Study Iv Tree Repair
Where trees have been properly cared for from their early start, wounds
and cavities and their subsequent elaborate treatment have no place. But
where trees have been neglected or improperly cared for, wounds and
cavities are bound to occur and early treatment becomes a necessity.
There are two kinds of wounds on trees: (1) surface wounds, which do not
extend beyond the inner bark, and (2) deep wounds or cavities, which may
range from a small hole in a crotch to the hollow of an entire trunk.
Surface wounds: Surface wounds (Fig. 116) are due to bruised bark, and a
tree thus injured can no longer produce the proper amount of foliage
or remain healthy very long. The reason for this becomes very
apparent when one looks into the nature of the living or active
tissue of a tree and notes how this tissue becomes affected by such
injuries.
This living or active tissue is known as the "cambium layer," and is
a thin tissue situated immediately under the bark. It must
completely envelop the stem, root and branches of the trees. The
outer bark is a protective covering to this living layer, while the
entire interior wood tissue chiefly serves as a skeleton or support
for the tree. The cambium layer is the real, active part of the
tree. It is the part which transmits the sap from the base of the
tree to its crown; it is the part which causes the tree to grow by
the formation of new cells, piled up in the form of rings around the
heart of the tree; and it is also the part which prevents the
entrance of insects and disease to the inner wood. From this it is
quite evident that any injury to the bark, and consequently to this
cambium layer alongside of it, will not only cut off a portion of
the sap supply and hinder the growth of the tree to an extent
proportional to the size of the wound, but will also expose the
inner wood to the action of decay. The wound may, at first, appear
insignificant, but, if neglected, it will soon commence to decay
and thus to carry disease and insects into the tree. The tree then
becomes hollow and dangerous and its life is doomed.
Injury to the cambium layer, resulting in surface wounds, may be due
to the improper cutting of a branch, to the bite of a horse, to the
cut of a knife or the careless wielding of an axe, to the boring of
an insect, or to the decay of a fungous disease. (See Fig. 117.)
Whatever the cause, _the remedy lies in cleaning out all decayed
wood, removing the loose bark and covering the exposed wood with
coal tar_.
In cutting off the loose bark, the edges should be made smooth
before the coal tar is applied. Loose bark, put back against a tree,
will never grow and will only tend to harbor insects and disease.
Bandages, too, are hurtful because, underneath the bandage, disease
will develop more rapidly than where the wound is exposed to the sun
and wind. The application of tin or manure to wounds is often
indulged in and is equally injurious to the tree. The secret of all
wound treatment is to keep the wound _smooth, clean_ to the live
tissue, _and well covered_ with coal tar.
The chisel or gouge is the best tool to employ in this work. A sharp
hawk-billed knife will be useful in cutting off the loose bark. Coal
tar is the best material for covering wounds because it has both an
antiseptic and a protective effect on the wood tissue. Paint, which
is very often used as a substitute for coal tar, is not as
effective, because the paint is apt to peel in time, thus allowing
moisture and disease to enter the crevice between the paint and the
wood.
Cavities: Deep wounds and cavities are generally the result of stubs
that have been permitted to rot and fall out. Surface wounds allowed
to decay will deepen in course of time and produce cavities.
Cavities in trees are especially susceptible to the attack of
disease because, in a cavity, there is bound to exist an
accumulation of moisture. With this, there is also considerable
darkness and protection from wind and cold, and these are all ideal
conditions for the development of disease.
The successful application of a remedy, in all cavity treatment,
hinges on this principal condition--_that all traces of disease
shall be entirely eliminated before treatment is commenced_.
Fungous diseases attacking a cavity produce a mass of fibers, known
as the "mycelium," that penetrate the body of the tree or limb on
which the cavity is located. In eliminating disease from a cavity,
it is, therefore, essential to go _beyond_ the mere decaying surface
and to cut out all fungous fibers that radiate into the interior of
the tree. Where these fibers have penetrated so deeply that it
becomes impossible to remove every one of them, the tree or limb
thus affected had better be cut down. (Fig. 118.) The presence of
the mycelium in wood tissue can readily be told by the discolored
and disintegrated appearance of the wood.
The filling in a cavity, moreover, should serve to prevent the
accumulation of water and, where a cavity is perpendicular and so
located that the water can be drained off without the filling, the
latter should be avoided and the cavity should merely be cleaned out
and tarred. (Fig. 116.) Where the disease can be entirely
eliminated, where the cavity is not too large, and where a filling
will serve the practical purpose of preventing the accumulation of
moisture, the work of filling should be resorted to.
Filling should be done in the following manner: First, the interior
should be thoroughly freed from diseased wood and insects. The
chisel, gouge, mall and knife are the tools, and it is better to
cut deep and remove every trace of decayed wood than it is to leave
a smaller hole in an unhealthy state. The inner surface of the
cavity should then be covered with a coat of white lead paint, which
acts as a disinfectant and helps to hold the filling. Corrosive
sublimate or Bordeaux mixture may be used as a substitute for the
white lead paint. A coat of coal tar over the paint is the next
step. The cavity is then solidly packed with bricks, stones and
mortar as in Fig. 119, and finished with a layer of cement at the
mouth of the orifice. This surface layer of cement should not be
brought out to the same plane with the outer bark of the tree, but
should rather recede a little beyond the growing tissue (cambium
layer) which is situated immediately below the bark, Fig. 120. In
this way the growing tissue will be enabled to roll over the cement
and to cover the whole cavity if it be a small one, or else to grow
out sufficiently to overlap the filling and hold it as a frame holds
a picture. The cement is used in mixture with sand in the proportion
of one-third of cement to two-thirds of sand. When dry, the outer
layer of cement should be covered with coal tar to prevent cracking.
Trees that tend to split: Certain species of trees, like the linden and
elm, often tend to split, generally in the crotch of several limbs
and sometimes in a fissure along the trunk of the tree. Midwinter is
the period when this usually occurs and timely action will save the
tree. The remedy lies in fastening together the various parts of the
tree by means of bolts or chains.
A very injurious method of accomplishing this end is frequently
resorted to, where each of the branches is bound by an iron band and
the bands are then joined by a bar. The branches eventually outgrow
the diameter of the bands, causing the latter to cut through the
bark of the limbs and to destroy them.
Another method of bracing limbs together consists in running a
single bolt through them and fastening each end of the bolt with a
washer and nut. This method is preferable to the first because it
allows for the growth of the limbs in thickness.
A still better method, however, consists in using a bar composed of
three parts as shown in Fig. 121. Each of the two branches has a
short bolt passed through it horizontally, and the two short bolts
are then connected by a third bar. This arrangement will shift all
the pressure caused by the swaying of the limbs to the middle
connecting-bar. In case of a windstorm, the middle bar will be the
one to bend, while the bolts which pass through the limbs will
remain intact. The outer ends of the short bolts should have their
washers and nuts slightly embedded in the wood of the tree, so that
the living tissue of the tree may eventually grow over them in such
a way as to hold the bars firmly in place and to exclude moisture
and disease. The washers and nuts on the inner side of the limbs
should also be embedded.
A chain is sometimes advantageously substituted for the middle
section of the bar and, in some cases, where more than two branches
have to be joined together, a ring might take the place of the
middle bar or chain.
Bolts on a tree detract considerably from its natural beauty and
should, therefore, be used only where they are absolutely necessary
for the safety of the tree. They should be placed as high up in the
tree as possible without weakening the limbs.
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Tree Studies
How To Identify Trees
Group I The Pines
The White Pine (pinus Strobus)
The Pitch Pine (pinus Rigida)
The Scotch Pine (pinus Sylvestris)
Group Ii The Spruce And Hemlock
The Norway Spruce (picea Excelsa)
Hemlock (tsuga Canadensis)
Group Iii The Red Cedar And Arbor-vitae
Red Cedar (juniperus Virginiana)
Arbor-vitae; Northern White Cedar (thuja Occidentalis)
Group Iv The Larch And Cypress
The European Larch (larix Europaea)
Bald Cypress (taxodium Distichum)
Group V The Horsechestnut, Ash And Maple
The Horsechestnut
The White Ash (fraxinus Americana)
Sugar Maple (acer Saccharum)
Silver Maple (acer Saccharinum)
Red Maple (acer Rubrum)
Norway Maple (acer Platanoides)
Box Elder (acer Negundo)
Group Vi Trees Told By Their Form: Elm, Poplar, Gingko And Willow
American Elm (ulmus Americana)
Lombardy Or Italian Poplar (populus Nigra, Var Italica)
Gingko Or Maidenhair Tree (gingko Biloba)
Weeping Willow (salix Babylonica)
Group Vii Trees Told By Their Bark Or Trunk: Sycamore, Birch, Beech,
Blue Beech, Ironwood, And Hackberry
The Sycamore Or Plane Tree (platanus Occidentalis)
Gray Or White Birch (betula Populifolia)
American Beech (fagus Americana)
Blue Beech Or Hornbeam (carpinus Caroliniana)
Hackberry (celtis Occidentalis)
Group Viii The Oaks And Chestnut
White Oak (quercus Alba)
Black Oak (quercus Velutina)
Red Oak (quercus Rubra)
Pin Oak (quercus Palustris)
Chestnut (castanea Dentata)
Group Ix The Hickories, Walnut And Butternut
Shagbark Hickory (hicoria Ovata)
Mockernut Hickory (hicoria Alba)
Black Walnut (juglans Nigra)
Group X Tulip Tree, Sweet Gum, Linden, Magnolia, Locust, Catalpa,
Dogwood, Mulberry And Osage Orange
Tulip Tree (liriodendron Tulipifera)
Sweet Gum (liquidambar Styraciflua)
American Linden (tilia Americana)
The Magnolias
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Informational