Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1902-11-25
OUR
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TREES
THOMAS H. MACBRlDE. Phi. D..
Professor of Botany, Iotod State
CnfpersitV.
IH.-Lonsevity Of Trees.

4AAs A<Su6SVAS1 W
~ROM what has been said in the
preceding chapters 1t might be
presumed that there Is no end
to the growth and develop
ment Of a tree. By its very structure
the tree is thing Of life wound up to
run on forever. It winds itself up,
the cambium renewing itself year aft.
er year. AS Wordsworth puts 1t. a
tree is
A living thing
Produced too slowly ever to decay.
OF form and aspect too magnificent
To be destroyed.
DR.. Holmes touches the subject more
lightly, but to the same effect:
In fact, there's nothing that keeps its
youth.
AS I'm informed, but a tree and truth.
Nevertheless trees are not immortal,
some of them far enough from 1t.
They have their limitations, constitu-
tional even, and share ultimately the
fate of all terrestrial things.
In the first place, most trees die by
violence, by accident Of one sort or
other. In battle with the wind and
storm the tree by its very form Is at
great mechanical disadvantage. This
disadvantage increases with every add
ed inch Of height or width. Other
things being equal, 1t is only ques-
ton of time, in an exposed position at
least, until by the very circumstance
Of growth the tree gives to the wind a
leverage sure to be disastrous. The
long branch or even the frightening
top may snap beneath an unusual
weight Of ice or snow. The loss to the
tree is threefold. 1t loses the part de.
stroyed, which is bad enough. 1t loses
equipoise. the balance which between
all its parts the slow progress Of the
years has brought about, and In 30
far becomes more certain Of destruc-
ton in some later storms. But, worse
than all, the tree is wounded with a
lesion that late or never heals, most
likely never. Decay ensues, the tree
becomes hollow. and presently the
fragile shell, even though living, sinks
| into ruin.
1t is interesting here to note the
adaptations in the form and habit OF
trees. the adaptations by means OF
which unfavorGble meteoric conditions
are more successfully resisted. For in
stance, all trees. especially when devel-
oped in isolation. have broad. far
spreading bases. If developed together,
the forest itself has an expanded base,
and the trees protect each other. The
deciduous leaved trees throw down
their leaves at the approach Of winter,
and thus strip for the battle with snow
and ice, which would otherwise crush
their branches to the earth. The cone
bearers, old fashioned trees that they
are, hold their foliage. part OF 1t, 1t Is
true, but note its peculiar character
| and the position 1t assumes. There Is
nowhere in the world prettier adap-
tation than the sparse. fringed needles
of the pine. through which the wind
and storm may whistle, or the droop-
ing, taper, fingerlike branches Of the
spruce or fir, shedding the falling snow
flakes. In all the trees the branches
themselves are specially constructed
| to meet the onset of the blast. Trees
shed not their leaves alone. but their
twigs. only q comparatively few sur
viving to carry forward the limbs e8-
tension. Compare the cottonwood, on
which the twigs are few; the elm even,
or the oak. where their number Is very
small when contrasted with the num-
Der started; the coffee bean tree, on
which there is scarcely one. Indeed,
we may say in general that If a tree
be closely studied its form will &C
curately proclaim the conditions by
which 1t has all along been surround
ed. The whole tree Is an adaptation to
Its environment
But. in the second place, the longevity
Of trees seems to great extent purely
q matter Of habit. Some trees are short
lived by habit. naturally short lived. as
we might say. The broad leaved aspen,
for instance, lives, ut least in many
parts of the country. but few dec
AIDES. in Iowa hardly thirty years. Such
trees seem to reach certain maturity
and then die for no appreciate reason.
Some oaks have similar constitutional
tendencies. The black oaks are said to
be less enduring than the white oaks.
Some species of the black oak group
die at fifty to seventy years. The oaks
Of Europe are apparently longer lived
than those Of North America. The ia
nous oak at Cozes, in southern France.
Is certainly more than 1000 years old.
Caesar may have stood beside 1t.
We reckon trees years by the num-
Der of its rings as seen upon its Sec
ton. Every year. certain as the sue
cessIon Of seedtime and harvest. wit
nesses for the tree the increment Of
yernal and autumnal wood. so that In
case of q fallen tree or Of tree any
part of whose section can be seen we
may count the rings Of growth and
know with very great exactness the
number of Its years. The only excep-
tons are found In the case Of very
young shoots or trees. where some
times more than one ring Is formed
In single year. So also on older trees
after accidental loss OF foliage Sec
ond feeble ring is sometimes added.
But as rule the rings Of tree are as
its years.
By counting thus the rings on Sec
ton and comparing the radius. half
the trees diameter, we easily obtain
the thickness Of the average annual
increase and 50 may estimate the age
of other trees Of the same sort whose