The Holly chieftain., 1908-05-29
PHYSIOLOGY OF TREES.
Some Facts as to Their Life and
Growth.

Roots and leaves are the life Or
gans Of trees. A large part of the
roots. however, only serve as con-
ductors Of water and food material.
The young fibrous roots that are COW
cred by fine hairs, are the only ones
which take water and minerals from
the soil. The trunk and branches
simply serve as conductors of food
material between the leaves and roots:
If the fibrous roots are cut off or ex-
posed 30 that they dry out, the tree
will, In all probability, die.
Some trees, like locusts, willows,
poplars, etc, have the power of re-
newing their roots readily. Such
trees always transplant easily. There
fore, the first care in transplanting
trees is to keep the fibrous roots from
drying out. and to protect them from
injury during the time which tran
spires before the tree is planted
again.
In growing, trees build up a body
OF cell tissues, make foliage, flowers
and fruit.
They take up food material from
the soil and air, changing it into eel
lulose and various other compounds
Like all other plants, trees depend
upon moisture, heat and light as the
means of performing their growth.
From the soil trees principally get
water by means Of the fibrous roots.
This water is carried to the leaves,
through the trunk and branches, be-
ing partly used for wood formation
on its way and partly given up to
the air by the leaves.
Minerals are taken only in small
quantities and consist mostly of lime,
potash. magnesa and nitrogen. They
are carried to the leaves where they
combine with part of the water in
food preparation.
The largest amount of water, how
ever, taken up by a tree, transpires,
or in other words, is given TO the air
in the form of vapor. So most of the
mineral substance remains in the
leaves, these in turn return it to the
soil. when they are shed and left to
decOmpOse on the ground. This ex-
plains the fertility Of soil in timber
land.
But now We must return to what
the tree gets from the air.
The solid portions Of a tree, writes
B. Schwering, in Farmers Voice, is
made largely of cellulose, which con-
sists Of carbon with hydrogen and
oxygen. The tree gets its car
bon by taking carbonic acid from the
air, into the leaves. This, under the
influence Of light, air and water, is de-
composed.
Oxygen is thrown out and the re-
naming carbon forms compounds
such as starch, sugar, etc, by combin-
ing with elements taken from the
water. These compounds, which are
| used as food matter, pass downward
through thu tree to the very tips
of It's root-, making new wood all
along.
| This process of food preparation
can be carried on only in the green
parts which are exposed to light and
air. therefore the more foliage and
light tree naA. the quicker will 1t
grow. The leaf and root systems are
both dependent upon each other. for
the roots need the food prepared by
| the leaves just as the leaves require
the water sent up by the roots.
A leaf consists Of cells, lying close.
ly together and covered by a sack
known as the epidermis. Between the
cells are small spaces known as in.
tercellular spaces. The epidermis has
minute openings which open into the
intercellular spaces. allowing the air
and other gases to come in contact
with the cells. These cells take car.
bon dioxide and give up oxygen.
AS oxygen is the gas which we need
in breathing, and carbon dioxide the
poison which we breathe out. 1t can
readily be seen that every plant or
tree is an important factor in the
health of plants and animals.
One spraying with Bordeaux mix.
ture before the grapes bloom is OF more
] value than three or four after that