<Economic Plants
Index> <Main Botany Menu> <Home>
(Contacts)
Please CLICK on Underlined
Categories to view:
[To search for Subject Matter, depress Ctrl/F
]:
=========================================================================
Forests occur on
all continents at least to some extent.
Although knowledge concerning the exact nature and distribution of
these forests is still incomplete, it is possible to estimate the amount of
forest land in the world in 2000 as about six billion acres, or 18 percent of
the earth’s surface. This area is
progressively decreasing as the human population soars. These forests are distributed on the
different continents as 25% in Asia, 24% in South America, 18% in North
America, 8 percent in Africa, 9% in Europe and only 3% in Australia and
Oceania. Forests were, of course, originally
much more abundant than they are at the present time. The softwoods or
conifers comprise 34 percent of the total forest area occurring in pure
stands or mixed with hardwoods. They
are especially abundant in the colder climates, about 90% occurring in the
north temperate zone. When they are
found in warmer regions, conifers are restricted to the higher altitudes
unless they have been imported as exotic species (e.g., Monterrey Pine). For hardwoods a distinction is usually
made between temperate and tropical species.
The former occur 16% and the latter 35% of the total forest area. As in the case of conifers, most of the
temperate hardwoods (ca. 85%) are located in the north temperate zone. It is interesting that three-quarters of
the world’s population lives in this area and consumes nearly 90% of all the
wood used. It is of great economic
importance that both softwoods necessary for general construction and
hardwoods have been readily available throughout this area. As a result of the depletion of native
forests, attention has been turned to the tropical forests, which continue to
be decimated by clear cutting. FORESTS OF NORTH &
CENTRAL AMERICA The forests of North America
occupied about 25 percent of the land area by the beginning of the 21st
Century. Conifers comprised about 72
percent, temperate hardwoods about 20 percent and tropical hardwoods about 8
percent of the forests. The northern
portion of North America (Alaska, Canada and Newfoundland) is primarily
coniferous, with 90 percent of the softwoods and 7 percent of temperature
hardwoods. The United States had
about 62 percent conifers and 38 percent temperate hardwoods. Mexico had about 47 percent conifers, 34
percent temperate hardwoods and 19 percent tropical hardwoods. In Central America tropical hardwoods
accounted for 75 percent and conifers 25 percent of the forests. The West Indies had an even higher
percentage of tropical hardwoods (ca. 85 percent), with the remainder in
conifers. The forest area present by
the 21st Century was only about half that of the original forests
that existed at the time of the first European settlements that began in the
16th Century. TYPES OF FORESTS IN NORTH AMERICA Forests in North America are found in about six
well-defined areas: (1) northern
coniferous forest, (2) eastern deciduous forest, (3) southeastern coniferous
forest, (4) Rocky Mountain forests, (5) Pacific Coast forests and (6)
tropical and subtropical forests. This is a predominantly evergreen
forest that extends across the continent from Newfoundland and Labrador to
the lower Hudson Bay region and Alaska, south of the treeless arctic tundra. The principal trees are white and black
spruce, balsam fir and larch, with some paper birch, aspen and balsam
poplar. From Nova Scotia and northern
new England to Minnesota and southward along the summits of the Appalachians,
there is a transitional region between the coniferous forest and the eastern
deciduous forest, with species of both these areas mixed. The prominent trees of this Northern
Hardwood Region, include white pine, red spruce, white cedar, beech, sugar
maple, hemlock, yellow birch and some red pine and jack pine. This
is one of the oldest forests on the North American continent that covers most
of the eastern and central portions of the United States. It flourishes in the lower Ohio valley and
on the slopes of the southern Appalachians, and it extends as far north as
Ontario and southern Quebec.
Prominent trees are oaks, hickories, tulip, chestnut, black walnut,
ash, basswood and formerly American elm.
At the northern limits the beech and maple become prominent mixed with
different conifers. Toward its southern
and southwestern limits the oaks and hickories occur with many of the pines
that are typically found in the southeastern coniferous forest. Westward the deciduous forest gradually is
confined to the river valleys of the prairie region. Southeastern Coniferous Forest This forest occurs along the sandy
Atlantic coastal plain from Texas to Virginia. Different species of pines, mainly shortleaf, longleaf,
loblolly and slash pines, occur on the uplands; in lower ground there occurs
the tupelo, live oak, red gum and magnolia.
Southern white cedar and cypress are found in swamps. This forest
consists mainly of coniferous species.
The area extends from northern British Columbia southward across the
United States and Mexico and on into Central America. There are many differences in the nature
of the forest as influenced by latitude and altitude. Western yellow pine is the most typical
species. Others include lodgepole
pine, white fir, Douglas fir, and western larch. Engelmann spruce and alpine fir are at the higher
elevations. In northern Idaho and
Montana a forest occurs that is similar to some of those found on the Pacific
Coast, with western red cedar, western hemlock and western white pine being
the main species. There are several
distinct forest areas located within the Pacific Coast region. Along the coast from Alaska south to
Washington, Sitka spruce is the main species. In southern British Columbia, the Puget Sound region and
eastern Oregon and Washington as far west as the summits of the Cascade Range
there is situated one of the most magnificent conifer forests in the
world. It can hardly be surpassed in
its density and the size of the trees, which reach heights of 200-250 ft. and
diameters of 8-15 ft. Mild winters
are created by the nearness of the Pacific Ocean and there is a very high
precipitation that can exceed 100 in. per year. Douglas fir is the dominant species and associated with it are
western hemlock, western cedar, Sitka spruce and several species of fir. Beginning in southwestern Oregon
and extending past the San Francisco Bay area the forests along the Coast
Range are dominated by redwoods. Much
of the original redwood forest had been cut by the end of the 20th
Century and farmland was substituted. East of the Cascade Range the
forests merge with those of the Rocky Mountains. The main trees are western yellow pine, western larch, Douglas
fir, lodgepole pine and some western white pine, Engelmann spruce and alpine
fir. This forest also extends
southward along the Sierra Nevada Mountains in California. There western yellow pine, sugar pine,
incense cedar, Douglas fir and white fir are common with red fir at the
higher elevations. The Big Trees are
found in isolated stands along the lower slopes of the Sierra Nevada. Although subtropical conditions
are found in south Florida, none of the trees are of commercial
importance. The true tropical forests
begin in the lowlands of Mexico (south of El Mante in the east and Mazatlán
in the west), on the eastern slopes of Central America and in the West
Indies. Most of the original forest
in the latter two areas has been destroyed as a result of migratory agriculture
and has been replaced by the dense, almost impenetrable tropical jungle. The more important tropical species of
North America will be discussed along with those of South
America. MAJOR WOODS
OF TEMPERATE NORTH
AMERICA There are more than 500 species of
temperate woody plants in North America, with about 100 being of commercial
importance. The principal species are
discussed as follows: These trees
all have a fragrant, light, soft wood that is even grained and decay
resistant. The wood is used mainly in
millwork and in the manufacture of woodenware, instruments, caskets, boats
and various appliances. Commercial
cedar includes seven different species. Port Orford Cedar, Chamaecyparis lawsoniana, is found in Oregon and California. It is the hardest of all the cedars and has some exceptionally
good technical properties. It yields
a strong, durable, heavy, stiff timber that takes a good polish. The wood is used for furniture, boats,
millwork, matches, floors, interior finish and posts. Alaska Cedar, Chamaecyparis nootkatensis, occurs from Alaska to Oregon along the Pacific Coast. The wood is light, stiff, hard and strong
and is easy to work and durable. It
is used for boats, shingles, fences and interior finish. Southern White Cedar, Chamaecyparis thyoides, is a smaller tree found in the Atlantic and Gulf Coast
states. The wood is useful for boats,
poles, shingles, ties, posts and cooperage.
During colonial times it was used to build single-story houses. Incense Cedar, Libocedrus decurrens, of California, western Nevada and Oregon has a close-grained
reddish wood of high value. It is
used in building, for posts and piling and to a great extent for lead
pencils. Eastern Red Cedar, Juniperus virginiana, is one of the most common trees of the eastern United States. The wood is very durable and is particularly resistant to weathering. It is used primarily for fence posts, poles, crosstrees and railroad ties. The sapwood is white and the heartwood is rich red and very fragrant due to the presence of an essential oil. The wood is soft with an even, fine grain; and it can be whittled easily. Panels, veneers chests and interior finish are made from eastern red cedar. Northern
White Cedar
or Arbor Vitae,
Thuja
occidentalis,
is a common tree in New England and the Great lakes area and adjacent
Canada It is soft and easily worked
and has been used mainly for canoe and boat building, woodenware, shingles,
fence posts, railroad ties, poles, tanks and silos. Western Red Cedar, Thuja plicata, occurs in the
northern Rocky Mountains and Pacific Northwestern United States. It is the largest of the cedars that may
reach a height of 150 ft. and a girth of 30 ft. The brownish-red, close, even-grained wood is soft but very
durable. Most of this wood has been
used for shingles. Other uses include
poles, fences, cabinetwork, interior finish and cooperage. The coastal Amerindians used this species
for their totem poles and war canoes, and also fabricated ropes and textiles
from the bast fibers of the inner bark. The Bald Cypress, Taxodium
distichum,
is a tree of the swamps along the Atlantic Coast from Delaware to Texas and
northeastern Mexico, and in the lower Mississippi valley. It is one of the strongest and heaviest of
the softwoods. It may reach a height
of 80-140 ft. and a girth of 5-12 ft.
The “cypress knees” are a typical feature,
which are conical outgrowths from the roots for the purpose of aeration. The tree is deciduous and the wood is a
rich red color with a distinct grain.
It is soft and coarse and is easy to work with. It has been used primarily in millwork for
cabinet and interior finishes. It is
also used for shingles, ties, posts, tanks, cisterns and other structures
that are prone to decay, because the wood is very durable. Other products that have been manufactured
from bald cypress are boats, cooperage and boxes. Douglas fir, Pseudotsuga taxifolia, is one of the most
economically valuable woods in North America. The tree covers a wide range in northwestern United States and
western Canada. It attains its best
development on the Pacific Coast from central California to British
Columbia. The trees may reach a
height of 200 ft. and a diameter at the base of 8-10 ft. The lowest branches are high on the trunk
so that the trees have been used frequently for masts, flagpoles and
spars. The size of the trunk also
makes possible timbers of many lengths and sizes. The wood is resinous with a close, even, well-marked grain, and
is of medium weight, strength, stiffness and toughness. It is very durable and, when well
seasoned, will not warp. Much Douglas
fir is used in heavy construction.
Other uses include railroad ties, paving blocks, piles, veneers,
floors and millwork. The bark has
been processed for use as a substitute for cork in making adhesives, plastics
and explosives. It also possesses
insecticidal properties. True firs are of comparatively
little economic importance. The wood
is very light, soft and brittle and has been used mainly in the manufacture
of crates and boxes. Fir is also used
as a source of pulpwood and in millwork.
The most important species are the Balsam fir, Abies balsamea, of the northern
coniferous forest and four western species, the Lowland white fir, A. grandis, , the Red fir, A. magnifica, the Noble fir, A. procera and the White fir, A. concolor. The last two species when young are of
commercial importance as Christmas trees.
Because of their dense stands in portions of the American western
mountains, they are extremely valuable as watershed species. Eastern Hemlock, Tsuga canadensis, is one of the most
characteristic trees of the northeastern transition forest. It furnishes an inexpensive coarse lumber
that is used primarily for framing timbers, sheathing, scantling, laths, rafters
and other types of crude construction. Western Hemlocks, Tsuga heterophylla & T. mertensiana, are larger trees that
have a superior wood, which is heavier, stronger, stiffer and more adapted to
heavy construction. Both species are
high in tannin. These species are
important pulpwood sources in the Pacific Northwest. Eastern Larch or Tamarack, Larix laricina, and Western
Larch, L. occidentalis, are the larch wood of
commerce. The first species is found
in the northeastern United States and across Canada, while the latter species
is a larger tree that grows mainly in Idaho, Montana and Washington. Larch is very heavy, strong and tough
softwood and is used mainly in furnishing heavy timbers for general building
construction. Because larch is very
durable it has been used for posts, poles, fences, railroad ties and paving
blocks. The naturally curving lower
parts of the trunk furnish ideal material for boat “Knees,” ribs and other
forms of ship timber (Hill 1952).
Larch is also used to manufacture planning mill products, boxes and
tanks. Pines have always
been of great importance commercially, and they constitute about half of the
total lumber supply. The wood is
obtained from different species that belong either to the soft pine or the
hard pine category. In North America
there are eight species of especial value.
The soft or white pines have a straight-grained soft wood of mellow
and uniform consistency that is relatively free of resin and is easy to
work. It is used for rough carpentry,
cooperage, cabinetwork, toys, boxes and crates. The hard or yellow pines have a resinous, heavy, strong, hard
and durable wood that finds great use in buildings, bridges, ships and other
types of heavy construction. Because
it is very durable, yellow pine is desirable for stairs, floors, planks and
beams. Northern White Pine, Pinus strobus, is one of the most
valuable timber trees. It was
formerly used more than any other species, both for domestic consumption and
for the export trade from America to Europe.
By the 21st Century so much of the wood had been cut that
it fell into sixth place in importance.
The tree is found in the northeastern United States and adjacent
Canada, and along the Appalachian Mountains to Georgia. Considerable stands still exist in
Michigan, Wisconsin, Minnesota and a small area of northwestern Illinois. It is a conspicuous member of the forest
flora in this region and trees may attain a height of 100-200 ft. and a
diameter of 3-9 ft. The wood is very
light and easy to work as it is one of the softest of timbers. However, it is very durable. Houses that had been constructed of white
pine in colonial days remain in good condition. The sapwood is white and the heartwood a pinkish brown, with a
fine, even grain and lustrous surface.
White pine has been used for building structures, doors, windows
sashes, cabinetwork, boxes, and matches. Other species with similar wood and uses that have been called
white pine in the lumber trade are Western White Pine, Pinus
monticola,
Sugar
Pine, P. lambertiana, one very large and
valuable timber tree of the West, and Lodgepole Pine, P. contorta. Yellow pines are a heterogeneous
group that is often classed together even though each species has a
distinctive wood. Eastern species are
very fast growers. The Southern yellow or Longleaf Pine, Pinus australis, is one of the two
most important timber trees of the United States. It occurs in the southeastern states from North Carolina to
Texas. The wood has a fine, smooth,
compact grain and is the heaviest, hardest, strongest, stiffest and toughest
of the softwoods. It is especially
durable and able to bear great weights.
Therefore, it main use is for beams, joists and other timbers for
heavy construction, and for wharves, ships, bridges and railroad ties. Some yellow pine is used for boxes and
millwork. The wood is very resinous
and the tree is the main source of the naval-stores industry. It is also an important pulpwood. Associated with the yellow pine in the
southern forests and often classified with it are the Shortleaf
Pine, Pinus echinata, the Slash
Pine, P. caribaea, and the Loblolly
Pine, P. taeda. Other important hard pines are the
Western Yellow Pine, Pinus ponderosa, and Red
Pine or Norway Pine, P. resinosa, of the Eastern United
States. Red pine is of considerable
economic importance in the Christmas Tree trade, the trees being grown in
some quantity on farmland. Coastal Redwood, Sequoia sempervirens, (Photos) is restricted to the
Pacific Coast area of central and northern California and southwestern
Oregon. It is one of the tallest
trees in the world that can reach a height of 200-300 ft. and a diameter of
8-122 ft. Only one other species,
the Mountain Sequoia, Sequoia
gigantean,
(Photos) can exceed these
dimensions and also attains a greater age estimated at 3,600 years. The wood of the Mountain Sequoia has
little commercial value and has consequently escaped decimation by logging
practices. However, Coastal Redwood
has been widely exploited in the 20th Century and only the efforts
of conservationists have made possible the preservation of a few stands of
primeval forest. The wood of Coastal Redwood is
fine and straight-grained, strong, light and very soft. The sapwood is pale while the heartwood
has a rich dull red color. The
cinnamon-brown bark, often one foot thick, is striking. Redwood does not warp or shrink readily
and is very durable, especially after seasoning. It has been used for general construction, shingles, siding,
tanks, coffins, silos, posts, water pipes, ties, furniture, cabinetwork and
interior finish. The fibrous bark ahs
been used as an insulating and stuffing material, and it yields a textile
fiber for use with wool. The fine
bark dust is used as a soil conditioner. Several species of spruce have a
light, soft, compact, straight-grained wood that is stiff, strong, and easy
to work and relatively free of resin.
Spruce has increased in importance as white pine has become less available. The main uses are for pulpwood, light
construction, boxes, millwork, and cooperage and as Christmas trees. The wood is resonant and so is used for
making the sounding boards of pianos and the bodies of violins and other
instruments. The main species is the White
Spruce,
Picea
glauca,
one of the most characteristic trees of the great coniferous forest that
extends from the northeastern United States to Labrador and across the
continent to Alaska. Other eastern
species are the Red Spruce, Picea rubens, and the Black
Spruce,
Picea
mariana,
both of which have a more restricted range. The most important spruce species
of Western North America is the Sitka Spruce or Tideland
Spruce,
Picea
sitchensis. This large tree may attain a height of 200-300
ft. It occurs along the coast from
Alaska to northern California. Sitka
spruce has found use in the manufacture of oars, boats and other wood
products that require a light, strong and elastic wood. It was once widely used in airplane
construction. Engelmann
Spruce,
Picea engelmannii, occurs in the Rocky
Mountain and Cascade Range region from Arizona and New Mexico to Canada, and
has had limited economic importance. This is a strong, tough, elastic,
stiff, hard and lightweight wood. It
is light reddish brown, easy to split and difficult to nail. It often bears beautiful figures and may
be highly polished. Other uses of ash
wood are the manufacture of oars, bats, handles, tennis rackets, cues, rods,
clothespins, toys, baskets and barrels.
It may also be used for building carriages, boats, farm implements,
furniture, cooperage and interior finish.
The most widely used species is White Ash, Fraxinus americana, of the eastern
deciduous forest in North America.
Other prominent species are the Red Ash, Fraxinus pennsylvanica, and a variety the Green
Ash, Fraxinus pennsylvanica
var. lanceoleata;
the Blue Ash, Fraxinus quadrangulata; the Black
Ash, Fraxinus nigra, and the Oregon Ash, Fraxinus oregona. Also called Linden, Tilia americana, occurs mainly in the
eastern deciduous forest of North America.
The tree may reach a height of 80 ft.
The wood is light colored and straight grained with a smooth uniform
texture. It is light, soft and weak
and not very tough. However, because
of its color, even grain and ease of working it is widely used. It has been used to manufacture boxes and
crates, millwork, woodenware, furniture, trunks, Venetian blinds, picture
frames, carriage bodies, beehives, plywood, cooperage, pulp, charcoal and
excelsior. The Northern Beech, Fagus grandifloia, is typically found in
the northeastern transition forest of North America. The wood is fine-grained in pinkish brown
in color. It is moderately strong,
hard and heavy and has a wide range of uses.
Beech has been used extensively to make boxes and crates because it
does not impart any taste or odor.
Flooring, interior finish, fixtures and furniture, tool handles,
woodenware, clothespins, wagon stock, shoe lasts and ties are among the other
products. The wood is also used for
fuel, charcoal and wood-distillation. This is a heavy, hard, strong and
tough wood with a fine wavy grain that is often beautifully figured and able
to take a high polish. It is
frequently stained and finished to imitate mahogany or cherry. The Yellow Birch, Betula lutea, that ranges from the
Lake States to New England and Georgia, and The Black
Birch, Betula lenta, which has a more
restricted range, furnishes most of the wood used in the manufacture of
doors, furniture, window frames, floors and other forms of millwork. Other articles include clothespins,
handles, shoe pegs and lasts, wheel hubs, woodenware, boxes baskets, dowels,
yokes, veneers and spools. White Birch or Paper
Birch, Betula papyrifera, occurs further north
on the continent of North America.
The wood is very strong and elastic with a fine uniform texture. It is used mainly for plywood, spools,
toothpicks, boxes, handles, dowels, bobbins and shoe lasts and pegs and in
turnery. Especially the Amerindians
have used the bark that peels off in typical layers to make canoes and fancy
articles. Birch is also used for fuel
and distillation. Wild
Black Cherry,
Prunus
serotina,
is the only one of several species in the same genus where the wood has
commercial value. The tree occurs in
the deciduous forests from Ontario to Florida and from the Dakotas to Texas. It is particularly abundant in the
southern Appalachians. The wood has a
fine, straight and close grain, and it is hard. The color varies from light to dark red depending on age, and
it is often stained before use. The
beautiful grain and color and the ease with which it can be worked make this
cherry especially desirable for furniture, interior finishes and
cabinetwork. The supply had become
greatly reduced by the end of the 20th Century. Other uses have been the stands for
scientific instruments, printer’s supplies, and turnery. Medicinal properties are in the bark, and
the ripe fruits are at times used to flavor liqueurs. The American Chestnut, Castanea dentata, was one of the most
important timber trees of the eastern United States. However, the accidental importation of
chestnut blight disease from Europe practically eradicated the tree. Before the disease epidemic American
Chestnut was very abundant and conspicuous because of its large size in the
deciduous forests from Maine to Tennessee.
It was especially plentiful in the southern Applachians. The wood was brown, soft and open grained
and very durable and easy to work. It
was used for millwork, caskets, furniture, musical instruments, woodenware,
boxes, veneers and plywood cores. Its
high durability made it excellent for poles, posts, piling, ties, fence
rails, shingles and cooperage. It was
also a source of pulpwood and a tanning material. The nuts were superior in quality to the European
Chestnut. The tree continues to
survive from suckers that arise from the roots, but they never reach a
reproductive age. Several elm species, especially
the Rock
Elm, Ulmus thomasi, and the Ornamental White Elm, Ulmus
americana,
yielded valuable wood with a beautiful grain. The wood of the Rock Elm is strong, tough, hard, elastic,
heavy, pliable and durable. It was
the most important source of hubs, spokes, fellies and wheel rims. It was also used for agricultural
implements and tool handles, butcher blocks, veneers and cooperage and in the
manufacture of furniture, musical instruments, woodenware and baskets. The White Elm has a softer, lighter and
weaker wood that was nevertheless tough and fibrous and had been used for the
same purposes. Dutch Elm Disease had
by the end of the 20th Century eliminated over 98 percent of the
White Elms. The tree survives only in
small, mostly far northern pockets where there is some protection from the
vectors of both a virus and the bacterium. Hickory trees are found in the
eastern deciduous forest from Ontario to Minnesota, Florida and Mexico. The wood of all species is used to some
extent, but the most important sources are the Shagbark
Hickory,
Carya
ovata,
the Mockernut, Carya tomentosa, and the Pignut, Carya glabra. The wood is one of the toughest, hardest,
heaviest and strongest and it is used where both strength and the ability to
withstand shocks are required. It is
a coarse straight-grained wood. The
sapwood is preferred to the heartwood.
Hickory has been used for spokes, fellics, axles and other parts of
wagons, and also for ax, pick and hammer handles, baseball bats, agricultural
implements, shafts of golf clubs, pump rods and cooperage. It is the standard for fuel wood and for
smoking meat. Black Locust, Robinia pseudoacacia, is another tree of
the eastern deciduous forest of North America. The wood is very heavy, strong, hard, durable and elastic. It has a coarse, open, crooked, compact
grain and a smooth, satiny surface.
It has been used mainly for insulator pins and brackets. It was also commonly used for tree nails,
boat ribs, fence posts, ties, sills, wagon hubs and mine timbers. The wood is of more importance in Europe
where it has been used for furniture and shipbuilding. Honey Locust, Gleditsia triacanthos, has similar
properties and uses. The leaflets are
much smaller than the Black Locust and the flowers are aromatic. This species has long thick seedpods. Maples constitute some of the most
important woods in North America. The
principal source of the commercial wood known as Hard Maple
is the Rock Maple or Sugar
Maple, Acer saccharum. This tree is a conspicuous species of the
eastern deciduous and northeastern transition forests. It ranges from southeastern Canada to
Georgia. Two other easier species,
the Silver Maple, Acer
saccharinum,
and the Red Maple, Acer
rubrum,
and the Oregon Maple, Acer
macrophyllum,
and the Oregon
Maple, Acer macrophyllum that occurs in
Washington and Oregon, furnish soft maple wood that is of lesser importance. Hard maple wood is tough, heavy,
compact, strong and very hard. It is
light brown in color with dense even grains and a fine texture. It may be finely polished and is often
beautifully grained and figured, as in the case of bird’s eye maple and curly
maple. These latter traits make it
one of the best woods for furniture, veneers, flooring, interior finish and
bowling alleys. It is also used for
violins and other musical instruments, shoe lasts, rulers, tool handles,
inlays, panels, keels of vessels, pianos, bowls, cooperage, charcoal, fuel
and wood distillation products. The
sap of the hard maples yields maple syrup and maple sugar. Oak has been regarded as the most
important of all hardwoods. The
timber has great commercial value, but the tree is also the largest and
finest of the hardwood forests. The
wood is tough, hard, resilient, durable and elastic. Its strength and ability to resist heavy
strains make it invaluable in shipbuilding and other types of heavy
construction. It also polishes easily
and is unmatched for decorative work.
There are more than 50 species of oaks in North America, about twenty
of which are of commercial importance These belong either to the white ok or
to the red oak group. Because
distinguishing between the woods of the different species, they are regarded
as either white or red oak. Lumber of white oaks is harder, stronger and more durable
than of red oaks. It is used for used
for building timbers, piling, railroad ties, machinery parts, agricultural implements,
furniture, flooring, cabinetwork, interior finish an cooperage. It is interesting to note that oak barrels
are the most satisfactory containers for wine, beer and alcoholic
spirits. The most important species
in this group include the White Oak, Quercus alba, the Bur
Oak, Quercus macrocarpa, the Post
Oak, Quercus stellata, the Chestnut
Oak, Quercus montana, the Swamp
Chestnut Oak,
Quercus
prinus,
the Oregon
Oak, Quercus garryana, and the Swamp
White Oak,
Quercus
bicolor. Lumber of the red oaks is softer,
more open grained, more porous and less durable than that of the white
oaks. The main species include the Red
Oak, Quercus borealis, the Black
Oak, Quercus velutina, the Scarlet
Oak, Quercus coccinea, the Pin
Oak, Quercus palustris, the Turkey
Oak, Quercus laevis, the Willow
Oak, Quercus phellos, the Texas
Red Oak,
Quercus
texana,
and the Shingle Oak, Quercus
imbricaria. There are several species of live oaks in North America, but the most important is Quercus virginiana, which as the hardest,
strongest and toughest wood of all the oaks.
It has been used in the construction of ships, wagons and farm
tools. There have never been great
quantities of this species available. Osage orange, Maclura pomifera, is a small tree
native to the Gulf States but which has been cultivated in other areas. The wood is the heaviest, toughest,
hardest and most durable of all the North American hardwoods. Only a small amount has ever been
available, which was used mainly for fellies, tree nails, insulator pins,
posts, stakes and woodenware. The
Amerindians used this wood for their bows, and it is the source of a
dyestuff. True poplars in North America are
referred to under several different names.
The most important is the Cottonwood, Populus deltoids, which is found in the
Central and Eastern portions of the continent. It has a soft, light, even-grained fibrous wood that is easy to
work with. Its main uses are as a
substitute for basswood in the manufacture of boxes and excelsior and as a
pulpwood. It has also been used for
woodenware, millwork and plywood. The Balsam Poplar, Populus
balsamifera,
several other large poplars, and the much smaller Aspens, Populus tremuloides and Populus grandidentata, have similar
uses. Aspen wood is also used in the
manufacture of furniture, matches and in cooperage and pulp for making book
paper. Red or Sweet Gum, Liquidambar
styraciflua,
has become of greater importance as a commercial wood by the middle of the 20th
Century. This tree ranges from
Connecticut to the mountains of Central America, attaining its finest
development in the Southeastern United States. The wood is soft and light, but resilient and tough. It is reddish brown in color, with a fine,
straight, close grain. It retains a
good polish. It is often stained to
imitate cherry, mahogany or walnut.
It has been extensively used for veneers, furniture, cabinetwork,
interior finish, fancy boxes and cooperage.
The wood is known in Great Britain under the name of Satin Walnut, and the tree is the source of Storax, a medicinal product.
The tree has a beautiful conical shape and has been planted widely as
an ornamental. The foliage changes to
a myriad of colors in autumn that rivals the hard maples. At latitudes of 31-38 deg. North in the
southeastern United States the autumn display occurs from October through
December and is as startling as that witnessed in the Northeastern portions
of the continent (see
Photos). Platanus occidentalis is a familiar tree
throughout the eastern deciduous forest of North America and it has a
characteristic bark that peels off in large patches. It is the largest hardwood tree, the wood
being tough, strong, hard and very durable.
It is light reddish brown with a close uneven grain. A mottled figure with lustrous rays is
created when quarter sawed. This is
often sold as lacewood.
Sycamore has been extensively used for tobacco boxes and other
containers because it is odorless. It
has also been used for millwork, furniture, interior decoration, butcher
blocks, yokes, boxes, crates, woodenware, cooperage, brushes and plywood. Liriodendron tulipifera is one of the largest
trees of the eastern deciduous forest of North America, reaching a height of
125-250 ft. and a diameter of 6-14 ft.
The wood is known commercially as Yellow Poplar or
Whitewood. It
is light, soft, and easily worked, with a fine straight grain. It is also stiff and durable although not
very strong. It has been used for
making boxes, furniture, carriage bodies, musical instruments, woodenware,
toys, and boats, light construction and veneers. There are two species that are
known commercially as tupelo, the Black Gum, Nyssa sylvatica, and Sour
Gum, Nyssa aquatica. Black gum is distributed from Michigan to
Maine and south to Florida and Texas, while the Sour Gum is restricted to the
swamps of the southeastern United States.
The wood is pale yellow with a dense, fine, twisted and interwoven
grain. It is soft, tough, light,
stiff and resistant to wear. Tupelo
has also been used for flooring, tobacco boxes, wheel hubs, woodenware,
veneers, railroad ties, handles, pulp, rollers, yokes and piling. The honey manufactured by bees from the
blossoms is of the very highest quality. Walnut & Butternut Black
Walnut,
Juglans
nigra,
has been one of the most valuable of North American woods. The tree is large and occurs in the
deciduous forest region from Minnesota and Massachusetts to Texas and
Florida. It is a moderately hard
wood, tough and strong and easily worked.
It is very durable. The color
varies from rich dark brown to purple black.
It has a fine even grain and a good figure and is able to take a high
polish. Black walnut has been
exploited to the point of becoming scarce.
It brings a high price, often being sold by the pound. It was being cultivated on farms by the
end of the 20th Century.
From the 17th Century onward it has been a principal wood
for the manufacture of gunstocks.
Other uses included furniture, millwork, cabinetwork, musical
instruments, airplane propellers, sewing machines and veneers. In pioneer days it was used locally for barns,
fences and light construction. The
nut that is produced is very flavorful. Butternut, Juglans cinerea, extends from New
Brunswick to Minnesota and south to Arkansas and Georgia. The wood is similar to Black Walnut in
nature and uses. However, the wood
lacks the color and is not as strong.
It is used primarily for boxes, furniture, crates, millwork, excelsior
and woodenware. Sugar is sometimes
obtained from the sap of the butternut and a dye is made from the green husks
that contain the fruit. Misc. Minor
Hardwoods Pyrus malus wood is usually
obtained from old orchards. It is
very strong, hard and compact with a uniform close grain. Uses have included the manufacture of tool
handles, knobs, pipes, mallet heads, canes, rulers and turnery. Alnus rubra is the largest of the
alders, and is of some commercial importance in Oregon and Washington west of
the Cascade Mountains. The wood has a
fine even grain, uniform texture and a reddish brown color. It works and polishes well and gives a
good imitation of Black Walnut and Mahogany.
Uses include the manufacture of furniture, millwork, handles and
novelties. Carpinus caroliniana is a small tree of
Eastern North America. The wood is
heavy, strong and very stiff. No
other wood exceeds its suitability for making levers. It is also used for charcoal and tool
handles.
Aesculus
octandra is
a tree of the Middle Western United States that has a soft, light, easily
worked wood. Uses have included the
manufacture of boxes, excelsior, millwork, piano keys, furniture, trunks and
artificial limbs. Magnolia acuminata is the largest and most
numerous of all the magnolias. It
ranges in the southern portion of the North American deciduous forest. Its soft, light, durable wood is used for
millwork, boxes, woodenware, excelsior and inexpensive furniture. In the trade it often is sold as yellow
poplar. Cornus florida is a small tree that
occurs throughout eastern North America but reaches its optimum development
in the southeastern United States.
The wood is very hard and heavy, with a fine, lustrous, close
grain. It is used mainly for shuttles
for cotton mills and is very resistant to wear. Other uses include wedges, bobbins, mauls, golf-club heads,
engraver’s blocks and cogs. Only the
sapwood has value. Catalpa speciosa is a small tree native
to the lower Ohio Valley. It has been
extensively planted in the Middle West.
The wood is very durable and is much used for railroad ties and fence
posts. The tree is often planted as
an ornamental, and has showy, aromatic blossoms in springtime. Gymnocladus dioica is a tree of the
eastern deciduous forest that has a strong and durable wood. It is used for the manufacture of
furniture, interior finish, bridges, sills, posts railroad ties and fuel. Celtis occidentalis is tree of eastern
North America. The wood is tough,
strong, heavy and moderately hard, and is used mainly in millwork and for boxes,
woodenware, furniture and cooperage. Ilex opacas is a prominent tree of
the Southern coastal area and lower Mississippi and Ohio Valleys of the
United States. It is perhaps best
known for its leaves and fruit that are associated with the Christmas
Season. The tough, close-grained,
whitish wood is used for inlays, brushes, fancy articles, and woodenware and
is often stained to imitate ebony. Ostrya virginiana occurs in Eastern
North America and is one of the hardest, toughest and strongest woods known,
but it is available only in small quantity.
It has been used for carriage parts, levers, handles and fence posts. Diospyros virginiana is a tree of the
southeastern United States. The
sapwood is very heavy, tough, hard, strong, elastic and resistant to
wear. It has been used mainly for
shuttles, boot and shoe findings, golf club heads and other sporting
materials and in turnery. The fruit,
which ripens in early autumn after a frost, is sweet and delicious. Sassafras albidum is a small tree of the
southeastern and Gulf portions of the United States. The wood is fragrant, durable, soft and
light. It has been used for
furniture, millwork, cooperage, fence rails and posts and boxes. A root beer is prepared from the roots. Salix nigra is the only species of
the numerous willows that has attained commercial importance. It is especially abundant in the flood
plains of the Mississippi and Ohio Valleys.
The smooth wood is soft, light, tough and somewhat strong. It has been used for boxes and crates,
plywood cores, excelsior, bats, boats, water wheels and charcoal. The long, slender, pliable young shoots
have been used to make wicker baskets and furniture. Forests in South America have been
decimated by indiscriminate logging and farming expansion, so that by the end
of the 20th Century less than 440 percent of the land area still
contained forest. The trees are
mostly tropical hardwoods (85 percent) with some temperate hardwoods (5
percent) and conifers (6 percent).
There are two major kinds of tropical hardwoods. The most abundant are in the dense humid
rain forest that occurs in the Guianas and the Amazon and Orinoco River
basins and along the eastern coast of Brazil. This forest is noted for the great number of species and for
the size and frequency of the individual trees. There were once over 2,500 different tree species in the Amazon
forest alone. This forest, which is
the most extensive body of solid forest in the world, has scant vegetation on
the forest floor due to the density of the canopy. Epiphytes and lianas are abundant and characteristic. In drier parts of Argentina and Brazil
there is an open deciduous type of tropical forest. Mixed forests of conifers and temperate hardwoods occur along the
northern Andes and again in the southern Cordilleras. Conifer forests are mainly of the Paraná
Pine, Araucaria angustifolia. These cover large areas in southern Brazil
and Argentina, while similar areas, with Araucaria araucana the dominant species,
occur in Central Chile. In Argentina
and Paraguay there are extensive areas of open forests composed mainly of Quebracho, Schinopsis lorentzii and Schinopsis balansae, important sources of
tanwood. Tropical forests in Mexico,
Central America, the West Indies and South America have been harvested for
centuries for some of the most high-grade cabinet and furniture woods of
commerce. However, these forests have
been little exploited as a source of ordinary lumber. The number of valuable species is
vast. Brazil alone may have more than
3,000 woody species, including 50 of the most valuable cabinet woods. Some of the more important species are
discussed. Ochroma pyramidale is a soft and pithy
wood that weighs only 10 lbs per cubic foot.
The tree is found in the tropical forests from southern Mexico to
northern Peru. Ecuador has furnished
most of the world’s supply. Balsa is
obtained mainly from wild trees, although some plantations have been
established. This species grows
faster than any other rain forest tree except the Papaya, and reaches a
height of 12 ft. in one year. It may
be harvested when only two years of age, but usually trees 6-9 years old are
selected. The presence of air in the cell
cavities gives this wood its light weight and buoyancy. It has been used for life preservers,
buoys, swimming belts, floats, rafts, pontoons, sea sleds, surfboards, toys
and motion picture sets and in airplane construction. The wood also possesses good insulating
properties and has been used to line refrigerators, vehicle bodies and the
olds of ships. It possesses sound
deadening properties and has been used to line ceilings and partitions under
heavy machinery to reduce vibrations.
The hairs from seeds have been used as stuffing material.
Gossypiospermum praecox has been used as a substitute for European boxwood in the
manufacture of engraver’s blocks, rulers and other scientific instruments,
shuttles, spools, musical instruments, inlays, bobbins and veneers. The supply originates mainly in Venezuela. Spanish or Cigar Box Cedar, Cedrela odorata, ranges throughout
tropical America, both as a native and introduced species. It is an important timber tree for local
use in tropical America. The wood is reddish
brown and aromatic with a straight coarse grain. It has been used for cigar boxes and it is an insect
repellent. Other uses include linings
for closets, chests, and shingles and as a substitute for mahogany. Brya elbenus is also called American Ebony or Granadillo. The wood is used for knife handles,
musical instruments (flutes and clarinets), turnery, inlays and
cabinetwork. It is a very hard and
durable wood and it polishes well.
The supply is mainly from the West Indies. Dalbergia retusa is a tree that occurs
from Mexico to Panama. It is one of
the showiest and most strikingly colored of the exotic woods. The heartwood is orange-to-orange red
in color, streaked with jet black. It
is very hard, tough and strong, and has been used for instruments, knife and
umbrella handles, steering wheels, inlays, lacquer and turnery. Carapa guianensis attains its best form
in the Guianas, although it occurs also in other parts of South America and
the West Indies. This very strong and
hard, brown wood is used as a substitute for mahogany. Ocotea rodioei is native to
Guyana. The greenish-brown wood is
used for structural timbers as it is one of the strongest and is hard, heavy,
tough, resistant to decay and insect injury and elastic. It has been widely used in Europe for
bridges, piles, wharves, paving blocks and shipbuilding. It is also used for shafts, spokes and
fishing rods. Two trees of the West Indies constitute the lancewood of
commerce: Lancewood, Oxandra lanceolata and Degame
or Lemonwood, Calycophyllum candidissimum. These give a yellowish wood with a fine
close grain and which is very tough, strong and elastic. They are used for fish poles, spars,
shafts, whips, ramrods, bows, cues, lances and turnery. Piratinera guianensis of Guyana yields a
very heavy ornamental wood. The color
is brown with peculiar black markings.
It has a close, fine and lustrous grain. It has been used for canes, umbrellas, violin bows, drumsticks,
veneers and inlays. Two species, Guaniacum officinale and G. sanctum supply this important
wood. The trees occur in southern
Mexico, Central America and the West Indies.
This is one of the hardest of commercial woods, and it is naturally
tough, strong and resistant. The
color is dark brown, streaked with black, with a very fine, intricately woven
grain. It also contains a resin that
acts as a natural lubricant and preservative. It has been used for bearings or bushing blocks for steamship
propeller shafts. It is also used to
manufacture bowling balls, pulley blocks and conveyors, instruments and
furniture. It was once believed that
Lignum Vitae possessed remedial powers for many human diseases, and that is
how it got its name “lignum vitae” or “wood of life.” A gum resin, Guaiacum,
is used in medicine and occurs in the form of tears excreted from the living
tree. Hymenaea courbaril is a very important
timber tree in tropical America. The
wood is hard and tough, and it is used for general carpentry, furniture
shipbuilding and cabinetwork. This
species supplies South American Copal. Several species of Mahogany make up the most
important export wood in tropical America, and they are the source of the
world’s most valuable timber and premier cabinet wood. These are Swietenia mahogany, the West Indian Mahogany or Spanish
Mahogany was used for woodwork by 1514 A.D. This species that ranges from the Florida Keys to the West
Indies, was the first to be harvested commercially and the first to be
exploited. It has been introduced
into Central America and other tropical countries. Another species, Swietensia macrophylla, occurs from Yucatan to northeastern
Colombia and Venezuela and along most of the southern effluents of the Amazon
in Brazil, Peru, and Bolivia.
Although there are a few other species, for practical purposes all the
native mahogany cut in North and South America probably belongs to this
species. The cathedral of Santo Domingo
that was built in 1550 contains some magnificent mahogany carvings that are
still in top condition. The early
Spanish explorers utilized the timber for shipbuilding, and it was also used
for building construction in England by 1680. From the beginning of the 18th Century it began to
be used as furniture wood. During the
years 1750 to 1825 great craftsmen of
furniture, Chippendale, Adam, Hepplewhite and Sheraton, used mahogany. Mahoganys are ornamental evergreen
trees that reach a height of 40-50 ft. with large buttresses at the
base. The trees occur scattered
through rich moist forests about one to the acre. The wood is reddish brown with a crooked grain. It is very heavy, strong, hard enough to
resist indentations, but easy to work with and it polishes and glues
well. It has been used for furniture,
fixtures, musical instruments, millwork, cars, ships and boats, caskets,
airplanes, foundry patterns, veneers and plywood. There are many substitutes and imitations, but the supply of
true mahogany is still abundant, especially as plantations production is
proving successful. Also known as Blue
Mahoe, Hibiscus
elatus
of the West Indies is a hard and slightly aromatic wood with a lustrous,
richly variegated, open grain. It has
been used for cabinetwork, carriages, gunstocks, fishing rods and ship’s
knees. It is the source of Cuba Bast. Mora excelsa of Guyana, Venezuela
and Trinidad yields a brown wood that is very hard, tough and even more
durable than teak. It has been used
primarily in Europe for shipbuilding, platforms, railroad ties and all types
of heavy construction. Sometimes called White
Mahogany,
Cybistax
donnell-smithii
occurs in southern Mexico, northern Honduras, El Salvador and Guatemala. The cream colored wood is used for
furniture and fixtures, millwork, ships. Boats, cars and veneers. The tree is also very ornamental with many
yellow flowers that appear before the leaves. Peltogyne paniculata occurs in Brazil, the
Guyanas and Trinidad. The brown wood
is very hard, tough, strong and durable.
It gradually turns purple on exposure to the air. It has been used for heavy construction,
furniture, billiard tables, cues, fishing rods, inlays and turnery. Brazilian
Rosewood,
Dalbergia
nigra, is
the best known of several different species.
The dark purple, almost black, wood is often striped and has a coarse,
dense, even grain. This is one of the
finest cabinet woods and also finds use for scientific instruments,
furniture, cars, pianos, sporting and athletic goods, brushes and handles. West Indian Satinwood, Zanthoxylum flavum, has been used to make
furniture for a long time. It was
especially valued in Great Britain by such builders as Sheraton, Adam and
Hepplewhite. The creamy or golden
yellow wood is smooth and lustrous and slightly oily. It has a very close, dense and even
grain. Other uses have included
millwork, musical instruments, caskets, brushes, inlays, cabinetwork and
veneers. The forests in Europe
have occupied about 30 percent of the land area for quite some time as they
are rigidly managed. About 70 percent
of the forests are coniferous, 24 percent are temperate hardwoods and less
than 2 percent are mixed forests. The
coniferous woodlands are especially numerous in the northern portion of the
continent, while the hardwood and mixed forests are found in Southern and
Western Europe. The original forest
cover of Europe has been greatly depleted from long utilization and the
necessity of clearing land for agriculture and industry. In the British Isles only about 5 percent
of the original forest was left by the end of the 20th
Century. In France, Spain, Belgium,
Italy and Greece about 10-20 percent was left. Over half the forests in Sweden and Finland are original, and
together with Russia, are the most heavily forested regions in Europe. There are many genera of American
origin found in European forests. The
principal conifers are the Scotch
Pine, Pinus sylvestris and Norway
Spruce,
Picea
abies. These furnish the woods referred to as Yellow
Deal and White
Deal,
respectively. Other conifers include
the Cluster Pine, Pinus pinaster, the Stone
Pine, Pinus pinea, the Silver
Fir, Abies alba, Larch, Larix deciduas, and Yew, Taxus baccata. American white pine and Douglas fir are also extensively
planted. Oak trees represent the most
important hardwoods in Europe. The
principal species are Quercus cerris, Quercus
robur and
Quercus
petraea. Other hardwoods include the Black
Alder, Alnus glutinosa, European
Ash, Fraxinus excelsior, European
Beech, Fagus sylvatica, European
Birches,
Betula
pendula
and Betula
pubescens,
European Cherry, Prunus
cerasus,
European Chestnut, Castanea sativa, European
Elm, Ulmus procera, Hazel, Corylus avellana, European
Holly, Ilex aquifolium, European
Hornbeam,
Carpinus
betulus,
European
Lime, Tilia cordata, European
Maple, Acer pseudoplatanus, European
Plane, Platanus orientalis, Rowan, Sorbus aucuparia, Blackthorn or Sloe, Prunus spinosa, and European Willow, Salix alba. The main European trees that have
been imported into North America include the Boxwood, Walnut, Briar and
Olive. Turkish Boxwood, Buxus sempervirens, of Southern Europe,
Asia Minor and Northern Africa, has practically disappeared due to over
exploitation. The wood of this tree
is very hard, with a fine, dense, uniform grain and a smooth, lustrous
texture. It was sued for blocks,
engraving, rulers and other instruments, shuttles, bobbins, firearms, whips,
canes, inlays, umbrellas and turnery. English Walnut, Juglans regia, also called Circassian Walnut, occurs naturally from the Black
Sea region across Asia Minor and Persia to northern India. The wood is hard and beautifully figured
and it takes a high polish. Wood
obtained from the burls is particularly valuable. It has been used for fixtures and furniture, millwork, musical
instruments, firearms, cabinetwork, turnery and veneers. European Olive, Olea europaea, has wood that is
suitable for brushes, canes and turnery, and of course the fruit is
invaluable for its oil. Briar
Root, Erica arborea, has been
traditionally used for tobacco pipes. By the end of the 20th
Century forests covered less than 19 percent of the land area in Asia. These forests are most abundant in the
northern and eastern parts of the continent and they are very sparse in the
southwest. Much of the original
forest area has been exploited to complete destruction. This is particularly evident in China,
where centuries of cultivation have not only destroyed the forests, but much
of the arable land as well because of over cultivation and subsequent
erosion. Conifers make up about 40 percent of the forest area. These are characteristic of most of
Siberia and also occur in the Himalayas and the mountains of Asia Minor,
Japan and China. European species are
found in the western part of the continent, giving way to more distinctive
Asiatic species of the same genera in the east. Pine, Spruce, Fir, Juniper, Cedar, Larch and Yew are the
principal groups. Temperate hardwoods make up about
26 percent of the forests. These and
mixed forests are found in the southern portions of Russia, Afghanistan,
Iran, Asia Minor, China and Japan.
European species are found in the western part of the continent,
giving way to more distinctive Asiatic species of the same genera in the
east. Maple, Ash, Basswood, Poplar,
Alder, Birch, Walnut, and Oak are the principal groups. Tropical hardwoods make up about 30
percent of the total forest area and are found south of the Himalayas. In many areas they comprise all of the
woody species. This is particularly
true in Sri Lanka, Thailand, the East Indies and Malaya. As in other tropical forests the number of
species is very large. India is
estimated to have about 2,000 and Japan 1,000 different species. Many of the Asiatic forests are dominated
by teak, while others are composed mainly of members of the Dipterocarpaceae and Leguminosae. The former family comprises over 75
percent of the tree species in the Philippines. A large number of these Asiatic woods enter into world
commerce, the most important of which include Ebony, Padouk, Satinwood and
Teak.. There are several species of tree
that furnish a wood known as ebony, the most important of which is the Macassar
Ebony, Diospyros ebenum, found from India to
the East Indies. The wood is black
with brown stripes. It is very hard
and heavy and has a fine grain. It
takes a high polish and has been used since ancient times as a cabinet
wood. Other uses include canes,
whips, umbrellas, piano keys, sporting and athletic goods, inlays, handles,
turnery and veneers. Also called Burmese
Rosewood, Pterocarpus indicus is a very ornamental
tree. The lustrous wood is red in
color with black stripes. It is hard
and durable and polishes well. Padouk
has been used for furniture, fine cabinetwork, car construction, millwork,
veneers and turnery. The tree has
been introduced into Honduras. East
Indian Satinwood, Chloroxylon swietenia, has a hard yellowish or dark brown heartwood that is
sometimes mottled. It has a satin
like luster and a fine, dense, even grain. Satinwood is used for cabinetwork,
furniture, brushes and veneers. Tectona grandis is native to
Southeastern Asia and Malaya. It is
one of the most durable of woods and is a very important timber of the
tropics. The wood is hard and it does
not warp, split, or crack. Thus it is
valuable for general construction. It
is also very resistant to termites and decay. The color is yellowish brown and greasy to the touch. It has been widely used in ship and boat
building, and for cabinetwork, furniture, millwork, piles, railway cars,
greenhouses and flooring. The tree
has been introduced into the West Indies and Panama where it has shown
phenomenal growth. One tree attained
a height of 64 ft. and a diameter of 18 in. in less than 16 years. Other important trees of tropical
Asia that supply valuable wood include the Acle or Pyinkado, Xylia
xylocarpa,
Deodar, Cedrus deodara, Sal, Shorea robusta, and Sissoo, Dalbergia sissoo. These have all been used for general
construction Additional species used
for cabinet manufacture include Moulmein Cedar, Cedrela toona, Laurelwood, Calophyllum inophyllum, Rosewood, Dalbergia latifolia and Asian
Sandalwood,
Santalum
album. The African
Continent consists of primarily of deserts or semi-deserts, so that forests
cover only about 10 percent of the area.
These begin south of the Sahara Desert. Tropical hardwoods are in the majority with over 95 percent of
the forests. Temperate hardwoods
account for less than 4 percent and conifers less than one percent, the
latter being restricted to lands along the Mediterranean and the higher
mountains in Central, Eastern and Southern Africa. Two main types of tropical forests
occur. First, the extensive dense
rain forest that covers much of equatorial Africa, especially the West
African coast and the Congo Basin.
This region has a rainfall of 60-160 in., which is uniformly
distributed throughout the year.
Salient characteristics of this forest are the mangrove swamps along
the coast. An open park like forest
exists in regions where rainfall is only 30-40 in. Large areas of this type of forest occur in the northeastern
and southern parts of Africa, especially in Angola and Zimbabwe. There are many important kinds of woods
that resemble those of tropical America and Asia, but they have not been as
extensively exploited. African
Mahogany,
Khaya
senegalensis,
a West Coast species, is exported in some quantity. This substitute for true mahogany has a wood that is
beautifully figured and colored. The
coastlands from Senegal in the west down through Mozambique in the east
contain scattered stands of palm thickets prominent among which is the Senegal
Date, Phoenix reclinata. An era of forest exploitation
began in the equatorial rainforest at the end of the 20th Century,
which is threatening the existence of many native species. Efforts to curb this devastation are met
with resistance from the local populations that are facing continuous
political unrest. In Australia only
about 6 percent of the land area is covered in forests. In New Zealand about 26 percent is
forested and in Oceania 70 percent.
The most extensively forested regions are New Guinea with 80 percent,
Samoa with 70 percent and Tasmania with 64 percent. Conifers comprise about 4 percent of the Australian forests and
11 percent are temperate hardwoods with the rest being tropical
hardwoods. Conifers are found in New
South Wales, Queensland and Tasmania and temperate hardwoods only in
Tasmania. Tropical hardwoods occur in
all the states except Tasmania. These
forests are dense and resemble the size and density of those along the
Pacific Coast in North America.
However, the species differ from those found in other parts of the
world. Most trees are either eucalyptus
or acacias. Over 70 commercial
species of Eucalyptus exist, the most important of which are the Karri, Eucalyptus diversicolor, and Jarrah, Eucalyptus marginata of Western Australia.
Karri may reach a height of 300 ft. with a clear length of 180
ft. Other valuable trees are the Blackwood, Acacia melanoxylon, and Silk Oak, Grevillea robusta. The predominant
coniferous species is Hoop Pine, Araucaria cunninghamii. About 68
percent of the forests in New Zealand are coniferous and the rest
hardwoods. The main species is the Kauri Pine, Agathis australis, one of the largest timber trees in the world. The wood is strong and durable and
generally free from knots. It has
been exported in large quantities. An
important resin is also extracted from the kauri. Other valuable species include the New Zealand White Pine, Podocarpus dacrydioides, Totara, Podocarpus totara, New Zealand Red Pine, Dacrydium cupressinum and
several species of beech. Forests in Oceania are composed
entirely of tropical hardwoods, with few being of importance for export. On the small island of Norfolk off the
east coast of Australia, the Norfolk Pine, Araucaria
heterophylla (excelsa), was being harvested
in considerable quantity in the 20th Century for timber. Its rapid growth enabled a viable industry
on the island, only five miles in diameter. |