A New Study of Some Problems Relating to the Giant Trees [pp. 305-316]

Some Problems Relating to the Giant Trees.
whose direction could still be determinedhalf as many as are now standing in the grove.
In the accompanying diagram, these fallen
trees are represented upon the point of compass toward which they fell; doublets upon
the same point are of necessity ranged side
by side. A glance at it reveals the overwhelming tendency which has borne them
down toward the south. The grove, it is proper to add, stands in a deep, narrow valley
opening toward the W. S. W. The stormns,
I am told, are from the S E., with occasional "northers."
DIAGRAM SHOWING DIRECTION OF
FALL.
Lastly, the effect of extensive burns at the
base of the trees must be noticed, since it in
part cooperates with the tendency just spoken of, and in part modifies it. The effect
of a burn is to destroy the vitality of parts
below the burn, rather than above, since
the nourishment moves downward. A burn,
then, at the collar of the tree, deprives the
roots immediately beneath of their life, and
they perish hopelessly to their remotest fibers.
In trees which have grown to the size of
these Sequoias, and have their far-reaching
root-system, such a burn may be a very extensive one-may involve even half of the
circumference, perhaps-and still not immediately cripple the growth above to any great
extent. Water is all that the leaf-laborato
ries must have from below: the pumps that
remain can be run at greater speed to meet
the emergency. The trunk itself is a mighty
reservoir of moisture, which may be drawn
upon to supply a deficiency., The gravest
menace which attends these burns is mechanical rather than physiological- a menace
to the tree's stability; and this, as we have
seen, becomes in the end the vital question.
Death of the roots along one face of the tree
means presently their decay. That means
crumbling of the foundation and inevitable
settling of the structure, if the load 2 bears at
all on that side; if it bears the other way,
it means cutting of the anchor chains and guy
ropes. In either case, the inevitable result
is greatly hastened. A study of the fallen
trees fully confirms this view, since their burnt
surfaces, in most cases, are generally beneath,
or more rarely on top, as the trunks now lie.
And, singularly enough, a study of the living trees shows a preponderance of heavy
burns on their southern face.
Gathering up the scattered threads from
this part of our discussion, we conclude that
the Sequoia has an astonishing exemption
from disease; that this exemption, taken in
connection with its sturdy build, gives it unusual immunity from accidents of storm and
flood; that the resources stored up within its
mighty trunk enable it to repair damages
which would be directly fatal to most trees;
that its thick, non-resinous bark gives it considerable defense against the sweep of lighter
forest fires, while the elevation of its top keeps
that from being scorched; that the effects
of fiercer fires, even in seasons of drought,
are not immediately fatal, though they tend
1 An astonishing proof of this was had in the case of
the poor tree which was literally flayed alive in i86i.
TIhe bark was wholly stripped off to the height of a
hundred feet or more from the ground. All vital connection with the roots was thus decisively ended. Yet
the top flourished on, much as if nothing had happened,
for three seasons more. And seven years after the
deed was done, twigs of green foliage might still be seen
here and there on the upper branches-poor, pitiful
signals that the struggle for life was not yet quite given
up.
2 In the case of the Pavilion tree, I find that the bare
trunk, as it stood, must have weighed 850 tons. The
branches, foliage, and bark would probably have brought
the whole weight up to l,ooo tons.
1886.]
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