry, and pale sweet shrub are often present. Vines
include the common greenbrier and Virginia creeper, while common herbs
and herblike plants include galax, trailing arbutus, white wood aster,
halberdleaf yellow violet, false foxglove, early pedicularis, and
goldenrods.
OPEN OAK AND PINE STANDS
Four kinds of oaks and an equal number of pines
dominate these forests which occur on dry exposed slopes and ridges.
The terrain is usually rocky. Whereas the trees normally do not form a
closed canopy, the shrub layer may be quite dense and is often dominated
by the evergreen mountain-laurel. The northern red oak of the closed oak
forests is replaced by the scarlet oak in these drier stands; otherwise
the same species of oak are dominant. Pines (Table Mountain, pitch, and
Virginia) are most plentiful on the driest sites; eastern white and
shortleaf pines may occur along with red maple, sourwood, blackgum,
sassafras, Allegheny serviceberry, and black locust. American chestnut
persists as basal sprouts. The majority of the tall-growing shrubs of
the closed oak forest are also to be found here. In addition,
huckleberries and blueberries may become abundant. Checkerberry
wintergreen, trailing-arbutus, eastern bracken, galax, various asters,
and pussytoes are common lower plants.
Cones of the Table-Mountain pine are the spiniest of any of the cones from the five
pine species found in the park.
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