The anti-monopolist. [volume] (Saint Paul, Minn.) 1874-1878, 1877-01-18
FORESTS.

Forests, 1t seems, have q fourfold effect
on climate and rainfall. There is the CHI emf
col action oftLeir leaves, which decompose
the carbonic acid of the air, fixing the car
bon in their woody tissue, and liberat;ng
the oxygen. There is their physical action
in hindering evaporation and stopping cur
rents Of air, and in covering the ground with
q vegetable mould which holds water like a
sponge. And the organic action of the
leaves, which in breathing, restore to the
air part OF the water which the roots
have drained from the soil. Lastly, there is
the mechanical action of the roots, which at
onco prevents the earth from being washed
away by rain, and also enables the water
TO filter down deep into the ground. Forests
then, ought to make country cooler, by
Withdrawing the carbon from the air; the
heat that is set free when wood is burned is
the very heat that was being absorbed while
1t was growing forest may be looked
upon as a vast condensing appapatus for
storing up the heat of the atmosphere That
is what theory says, and experiment con-
firms 1t. The mean temperature of wood
ed country is always lower than that of q
similarly Situated treeless country; but
and this is importantly the cold is l,ss ex>
IRENE as well rs the heat, and changes Of
temperature are gradual. OF course, since
rain comes because the rain is too cool TO
held its moisture any longer in solution,
there ought TO be more rain in wooded
than IN q treeless district and so there is
from six to eight per cent. as NJ. Frantrat
found by putting up several rain gauges,
some In forest, seven yards above the
tree>tops, others on treeless ground some
two hundred yards off. Bare soil soon gets
heated, and heats the surrounding air.
Every one must have felt the soft warmth
Of the air in wool just after nightfal so
different from the chill that comes on after
u hot day in an open plain. No wonder
evaporation and radiation Of heat are much
greater in the after than in the former.
But, it may be said. if the trees bring more
rain, they use up more than the treeless
ground, for their roots drain the soil, and
their leaves drain the atmosphere Not So:
though wood is more than half water, the
amount of water contained in all the wood
IN forest isthe veriest trife compared with
the rain that falls on it during tho year.
Moreover, series Of experiments seems to
snow that the amount of water decomposed
by on acre of forest is very much less Than
that required by an acre OF cabbage, or
wheat. or clover. Again, because pines and
other trees (notably the blue gum Eucalyp
the glohulns. which is being planted by the
million in Algeria dry up marches, il has
been argued that trees mist lesson the water
supply. But here again experiment comes
In. and proves that this drying up is not
due TO evaporation through the leaves. or
TO the water being in any other way sucked
up by the trees. All the trees that have
this property can, and do. thrive also in
dry, hungry soils; they drain the soil by
virtue Of their spreading roots. which en-
ables the water to run of into the lower
strata.
Hence 1t seems clear that the forests low
or the temperature, while they prevent ex-
tremes, and increase the raiafuil. nj the
same time that they regulate il, and keen
eff those deluges OF rain which cause sudden
and destructive foods. Floods do come in
wooded countries: but they are not floods
ike those of the Loire. which rising in bare
granite mountains. brings down. when i,
overfiows. mass of sand and single which
ruins some of the best land in France. Dnr-
ing the terrible rains of September. 1866.
careful observations we're made in Savoy
and Auvergne, and it was seen that when