moss and leaves of
the forest floor. Birds also scatter tree seed here, there, and
everywhere over the forests and the surrounding country. Running
streams and rivers carry seeds uninjured for many miles and
finally deposit them in places where they sprout and grow into
trees. Many seeds are carried by the ocean currents to distant
foreign shores.
The decay of leaves and woodland vegetation forms rich and
fertile soils in the forests, in which conditions are favorable
for the development of new tree growth. When living tree seeds
are exposed to proper amounts of moisture, warmth and air in a
fertile soil, they will sprout and grow. A root develops which
pushes its way down into the soil, while the leaf-bud of the
plant, which springs from the other end of the seed, works its
way upward toward the light and air. This leafy part of the seed
finally forms the stem of the tree. But trees may produce plenty
of seed and yet fail to maintain their proper proportion in the
forest. This results because much of the seed is unsound. Even
where a satisfactory supply of sound fertile seed is produced, it
does not follow that the trees of that variety will be maintained
in the forest, as the seed supply may be scattered in unfavorable
positions for germination. Millions of little seedlings, however,
start to grow in the forest each year, but only a small number
survive and become large trees. This is because so many of the
seedlings are destroyed by forest fires, cattle and sheep
grazing, unfavorable soil and weather conditions, and many other
causes.
Beech and chestnut trees and others of the broad-leaved type
reproduce by means of sprouts as well as by seed. Generally, the
young stumps of broad-leaved trees produce more sprouts than the
stumps of older trees which have stood for some time. Among the
cone-bearing trees reproduction by sprouts is rare. The redwood
of California is one of the few exceptions. The pitch pine of the
Eastern States produces many sprouts, few of which live and
develop into marketable timber.
When trees are grown in nurseries, the practice is to sow the
seed in special beds filled with rich soil. Lath screens are used
as shade. They protect the young seedlings from the sun just as
the parent trees would do in the forest. The seedbeds are kept
well cultivated and free of weeds so that the seedlings may have
the best opportunities for rapid growth. Generally the seeds are
sown in the spring between
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