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

Forests, it seems, have fourfold effect
on climate and rainfall. There is the CHI emf
cal action oftLeir leaves, which decompose
the carbonic acid Of the air, fixing the car.
bon in their woody tissue, and lberat;ne
the oxygen. There is their physical action
in hindering evaporation and stopping cur
rents Of air, and in covering the ground with
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
oDco 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 q 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
it was growing a forest may be looked
upon as vast condensng appapatus for
storing up the heat of the atmosphere That
is what theory says, and experiment con-
firms 1t. The mean temperature of a wood
ed country is always lower than that of q
similarly situated treeless country; but,
land this is importantly the cold is l., IS ex>
IRENE rs well Ms the heat, and changes Of
temperature are gradual. OF course, since
rain comes because the rain ID too cool to
held It's 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 q 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 a wool just after nightfall, so
different from the chill that coues 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, il 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 is the veriest triae compared with
the rain that falls on it during the year.
Moreover, series of experiments seems TO
snow that the amount of water decomposed
by on acre Of forest is very much less than
Aact aSduaSa W aA acre OF CaNnAGc. or
wheat. or clover. Again, because pines and
other trees (uotably the blue gum. Eucalyp
the globulns, which is being planted by the
million in Algeria.) dry up marches, il has
been argued that trees most 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-
aoies the water to run of into the lower
strata
Hence 1t seems clear sha, the forests low
er the temperature, while they prevent ex-
tremes. and Increase the rainfall. at the
same time that they regulate it. and keep
OF those dslugss 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 ii
overflows, . mass Of sand and single which
ruins some OF the best land ia France. Oar
ing the terrible rains of September. 1865.
careful observations we're made in Savoy
and Auvergne, and it was seen that when