Staunton vindicator. [volume] (Staunton, Va.) 1860-1896, 1888-03-30
ANIMALS MAKE SOIL.
TWENTY SPECIES OF AMERICAN
MAMMALS ARE BORROWERS.

| The Wonderful Work Done by Ants.
| complish-Activity of the Crayfish in
| Wet Ground-Observations.
| Although the earthworms are undoubtedly
| very important agents in overturning and
breaking up of soil, it appears to me that
| they are most effective in the titled fields or
in the natural and artificial grass lands. SO
| far as | have been able to OBSERVE these
] creatures are rarely found in our ordinary
4. forests, where thick layer of leaf mold,
commingled with branches, lies upon the
| earth. The character of this deposit is such
| that the creatures are not competent to make
! their way through it, and they, therefore, in
| the main avoid such situations Moreover,
wherever the soil is of very sandy nature
earthworms are scantily found, if they are
present at all. These worms are practically
limited to the soils of a somewhat claycy
character, which have no coating of decayed
vegetation upon them.
As the greater portion Of the existing soil
has been produced in forest regions, l shall
first examine the action of various animals
upon the soils of wooded countries The
mammals are of all our vertebrates the most
forests. Twenty species or more of our
American mammals are burrowers in the
forest bed. They either make their habita-
tions beneath the ground or resort to it in
pursuit of food Of these our burrowing
rodents are perhaps the most effective, but a
large number of other small mammals resort
to the earth and make considerable excava-
tons In forming their burrows or in the
pursuit of other burrowing animals these
creatures often penetrate through the whole
or greater portion of the soil covering. The
material which is withdrawn from the bur-
row is accumulated about its mouth. The
, result is the overturning of q considerable
amount of the earth and a consequent COM
mingling of the material with vegetable
matter. When brought to the surface and
left exposed to the action of frost the break
ing up of the material is greatly favored, and
thus the formation of the soil is facilitated.
Considerable as is the effect of burrowing
mammals, the principal overturning of the
earth in our primeval forests is accomplished
by the invertebrate animals Where the
woods are not very dense, and particularly
where the soil is somewhat sandy, our largest
species of ants are very effective agents in
working over the soil Their burrows extend
to the depth of some feet below the surface,
and each hill brings to the air several cubic
feet of excavated matter, which, as slight in
spection shows, is much commingled with
vegetable matter. Wherever these ant hills
abound they commonly exist to the number
of a score OF more on each acre, and the oc-
cupants of each hill, in many cases, bring as
much as cubic foot of matter to the surface
in the course of single year. The action of
rain constantly operates to diffuse this ma
terial on every side of the hill. We may often
observe thin layer of sediment extending
for considerable distance from the elevation.
AS is we'll known to all those who have in
spected the soil within virgin forests, the
earth is occupied by a host Of larval insects,
principally belonging to the group of beetles,
but including also many orthopterous insects.
These creatures in the course of their life I'M
derground displace good deal of soil, por-
ton of which is thrown upon the surface, the
greater part, however, being merely dislodged
beneath the surface. The effect, however is
to conlmingle and to break up the soil, and
thus favor its communion. Although the
roots of trees do by far the larger part of the
rending which is accomplished in the soil
layer, they do not bring about much COM
mingling of the soil.
Where the woods are wet and favor the de-
y
group of animals ON the overturning of the
soil is extremely great. 1t probably exceeds
that which is accomplished in our ordinary
fields by the action of the earthworm. A
single crayfsh will often bring in the course
of single seasons activity not less than half
cubic foot of earthly matter to the surface
In certain districts where these animals
abound there appear to be not less than 1000
to each acre of surface IT such be their
number it is evident that not less than 800
cubic feet of matter is brought to the surface
from considerable depth i'll the course of a
year. AS this matter is generally of a rather
fine nature and easily dissolved in water it
rapidly washes away and forms a thin sheet
on the surface | ana inclined to believe that
large areas of our wet woods and the open
border lands along our streams are completely
overturned to the depth of two feet or more
in the course of half a century by the actions
of these animals.
In open grounds, in natural prairies or
grass plains, the smaller species of ants are
extremely effective agents in overturning
the soils. Wherever the ground remains for
some time unplowed it becomes occupied by
these creatures In the sandy soils of east
ern Massachusetts the oyerturning accom-
piished by these creatures assumes geologi-
cal Importance. For many years 1 have
been puzzled by the fact that the glacial
terraces and plains of this region We're ex-
tensively covered to the depth of a foot or
more by a coating of fine sand and very
small pebbles, while below the depth of a.
foot pebbles of larger size are very numer,-
GUS, and the spaces between them but I'M
perfectly occupied with any material. 1t is
obviously impossible to explain these condi-
lions through the action of earth worms, for
the reason that these creatures are rarely
found in soils of this description From
much observation have become convinced
that this coating OF sandy material is to Il
great extent to be explained by the action Of
various species of ants, in the forest condi-
ton by the work of the larger black ants,
and in the condition of open plains by that
of the smaller species. N. S. Sha-
Ter in Popular Science Monthly.