Albert Francis Blakeslee.

Trees in winter; their study, planting, care and identification online

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eighty winters. Looked at from east or west the tree is narrow —
perhaps from crowding in its youth by neighbors now no longer
present. From north or south the crown shows the broad, egg-
shaped outline more typical of the species. On the eastern side are
several ragged limbs broken some four or five years since by an ice
storm that blew in a too heavy load of sleet from the east. On the
western side the tree seems perfect. From above on the north its
outlines are partially blocked by buildings and obscured by the
background of the fields below. From the south it seems to raise
its head and shows the limbs clear-cut above the sky line. From a
distance it is a conspicuous landmark and always interesting . We
can picture the tree from different viewpoints. AYe can see it in
different lights and shadows. We can follow the changes in the
background of the picture — the bare ground, the snow, the green
fields; the mists, the rain, the full sunlight, the long shadows and

Fig. 1. (Upper right hand figure) the tree viewed from the south.

Fig. 2. (Middle right hand figure) the tree viewed from the west.

Fig. 3. (Lower right hand figure) the tree viewed from the east.

Fig. 4. (Upper left hand figure) the tree from the north.

Fig. 5. (Middle left hand figure) the tree in an ice storm.

Fig. 6. (Lower left hand figure) the tree in summer foliage.



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Figures 1-6. A Sugar Maple. See footnote page 14.



Fig-. 7. (Upper figure) across the meadow.
Fig. 8. (Middle figure) beyond the cornfield.
Fig. 9. (Lower figure) up the road.



Fig. 10. The Maple framed in by Elms.

Fig-. 11. The Maple in sunlight and shadow.

the bright tints at sunset or at dawn. ^Ye can watch the changes
in the tree itself, can note in winter its type of branching and the
fine penciling of its twigs against the sky, in spring the opening
of its buds and the rapid growth of flower and leaf, in summer the
full foliage, in autumn the rich leaf coloring and the fall of leaf
and fruit.

A swing hangs from a broad spreading lower limb. Children
play about it. Eobins have built their nests in its branches and
here they rear their young. Throughout the long, hot summer
days its dense covering of leaves gives a grateful shade below. To


the sleepy child the moonlight casts weird fairy shadows of the
limbs upon the bedroom floor and the soft rustle of its leaves lulls
him to sleep. Is there great wonder then that in after years
this same child holds the old family tree dear — an inseparable part
of his youth. The tree has helped to make the house a home.
We have been viewing a tree in its human relations. Such a view
may not be botany, but whoever has had a home with a tree, knows
that it is life.

Tree Photo grapliy — It is fortunate for us who are not painters
that the photographic camera offers a means of recording the
pictures as we find them. The ground glass or the "finder" on the
camera or even an empty frame held at varying distances from the
eye will separate for us the view from its surroundings. Only
experience however, will show what results to expect in the de-
veloped picture. In general better effects will be obtained from
near views or from distant views with prominent features in the

The condition and position of the sunlight are matters of prime
importance in the photographing of trees. Full light is desir-
able and the sun should be somewhat behind and considerably to
one side of the camera. If light comes from behind the tree a
mere silhouette of the branching is obtained, while if the light
is directly back of the camera the trunk and crowTi appear flat from
lack of contrast. When one side of the trunk, as viewed from
the camera, appears dark and the other side in direct sunlight, all
the branches of the tree in the finished picture, as well as the trunk,
will appear solid. The position of the light is of even more im-
portance in photographing the bark. Depressions and ridges
seem to disappear when the light shines directly against them
and a somewhat lateral illumination is therefore necessary to bring
out the details of the bark sculpturing.

The position of the camera must also be considered. A tree
viewed from below appears different from what it would if viewed
on the level and from a distance. Habit views are often taken
too near the trees. Moreover, the camera is generally placed be-
low the usual eye level and this position tends to give the tree
an unnatural appearance. It is generally useless to attempt to
show much detail in the method of branching of an individual
tree if the crown cannot be seen clear above the sky line. A cover-


ing of snow, however, may offer as good a background as the sky
and allow a tree to be photographed against a hillside where other-
wise a satisfactory photograph would not be possible (p. 357). A
white sheet held behind the trunk may afford an artificial back-
ground for a bark photograph. Generally this is not
necessary since bark photograi^hs are taken at close range
and the surrounding objects are mostly out of focus.
If need be, the background can be painted out on the
negative. For habit pictures in sunlight we have found a No.
16 stop and 1/25 — 1/20 second exposure to give good results when
the wind will allow so long an exposure. For bark pictures the
smallest stop and a proportionately longer exposure, say 1/2 to 1
second, will give the greater detail desired in such pictures.

To one interested in botany as an avocation, trees furnish an
especially available subject for outdoor study. They are acces-
sible in city or in country, in winter or in summer. Their size
renders them conspicuous. They can accordingly be studied from
a carriage, an automobile, or a rapidly moving train, and in this
way much learned that would be impossible to discover if the study
were confined to a single locality or if the student were dealing
with smaller forms.

Tree Ecology — Ecology, the study of plants in relation to
their environment, finds in trees a most convenient group in
which to carry on investigations. The subject is comparatively
new and many problems are as yet unsolved. After some familiarity
has been gained with the trees that grow in one's own locality, it
will be possible to discover something about their distribution. A
list of the local tree flora of one's state, county or town or even of
a more restricted area has a distinct value if carefully made, but it
is far from being the end of tree study. What trees are usually
found growing together and what are the causes that bring them
to be thus associated? Is there a swamp "association," a dry hill-
side association or other associations of more or less well marked
character? What is the influence exerted upon the various species
by differences in character of the soil and its chemical composition
— the presence or absence of lime for example — the amount of
available moisture, the altitude, the exposure to the sun and wind
on different sides of a hill or mountain, the climate and other such


factors and how do they become effective? What influence do they
have upon the growth .of the individual tree?

If a wood& is cut do^A^l or burned over or if a pasture is neg-
lected^ what are the first trees most likely to grow up? How have
they come there? Are these the trees that will prevail after fifty or
one hundred years? What is the character of the '^climax forests"
in the region investigated? In the northeastern part of the United
States there is no lack of deserted pastures in all stages of return
to the forest condition and old, gnarled apple trees even, the rem-
nant of some forgotten orchard, may be foimd still living in the
midst of the woods and completely surrounded by forest trees.
These various stages of development may be pieced together and
may enable us to make out the order of "forest succession."

The climate of a given locality is the resultant of such diverse
factors as latitude, altitude, rainfall and exposure to wind and
sun. It is expressed by the character of the vegetation. The length
of the growing season, from the gradual awakening of growth in
the spring till its cessation in the fall, is of prime importance to
agriculture. Are the springs and falls early or late in a given lo-
cality? The progress of the seasons can best l)e measured in terms
of tree activities, such as the appearance of the leaves and flowers,
the ripening of the fruit and the falling of the leaves in different
species. Observations of these points in the yearly history of dif-
ferent species of trees is of so much importance in measuring gen-
eral and local climate, that the Forest Service, Washington, D. C,
is attempting to obtain records on this subject from as many dif-
ferent places as possible. They will gladly send record blanks to
anyone willing to co-operate with them in making observations.
The time of opening of the bud, of flowering and of leaf fall if ac-
curately recorded, especially for a series of years, although for
only a single species, will be information of value.

The life of the individual tree will well repay our study. What
are the problems that it must solve in order to lead a successful ex-
istence, and how are these problems solved by different kinds of
trees? These questions are discussed in Chapter II. The effect of
external conditions upon the habit is touched upon in Part II.

Tree Measurement — The information regarding the dimensions
of a tree are of minor importance for purposes of identification, but
are of considerable value to the woodsman. The diameter of the


trunk may be best measured directly by calipers at breast height from
the ground or indirectly obtained by dividing the circumference by
3 (more accurately by ir =3.1416). A number of rough methods
of estimating height are given in books on forestry. For example,
from a distance equal to several times the length of the tree, the
height of a 10 ft. pole beside the trunk or a mark on the trunk
of known height may be compared with the height of the whc

The height to which one can reach may be detennined by trial
and this kept in mind as a unit of measure. A piece of paper is
fastened to the trunk at this height from the ground. From a
distance, with arm fully extended, we measure oif w4th the finger
on a lead pencil the height of the paper from the ground which
we will imagine to be 7 feet. Using this distance on the pencil
as a scale, we continue sighting upward and find that the top of
the tree is 8^ units, let us say, from its base. Each unit being
7 feet the total height is, therefore, approximately 59^^ feet. Ex-
perience has shown that if the distance from which the sights are
made is at least three or four times the height of the tree and the
arm is kept fully extended during the process of sighting, the re-
sults show a fair degree of accuracy.

The shadow of the tree may be compared w^ith the shadow of an
erect pole of known height and the height of the tree computed by
the rule of three. A right angle triangle constructed of wood or
cardboard with two sides equal may be used as a measure. One
of the equal sides is kept vertical by an attached plumb line and
sights are made along the long edge from different distances till
the top of the tree is just seen above the line of sight. The dis-
tance paced to the tree gives the height of its top above the eye.
Instead of using a triangle to find the point from which to pace to
the tree, German foresters are said to sometimes use a cruder
method which consists in bending over with the back to the tree
and finding the distance where the top is just visible when viewed
with the head between the knees. This method, however, has
natural limitations. The last three methods are conditional upon
the tree standing upon approximately level ground.

Instruments for more accurate measurement are on the market
under the name of hypsometers. A home-made instrument may
readily be constructed which has been found to compare favor-



ably in accuracy with the expensive Faustmann hypsometer of
which it is a modification. A rectangular board about a foot in
length is ruled in squares or more conveniently has squared co-

Fig*. 12. Home-made Height Measurer.

ordinate paper pasted on one side (fig, 12). Care should be
observed that the top of the board AF is straight and accurately
parallel to the lines running lengthwise of the paper. The line
MC is numbered from M in any convenient unit, say up to 100,
and using the same unit, the line HK is numbered in both direc-
tions beginning at C. A thread with a weight is attached at M
and* hangs free from the zero point at the top of MC. In use a
convenient distance, say 100 ft. from the tree, is first measured off
as a base line, and upon this measurement largely depends
the accuracy of the height estimation. At the 100 ft. mark the



top of the tree is sighted along the straight edge AF which may
more conveniently be fitted with some simple form of sights. At
the point B, where the plumb line crosses the line CK the height
of the tree above the eye is indicated in feet. The height of the
eye above the ground is added to this reading if the measurement
is on the level, or a second sight may be made to the base of the
tree and the reading noted on CH added or subtracted, according
to whether the base of the tree is below or above the eye level. If
in the instrument as figured, the base line had been 100 ft. as
suggested, the height of the tree above the eye is given as 40 ft.
If, however, the base line had been 50 ft. the height is given at 20
ft., the reading being taken at the intersection of the thread with
the line running lengthwise through whatever number on MC has
been used to represent the base line. The two smaller diagrams
show the instrument in position for sighting to top and base of tree
respectively. In figure 13 the eye is assumed to be on the level








Fig. 13. Height Measurer in position for sighting to top of tree.

with the base of the tree and only a single sight is necessary. In
figure 14, the base of tree is below eye level and the distance CD
must be found by a downward sight and added to the reading
obtained for BC. It can be readily seen from inspection of the
figures that the method is based upon the similarity of the triangles
ABC and ACD with the smaller triangles abc and acd.




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Fig. 14. Height Measurer in position for sighting to base of tree.

Tree Collections — Tlie collecting instinct is said to be one
of the early marks of a naturalist. Whether this is true or not,
it is certain that the gathering and arranging of a collection is a
sure means of becoming familiar with objects of natural history.
For many it has an irresistable fascination. To the specialist
in systematic botany, a well ordered collection is indispensable.
In any large herbarium it will be found that a considerable part
of the collections have been contributed by amateurs. It is not
enough to have a species represented by a single specimen. All
parts of the plant should be collected in different stages of devel-
opment. It is surprising, therefore, that even the best herbaria
are strongly in need of material illustrating the winter condition of
woody plants, although the winter twigs form one of the best
means of identifying tree species. Plants vary so much, whatever
mark of distinction is considered, that specimens are desired from
different situations and from different geographical regions in order
to show how widely the individual species may vary. The possi-
bilities of collecting, therefore, are practically limitless to those
who are interested in this form of study.

In the preceding paragraphs, some of the methods of tree
study that it has been thought might prove suggestive to the am-
ateur individual student of the subject have been outlined. In
the remaining sections of the chapter, the subject of tree study
in schools will be briefly considered. Forestry schools and for-

N". C, State College


estry classes nee^ not be discussed in this connection. An inti-
mate practical knowledge of trees is the goal of their existence.

Tree Study in High Schools and Colleges — Botany in colleges
and in high schools under college influences gives in general
little encouragement for outdoor work. This is due in part
to the relative ease of handling students indoors, but more
perhaps to a reaction against the somewhat narrow botany
of the earlier naturalists which consisted largely in becoming fa-
miliar with the mere names of the individual plant species. In
consequence, students after taking an elementary course in the sub-
ject sometimes complain that of the common forms they meet every
day they are no better able to tell one plant from another.

Botany, aside from the subject matter it may offer to the bot-
anical specialist, to the horticulturist, or to the forester, may rea-
sonably be included with other sciences in a general college course
upon tAvo grounds : — First, the power it may be expected to give
the student to observe accurately, to form correct conclusions from
the facts in hand and to express his thoughts with clearness:
Second, the accumulation of a body of facts that will tend to make
the world about us more intelligible and life, therefore, more in-
teresting. Too frequently we forget that the student and the
student's viewpoint are of more importance than botany and the
botanist's viewpoint. True a certain amount of knowledge of
the internal structure and physiology of plants is necessary to an
understanding of their life activities and rightly forms a promi-
nent part of the result obtained from a general course in botany.
To make anatomy and physiology the total result is to take some-
what the viewpoint of those books on systematic botany which
refuse to consider a plant that has acquired enough human in-
terest to be brought into cultivation, unless the form in question
is also found growing wild.

The questions of a layman will often give us a clue as to what
parts of our subject are of most general interest. The inner mech-
anisms and functions of a bird may be nearly of as much interest to
the laboratory specialist as they are of value to the bird itself, yet
they are of minor interest to the general public. In the writer^s
experience. Bird Study and Tree Study form two of the most
popular summer school courses, and largely it is believed because
their air has been an out-of-doors acquaintance with common forms


of wide familiarity. If, in our general course, we should teach
our plant forms more from the standpoint of the human interest
they arouse, and less from that of their evolutionary relationshipb.
we need not thereby suffer in either of our ideals of training for
power or of acquiring a stock of useful information. Even the
much-maligned analysis work, the identification of plants by an
artificial key, has certain peculiar educational advantages too often
neglected. The use of a key demands accurate observation and
careful judgment. If these are not given, the student discovers
his mistake by failure to find the correct species and is automatically
led to repeat his observations.

Field Worl' — Field work to be successful must be fully
as carefully planned as indoor laboratory work. In order to pre-
vent the exercise from degenerating into a mere picnic, the purpose
of the trip should be definite and the objects to be observed or the
problems to be studied not too numerous. It is as important to
decide what to leave out as what to include. The ground to be
visited should be gone over by the teacher before each excursion
for the same reason that demonstration experiments in physics or
chemistry must be tried in private in order to insure their successful
performance before a class.

Experience has shown that some form of report, though but
brief, is as necessary with students out of doors as their records
made within the laboratory. Further, the number of students
that can be successfully handled on a field trip is a matter to be
considered. It will differ with the character of the work and the
skill of the teacher. Lack of proper regard for some of the re-
quirements of outdoor work with students has often foreordained
well-meaning efforts to failure, but such failures do not detract
from the education value of the work when properly planned and

The writer has conducted his identificational tree study in the
following manner. A squad of students provided with writing ma-
terial is brought to the first tree to be investigated and without
being told its name they are asked to write down independently,
each for himself, what they think the tree is. After they have
made their guess, its correct name is given and they are led to
work out the distinguishing characteristics of the tree taking with
them for later comparison specimens of leaves, twigs or fruit ac-


cording to the season. Each tree on the trip is first guessed by
the student before it is discussed by the instructor. A correct
guess counts 1 for such fonns as the Tulip Tree, which is the
only one of its genus in the region. Sugar Maple if correctly
guessed would score 2, since there are several Maples to be dis-
tinguished. The guess, Maple or Red Maple for the Sugar Maple,
would score 1, or one-half the value given the full correct name.
At the end of the trip the trees are reviewed from the specimens
collected and the individual scores of the students calculated and
reported. Naturally these scores are not counted at all as marks
in making up the class standing, but the scoring game has been
found to add a decided zest to the exercises. The report called
for consists of a list of the trees studied with a very brief character-
ization of the distinguishing features of each. At the beginning of
each new trip, the trees of the previous exercises are reviewed from
specimens. These frequent reviews are essential. -Occasionally,
quizzes consisting in identifying actual specimens on exhibition
or the trees themselves are of value. In summer the distinguish-
ing characters have been taken from the leaves, in winter from
the twigs. The latter from reasons of convenience have been
studied largely in the laboratory.

Ability to distinguish trees from a distance by habit and bark
characters has been much more readily acquired by students than
was at first thought possible. On account of weather considerations,
this work has been carried on chiefly in March and April, before
the opening of the buds and while the method of branching in con-
sequence is still discernible. The process has been the same as in
the field exercises already described, except that the student's guess
must be made before coming near enough to see the detailed marks
of distinction. A closer approach determines the correctness of
his first impression. In review, unfamiliar photographs, respec-
tively of the habit and the bark of the tree in question are ex-
posed together and slowly carried from one end of a row of stu-
dents to the other. This method is in imitation of the car window
identification of trees, and it is surprising how readily photographs
can be thus recognized when once a familiarity with the distin-
guishing habit and bark characters has been acquired. Lantern
slides would doubtless be of much service in this connection.


Students' Collections — Students' collections formed a prom-
inent part in the older courses ill botany. To identify,
collect, press and mount a hundred specimens, as was frequently
required, gave certainly an added familiarity with plants, but the
amount of mechanical labor involved is unduly large in proportion
to the results obtained.

With trees the flowers are of minor interest, leaves and winter
twigs furnishing the chief identificational features avail-
able for collections. Individual leaves can be easily pressed,
placing them between the pages of a book being frequently suffi-
cient. Winter twigs need no preparation before being sewed

Online LibraryAlbert Francis BlakesleeTrees in winter; their study, planting, care and identification → online text (page 2 of 31)