A TREE'S PERILOUS LIFE
Hemlock spruce and pine forests--Story of a pine seedling--Its
struggles and dangers--The gardener's boot--Turpentine of
pines--The giant sawfly--Bark beetles--Their effect on
music--Storm and strength of trees--Tall trees and long
seaweeds--Eucalyptus, big trees--Age of trees--Venerable
sequoias, oaks, chestnuts, and olives--Baobab and
Dragontree--Rabbits as woodcutters--Fire as protection--Sacred
fires--Dug-out and birch-bark canoes--Lake dwellings--Grazing
animals and forest destruction--First kind of cultivation--Old
forests in England and Scotland--Game preserving.
"The murmuring pines and the hemlocks
Stand like harpers hoar with beards that rest on their
bosom."--_Longfellow._
Of course the Hemlock here alluded to is not the "hemlock rank
growing on the weedy bank," which the cow is adjured not to eat in
Wordsworth's well-known lines. (If the animal had, however, obeyed
the poet's wishes and eaten "mellow cowslips," it would probably have
been seriously ill.) The "Hemlock" is the Hemlock spruce, a fine
handsome tree which is common in the forests of Eastern North America.
These primeval forests of Pine and Fir and Spruce have always taken
the fancy of poets. They are found covering craggy and almost
inaccessible mountain valleys; even a tourist travelling by train
cannot but be impressed by their sombre, gloomy monotony, by their
obstinacy in growing on rocky precipices on the worst possible
soil, in spite of storm and snow.
[Illustration: _Canadian Pacific Railway_
A GIANT DOUGLAS FIR
This species of fir tree grows to an enormous height in British
Columbia. It is now being planted in many Scotch forests.]
But to realize the romance of a Pine forest, it is necessary to
tramp, as in Germany one sometimes has to do, for thirty miles
through one unending black forest of Coniferous trees; there are no
towns, scarcely a village or a forester's hut. The ground is covered
with brown, dead needles, on which scarcely even green moss can
manage to live.
Then one realizes the irritating monotony of the branches of Pines
and Spruces, and their sombre, dark green foliage produces a morose
depression of spirit.
The Conifers are, amongst trees, like those hard-set, gloomy, and
determined Northern races whose life is one long, continuous strain
of incessant endeavour to keep alive under the most difficult
conditions.
From its very earliest infancy a young Pine has a very hard time. The
Pine-cones remain on the tree for two years. The seeds inside are
slowly maturing all this while, and the cone-scales are so welded
or soldered together by resin and turpentine that no animal could
possibly injure them. How thorough is the protection thus afforded to
the young seeds, can only be understood if one takes a one-year-old
unopened cone of the Scotch Fir and tries to get them out. It does
not matter what is used; it may be a saw, a chisel, a hammer, or an
axe: the little elastic, woody, turpentiny thing can only be split
open with an infinite amount of trouble and a serious loss of calm.
When these two years have elapsed, the stalk of the cone grows so
that the scales are separated, and the seeds become rapidly dry and
are carried away by the wind.
These seeds are most beautiful and exquisitely fashioned.
The seed itself is small and flattened. It contains both resin and
food material, and is enclosed in a tough leathery skin which is
carried out beyond the seed into a long, very thin, papery wing,
which has very nearly the exact shape of the screw or propeller of a
steamer. This wing or screw is intended to give the seed as long a
flight in the air as possible before it reaches the ground. If you
watch them falling from the tree, or throw one up into the air and
observe it attentively, you will see that it twirls or revolves round
and round exactly like the screw of a steamship. It is difficult to
explain what happens without rather advanced mathematics, but it is
just the reverse of what happens in the steamer.
The machinery in the steamer turns the screw, and the pressure of the
water, which is thrown off, forces the boat through the water; in the
case of the pineseed, the pressure of the air on the flying wings
makes the seed twirl or turn round and round, and so the seed must
be a much longer time in falling. They often fly to about 80 or 100
yards away from the parent tree.
Once upon the ground, the seed has to germinate _if it can_; its root
has to pierce the soil or find a way in between crevices of rocks or
sharp-edged stones. All the time it is exposed to danger from birds,
beasts, and insects, which are only kept off by its resin. But it is
difficult to see, for its colour is just that of dead pine needles
and its shape is such that it easily slips into crevices. Then the
seven or eight small green seed leaves break out of the tough seed
coat, and the seedling is now a small tree two inches high. It may
have to grow up through grass or bramble, or through bracken, which
last is perhaps still more dangerous and difficult. It will probably
be placed in a wood or plantation where hundreds of thousands of its
cousins are all competing together. "In this case, the struggle
for life is intense: each tree seeking for sunlight tries to push
its leader-shoots up above the general mass of foliage; but all are
growing in height, whilst the lateral branches which are cramped
by the neighbouring trees are continually thrown off. The highest
branches alone get sufficient light to remain alive, but they cannot
spread out freely. They are strictly limited to a definite area; the
crown is small and crowded by those of the trees next to it, and the
trunk is of extraordinary length."
The above quotation from Albert Fron's _Sylviculture_ (Paris, 1903)
refers to an artificial forest cultivated and watched over by man.
But the trees in such forests have "extra" dangers and difficulties
to fight against. Even scientific foresters admit that they are very
ignorant of what they are trying to do. In fact, the more scientific
they are, the more readily they will confess how little they really
know.
Watch a labourer in a nursery transplanting young pine trees; each
seedling tree has a long main root which is intended to grow as
straight down into the ground as it possibly can. All the other roots
branch off sideways, slanting downwards, and make a most perfect
though complicated absorbing system. With his large hand the man
grasps a tree and lifts it to a shallow groove which he has cut in
the soil. Then his very large, heavy-nailed boot comes hard down on
the tender root-system. The main root, which ought to point down,
points sideways or upwards or in any direction, and the beautifully
arranged absorbing system is entirely spoilt. The wretched seedling
has to make a whole new system of roots, and in some trees never
recovers.
All sorts of animals, insects, and funguses are ready to attack our
young tree. Squirrels in play will nibble off its leading shoots.
Cattle will rub against its bark, and the roedeer, a very beautiful
creature, and yet a destructive little fiend from the tree's point of
view, nibbles the young shoots and tears the bark with its horns.
A tree's life is full of peril and danger. Yet it is most wonderfully
adapted to survive them. Take a knife and cut into the bark of a pine
tree, and immediately a drop of resin collects and gathers on the
wound. After a short time this will harden and entirely cover the
scar. Why?
There are in the woods, especially in Canada and North Russia,
hundreds of insects belonging to the most different kinds, which have
the habit of laying their eggs in the wood of tree-trunks. In those
regions the entire country is in the winter covered with snow and
ice for many months. Insects must find it difficult to live, for the
ground is frozen to a depth of many feet. Where are the eggs of these
insects to be stored up so that they can last through the winter
without injury?
There is one insect at least, or rather many, of which the Giant
Sawfly may be taken as an example, which have ingeniously solved
this problem. She painfully burrows into the trunk of a tree and
deposits her eggs with a store of food at the end of the burrow. A
drop of resin or turpentine, which would clog her jaws, makes this a
difficult task, but, as we find in many other instances, it is not
impossible, but only a difficulty to conquer. If it were not for the
resin, trees might be much more frequently destroyed by Sawflies than
they are.
The larvæ of the Sawfly is a long, fleshy maggot. Just at the end
are the strong woodcutting jaws by which it devours the wood and
eats its way out as soon as it feels the genial warmth of spring
penetrating through the tree-bark. Many other insects hibernate or
lay their eggs in tree-trunks. Some are caterpillars of moths, such
as the well-known Goat moth; others are beetles, such as one which
burrows between the bark and the wood of apple trees. The mother
beetle lays a series of eggs on each side of her own track. Each
egg produces a grub which eats its way sideways away from the track
of the mother. The track made by these grubs gets gradually wider,
because the maggots themselves grow larger and more fat with the
distance that they have got from their birthplace. We shall find
other instances of burrowing insects when we are dealing with rubber
plants.
This resin or turpentine is a very interesting and peculiar
substance, or rather series of substances. It is valuable because
tar, pitch, rosin, and colophony are obtained by distilling it.
When travelling through the coast forests of pine trees in the Landes
of Western France, one notices great bare gashes on the stems leading
round and down the trunk to a small tin cup or spout. These trees are
being tapped for resin, from which rosin is manufactured. It would be
difficult to find any obvious connexion between music and the Giant
Sawfly. Yet the rosin used by Paganini and Kubelik has probably been
developed in Conifers to keep away sawflies and other enemies. This
very district, the Landes in France, was once practically a desert,
and famous as such in French history. The soil was so barren that no
villages or cultivation were found over the whole length of it. Now
that it is planted with trees which are able to yield firewood and
rosin, it is comparatively rich and prosperous.
Storms are also very dangerous for tree-life. One can only realize
the beauty of a tree by watching a pine or ash in a heavy gale of
wind. The swing of the branches, the swaying of the trunk, the
balancing support of the roots which, buttress-like, extend out into
the soil, give some idea of the extraordinary balance, toughness,
and strength in trees. Except in the case of the common umbrella,
which is an inefficient instrument in high wind, engineers have
never attempted the solution of the problem satisfactorily solved by
trees. A factory chimney only 51 feet in height will have a diameter
at the base of at least three feet. This means that the height is
about seventeen times its diameter. But the Ryeplant, with a diameter
at base of 3 millimetres, may be 1500 mm. high! That is, the height
is five hundred times its diameter, and the Ryeplant has leaves
and grain to support as well as its own stem! In Pine forests on
exposed mountain sides there is almost always at least a murmuring
sound, which in a storm rises into weird howls and shrieks. With
Greek insight and imagination, the ancients supposed that spirits
were imprisoned in these suffering, straining pines. That is most
beautifully expressed in _The Tempest_, where the dainty spirit
Ariel had been painfully confined in a pine tree for a dozen years,
and "his groans did make wolves howl and penetrate the breasts of
ever-angry bears."
One of the most interesting points in botany depends on the fact that
evil conditions of any sort tend to bring about their own remedy.
Endymion's spear was of "toughest ash grown on a windy site" (Keats).
The prosaic chemical analyses of German botanists have, in fact,
confirmed the theory there suggested, for it is found that the wood
of trees grown in exposed windy places is really denser and tougher
than that of others from sheltered woods.[11]
[11] Hartig finds the specific gravity of the wood in a tree is
increased from 0-60 to 0.74 when the surrounding wood has been
cut down.--_Bot. Central_, vol. xxx, p. 220.
If one realizes all these dangers from insects, animals, and storms,
the height to which some trees grow and the age to which they live
become matters for astonishment and surprise.
The tallest trees in the world are probably certain Eucalyptus of
Australia, which have obtained a height of 495 feet above the ground.
They are by no means the _longest_ plants, for there are certain
_rattans_ or canes, climbing plants belonging to the Palm family,
which may be 900 feet long, although their diameter is not more than
two inches.[12] There are also certain Seaweeds in the Southern
Ocean, off the coast of Chile, which attain a prodigious length
of 600 feet (_Macrocystis pyriferus_, or "Kelp"). That is not so
remarkable, for their weight is supported by other plants in the case
of the rattans, and as regards the seaweeds, by the water in which
they float.
[12] Bonnier, _Cours de Botanique_.
The next in order to the Eucalyptus are those well-known Mammoth
or Big trees of California (_Sequoia gigantea_). They grow only in
certain valleys in the Sierra Nevada, at an altitude of 5000-8000
feet. Their height is usually given as from 250-400 feet, and the
diameter sometimes exceeds thirty-five feet. Since they have become a
centre of the tourist-industry in the United States, various methods
have been adopted to make their size more easily realized. Thus a
coach with four horses and covered by passengers is (or used to be)
driven through a gateway made in one of them. The trunk of another
has been cut off some feet from the ground, and a dancing-saloon has
been made on the stump. It is at least doubtful if dancing would be
very agreeable upon such a cross-grained sort of floor! A complete
section of one of them was carried across the United States to make
a dining-room table for an American millionaire. The age of one of
these trees has been estimated at 3300 years. That is to say that
it was a seedling in 1400 B.C., and has been peacefully growing in
a Californian valley during all the time when Greece, Rome, Spain,
France, Britain, and of course the United States, developed their
civilizations. The specimen of the Mammoth tree in the Natural
History Museum in London was 1335 years old.
The possible age of many of our common trees is much greater than any
one would suppose. The "Jupiter" oak in the forest of Fontainebleau
is supposed to be 700 years old. Another oak which was cut down at
Bordya, in the Baltic provinces of Russia, was supposed to be about
1000 years old. Other millennial trees are or were another oak and
two chestnuts: the oak grew in the Ardennes, the chestnuts still
flourish, one at Sancerre (France), and the other the famous specimen
on Mount Etna. There are also eight olive trees in the garden of
Gethsemane at Jerusalem, which are certainly 1000 years old, and
were, according to tradition, in existence in the time of Jesus
Christ.
And yet all these trees are mere infants compared to Adanson's Baobab
and the Dragon tree of Orotava. The celebrated traveller alluded to
visited the Cape Verde islands in 1749 and found inscriptions made by
English travellers on the trunk 300 years before his time. From the
growth since then, he calculated that some of these trees were about
6000 years of age, and they were 27 feet in diameter.[13]
[13] Bonnier, _l.c._
[Illustration: A DRAGON TREE IN THE CANARY ISLANDS
Said to be about eight hundred years old]
The record is held by the Dragon tree of Orotava, in the Canary
Islands.
When the Spaniards landed in Teneriffe in 1402, its diameter was
very nearly 42 feet. It was, however, greatly injured by a storm in
1827, and finally destroyed in 1851. (The wood was then made into
walking-sticks and snuffboxes.) The age has been estimated at 10,000
years, or by other authorities at 8000 years only. The "dragon's
blood" of the Canaries, a well-known remedy in the Middle Ages,
was not, as is popularly supposed, derived from this tree, but was
obtained from a totally different plant.
But there is a hazy tradition to the effect that the story of the
Dragon which guarded the golden fruit in the island of the Hesperides
was nothing but a garbled account of this redoubtable veteran of the
plant world.
There is no particular advantage in growing to these enormous heights
and clinging to life in this way for hundreds and thousands of years.
Nature seems to have found this out and preferred the ordinary pines,
oaks, and larches, which are mature in a few hundred years. In a
thousand years, ten generations of larch or pine can be produced,
and, as each is probably better than its predecessor, a distinct
improvement in the type is possible. All these long-lived giants
belong in fact to the less highly specialized orders of plants.
They are like the primeval animals, the Mammoths, Atlantosauri, and
Sabretoothed Tigers.
Yet when we come to think of the many and diverse perils to which
trees are exposed, the existence of even these exceptional monsters
seems very wonderful.
After a violent storm which had blown down many of the trees in a
friend's park,[14] I visited the scene of destruction and discovered
what had apparently in almost every instance produced it. Rabbits had
overthrown these trees!
[14] Dunlop House, Kilmarnock.
They had nibbled away part of the cork and part of the young wood
on the projecting buttress-like roots at the base of the tree. In
consequence, water, bacteria, and fungus spores had entered at the
injured places, and part of the roots had become decayed and rotten.
When the gale began to sway them backwards and forwards and a severe
strain came on what should have been a sound anchoring or supporting
buttress, the rotten part yielded, and these fine, beautiful trees
fell a prey to the rabbit.
The influence of forests and timber on the daily life of mankind is a
most romantic and interesting chapter in history.
Every savage tribe, every race of man, however degraded or backward,
is acquainted with fire. Fuel is therefore a necessity of existence
for all savages, and not merely for cooking. There is a very
interesting passage in London's _The Call of the Wild_, when the
Dog "Buck" in his dreams remembers a hairy man crouching over the
fire with Buck's ancestor at his feet, whilst in the darkness all
round them the firelight is reflected from eyes of wolves, bears,
and even more terrible and dangerous brutes which have now happily
vanished from the world. For protection at night fire was an absolute
necessity. Even at that long-distant period, therefore, man had
commenced to attack the forest. Unless one has had to tend a wood
fire for twelve hours, it is difficult to realize what a quantity
is required. To prepare fire was a long, laborious, and difficult
operation; one piece of wood was placed on the ground and held in
position by the toes, a pointed stick was taken between the two palms
of the hand and twirled vigorously round and round until the heat was
enough to ignite a piece of rotten wood placed as tinder.
Therefore smouldering branches were kept always burning, as they
are to-day amongst the Fuegians and some other savages. It was a
sacred duty to watch this fire, and the woman (usually old) who was
entrusted with the task was very probably put to death if she failed.
From this very ancient savage custom probably arose the cult of the
Vestal Virgins in Ancient Rome.[15]
[15] It will be remembered that they were obliged to keep the
sacred fire always burning, and were put to death if they
misbehaved. The fire was never allowed to go out during the whole
of Roman history, and the custom has been even preserved in some
Roman Catholic convents and chapels.
Another very important factor in savage life was the canoe or piroque
necessary for fishing or to cross lakes and rivers. The first chantey
of Rudyard Kipling has a probable theory, and is a beautiful account
of how man first thought of using a floating log.[16] They hollowed
out the log and "dug out" the canoe, by first lighting a fire on it
and then scraping away the cinders; then the sides were pressed out,
and it was trimmed and straightened to the right shape. All this
was the idea of some paleolithic genius far more persevering and
ingenious than any marine architect of our own days.
[16] _Seven Seas._
"Birchbark" canoes are not so common as Dug-outs. The tree, the White
or Paper Birch, is found in Canada and the Northern United States;
those Indians who discovered that the light, waterproof cork-bark
could be fashioned into a canoe made a very great discovery, and
indeed it was their canoes that made travel or exploration possible
in North America.
When man began to long for a settled permanent home, it was
absolutely necessary to find a way of living in safety. Wolves,
bears, hyenas and other animals were abundant; neighbours of his own
or other tribes were more ferocious and more dangerous than wild
beasts. Some neolithic genius imagined an artificial island made of
logs in the midst of a lake or inaccessible swamp. Such were the lake
dwellings which persisted into historic times, and which are indeed
still in existence in some parts of the earth.[17]
[17] Munro, _Lake Dwellings_.
The trees were abundant; they could be felled by the help of fire and
an axe, and the lake dwelling gave a secure defence. The wood of some
of the piles supporting the great villages in Switzerland seems to be
still sound, though it has been under water for many centuries. Some
villages are said to have required hundreds of thousands of trees.
The forest afforded man almost everything that he used, bows and
arrows, shelter, fuel, and even part of his food.
Nuts and fruits would be collected and when possible stored. In
seasons of famine, they used even to eat the delicate inside portion
of the bark of trees.
But as soon as the first half-civilized men began to keep cattle,
sheep, and especially goats, more serious inroads still were made
upon the forest. Where such animals are allowed to graze there is
no chance for wood to grow (at any rate in a temperate country).
The growing trees and the branches of older ones are nibbled away
whilst they are young and tender. The days of the forest were nearly
over when cultivation commenced. Dr. Henry describes the process of
"nomadic" culture in China as follows: "They burn down areas of the
forest; gather one or two crops of millet or upland rice from the
rich forest soil; and then pass on to another district where they
repeat the destruction."[18] A very similar process of agriculture
existed until the eighteenth century in Scotland.
[18] _Royal Dublin Society_, vol. i. part v. No. 11.
[Illustration:
_Stereo Copyright, Underwood & Underwood_
_London and New York_
SHOOTING THE HOZU RAPIDS IN JAPAN
The logs in the long train of rafts are of bamboo tied together.
In spite of their fragile nature the lumbermen are so fearless
and agile that they cleverly steer the frail bundles with but few
accidents.]
Thus the forest was being burnt or cleared for cultivation. It was
devastated by black cattle, goats, and other animals, and it was
regularly exploited for fuel and building every day by every family
for centuries.
It is not, therefore, surprising that the ancient forests in Britain
have disappeared. Dr. Henry mentions one square mile of virgin
forest on the Clonbrock estate in Ireland. The _Silva Caledonica_
of the Romans is said to exist in Scotland at the Blackwood of
Rothiemurchus, at Achnacarry, and in a few other places. Of the
original oak forest, which covered most of England and Southern
Scotland, not a vestige (so far as is known to the writer) remains
to-day.
There are in places very ancient forests. A few miles from Retford
are considerable remains of Sherwood Forest, which is for ever
associated with that genial bandit Robin Hood. One huge oak (called
the Major) has or used to have a keeper always on guard and paid by
Lord Manvers, but there are hundreds of aged oaks all round it. Then
there is the Knightwood Oak and some other ancients in the New Forest.
But it is not certain that these even date so far back as the time of
Canute, for so far as the New Forest is concerned, it seems that this
was formed either by Canute or by William I. The Saxons seem to have
destroyed most of the English forests.
In Scotland oak forest existed as far north as the Island of Lewis,
in Caithness, Dornoch, Cromarty, and along Loch Ness, as well as
in every county south of these.[19] The deer forests and grouse
moors, now desolate, whaup-haunted muir-land and peat mosses, were
flourishing woods of magnificent Scots fir at no very distant
period. They ascended the hills on the Cairngorms to 1400 or 1500
feet, and in Yorkshire to 2400 feet.[20]
[19] Niven, _Bot. Section British Association_, 1901.
[20] Boyd Watt, _Cairngorm Club Journal_, vol. iv. No. 20,
January, 1903; Smith, Lewis, _Roy. Geog. Soc. Journal_.
Even in remote historical times, such as those of Canute, the
forests had become seriously and dangerously destroyed. This king
was apparently the first to artificially protect the woods as a
hunting preserve. He was followed by William the Conqueror and other
sovereigns. The game preserves of the landed proprietors to-day are,
of course, the remains of the same custom.
Fortunately, however, we do not kill poachers or cut off their right
hands, and we do not cut off the forepaws of poaching dogs, as used
to be done in medieval days.
This connexion of forests with game no doubt prevented the entire
disappearance of wood, but when, as is the case in England, the
comfort of pheasants is thought of more importance than the
scientific cultivation of forests, the result is often very
unfortunate.
The use and value of timber is, however, too important a matter to
take up at the end of a chapter.