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A PRIMER OF FORESTRY
PART II - PRACTICAL FORESTRY
By GIFFORD PINCHOT
Forester
Bulletin 24, Part II
Bureau of Forestry
U.S. Dept. of Agriculture
Washington:
GOVERNMENT PRINTING OFFICE.
1905.
Lumbering,
A Part of the Practice of Forestry.
LETTER OF TRANSMITTAL.
U.S. Department of Agriculture,
Bureau of Forestry,
Washington, D.C., June 26, 1903.
Sir: I have the honor to transmit herewith the manuscript of the
second half of "A Primer of Forestry," and to recommend its publication
as Bulletin No. 24, Part II, of this Bureau. The second part (Practical
Forestry) deals with the practice of forestry, with work in the woods,
and with the relation of the forest to the weather and the streams, and
concludes with a short account of forestry at home and abroad.
The illustrations are from photographs in the collection of the Bureau
of Forestry, some of which were contributed by gentlemen not members of
the Bureau, to whom I desire to express my acknowledgments.
Respectfully,
GIFFORD PINCHOT,
Forester.
Hon. JAMES WILSON,
Secretary of Agriculture.
CONTENTS.
Page.
CHAPTER I.
THE PRACTICE OF FORESTRY --------------------------------- 1
The service of the forest -------------------------------- 1
The uses of the forest ----------------------------------- 1
Four requirements for the best service ------------------- 2
The yield of a forest ------------------------------------ 3
Silvicultural systems ------------------------------------ 4
Simple coppice ------------------------------------------- 4
Stored coppice ------------------------------------------- 5
Seed or high forest -------------------------------------- 5
Regular seed forest -------------------------------------- 6
Two-storied seed forest ---------------------------------- 7
Selection forest ----------------------------------------- 7
Localized selection -------------------------------------- 7
The group system ----------------------------------------- 8
The strip system ----------------------------------------- 9
Improvement cuttings ------------------------------------- 9
CHAPTER II.
WORK IN THE WOODS ----------------------------------------10
Conservative lumbering -----------------------------------11
Conservative lumbering and ordinary lumbering ------------11
Felling the trees ----------------------------------------11
Swamping and sawing --------------------------------------12
Skidding -------------------------------------------------12
Transportation -------------------------------------------13
At the mills ---------------------------------------------13
Waste in lumbering ---------------------------------------14
Planting -------------------------------------------------14
CHAPTER III.
THE WEATHER AND THE STREAMS ------------------------------15
Forests and climate --------------------------------------15
Effect of forest cover on temperature --------------------16
Extremes of heat and cold --------------------------------17
Moisture in forest air -----------------------------------17
Evaporation ----------------------------------------------18
Rainfall -------------------------------------------------18
Fallen rain ----------------------------------------------19
CHAPTER IV.
FORESTRY ABROAD AND AT HOME ------------------------------21
Forestry abroad ------------------------------------------21
The forest in early times --------------------------------21
Modern forestry ------------------------------------------21
Germany --------------------------------------------------22
France ---------------------------------------------------22
Switzerland ----------------------------------------------23
British India --------------------------------------------23
Forestry at home -----------------------------------------24
The settler and the forest -------------------------------25
First steps in forestry ----------------------------------25
The public domain ----------------------------------------26
Federal forest reserves ----------------------------------26
State forestry -------------------------------------------27
A PRIMER OF FORESTRY.
CHAPTER I.
THE PRACTICE OF FORESTRY.
THE SERVICE OF THE FOREST.
Next to the earth itself the forest is the most useful servant of
man. Not only does it sustain and regulate the streams, moderate the winds,
and beautify the land, but it also supplies wood, the most widely used
of all materials. Its uses are numberless, and the demands which are made
upon it by mankind are numberless also. It is essential to the well-being
of mankind that these demands should be met. They must be met steadily,
fully, and at the right time if the forest is to give its best service.
The object of practical forestry is precisely to make the forest render
its best service to man in such a way as to increase rather than to diminish
its usefulness in the future. Forest management and conservative lumbering
are other names for practical forestry. Under whatever name it may be known,
practical forestry means both the use and preservation of the forest.
THE USES OF THE FOREST.
Alpine hemlock in a protection forest. Cascade Mountains, Washington.
A forest, large or small, may render its service in many ways. It
may reach its highest usefulness by standing as a safeguard against floods,
winds, snow slides, moving sands, or especially against the dearth of water
in the streams. A forest used in this way is called a protection forest,
and is usually found in the mountains, or on bleak, open plains, or by
the sea. Forests which protect the headwaters of streams used for irrigation,
and many of the larger windbreaks of the Western plains, are protection
forests. The Adirondack and Catskill woodlands were regarded as protection
forests by the people of the State of New York when they forbade, in the
constitution of 1895, the felling, destruction, or removal of any trees
from the State Forest Preserve.
A farmer living directly on the produce of his land would find his
woodlot most useful to him when it supplied the largest amount of wood
for his peculiar needs, or the best grazing for his cattle. A railroad
holding land which it did not wish to sell would perhaps find it most useful
when it produced the greatest number of ties and bridge timbers. In both
cases the forest would render its best service by producing the greatest
quantity of valuable material. This is the central idea upon which the
national forests of France are managed.
Plate II. (plates not shown)
Plate III.
The greatest return in money may be the service most desired of the
forest. If a farmer wished to sell the product of his woodlot instead of
consuming it himself, his woodland would be useful to him just in proportion
to its net yield in money. This is true also in the case of any owner of
a forest who wishes to dispose of its product, but who can not, or will
not, sell the forest itself. State forests, like those in the Adirondacks,
often render their best service, in addition to their usefulness as protection
forests, by producing the greatest net money return.
Fig. 2. (not shown)
Regarded as an investment of capital, a forest is most useful when
it yields the highest rate of interest. A forest whose owner could sell
it if he chose, but prefers to hold it as productive capital, is useful
in proportion to the interest it yields on the money invested in it. Thus,
an acre of spout land may be worth only $5, while the investment in adjoining
land stocked with old trees may be $50 an acre. This is the view which
controls the management of State forests in Germany. Lumbermen also regard
timberland as an investment, but usually they take no care except for the
yield at the moment. They disregard the future yield altogether, and in
consequence the forest loses its capital value, or may even be totally
destroyed. Well managed forests, on the other hand, are made to yield their
service always without endangering the future yield, and usually to its
great advantage. Like the plant of a successful manufacturer, a forest
should increase in productiveness and value year by year.
Fig. 3. (not shown)
Under various circumstances, then, a forest may yield its best return
in protection, in wood, grass, or other forest products, in money, or in
interest on the capital it represents. But whichever of these ways of using
the forest may be chosen in any given case, the fundamental idea in forestry
is that of perpetuation by wise use; that is, of making the forest yield
the best service possible at the present in such a way that its usefulness
in the future will not be diminished, but rather increased.
FOUR REQUIREMENTS FOR THE BEST SERVICE.
A forest well managed under the methods of practical forestry will
yield a return in one of the ways just mentioned. There are, however, four
things a forest must have before it can be in condition to render the best
service.
Fig. 4. (not shown)
The first of these is protection, especially against fire, overgrazing,
and thieves, for without such protection no investment is secure and the
most skillful management is of little effect.
The second is strong and abundant reproduction. A forest without
young growth is like a family without children. It will speedily die out.
The third requirement is a regular supply of trees ripe for the ax.
This can be secured only by the right proportion of each of the smaller
sizes constantly coming on in the growing forest. Thus, a farmer in need
of fuel might be much inconvenienced to find no trees on his woodlot big
enough for cordwood, and it would not help him to know that twenty years
later he would have an oversupply. In the same way a larger forest may
yield only a very irregular and unsatisfactory product if at one time there
are too many ripe trees and at another too few. For example, if 100 acres
become fit to cut this year, and 200 next year, and after that none at
all until 500 acres become ripe fifteen years later, it is easy to see
that the yield would come at very irregular and perhaps very inconvenient
times. But a forest of 10,000 acres, composed of 100 even-aged groups of
trees of every age from 1 to 100 years, each group 100 acres in extend,
would plainly be able to furnish every year 100 acres of 100-year-old trees
ready for the ax. In such a forest the right proportion of young trees
would always be coming on.
Fig. 5. (not shown)
The fourth requirement is growing space enough for every tree, so
that the forest as a whole may not only produce wood as fast as possible,
but the most valuable sort of wood as well. If the trees stand too far
apart, their trunks will be short and thickly covered with branches, the
lumber cut from them will be full of knots, and its value will be small.
If, on the other hand, the trees stand too closely together, although their
trunks will be tall and clear of branches, they will be small in diameter,
and for that reason low in value. With the right amount of growing space,
trees grow both tall and of good diameter, and their trunks supply lumber
of higher price because it is wide and clear.
Fig. 6. (not shown)
THE YIELD OF A FOREST.
One of the central ideas of forestry is that the amount of wood taken
from any healthy forest and the amount grown by it should be as nearly
equal as possible. If more grows than is cut, then the forest will be filled
with over mature, decaying trees; but if more wood is cut than is grown,
then the supply of ripe trees will be exhausted, and the value of the forest
will decline. To make the cut equal to the growth does not mean that the
volume of wood grown each year on every acre should be cut from that acre,
but that the total growth of all the acres, for one or for a number of
years, should be cut from the forest in the corresponding period. Thus,
if the growth or increase is 100 cords a year, that amount might be harvested
yearly by cutting every tree on a small area, by cutting fewer trees per
acre on a larger area, by distributing the cut every year over the whole
surface of the forest, or by cutting 1,000 cords in any one of these ways
once in ten years.
Fig. 7. (not shown)
There are many different methods of finding what is the annual increase
of wood in a forest. One of the simplest is to count the number of trees
upon an acre and select an average tree, then to cut it down, measure its
cubic contents, and find its age by counting the annual rings. That done,
the yearly increase of the average tree may be found by dividing its cubic
contents by the years of its age. Finally, since we have found the yearly
increase per tree and the number of trees per acre, it is easy to find
the average yearly increase per acre. It is unfortunate that this simple
and easy process is not always reliable, because it is hard to find either
an average acre or an average tree.
Fig. 8. (not shown)
The yield of a forest is the amount of wood that is taken from it
in a given time. When a forest is put under conservative management, one
of the most important steps is to decide how much timber can safely be
taken from it; in other words, to determine the yield. there are three
principal ways of doing so.
The first, and the least used, is to fix the yield at a certain number
of mature trees. By this plan the yield of a certain forest might be 100
pines, 260 spruces, and 180 hemlocks, each of a given diameter, every year.
The second way is to fix the yield at a certain amount or volume
of wood. Thus, the yield of a large forest might be fixed at 25,000,000
feet board measure every ten years, and that of another smaller one at
750 cords every year.
The third way is to settle upon a certain number of acres to be cut
over yearly or once in a given number of years. By this method the yield
of a forest of 600 acres might be fixed at 6 acres of mature timber a year,
and that of another at 300 acres every twenty-five years. The time between
two successive cuttings on the same area must be long enough to allow the
young trees left standing to mature. That time if found by studying the
rate of growth in diameter.
This method of determining the yield by area is much the most practicable
of the three for the forests of the United States, and in general it is
the simplest and most widely useful of all, because it does away with the
difficult task of determining the yearly increase in wood.
Fig. 9. (not shown)
The objects in handling forests are so various that sometimes no
single one of these methods is satisfactory, and then combinations of them
are of great use. Thus, by combining the method by volume and the method
by are the annual yield of a forest might be established at 250 board feet
per acre. This yield might be cut from the forest every year, or it might
be allowed to accumulate for twenty years, and then 5,000 board feet per
acre might be cut.
SILVICULTURAL SYSTEMS.
Plate IV. (not shown)
After the yield has been found it must be cut not only without injury
to the future value of the forest, but in such a way as to increase its
safety and usefulness. To this end certain ways of handling forests, called
silvicultural systems, have grown up. They are based on the nature of the
forest itself, and are chiefly imitations of what men have seen happen
in the forest without their help.
From the point of view of forest management, one of the principal
differences between trees is whether they spring directly from seed or
are produced as sprouts from stumps or roots already in the ground. A forest
composed of seedling trees is called a Seed Forest, or more commonly but
less suitably, a Seedling or High Forest. One composed of sprouts is spoken
of as a Sprout or Coppice Forest, or, more often, simply as Coppice, or
as Sprout land. Seed Forests are usually composed of coniferous trees,
which rarely sprout, or of broadleaf trees allowed to reach large size.
Sprout Forests are common wherever broadleaf trees are cut while they are
still young, for the sprouting power usually diminishes with age. Sprouts
never reach so great a height and diameter as seedling trees, although
in youth they grow much faster; and they are apt to be unsound, because
the old stumps decay and infect the sprouts which spring from them.
SIMPLE COPPICE.
It often happens, as in Pennsylvania or New Jersey, that a fire sweeps
over the second-growth hardwood lands and fills all the young trees down
to the ground; but the roots remain alive, and from them spring young sprouts
about the bases of the burned trunks. After several years a second fire
may follow and fill back the sprouts again, and other fires may continue
at intervals to burn over the land, each followed by a new crop of sprouts.
When a farmer does with the ax what is often done by fire he is using the
system of Simple Coppice. Let us suppose a farmer has a woodlot covered
principally with chestnut sprouts which he wants to manage for the steady
production of railroad ties. He knows that chestnut sprouts are usually
large enough for ties at the age of 35 years. In order to insure a steady
yield of trees fit for ties, he divides the whole woodlot into thirty-five
parts of equal productive capacity, and cuts one part clean every year.
All the new sprouts that spring up on the part cut in any year are of the
same age. At the end of thirty-five years, when the whole woodlot has been
cut over, the thirty-five parts form a series of even-aged groups of sprouts
from 1 to 35 years old. Every year the sprouts on one part reach the age
of 35 years and are ready for cutting.
Fig. 10. (not shown)
Simple Coppice is a very useful silvicultural system, and the easiest
of all to apply. The chief requirements for its success are good reproduction
from the stumps, proper thinning (where thinning can be made to pay), and
enough young seedlings among the sprouts to replace exhausted stumps with
vigorous young ones. Stumps from which the sprouts have been cut many times
finally grow weak and lose their power of sprouting.
Fig. 11. (not shown)
In cutting sprouts it is important not to loosen the bark on the
stumps, for that impairs their sprouting power, and to make the cut as
near the ground as possible. Stumps cut level with the surface sprout best
of all. In Simple Coppice, well handled, the reproduction takes place of
itself without the need of further attention from the forester.
Many thousands of acres of American woodland, especially in New England,
New York, Pennsylvania, and New Jersey, and in other places where chestnut
is the principal tree, are treated under a rough system of Simple Coppice.
STORED COPPICE.
Among the trees which will produce only fuel, fence posts, or railroad
ties there often stand in a woodlot others which would yield much larger
returns if they were allowed to reach a greater age and size than the trees
about them. If there were some white oaks scattered through the chestnut
coppice just described, it might e well to let them grow large enough for
the production of high-priced material like quartered oak lumber. In that
case it would be necessary at the time of cutting the sprouts to select
and leave standing a certain number of white oaks on every acre. As many
of them as survived the increased exposure to wind and sun following the
sudden removal of their neighbors would remain as standards over the young
sprouts. The white oak standards thus chosen would remain uncut during
two, three, four, or sometimes even five successive crops of sprouts, and
would form stout trunks with little taper, clear of branches almost to
the full height reached by the sprouts.
This is the silvicultural system called Stored Coppice, or sometimes
Coppice under Standards. The successful management of a forest under it
depends largely upon the choice of the standards. They should be seedlings,
for seedlings make the best trees, or the most vigorous and healthy sprouts
if seedlings can not be found, and they should be distributed as regularly
as possible over the ground. The standards should be numerous enough at
first to allow for heavy loss from wind and shock when the sprouts are
cut away, but they should never be allowed to suppress the lower story
of growth.
Stored Coppice is a very useful system where the principal demand
is for small material, like fuel, ties, and fencing, but where some large
timber also is required. It was developed chiefly by the French, who use
it with admirable results.
SEED OR HIGH FOREST.
plate 5. (not shown)
By far the most useful and important forests are, as a rule, those
which spring directly from seed, such as the pine forests of the Southern
States, and the great hardwood forests of the Mississippi Valley. Such
forests are called Seed Forests. The Seed forest systems are of many kinds,
some of which are peculiarly adapted for the management of certain forests
in the United States. Just as the Sprout Forest systems are chiefly useful
to produce fuel, posts, ties, and trees of small size, so the Seed Forest
systems are produces of sawlogs and large timbers.
REGULAR SEED FOREST.
Fig. 12. (not shown)
When a tract of woodland is destroyed by fire in one of the Rocky
Mountain States, it often happens that the seeds of the lodgepole pine
are scattered over it by the wind in prodigious numbers. The seeds germinate
abundantly, seedlings spring up, and in a very few years a young even-aged
forest of lodgepole pine covers the ground. As it grows older fires destroy
patches of it here and there, and in time every patch is covered again
with a younger generation of even age. After many years the forest which
sprang up after the first fire has become broken into a number of even-aged
patches without uniformity in size or regular gradations in age.
Now let us suppose that this land was taken in hand by the Government
when the lodgepole pine first came in, and that the lodgepole reaches its
maturity at 80 years. If the Government forest officers had divided such
a forest into eighty parts, and then had cut the timber from one part each
year, after a time they would have had eighty divisions, each covered with
even-aged forest, but differing in age among themselves from 1 to 80 years.
Every year one part would reach the age of 80 years and would be cut, and
evidently the other seventy-nine parts would always be stocked with trees
from 1 to 79 years old.
Plate VI. (not shown)
When the trees on one of the eighty divisions just mentioned become
ripe for the ax, provision must be made for a new crop. This would be a
very simple matter if the forest on that division could be reproduced naturally
in one year, but that is practically impossible. Such rapid reproduction
can be got only by planting, which is chiefly useful in the United States
for making new forests and restoring injured forests, not for renewing
old ones. Reproduction from the seed of the old trees is the only kind
we need consider here. In order to bring it about a few ripe trees are
first cut down, to prepare a seedbed by giving light to the soil, and to
fit the seed trees to bear more abundantly by giving the crowns more room.
Then, when a good crop of seed is likely to appear, a few more trees are
removed to give the future seedlings light enough for healthy growth, but
not enough to expose them to danger from frost, drought, or the choking
of grass and weeds, for young trees just starting in life are very sensitive
and easily destroyed. Finally, as the young trees grow taller and stronger,
what remains of the old crop is gradually cut away. When it is all gone,
usually from ten to twenty years have passed since the reproduction cuttings
were begun.
This is the system of Regular Seed Forest. It is difficult to apply,
and unsafe except in experienced hands. It has often been necessary to
plant large areas at great expense because reproduction cuttings in Regular
Seed Forest have failed. The transportation of the timber is frequently
expensive, because it must be spread over a number of years. On the other
hand, when it is well applied this system produces the highest type of
forest, full of tall straight trunks clear of branches, and consequently
yields a high grade of timber and a large return in money.
Fig. 14. (not shown)
TWO-STORIED SEED FOREST.
After a forest fire in Maine it frequently happens that the first
tree to cover the ground is the popple, or quaking aspen. It is a slender,
short-lived tree, intolerant of shade, with a light crown. After the popple
has grown for some years, spruce seedlings spring up under the friendly
cover, and rapidly follow the popple in height. There grows up in this
way a forest composed of an upper and a lower story of growth, in which,
as so often happens, the lower story is of more importance.
The system of Two-Storied Seed Forest is useful when a tolerant tree
like the spruce is to be grown under the shade of an intolerant tree like
the aspen. In countries where forestry is well developed it is usually
to plant young trees of tolerant species under older intolerant trees,
to make a acre for the soil and to prevent the growth of grass and weeds.
Forests which closely resemble two-storied seed forests are common in the
United States, but usually as the result of fire or careless cutting. Such
are, for example, the forests of pine over oak in the southeastern United
States, and of birch, beech, and maple under white pine in Michigan, Wisconsin,
and Minnesota. It often happens, as in the case of the spruce and aspen,
that both stories can not live on in good health together, and that the
upper one must die or be cut away if the lower is to prosper.
SELECTION FOREST.
Fig. 15. (not shown)
When a stand of aspen dies away from a young crop of spruce, the
ground is no longer completely shaded, and there is light and room for
other kinds of trees to come in. Thus, birch and maple seeds may be blown
in by the wind and beechnuts carried and planted by squirrels, and eventually
the pure stand of spruce is changed into a mixed forest of various ages.
As the trees grow older, some of the spruce may be destroyed by beetles
or thrown by the wind, and some of the broadleaf trees may die from fungous
disease. Into the openings made by the death of older members of the forest
fall the seeds from which younger members spring. So little by little the
forest loses its even-aged character and there comes into existence what
is called a Natural or Selection Forest, in which trees of all ages are
everywhere closely mixed together. Most virgin forests are selection forests.
Plate VII. (not shown)
The silvicultural system called Pure Selection is applied to forests
of this kind. It is used chiefly for protection forests in places where
it is desirable to keep the cover always unbroken; elsewhere it is out
of place. Under this system the annual increase of the forest must be found
before the yield can be determined. Then the fully mature trees are cut
in every part of the forest every year. The cost of logging is high, for
where single trees are taken here and there, roads or other means of transport
must be very numerous and costly in proportion to the amount of the cut.
Fig. 16. (figures not shown)
Fig. 17.
LOCALIZED SELECTION.
Logging under the system just mentioned is so expensive as to prevent
its application in the United States, except for woods like cherry and
black walnut, which have a special and unusual value. But if, instead of
taking the yield from every part of a selection forest, a comparatively
small area is cut over each year, the cost of logging may be very greatly
reduced. Such a method is admirably adapted to certain forest regions in
the United States, as, for example, to the Adirondack Mountains of New
York, where the forest is composed about equally of coniferous and broadleaf
trees. The conifers are the more valuable, and among them the principal
lumber tree is the spruce.
Fig. 18. (not shown)
The Bureau of Forestry has found by many careful measurements that
if all spruce trees 12 inches and over in diameter are cut from certain
portions of the Adirondack forest, the younger spruce will grow up and
replace the original stand of timber in about twenty years. But this will
not happen unless the rules for cutting are faithfully observed, nor will
it happen more than once unless enough old trees are left standing for
seed. Such a forest may then be divided into twenty parts, and the merchantable
timber about 12 inches in diameter may safely be cut from one division
every year. By the time the last of the twenty divisions has been cut over,
the first will have upon it a stand of mature spruce equal in quantity
to that of twenty years before. The yield of the whole forest in spruce
for a single year may be cut each year from one-twentieth of the whole
area. If all the divisions were cut over five times in the life of a mature
tree, then one-fifth of the standing timber would be taken from each division
at each cutting. Thus, if it took one hundred years for a tree to become
ripe for the ax, the cutting (at intervals of twenty years) would retain
five times during the life of the tree, at its twentieth, fortieth, sixtieth,
eightieth, and one hundredth years.
Fig. 19. (not shown)
This is the system of Localized Selection. It is simple and easy
to apply, and even if mistakes occur they are not apt to have dangerous
consequences. It is very elastic and has many forms, and it is well adapted
to many different kinds of forest. Logging is cheap, because the area cut
over in any one year is small, and the reproduction is provided for by
natural seeding in the openings of the forest.
THE GROUP SYSTEM.
Fig. 20. (not shown)
It often happens that all the trees of a small group in the forest
are killed by fire or insects at about the same time. In the opening thus
made the ground is quickly covered with young growth, which extends back
under the old trees as far as the light will permit. The seedlings are
usually tallest, strongest, and most numerous directly under the middle
of the opening, and gradually decrease at the sides. If the wind should
throw some trees at the edges of such an opening, the young growth would
gradually extend, and if the same thing should continue to happen, in the
end all the old trees would have disappeared and their places would have
been taken by young growth. The Group System is an imitation of this process.
Under the Group System openings are made here and there in the forest by
cutting away ripe trees. As the reproduction proceeds, the old trees about
the openings are gradually cut away, and the groups of young growth, spreading
from the original openings like drops of oil on water, finally meet.
Fig. 21. (not shown)
This is one of the simplest and most useful of all the systems, and
when the openings are made small at first no other is so safe. It is especially
adapted to small pieces of forest, such as woodlots, because it is simple,
and because it assures the safety of the forest even with very little skill
or care on the part of the owner.
THE STRIP SYSTEM.
Fig. 22. (not shown)
in nearly every wooded region of the united states a tornado occasionally
destroys the trees in a long and narrow belt through the forest. Fire often
follows and clears the strip by burning up the fallen timber. Seeds then
fall in the opening, carried from the trees on either side, the seeds germinate
and grown, and the reproduction of the forest takes place.
When the ax takes the place of the tornado and the timber is logged
instead of being burned, the Strip System is applied. Reproduction follows
from trees on either side, as before. The Strip System consists in cutting
long narrow openings in the mature timber instead of the circular openings
of the Group System, to which it is similar in many ways. It is simple
and effective when natural reproduction is good, and well suited for extensive
operations in places where careful work is impossible. The strips are usually
not over 100 yards in width. Where the soil is dry, they are run east and
west to protect the young growth against the sun, and are comparatively
narrow. If there is serious danger of windfall, they lie at right angles
to the direction of the wind.
These are the more important of the silvicultural systems. They have
many modifications, and indeed each forest may require a special form if
its own, which must be devised or adapted for it by the forester. But whatever
the form, the object is always to use the forest and provide for its future
at the same time.
IMPROVEMENT CUTTINGS.
Plate VIII. (not shown)
Very many forests in the United States, and especially many woodlots,
are in poor condition and unfit for the immediate application of any silvicultural
system. They need to be put in order, and for the purpose Improvement Cuttings
are usually required. In the end these cuttings should remove all trees
which the forest is better without, but they should be made gradually,
so as not to open the cover too much and expose the soil to the wind and
the sun. In general, it is unwise to cut more than 25 per cent of the poles
and older trees in a dense mature forest, or to cut oftener on the same
ground than once in five years. Improvement Cuttings of course should never
fall on trees which are to form the future crop, but they should remove
spreading older trees over promising young growth; poor trees which are
crowding more valuable ones; unsound trees whose places will be taken by
others of greater value, or which are themselves becoming less valuable
from year to year; and seed trees of undesirable species likely to reproduce
themselves, if reproduction of more useful kind is well assured. The great
majority of woodlots need such cutting, and when they do, whatever wood
is taken from them should be cut in this way.
Plate IX. (not shown)
CHAPTER II.
WORK IN THE WOODS.
The products of the forest are among the things which civilized men
can not do without. Wood is needed for building, for fuel, for paper pulp,
and for unnumbered other uses, and trees must be cut down to supply it.
It would be both useless and mistaken to try to stop the cutting of timber,
for it could not cease without great injury, not to the lumbermen only,
but to all the people of the nation. The question is not of saving the
trees, for every tree must inevitably die, but of saving the forest by
conservative ways of cutting the trees. If the forest is to be preserved,
the timber crop now ripe must be gathered in such a way as to make sure
of other crops hereafter.
In general, it is true that the present methods of lumbering are
unnecessarily destructive and wasteful. This is not because lumbermen are
more greedy of gain or less careful of public interests than other business
men, for they are not. It happens partly because in this country, compared
with France and Germany and other densely populated regions, there is so
much timber in proportion to the population that it does not pay the lumberman
to take anything more than the better parts of the trees he fells. The
lumberman can not do his work unless he does it at a profit, and he must
do it, for lumber is indispensable. Consequently, although much of the
waste in lumbering is not only unnecessary, but actually costly to the
lumberman, for the present it is impossible to avoid waste altogether.
It will be easier to do when the methods and advantages of conservative
lumbering, which is forestry, are better known to the American lumbermen,
and are therefore in more general use. Although rough conservative methods
have often been practiced in the past, the success of the lumbermen who
made the trial was generally but partial, because their knowledge of the
forest was partial also. They were often deceived by underestimates of
the capacity for tree growth of the lands they were handling, because accurate
measurements were wanting, and they seldom made full use of the reproductive
power of the forest. More recent attempts, based on better knowledge, have
been successful in almost every case.
Lumbermen in America are second to none in skill and ingenuity, in
the perfection of their tools, and in the effectiveness of the methods
they have devised. The nations of Europe, although they have given far
more attention to forestry than we, are very much behind the United States
in these respects. So it is not surprising that Americans have been slow
to change their methods, especially when methods and lumbermen alike have
often been attacked as wrongly and intemperately as the foreign methods
have been praised and recommended. German methods would be as much out
of place in America as American methods in Germany. What American foresters
should do and are doing is to combine the general principles of forestry,
which are true all the world over, with American methods of lumbering.
The product will be a system of forestry especially adapted to the United
States. The foundations of such a system are already laid.
CONSERVATIVE LUMBERING.
Figure 23. (not shown)
Something was said in the last chapter about the systematic methods
of conservative lumbering. With the gradual understanding and application
of these methods by American lumbermen, already well begun, and with the
work in the woods rightly carried out, there is but one reason why the
great majority of the forests now standing in the United States should
not in the end be lumbered steadily and systematically, or why they should
fail to yield a steadily increasing return. That reason is the rapid destruction
of the forests themselves. There is grave danger that the best of our forests
will all be gone before their protection and perpetuation by wise use can
be begun. The spread of a working knowledge of practical forestry is likely
to be too slow.
CONSERVATIVE LUMBERING AND ORDINARY LUMBERING.
Conservative lumbering is distinguished from ordinary lumbering in
three ways:
First. The forest is treated as a working capital whose purpose is
to produce successive crops.
Second. With that purpose in view, a working plan is prepared and
followed in harvesting the forest crop.
Third. The work in the woods is carried on in such a way as to leave
the standing trees and the young growth as nearly unharmed by the lumbering
as possible.
A forest working plan is intended to give all the information needed
to decide upon and carry out the best business policy in handling and perpetuating
a forest. It gives this information in the form of a written statement,
which covers some or all of the following topics. It shows the present
stand and condition of the forest, and gives rules for the selection and
marking of trees to cut, for making the reproduction sure, and for the
protection of young and old standing trees during the logging. The working
plan also predicts the future yield of the forest, basing its prediction
on careful measurements which show how many standing trees of different
diameters will be left per acre after the first cutting, and how fast these
young trees grow. Finally, it estimates the future return in money, taking
into account the taxes, interest, and other expenses on one side, and the
future crop on the other. In order to make this estimate entirely safe,
it is usually based on the present price of stumpage, although its future
value will certainly be much higher.
FELLING THE TREES.
Figure 24. (not shown)
The difference between the practical work under ordinary lumbering
and under conservative lumbering is chiefly in the selection of the trees
to cut, in felling them, and in the first part of their journey from the
stump to the mill. Under a working plan the trees to cut are chosen in
such way that when they are gone the forest will suffer but little from
their absence, because their places will be taken by others as quickly
as possible. Usually the trees selected are first stamped with a marking
hatchet to prevent mistakes, and then the next step is to cut them down.
The amount of harm done to the forest by cutting depends considerably
upon the season of the year when the work in the woods is carried on. Less
damage results to the young growth and the trees left standing if the lumbering
is done after the growing season is over than if it goes on in the spring
and summer, while the bark is loose and the leaves and twigs are tender.
Figure 25. (not shown)
A tree may be felled either with the ax or with the saw. In either
case the first thing to consider is the height above the ground at which
the cut is to be made. high stumps needlessly waste the best timber in
a sound tree. Low stumps are slightly more difficult to cut, and therefore
a little more expensive, but the additional cost is more than balanced
by the gain.
The measurements made by the Bureau of Forestry have shown that the
loss from cutting high stumps on a tract of 100,000 acres in the Adirondacks,
yielding on an average 15 standards per acre, would be 30,000 standards,
or at a stumpage value of 50 cents per standard, would be $15,000.
Figure 26. (not shown)
The second thing to consider in felling a tree is how to get it down
without breaking or splitting the trunk. On rocky, uneven ground this is
often a hard thing to do, but unless it can be accomplished the tree would,
as a rule, better be left untouched.
Plate 10. (plates not shown)
Plate 11.
Most important of all for the perpetuation of the forest, each tree
must be thrown where it will not unnecessarily injure other trees or crush
in its fall the young seedlings on which the future of the forest depends.
It happens very commonly in ordinary lumbering that vigorous, sound young
trees are split and ruined in great numbers by old trees falling upon them,
when it would be perfectly easy, and almost or quite as convenient, to
throw the latter where they would do little or no harm.
Figure 27. (not shown)
Finally, it must cost as little as possible to fell each tree, for
the be successful conservative lumbering must pay.
SWAMPING AND SAWING.
When the trees are down, their lower branches are chopped off and
the trunks are sawed into logs. In falling, a tree is very apt to bend
and hold down beneath its trunk and branches many younger trees, which
will spring up straight again if they are quickly released, but which otherwise
will be killed or permanently hurt. Therefore it is very important to work
up both the trunk and the top of each tree as soon as it is cut down, and
so prevent it from destroying the young trees which should take its place.
Except when they are to be burned, even the branches of tops which can
not be used should ordinarily be cut away enough to let the tops sink close
to the ground, where they will rot as speedily as possible. Dry crowns
propped clear of the ground by their branches rot slowly, burn fiercely,
and are very dangerous in case of fire.
Figure 28. (figures not shown)
Figure 29.
Figure 30.
SKIDDING.
When the trunks have been sawed into logs, the latter are dragged
away by horses, mules, or oxen, or in some cases by a long wire rope which
is would on the drum of a donkey engine. This is called "skidding
the logs." In this way they are collected in piles called "rollways,"
or assembled in "yards," or otherwise made ready for the next
step in their progress to the mill.
Figure 31. (not shown)
Care is needed in skidding not to rub or tear the bark from valuable
standing trees, or to break the young growth down, for much harm is quickly
done in this way. Promising young trees are often cut because it is easier
to use them for corduroy or skids, or for other purposes in the logging
than to take others less straight or less conveniently at hand, or because
they are somewhat in the way, or even from habit, when it would really
be easier to let them alone. A very little care in preserving young growth
makes an astonishing difference in the future value of a forest.
Plate 12. (plates not shown)
Plate 13.
TRANSPORTATION.
Figure 32.
After the skidding, the logs may be transported to the sawmill in
many different ways. Sometimes they are loaded on sleds and drawn over
carefully made ice roads to a logging railroad or to the bank of a stream.
When the stream is not swift or deep enough to carry the logs of itself,
splash dams are built, in which great quantities of water are held back
for a time. (See Pl. XV.) When such a dam is opened the water is set free,
and great numbers of logs may be driven far down the steam by the sudden
flood. In larger streams the logs are sometimes made into rafts, or they
may be driven singly down the river. The log drivers who do this work learn
to balance themselves on the floating, rolling logs, and walk on them almost
as easily as on the solid ground. Sometimes locomotives drag the logs behind
them over the ties, or they are hauled on cars which run over poles cut
in the woods instead of over metal rails; often they are rolled into slides
built of other logs, and either move downhill by their own weight or are
dragged along by horses, cattle, or steam. In southern swamps the logs
are sometimes swung up by a wire rope suspended from the trees, and so
are loaded on the great flatboat which carries them to the mill.
Figure 33. (figures not shown)
Figure 34.
Plate 14.
Plate 15.
AT THE MILLS.
At the mills the logs are cut into lumber by various kinds of saws.
Of these the circular saw is still very widely used, although the wide
bite or kerf which it cuts in the log makes it very wasteful of timber.
A large circular saw makes a kerf a quarter of an inch wide, so that in
cutting four one-inch boards enough wood to make a fifth board is ripped
into sawdust. Band saws are far less wasteful, for they are thinner and
make a narrower kerf. Hence they are taking the place of the circular saws,
although they do not work so rapidly. Many mills, in addition to their
band saw or circulars, use gang saws, which cut out several boards at the
same time.
Figure 35.
Besides lumber the best sawmills produce great quantities of lath
and shingles, made either from small logs called "bolts," cut
specially for that purpose, or from slabs, edgings, and other pieces of
wood which might otherwise be wasted. But in spite of every effort to prevent
waste in the mill, by using sawdust and other refuse for fuel, and in other
ways, very many thousands of tons of wood a year are thrown into great
burners as the cheapest method of getting it out of the way.
Figure 36. (not shown)
When the lumber has been sawed it may be piled and seasoned in the
yard or kiln dried before it is sent to market or sold at the mill. Some
sawmills on Puget Sound are built on piles over the water, so that the
lumber is loaded into vessels directly from the saws. Others load their
product on the cars and distribute it by rail. Still others on the Pacific
slope float their timber away in a narrow wooden trough called a flume
through which flows a rapid stream of water. (See Pl. XVII.) These flumes
are sometimes over 40 miles in length, and cost almost as much to build
as a railroad. Many sawmills have connected with them planning mills or
woodworking factories of other kinds, so that the rough lumber from their
saws is changed into the form of a finished product before it reaches the
market.
Plate 16. (figures not shown)
Plate 17.
WASTE IN LUMBERING.
Figure 37.
This is very briefly the way in which a tree gets into the market
at the end of its life. At every step there is some waste. Although it
may be sound throughout, the lumbermen in the woods can take but a portion
of the trunk and all of the top to rot on the ground. When
each log comes to the saw there is a further loss of nearly all the
slabs and edgings and all the sawdust that is not used for fuel. On the
average it is doubtful whether more than half of the cubic contents of
a standing tree is finally used. As prices rise and as conservative lumbering
comes to be generally practiced, the greater part of this enormous loss
will be avoided, but it can probably never cease altogether.
Figure 38.
PLANTING.
It has often been proposed to plant trees in order to repair the
damage done to the forests by the lumbermen. Tree planting is most useful
in all the treeless or scantily wooded portions of our country where planted
trees will grow, and wherever forests have been very severely injured or
destroyed, but it is generally far too expensive t take the place of conservative
lumbering in regions already forested. An acre of growing natural forest
can be bought in nearly every forested part of our country for less than
it would cost to plant, 4 feet apart, an acre of seedlings a few inches
high. The true way to save the forests is not to plant new ones, but to
protect and rightly use those which are standing now. The extension of
the forest to regions which are without it is a most important task, but
it must not be confounded with the conservative use of the forests now
standing. For such use there is no substitute whatever.
CHAPTER III.
THE WEATHER AND THE STREAMS.
The central point of public interest in forestry in the United States
was until recently the influence of forests on climate. It is natural that
the connection between the immense forests and vast plains and the wonderfully
various climates of this continent should have awakened attention. It is
a matter which is easily written and talked about without any thorough
understanding of forestry itself, and in this it differs from other branches
of the subject. In dealing with the weather it touches a thing which affects
the daily life of everyone, and which, to very many, holds the balance
between poverty and prosperity. It is therefore unfortunate that so much
of the writing and talking upon this branch of forestry has had little
definite fact or trustworthy observation behind it. The friends and the
enemies of the forest have both said more than they could prove. Both have
tried to establish the truth of their opinions by referring to observations
of temperature and rainfall which cover too short a time to prove anything,
or by hearsay and general impressions, which are not to be trusted in such
matters. Such discussions make nothing clear except that the pith of the
matter has not been reached by either party.
FORESTS AND CLIMATE.
The discussion of forest influence on climate began in this way.
When the French revolution broke out in 1789, the old restrictions on the
management of private forests were done away. A wholesale cutting of these
timberlands promptly followed, and as early as 1792 the consequences began
to be observed. The question of forests and climate was then raised for
the first time; but questions of this kind can not be answered without
long and careful observations. Such observations were begun by Becquerel
in France and Krutsch in Germany about the middle of the last century,
but it was not until 1867 that a satisfactory way of making them was devised.
This was the system of double stations--one within the forest, the other
at a distance in the open. It was first put in operation by Professor Ebermayer,
now of the Bavarian Forest School. By this means the amount of moisture
and heat in the forest may be compared with that in the open, and in the
end a full and satisfactory answer will probably be reached.
In order to find how great the influence of forests on climate may
be, we must first see what re the factors which make climate. Then we may
ask which of these factors can be affected by the forest, and in what way.
The climate of any place on the earth's surface results from the
action of the sun's heat upon it. climate is the average condition of the
weather. It depends, first of all, on the distance of a place from the
equator and its elevation above the sea. Secondly, it depends on the distribution
of land and water, the relief of the land, whether flat, hilly, or mountainous,
and the character of the surface covering. These are all connected with
the temperature in a special manner. Lastly, it is affected by the winds
and the moisture of the atmosphere. Now, it is clear that of all these
factors of climate the forest can influence only the wind, the moisture,
and the surface covering; but heat (with which the surface covering has
so much to do), moisture, and wind are the three things which change when
we say that the weather changes. These ar just the points where a change
due to the forest would have most effect on daily life. The influence of
the forest is exerted upon them in two ways;
Figure 39. (not shown)
First. The forest cover intercepts the rain and the rays of the sun,
checks the movement of the air, and reduces the radiation of heat at night.
Second. The waste from the trees and from certain plants which grow
only in their shade forms the forest floor, which has much to do with the
movement of water on the ground and within it. The influence of the forest
cover and the forest floor appears in the temperature of the air, the evaporation
of water, the rainfall, and the course of the rain water after it has reached
the earth.
Figure 40. (not shown)
EFFECT OF FOREST COVER ON TEMPERATURE.
So far as the influence of the forest is concerned, the temperature
of the air is affected chiefly by the forest cover. The leaves, which compose
the greater part of the cover, contain from 50 to 70 per cent of water.
More heat is required to raise the temperature of a point of water one
degree than for a pound of almost any other substance, and so it happens
that bare soil or rock exposed to the rays of the sun becomes heated many
times faster than the water in the leaves. While the heated rock or soil
was warming the air about it the forest cover would still be absorbing
heat and keeping the air below it cool. The leaves of the cover also tend
to cool the air by transpiration, which is the evaporation of water from
the leaves. This is water vapor, and a part of the sun's heat is taken
up for this purpose. In these two ways the forest cover acts somewhat like
a surface of water.
The growth of the tree itself also helps to cool the air. When the
leaves take carbonic-acid gas from the air they break it up and force its
carbon into new chemical compounds, which are then stored away as new material
in the tree. So with water and the other substances upon which the plant
feeds. But the elements are less at ease in these new compounds, and heat
is required to force them to make the change. When we burn wood for fuel
we are simply getting back again the heat which was used to bring about
this change. So we may say roughly that the air about the tree during its
lifetime has been deprived of as much heat as would be given off if the
whole tree were burned.
The effect of the cooler air of the forest is felt to some distance
in the open country. During the day, in calm summer weather, when the air
is warmer than the tree tops, it is gradually cooled by contact with the
cooler leaves and twigs. In cooling it becomes heavier and falls toward
the ground. A rising current of warmer air is formed to supply its place,
and so the colder air flows off along the surface into the open country
and causes local breezes. At night the air currents are reversed. The air
in the forest is then warmer than the air outside, because the cover checks
the radiation of heat, and so the colder air moves from the open country
toward the woods. In these ways the influence of the forest is felt at
a distance.
The amount of this cooling of the air has been measured in certain
places. It is naturally found to be greatest in summer; while in winter
and at night the air in the tree tops is a little warmer than in the open.
It is important to add that the cooling effect of the forest is greater
than the average in the mountains, and less in the plains.
EXTREMES OF HEAT AND COLD.
The extremes of heat and cold are moderated by the forest. Observations
on this point have been made, for example, in Bavaria and Wurttembert.
They showed that the lowest temperature of every day in the year was higher,
on an average, by nearly 20 in the forest, while the highest temperature
was lower by nearly 40. The greatest heat of the day in the summer was
7 1/20 less in the forest than outside. Prussian observations showed that
for ten years the greatest heat of the day in July was, on an average,
nearly 60 lower in the forest, and the greatest cold of the night in January
nearly 30 less than outside. It should not be forgotten that the latitude,
the elevation, and the exposure had a powerful influence on these differences,
which are also greatly affected by the kind of trees and the density of
the forest.
It must be borne distinctly in mind that the figures given above
are reliable only for the places in central Europe where they were observed.
But the principles on which they depend are just as true in America as
they are in Europe. Natural laws are the same the world over. It is safe
to conclude, then, that in the United States the forest modifies the temperature
of the air in certain ways and for certain reasons, both of which we have
seen. Just how great this influence is in different parts of the continent
it is as yet impossible to tell. But it is probably greater on the average
than these observations indicate, for two reasons: First, the extremes
of heat and cold, moisture and dryness, are much greater here than in central
Europe, and changes are more sudden; second, in most of the double stations
mentioned above the station outside the forest was within less than a mile
of it, and thus likely to be influenced by the cooler air currents flowing
from it; that is, the real effect of the presence or absence of woods over
large stretches of country is probably greater than these observations
show.
A system introduced in Austria is expected to give a clearer idea
of the distance to which the forest influence reaches. It consists of lines
of stations beginning in the center of a large forest and extending step
by step into the open country beyond.
MOISTURE IN FOREST AIR.
The moisture of the air is greater in the forest than outside. The
absolute quantity of water vapor in a cubic foot of air is generally the
same in both places, but the forest air is cooler, and therefore its relative
humidity is greater. Relative humidity is the amount of vapor actually
in the air, expressed a so much per cent of all it could hold at the same
temperature. The amount of water that the air can hold changes when the
temperature changes, but in such a way that air cooled until it is only
half as warm as before can hold much less than half as much vapor. If a
hot and a cold stream of air, both saturated with water vapor, meet and
mix, the mixture can no longer hold as much vapor as the two streams separately,
and a part is condensed, usually in the form of rain or snow. German and
Swiss observations have shown that the average humidity is greater in the
forest by from 3 to 10 per cent. This difference increases with the altitude
above sea level and the density of the forest cover. The increase of humidity
explains why dew is more frequent in the neighborhood of the forest than
at a distance.
EVAPORATION.
The water which falls to the earth from the atmosphere had first
to be evaporated, so that year by year the quantity of water which the
air takes from the surface of the globe by evaporation is the same as that
which falls upon it in the shape of rain, hail, snow, and dew. The effect
of the forest on this great movement of water is to detain more of it on
those portions of the earth which are sheltered by trees. It does this
partly by tending to increase the rainfall, but its effect in lessening
the loss of water through evaporation is probably much more important.
The colder and moister air of the forest has less capacity for taking up
water vapor than that of the open country. It is also quieter, which means
that the winds are less active in replacing saturated air with air which
can still take up more water. The forest acts powerfully in checking the
force of the winds because the elastic swaying of the twigs and branches
is a very effective hindrance to the movement of the air. Strong winds,
although they are often dangerous in themselves, do most harm by drying
up the moisture in the soil and in the plants which grow from it. Thousands
of miles of windbreaks have been planted by farmers in the western parts
of this country to protect their crops and homes against the wind. These
windbreaks serve a most useful purpose, but they are naturally far less
effective in preventing evaporation than the forest itself. So great is
the power of the latter that direct observations made in Bavaria and Prussia
showed that evaporation from a free surface of water in the forest was
only 40 per cent of that in the open.
Figure 41. (not shown)
The presence of absence of leaf mold has a powerful effect on the
amount of evaporation from forest soil. The experiments of Dr. Ebermayer,
a famous German forest meteorologist, showed that evaporation from forest
soil without a layer of mold was 47 per cent of that from soil in the open,
while with a layer of mold it was less than half as much, or 22 per cent.
The greater the altitude above the sea the greater is the effect of the
forest in preventing evaporation. This is a powerful reason for preserving
mountain forests at the headwaters of streams, especially in the Rocky
Mountain regions of the United States. Evaporation is there so active that
great banks of snow lying in the full glare of the sun often disappear
without melting even enough to moisten the ground on the hillsides below
them. Vast quantities of water evaporate in this way without ever reaching
the streams. Measurements made by the Bureau of Forestry show that evaporation
from snow may be four or five times as great as from water under like circumstances.
Figure 42. (not shown)
RAINFALL.
The causes of rain are for the most part wholly beyond the reach
of influence from the forest. Such are the great currents of warm and cold
water in the ocean, the direction of the prevailing winds, and the presence
or absence of mountain ranges. But there re two reasons which lead us to
believe that forests do affect the rainfall. These are their colder and
moister air, and the resistance which they offer to the motion of the winds.
A great number of observations has been made in different parts of the
world to discover how much the rainfall really is affected by the forest,
but for several reasons no generally accepted result has yet been reached.
In the first place, accurate observations on rainfall are not easy to make.
The height above the ground at which a rain gauge is placed affects it
very seriously. A variation of 10 feet in height will often make more difference
in the amount of rain caught than most observers claim for the whole action
of the forest. The rainfall of two stations at unequal heights above sea
level is sometimes wrongly compared, because the difference in rainfall
may be caused by the difference in altitude. Finally, the best observations
that have been made point to different conclusions. For example, measurements
taken in Prussia go to show that there is an increase of rain over the
forest, and that it is greater the higher the station. Thus, near the level
of the sea it was only 1.25 per cent greater than over the open country,
while at altitudes between 2,000 and 3,000 feet it reached 43 per cent.
Observations made a Nancy, in France, which lies about 700 feet above the
sea, show an average yearly increase of 16 per cent. The Bavarian observations,
on the contrary, do not indicate more rain over the forest. The best evidence
at hand fails to show a decrease in rainfall over the United States in
the last hundred years, in spite of the immense areas of forest that have
been burned and cut. But it should not be forgotten that most of those
areas have grown up again, first with brush, and afterwards with trees,
so that the proportion of land covered with leaves is still very large
in all part of the country which was once under forest. In India, again,
a large amount of statistics has been collected which leads to the conclusion
that forests do influence rainfall. The truth probably is that more rain
falls over the forest than over open country similarly placed, but how
much more it is impossible to say. The excess falls chiefly in the form
of summer showers. One of the best in the form of summer showers. One of
the best authorities has estimated the differences at 10 per cent.
FALLEN RAIN.
Whatever doubt there may be about the action of the forest in producing
rain, there is none about its effect on rain water after it has fallen.
When rain falls over a dense forest from less than on-tenth to about one-fourth
of it is caught by the trees. A small part of this water may reach the
ground by running down the trunks, but the greater part of it is evaporated
and so increases the humidity of the air. That which passes through the
crowns falls upon the forest floor, which sometimes has an absorbing power
so great that it can hold for a while a rainfall of 5 inches. Yet this
water does not remain in the porous floor, but in the end runs off into
the streams, or is evaporated, or sinks into the ground. That which gets
into the ground is either taken up by the roots or goes to feed the springs
and watercourses.
Rain which falls over a bare slope acts differently. It is not caught
by the crowns nor held by the floor, nor is its flow into the streams hindered
by the timber and the fallen waste from the trees. It does not sink into
the ground more than half as readily as in the forest, as experiments have
shown. The result is that a great deal of water reaches the streams in
a short time, which is the reason why floods occur. It is therefore true
that forests tend to prevent floods. But his good influence is important
only when the forest covers a large part of the drainage basin of the stream.
Even then the forest may not prevent floods altogether. The forest floor,
which has more to do with the fallen rain water than any other part of
the forest, can affect its flow only so long as it has not taken up all
the water it can hold. That which falls after the forest floor is saturated
runs into the streams almost as fast as it would over bare ground.
Figure 43. (not shown)
An unforested drainage basin in the san Bernardino Mountains of southern
California was found by the Bureau of Forestry to discharge the rain it
received more than twice as rapidly as similar forested basins near by.
In consequence, the stream in the former went dry, while the streams in
the latter were still flowing abundantly.
In these ways it happens that in mountain countries, where floods
are most common and do most harm, the forests on the higher slopes are
closely connected with the prosperity of the people in the valleys below.
Figure 44. (not shown)
Water in motion was nature's most powerful tool in shaping the present
surface of the earth. In places where the slopes are steep, the structure
of the ground loose, and the rainfall abundant, water may work very rapidly
in cutting away the heights and filling the valleys. The destruction of
the forest in such a region exposes the surface to the direct action of
falling rain and is certain to be followed by the formation of torrents.
The danger is greatest when the soil has been laid bare by the browsing
and the hoofs of grazing animals, among which sheep and goats are especially
destructive, or where the forest floor has been burned away.
Figure 45. (not shown)
When these conditions are both present, as in parts o the sierra
Nevada mountains of California, of the Cascade Range in Oregon, and in
many other parts of the West, the prosperity of the valleys is in serious
danger. Fire and overgrazing on the mountains combine to endanger the future
water supply of irrigated or irrigable areas in the valleys below. When
rain falls over mountains which have so been deprived of their natural
protection it is no longer caught and held back by the trees and the forest
floor. The roots, which were once the strongest means of binding the soil
together, now are gone and leave it without protection against the rushing
water. Heavy rains or sudden thaws swell the streams with marvelous quickness,
and give them a wonderful power to cut away their banks. Where the waterway
is very steep such a flood often carries with it many times its own weight
of earth and stones. As it nears the valley it breaks from its bed and
makes new channels, or spreads over the lowlands. The current loses its
swiftness, and its load of stones and sterile earth sinks to the bottom,
the heavier pieces first. Where it falls the beds of rivers are filled
up and fertile lands are covered with pebbles and sand.
Figure 46. (not shown)
For a time after such a flood the streams are usually low, because
the water which should have fed them for weeks or months has run off in
a few days. This may be quite as serious a matter for the farmers as the
destruction of their fields, as for example in places like southern California,
where the crops depend on irrigation with the water of streams which rise
in the mountains. Torrents have begun to form there in the san bernardino
Mountains, and have already carried stones and sand into the orange groves
and even into the towns of the San Gabriel Valley. Before the water of
the San Gabriel River was so largely taken out for irrigation it was rapidly
cutting away the fertile land on either side of its shifting bed, and it
seemed likely that serious loss of property would follow. This is the direct
result of fire and grazing in the mountains.
Figure 47. (not shown)
The pasturage of sheep in the Alps of southern France was the chief
cause of the destructive torrents with which the French Government has
been struggling for many years. The direct loss to the French people has
been enormous, and in addition the work of correction alone has cost upward
of $35,000,000. Although wonderfully successful hitherto, it is still far
from finished.
Plate XYIII. (not shown)
CHAPTER IV.
FORESTRY ABROAD AND AT HOME.
FORESTRY ABROAD.
Except China, all civilized nations care for the forest. Until recently
the United States ranked nearly with China in this respect, and our country
still remains far behind the progressive modern nations in nearly all that
relates to the protection, preservation, and conservative use of the forest.
Japan has a well-developed forest service and a national forest school.
In Austria, Italy, and Norway and Sweden government forestry is a well-established
portion of the national life. Turkey, Greece, Spain, and Portugal give
attention to the forests. Russia, dealing like ourselves with vast areas
of forests in thinly peopled regions, but by methods wholly different from
our own, is drawing enormous revenues from the systematic care and use
of the forests. In Germany the scientific treatment of forests has reached,
perhaps, its highest development. The foresters of France have perfected
a most practical and effective general system of forestry, and have created
the difficult art of controlling the floods of mountain torrents by planting
trees. The Republic of Switzerland, by the use of methods most instructive
to citizens of the United States, has developed a type of government forest
policy more worthy of our attention and imitation than any other in Europe.
In Australia and New Zealand forestry has already made important advances.
In Canada the English have made real progress in forestry; the government
sells the timber from its forests, but retains possession of the lands
and employs fire guards; at the Cape of Good Hope they have an excellent
forest service; in British India they have met and answered many questions
which still confront the American forester, and in a little more than thirty
years have created a forest service of great merit and high achievement.
The United States has scarcely yet begun.
THE FOREST IN EARLY TIMES.
In very early times the forest was preserved for the game it contained.
Forestry then meant the art of hunting, and had very little to do with
the care of trees. Even the word forest, which really comes from the Latin
foris, meaning out of doors, was thought in England to be derived
from the fact that it was a place given up to wild animals for rest.
But gradually the forest came to be considered more than the game, and
the serious study of forestry began.
MODERN FORESTRY.
Forestry as a science is of comparatively recent origin, although
a work in which all the european trees are described was one of the earliest
printed books. Until the end of the eighteenth century forestry was discussed
chiefly by men who were either scholars or practical woodsmen, but who
were not both. Then appeared Hartig and Cotta, two men who united these
points of view, and their writings are at the base of the whole modern
growth of the subject. Both were German. Each covered the whole field as
it was then understood, and together they exerted an influence which has
not been approached by any other authors since. From Germany their teaching
spread to France, and early in the nineteenth century their doctrines were
introduced into the French Forest School at Nancy by Lorentz, who, with
his successor, Parade, was the founder of modern forestry in France.
Under the feudal system, which was finally destroyed in France by
the revolution of 1789, the forest was the property of the feudal lord.
In order to make the life of their serfs, who were useful both as taxpayers
and as fighting men, easier, and so increase their number, he gave them
the privilege of taking from his forest the wood which they required. For
similar reasons the wealthy religious houses, like that of the Grande Chartreuse,
made grants of land and of rights in the forest. But after a time the number
of peasants increased so much that their wants absorbed nearly the whole
produce of the woodlands. Then it was found necessary to limit the prescriptive
rights to forest products by restricting them to certain parts of the forest,
or to make an end of them by exchanging them for the absolute ownership
of smaller areas. Thus many of the communities, to which, and not to individual
peasants, these rights belonged, came to possess forests of their own.
But the communes, as they were called, managed their forests badly, and
about three hundred years ago the Government was forced to intervene. Under
the management of officers of the Government forest service, the results
from the communal forests have been excellent. At present these forests
not only supply fuel to the villages which own them, but in some cases
they produce enough to pay all the village taxes as well.
Germany.
Germany still holds the high position in forest science which began
with Hartig and Cotta. The German forest schools, of which there are seven
of the higher grades, are still among the very best, and the study of forestry,
both in the schools and in the forest experiment stations, is eagerly pursued.
The forests in Prussia, Saxony, and other Germany States are admirably
managed, and yield important returns. The total value of the German forests,
public and private, is said to be about $4,500,000,000.
France.
Forestry in France has long been associated with the names of famous
men. Henry of Navarre and his friend and minister, Sully; Palissy, the
great potter, who called the neglect of the forest prevalent in his time
"not a mistake, but a calamity and a curse for France;" Colbert,
the minister of Louis XIV; the botanist Duhamel du Monceau; Buffon, the
celebrated naturalist, are among the men to whom France owes the rise and
progress of her present excellent forest policy. Their peculiar service
was to lay the foundation, both in law and in public opinion, upon which
modern forestry in France now rests.
The forests of the French Government are admirably managed. They
cover only about 2,750,000 acres, but they yield a net return each year
of more than $2 per acre. Besides handling their national forests with
great intelligence and success, the French foresters have done much for
the general progress of forestry. They developed the art of reforesting
denuded mountains, and were the first to plant trees on moving sand dunes
along the seashore. More than 150,000 acres of these dunes, which once
were blown about by the wind until they overwhelmed great stretches of
fertile ground, and even threatened to bury whole towns, are now covered
with forests of pine, and produce great quantities of turpentine, lumber,
and charcoal.
Switzerland.
In Switzerland forestry received attention from very early times.
Nearly two hundred years before the discovery of America the city of Zurich
began to make rules for the protection and management of the Sihlwald,
a forest which it still owns, and which now yields an annual return of
about $8 per acre. In the Canton of Bern a decree of the year 1592 warned
the people against the wasteful use of timber and provided for the protection
of the forest along various lines. It also directed that for every tree
cut down a young one should be planted in its place. It is curious to find
this mistaken prescription for the ills of the forest already in fashion
more than three centuries ago. To save the forest every old tree must be
replaced by many young ones.
The first general forest law of Bern was passed as early as 1725.
It embodied the most important principles of wise forest legislation as
we know them to-day. But this was only one of a long series of forest laws
in which, from the beginning, the idea of the importance of the forest
to others besides its owner became steadily stronger. The citizens of Bern
have grown ever more willing to place restrictions on themselves for the
benefit of the Commonwealth.
There were great floods in Switzerland in 1834, and they were the
cause of a general awakening of interest in forestry. Somewhat later a
federal forest commission was appointed. Since the appearance of its final
report in 1861 the progress of forestry in Switzerland has been steady.
In 1875 a federal forest inspector was appointed, and a year later the
first Swiss forest law was passed. This law does not extend to the whole
of Switzerland, but only to the Alps and the steeper foothills. In a country
of steep mountains it is of first importance to guard the forests on these
higher slopes. Consequently all the forests on these higher lands which
serve to protect the lowlands against floods, avalanches, and other similar
dangers of wind and weather are put in charge of the Swiss federal forest
service.
A great saying of Landolt.-- "Our forest laws,"
said Elias Landolt, a great and simple man, who name stands first among
Swiss foresters, "are intended to work more through instruction, good
example, and encouragement than by severe regulations. This method is somewhat
slower than one which should involve harsher measures, but the results
achieved are more useful and lasting. When forest owners do something because
they are convinced of its usefulness it is done well and with an eye to
the future, but what they do under compulsion is done carelessly and neglected
at the first opportunity. What they have come to learn in this way and
have recognized as good will be carried out, and that better and better
from year to year."
British India.
For many years after the British conquest forestry in India made
very little progress. Much time was wasted in half measures, until in 1856
Dr. (now Sir Dietrich) Brandis was put in charge of the teak forests of
Pegu. He acted at once upon the idea of preserving them by making them
pay. At first the output of teak had to be somewhat restricted, much against
the will of the timber merchants of Rangoon, who protested that the business
of their city would be ruined. But after this momentary check the teak
trade of Rangoon grew until it was far greater than ever before, and it
is now a chief and increasing source of the prosperity of that city.
The appointment of Dr. Brandis was the beginning of the Indian forest
service. In 1866 he was made inspector-general of forests, and from that
time progress was rapid. the Indian forest service now has nearly 300 superior
officers and over 10,000 rangers and forest guards. It has charge of about
200,000 square miles of forest, and produces a net revenue, after all expenses
have been paid, of about $3,000,000 a year. In addition, the forests furnish
to peasant holders of forest rights products whose value is estimated to
be considerably greater than the whole cost of the forest service. About
30,000 square miles are effectively protected against fire, at an average
yearly cost of less than half a cent per acre. These admirable results
are especially interesting because India is like the United States in the
great extend and variety of her forests and in the number and fierceness
of forest fires.
FORESTRY AT HOME.
The forests of the United States cover an area of about 699,500,000
acres, or more than 35 per cent of the surface of the country. Before so
large a part of them was destroyed they were, perhaps, the richest on the
earth, and with proper care they are capable of being so again. Their power
of reproduction is exceedingly good.
In the Northeastern States, and as far west as Minnesota, once stretched
the great white pine forest from which, since settlement began, the greater
part of our lumber has come. South of it, in a broad belt along the Atlantic
and the Gulf coasts, lies the southern pine forest, whose most important
tree, both for lumber and naval stores, is the southern yellow pine. In
the Mississippi Valley lies the interior hardwood forest of oaks, hickories,
ashes, gums, and other hardwood trees. It is bordered on the west by the
plains, which cover the eastern slope of the continental divide until they
meet the evergreen Rocky Mountain forest which clothes the slopes of this
great range from the Canadian line to Mexico. Separated from the Rocky
Mountain forest by the interior deserts, the Pacific Coast forest covers
the flanks of the Sierras, the Cascades, and the Coast ranges. Its largest
trees are the giant sequoia and the great coast redwood, and its most important
timber is the fir.
The forests of the Philippine Islands cover an area of more than
40,000,000 acres. Their timbers, almost wholly different from those of
the United States, are exceedingly valuable, both as cabinet woods and
as construction timber. An efficient forest service was organized in 1898,
and following its reorganization in 1902 a new and excellent forest law
was passed in 1904. The Philippine forest service costs but half as much
s the revenue received from the forests of the islands.
The island of Porto Rico contains a national forest reserve, the
site of which was once covered with valuable hardwoods; but this forest
has been much abused. Porto Rico, like the Philippines, has many kinds
of wood valuable for cabinetmaking.
THE SETTLER AND THE FOREST.
When the early settlers from the Old World landed on the Atlantic
coast of North America they brought with them traditions of respect for
the forest created by generations of forest protection at home. The country
to which they came was covered, for the most part, with dense forests.
There was so little open land that ground had to be cleared for the plow.
It is true that the forest gave the pioneers shelter and fuel, and game
for food, but it was often filled with hostile Indians, it hemmed them
in on every side, and immense labor was required to win from it the soil
in which to raise their necessary crops. Naturally, it seemed to them an
enemy rather than a friend. Their respect for it dwindled and disappeared,
and its place was taken by hate and fear.
The feeling of hostility to the forest which grew up among the early
settlers continued and increased among their descendants long after all
reason for it had disappeared. But even in the early days far-sighted men
began to consider the safety of the forest. In 1653 the authorities of
Charlestown, in Massachusetts, forbade the cutting of timber on the town
lands without permission from the selectmen, and in 1689 the neighboring
town of Malden fixed a penalty of 5 shillings for cutting trees less than
1 foot in diameter for fuel. An ordinance of William Penn, made in 1681,
required that 1 acre of land be left covered with trees for every 5 acres
cleared. But these measures were not well followed up, and the needless
destruction of the forest went steadily on.
FIRST STEPS IN FORESTRY.
More than a hundred years later, in 1795, a committee of the Society
for the Promotion of Agriculture, Arts, and Manufactures in New York made
a report on the best way to preserve and increase the growth of timber.
Four years afterwards Congress appropriated $200,000 for the purchase and
preservation of timberlands to supply ship timbers for the Navy, and in
1822, with the same object in view, it authorized the President to employ
the Army and Navy, and President to employ the Army and Navy to protect
and preserve the live oak and red cedar timber of the Government in Florida.
Since that time more and more attention ahs been given to the forests.
In 1828 Governor DeWitt Clinton, of New York, spoke of the reproduction
of our woods as an object of primary importance, and in the same year the
Government began an attempt to cultivate live oak in the South for the
use of the Navy. Three years later an act was passed which is still almost
the only protection for the much-abused forests of the public domain.
In 1872 the Yellowstone National Park was established, and in 1873
Congress passed the timber-culture act, which gave Government land in the
treeless regions to whoever would plant one-fourth of his claim with trees.
In 1875, the American Forestry Association was formed in Chicago through
the efforts of Dr. John A. Warder, who was one of the first men to agitate
forest questions in the United States. In the centennial year (1876) Dr.
Franklin B. Hough, perhaps the foremost pioneer of forestry in America
was appointed special agent in the Department of Agriculture was established
as a division in 1881.
About this time forest associations began to be established in the
different States, the most influential and effective of which has been
that in Pennsylvania. The States Also began to form forest boards or commissions
of their own.
In 1888 the first forest bill was introduced in Congress. It failed
to pass, but in 1891 an act was passed which was the first step toward
a true policy for the forests of the nation. The first step toward national
forestry is control of the national forests. This act, whose chief purpose
was to repeal the timber-culture act, contained a clause which authorized
the President to reserve timberlands on the public domain, and so prevent
them from passing out of the possession of the Government.
THE PUBLIC DOMAIN.
In all the states except Texas, and in Ohio, Indiana, Illinois, Michigan,
Wisconsin, Florida, Alabama, and Mississippi, all the land originally belonged
to the Government. This was the public domain. It has gradually been sold
or given away until in many of the States it has all or nearly all passed
to other owners. But it still includes more than 470,000,000 acres, or
nearly one-third of the United States, not including the Territory of Alaska,
which has an area of about 350,000,000 acres. A large part of the public
domain has been surveyed by the Government and divided first into squares
of 1 mile, called sections, and these again into quarter sections and smaller
divisions. The lines which mark these divisions are straight and at right
angles to each other. When any part of the public domain is reserved or
disposed of it is usually located by reference to these lines.
FEDERAL FOREST RESERVES.
When the President was given the power to make forest reserves, the
public domain still contained much of the best timber in the West, but
it was passing rapidly into private hands. Acting upon the wise principle
that forests whose preservation is necessary for the general welfare should
remain in Government control, President Harrison created the first forest
reserves. President Cleveland followed his example. But there was yet no
systematic plan for the making or management of the reserves, which at
that time were altogether without protection by the Government. Toward
the end of President Cleveland's second Administration, therefore, the
National Academy of Sciences was asked to appoint a commission to examine
the national forest lands and report a plan for their control. The academy
did so, and upon the recommendation of the National Forest Commission so
appointed, President Cleveland doubled the reserved area by setting aside
13 additional forest reserves on Washington's Birthday, 1897.
The Cleveland forest reserves awakened at once great opposition in
Congress and throughout the West, and led to a general discussion of the
forest policy. But after several years of controversy widespread approval
took the place of opposition, and at present the value of the forest reserves
is rarely disputed, except by private interests impatient of restraint.
The recommendations of the National Forest Commission for the management
of the forest reserves were not acted upon by Congress, but the law of
June 4, 1897, gave the Secretary of the Interior authority to protect the
reserves and make them useful. The passage of this law was the first step
toward a national forest service. The second step was the act of Congress,
approved February 1, 1905, which transferred the control of the national
forest reserves from the Department of the Interior to the Department of
Agriculture. This act consolidated the Government's forest work, which
had been divided between the General Land Office and the Bureau of Forestry,
and secured for the reserves the supervision of trained foresters.
President McKinley and after him President Roosevelt continued to
make forest reserves. The latter introduced a system of examining the proposed
forest reserves, so that now their boundaries are better located than ever
before. Under him great progress has been made by the Government in bringing
about the practice of forestry by forest owners and in awakening the great
lumber interests, as well as the people in general, to the dangers of forest
destruction.
The forest reserves lie chiefly in high mountain regions. They are
62 in number, and cover an area (January 1, 1905) of 63,308,319 acres.
They are useful first of all to protect the drainage basins of streams
used for irrigation, and especially the watersheds of the great irrigation
works which the Government is constructing under the reclamation law, which
was passed in 1902. This is their most important use. Secondly, they supply
grass and other forage for many thousands of grazing animals during the
summer, when the lower ranges on the plains and deserts are barren and
dry. Lastly, they furnish a permanent supply of wood for the use of settlers,
miners, lumbermen, and other citizens. This is at present the least important
use of the reserves, but it will be of greater consequence hereafter. The
best way for the Government to promote each of these three great uses is
to protect the forest reserves from fire.
STATE FORESTRY.
Many of the States have taken great and effective interest in forestry.
Among those which have made most progress are New York and Pennsylvania.
New York ahs a State forest preserve of 1,436,686 acres, and Pennsylvania
one of 700,000 acres. Michigan, Minnesota, and other States are rapidly
following their example.
In 1892 the first example of systematic forestry in the United States
was begun at Biltmore, in North Carolina. It is still in successful operation.
The first professional foresters in the United States were obliged
to go abroad for their training, but in 1898 professional forest schools
were established at Cornell University in New York, and at Biltmore, in
North Carolina, and they were followed by the Yale Forest School in 1900.
Others have sprung up since. At present, thorough and efficient training
in professional forestry can be had in the United States.
THE END.
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