THE FOREST FAMILIES
Trees are as queer in picking out places to live and in their
habits of growth as are the peoples of the various races which
inhabit the world. Some trees do best in the icy northland. They
become weak and die when brought to warm climates. Others that
are accustomed to tropical weather fail to make further growth
when exposed to extreme cold. The appearance of Jack Frost means
death to most of the trees that come from near the equator. Even
on the opposite slopes of the same mountain the types of trees
are often very different. Trees that do well on the north side
require plenty of moisture and cool weather. Those that prosper
on south exposures are equipped to resist late and early frosts
as well as very hot sunshine. The moisture needs of different
trees are as remarkable as their likes and dislikes for warmth
and cold. Some trees attain large size in a swampy country. Trees
of the same kind will become stunted in sections where dry
weather persists.
In some parts of the United States forestry experts can tell
where they are by the local tree growth. For example, in the
extreme northern districts the spruce and the balsam fir are
native. As one travels farther south these give way to little
Jack pine and aspen trees. Next come the stately forests of white
and Norway pine. Sometimes a few slow-growing hemlock trees
appear in the colder sections. If one continues his journey
toward the equator he will next pass through forests of
broad-leaved trees. They will include oak, maple, beech,
chestnut, hickory, and sycamore.
In Kentucky, which is a centre of the broad-leaved belt, there
are several hundred different varieties of trees. Farther south,
the cone-bearing species prevail. They are followed in the march
toward the Gulf of Mexico by the tropical trees of southern
Florida. If one journeys west from the Mississippi River across
the Great Plains he finally will come to the Rocky Mountains,
where evergreen trees predominate. If oak, maple, poplar, or
other broad-leaved trees grow in that region, they occur in
scattered stands. In the eastern forests the trees are close
together. They form a leafy canopy overhead. In the forests of
the Rockies the evergreens stand some distance apart so that
their tops do not touch. As a result, these Western forests do
not shade the ground as well as those in the east. This causes
the soils of these forests to be much drier, and also increases
the danger from fire.
The forests of western Washington and Oregon, unlike most
timberlands of the Rocky Mountain Region, are as dense as any
forests in the world. Even at midday it is as dark as twilight in
these forests. The trees are gigantic. They tower 150 to 300 feet
above the ground. Their trunks often are 6 feet or larger in
diameter. They make the trees of the eastern forests look
stunted. They are excelled in size only by the mammoth redwood
trees of northern California and the giant Sequoias of the
southern Sierras.
[Illustration: THE SEQUOIAS OF CALIFORNIA]
Differences of climate have largely influenced tree growth and
types in this country. The distribution of tree families is
changing all the time. It shifts just as the climate and other
conditions change. Trees constantly strive among themselves for
control of different localities. For a time one species will
predominate. Then other varieties will appear and displace the
ones already established. The distribution of trees changes very
remarkably from one century to another. For example, in some
sections, the red and black oaks are replacing the white oaks.
Some trees are light-lovers. They require much more sunlight than
others that do well under heavy shade. Oak trees require plenty
of light; maples or beeches thrive on little light.
The seed of trees requiring little light may be scattered in a
dense forest together with that of trees which need plenty of
daylight in order to make normal growth. The seedlings that like
shade will develop under such conditions while those that need
light will pine away and die. Gradually the shade-loving trees
will replace the light-loving trees in such a forest stand. Even
the different trees of the same family often strive with one
another for light and moisture. Each tree differs from every
other one in shape and size. Trees will adapt themselves to the
light and moisture conditions to which they are exposed. A tree
that has access to plenty of moisture and sunlight grows evenly
from the ground to its top with a bushy, wide-spreading crown.
The same tree, if it grows in the shade, will reach a greater
height but will have a small compact crown. Trees run a race in
their rapidity of growth. The winners get the desirable places
in the sunlight and prosper. The losers develop into stunted
trees that often die, due to lack of light exposure. A better
quality of lumber results from tall straight trees than that
produced by the symmetrical, branching trees. That is why every
forester who sets out trees tries to provide conditions which
will make them grow tall and with the smallest possible covering
of branches on the lower part of the trunks.
Where trees are exposed to strong winds, they develop deep and
strong root systems. They produce large and strong trunks that
can bend and resist violent winds which sway and twist them in
every direction. Such trees are much stronger and sturdier than
those that grow in a sheltered forest. The trees that are blown
down in the forest provide space for the introduction and growth
of new varieties. These activities are constantly changing the
type of tree growth in the forest.
Our original forests which bordered the Atlantic coast line when
America was first settled, were dense and impenetrable. The
colonists feared the forests because they sheltered the hostile
Indians who lurked near the white settlements. In time this fear
of the forest developed into hatred of the forest. As a result,
the colonists cut trees as rapidly as they could. In every way
they fought back the wilderness. They and their children's
children have worked so effectively that the original wealth of
woodlands has been depleted. At present, cleared fields and
cutover areas abound in regions that at one time were covered
with magnificent stands of timber.
In many sections of the country our forests are now so reduced
that they are of little commercial importance. However, these
areas are not yet entirely denuded. Predictions have been made
frequently that our woodlands would soon disappear. Scientific
foresters report that such statements are incorrect. There are
only a few districts in the country which probably will never
again support much tree growth. Their denuded condition is due
largely to the destruction of the neighboring mountain forests
and to the activities of erosion. Under ordinary conditions,
natural reforestation will maintain a satisfactory tree growth on
lands where a practical system of forest protection is practiced.
The complete removal of the forest is now accomplished only in
fertile farming regions, where the agricultural value of the
land is too high to permit it to remain longer in forest cover.
Even in the Mississippi Valley and the Great Lakes belts there
are still large areas of forest land. Most of the farms have
woodlots which provide fuel, fencing, and some lumber. For the
most part, these farm woodlots are abused. They have not been
managed correctly. Fortunately, a change for the better is now
evident. The farm woodlot owners are coming to appreciate the
importance of protecting the trees for future use. In some cases,
they are even replanting areas that have been cut over. There are
large tracts of sandy, rocky and swampy land in these districts
that are satisfactory for tree production. In fact, about all
these fields are good for is the growing of timber. Campaigns are
now under way to increase tree planting and develop the
production of lands adapted for forestry which previously have
been idle.
The United States of the future will not be a desert, tree-less
country. However, immediate measures to save our remaining trees
must be developed. The greater part of our virgin timber has
already been felled. The aftermath forests, which succeed the
virgin stand, generally are inferior. Our supplies of ash, black
walnut and hickory, once abundant, are now seriously limited.
Formerly, these mixed forests covered vast stretches of country
which today support only a scant crop of young trees which will
not be ready for market for many years. These second-growth
stands will never approach in value or quality the original
forests. Over large areas, poplar, white birch, and Jack pine
trees now predominate on lands which formerly bore dense stands
of white pine. In many places, scrubby underbrush and stunted
trees occupy lands which heretofore have been heavy producers of
marketable timber trees.
Generally speaking, farm lands should not be used for forestry
purposes. On the other hand, some forest lands can be profitably
cleared and used for agriculture. For example, settlers are
felling trees and fighting stumps in northern Wisconsin,
Michigan, and Minnesota. Some of these virgin lands are valuable
for farming purposes, others are not. It is preferable that they
should produce farm crops instead of tree crops if the land is
best adapted to agricultural use. It is an economic necessity
that all lands in this country best suited for farming purposes
should be tilled. Our ever-increasing population demands that
every acre of land useful for growing crops should be cleared and
devoted to farming. Under such conditions, the settlers should
reserve sufficient woodlands for their home needs, carefully
distinguishing between the land that is best for agricultural
purposes and the land that is best for forestry purposes, and
thus doubling their resources.
Thoughtless lumbermen have pillaged millions of acres of our most
productive forests. The early lumbermen wasted our woodland
resources. They made the same mistakes as everyone else in the
care and protection of our original forests. The greatest blame
for the wasting of our lumber resources rests with the State and
Federal authorities who permitted the depletion. Many of our
lumbermen now appreciate the need of preserving and protecting
our forests for future generations. Some of them have changed
their policies and are now doing all in their power to aid forest
conservation.
The ability of a properly managed forest to produce new crops of
trees year after year promises us a future supply of wood
sufficient for all our needs if only we will conserve our
timberlands as they deserve. It is our duty to handle the
forests in the same way that fertile farming fields are managed.
That is to say, they should be so treated that they will yield a
profitable money crop every year without reducing their powers of
future production. Private owners and farmers are coming slowly
to realize the grave importance of preserving and extending our
woodlands. The public, the State and the Nation are now solidly
behind the movement to improve our forestry and to safe-guard
our forests. Several of the States, including New York and
Pennsylvania, have purchased large areas of timberlands for State
forests. These will be developed as future sources of lumber
supply.