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S. DEPAR AR RTME NT OF AGRICULTURE.

BUREAU OF PLANT INDUSTRY —BULLETIN NO. BY, a : a

bse he B. ‘r GALLOWAY, ee. o Bureau, Be 3s ‘ is

- METHODS USED)

Sang FOR i y

B CONTROLLI NG AND RECLAIMIN G
“SAND. DUNES...) 1/8

A... 5. HITCHCOCK;
Assistant AGROSTOLOGIST, IN CHARGE OF COOPERATIVE
EXPERIMENTS. ees

GRASS AND FORAGE. PLANT INVESTIGATIONS, 9 49 0
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Issumep Maren 10, 1904.
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Bul. 57, Bureau of Plant Industry, U. S. Dept. of Agriculture. PEATIERE

BEACH GRASS (AMMOPHILA ARENARIA LINK).

eo. DEPARTMENT OF AGRICULTURE.
BUREAU OF PLANT INDUSTRY—BULLETIN NO. 57.

B. T. GALLOWAY, Chief of Bureau.

METHODS USED

FOR

CONTROLLING AND RECLAIMING
SAND DUNES.

BY

A. S. HITCHCOCK,

AssIsTANT AGROSTOLOGIST, IN CHARGE OF COOPERATIVE
EXPERIMENTS.

GRASS AND FORAGE PLANT INVESTIGATIONS.

IssupED Marcu 10, 1904.

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WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1904.

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BUREAU OF PLANT INDUSTRY.

Brverty T. GAtitoway, Chief of Bureau.

GRASS AND FORAGE PLANT INVESTIGATIONS.
ScrenTiFic STarr.
W. J. SPILLMAN, Agrostologist.

A. S. Hitcucocr, Assistant Agrostologist, in Charge of Cooperative Experiments.
C. V. Pirrr, Systematic Agrostologist, in Charge of Herbarium.

C. R. Batu, Assistant Agrostologist, in Charge of Work on Arlington Farm.
Davip GriFFitHs, Assistant Agrostologist, in Charge of Range Investigations.

2

JAN 8 1907
D. of

LETTER OF TRANSMITTAL.

U. S. DEPARTMENT OF AGRICULTURE,
Bureau oF Priant Inpustry,
OFFICE OF THE CHIEF,
Washington, D. C., January 7, 1904.

Str: I have the honor to transmit herewith a paper on ‘‘ Methods
Used for Controlling and Reclaiming Sand Dunes,” and respectfully
‘recommend that it be published as Bulletin No. 57 of the series of this
Bureau.

This paper was prepared by Mr. A. S. Hitchcock, Assistant Agros-
tologist, in Charge of Cooperative Experiments, Grass and Forage
Plant Investigations, and has been submitted by the Agrostologist
with a view to publication.

Respectfully,
B. T. GaLLoway,
Chief of Bureau.
Hon. JAMES WiItson,
Secretary of Agriculture.

we

PR EASAC E.

On the Atlantic and Pacific coasts,.on the shores of the Great Lakes,
and at numerous places inland, there are areas of sandy land, for the
most part originally covered by vegetation, but now denuded of plant
growth through the shortsighted policy which has so often prevailed in
this country of utilizing everything in sight without reference to the
future. The Department of Agriculture is frequently called upon for
advice concerning the proper methods of controlling this sand and pre-
venting it from drifting. In some cases cultivated fields have been
invaded and railroad tracks covered. The sand has even invaded
cities, covering up houses and filling the streets, and much valuable
property has thus been destroyed.

Much work has been done in controlling shifting sand dunes in
Europe during the past century, and methods have been developed
whereby it is possible to control the sand and in many cases to cover it
again with vegetation. On account of the importance of the subject, '
Prof. A. S. Hitchcock, of this office, was sent to Europe recently to
study the methods there used in this work. In the autumn of 1902 he
visited the Netherlands, Denmark, Germany, and France for this pur-
pose. An outline of the methods that have been successfully employed
in those countries is given in this bulletin, together with some other
information of general interest concerning the subject of sand dunes.

, ; W. J. SPILLMAN,

Agrostologist.

OFFICE OF THE AGROSTOLOGIST, :
Washington, D. C., December 16, 1903.

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PLATES.

Page.
Pure I: Beseh prassess 5.25252 fee th ek acceeel ses a 5e pooner Frontispiece.

II. Fig. 1.—Dunes held by covering of heather. Fig. 2.—Making a road
in the Gunes ee -o-2s2ce fos 2. aot keel a ee 36

IIf. Fig. 1.—Pine plantation in covering of heather. Fig. 2.—Heather
among ttheidunes= ssi. osc os ee oe ee eee ae 36

IV. Fig. 1.—Beach grass plantation along base of dunes. Fig. 2.—Beach
grass and sand fence on barrier dune --. +2 °2.....2 2-25-22 eeee 36

V. Fig. 1.—Lee slope of barrierdune. Fig. 2.—Remains of once buried
TORESHE ee ea ie Ae Rn Nr oe is oe epee See 36

VI. Fig. 1.—General view of barrier dune. Fig. 2.—Unreclaimed shift-
ing dunes) ores tls Soe ee Se er ee 36

VII. Fig. 1.—Digging beach grass for planting. Fig. 2.—Transplanting
beach prass. 298506 25 aieice Shoo. 2 Lee ee eee 36

VIII. Fig. 1.—Sand fences protecting base of dune. Fig. 2.—Protecting a
road through ‘the dunes, <2. 22.2. 4.-4 2c 220s bee eee eee 36°

IX. Fig. 1.-—Shifting dunes held by brush fences. Fig. 2.—Shifting dunes
held: by reed fences... ...= 2... Ssocc2.. sin ce cece eee 36

TEXT FIGURES.

Fie. 1. Drifting sand as affected bya solid fence..-.-.--.....--.---+-:---e-6 12
2. Drifting sand as affected by an open, inflexible obstruction .......--- 12
3. Drifting sand as affected by an open, flexible obstruction .......---- a 12
4, Spade used for planting beach grass! 2.4... 4. 4222222. eee 15
5. Method used in planting beach erase ~2.22.422225-22.-2--5 eee eee 16
6. Diagram showing the successive steps taken in forming a barrier dune. i
7. Repairing a small breach in a barrier dune by planting grass. -.------- 18
8. Repairing a larger breach by means of sand fences -.---..----------- 18
9. Spade used in Prussia for transplanting young trees..........-.------ 21

8

B. P. I.—92. G. F. P. I.—102.

METHODS USED FOR CONTROLLING AND RECLAIM-
ING SAND DUNES.

INTRODUCTION.

The sand-dune areas of Europe are of especial interest because they
present conditions similar to those found in the United States and
because it is there that the methods of reclamation were first applied
and later most successfully developed.

In order to investigate the methods used and determine to what
' extent they might be applied in this country, the writer visited several
regions in Europe where the conditions and methods may be considered
representative—the Netherlands, Denmark, the southwest coast of
France, and the Kurische Nehrung on the northeast coast of Germany.
In Prussia much work has been done along the coasts of the Baltic and
North seas, but this is so well described in Gerhardt’s” admirable book
upon the dunes of Germany that other points than the ones mentioned
were not visited.

There are other localities of minor importance where dunes occur
and where efforts toward reclamation have been made, but it was not
learned that the methods used differed essentially from those investi-
gated. Lack of time prevented visits to certain other interesting
interior regions, such as the Banat plain of southern Hungary, the
north shore of the Black Sea, and Russian Turkestan. The last two
regions are of importance because of the efforts put forth by the rail-
roads to prevent the enroachment upon their right of way by shifting
dunes.

FORMATION OF SAND DUNES.

Sand hills or dunes usually occur along a sandy seacoast. The sand
is constantly washed up by the waves and when dry is readily carried
inland by the wind. Ona rocky or marshy coast this does not occur.

# Paul Gerhardt, Handbuch des deutschen Diinenbaues, Berlin, 1900. This is a very
complete and detailed account of the sand dunes of Germany, including geology, flora,
formation, reclamation, and historical notes, and is the most elaborate work of this
nature thus far published. The writer is indebted to this work for the text figures
used in this bulletin. Mr. Gerhardt was superintendent of the Kénigsberg district
(Regierungs und Baurat) and was later advanced to the charge of the entire work at
Berlin.

9

10 METHODS USED FOR CONTROLLING SAND DUNES. -

Under the action of the wind the sand accumulates in ridges or hills of
irregular contour and extent, depending upon the force and direction
of the prevailing winds. It is not intended here to go into the details
of dune formation, a subject which has been elaborated in Gerhardt’s
book and also in numerous lesser works. Suffice it to say that ordi-
narily a dune passes through a rather definite series of changes. It is
formed near the beach and travels back toward the interior. <A typ-
ical wandering dune presents a gradual slope toward the wind and an
abrupt slope on the lee side. The wind forces the sand up the slope
and it falls over the edge. The hill or ridge then travels in the direc-
tion of the prevailing wind at a rate depending on the force and con-
stancy of the latter. Such a hill is called a wandering dune. As the
dune recedes from the coast a new one may form at the beach.

Upon the wandering or active dunes the sand is shifting to such an
extent that vegetation does not establish itself. Consequently such
dunes are bare. During wet periods seeds may germinate, but sooner
or later the flying sand destroys the plants either by cutting them off
as by a sand blast or by burying or uncovering them. However, as
the action of the wind becomes less forcible at a distance from the
strand, vegetation is at last able to become established and resist the
enfeebled sand blast. A wandering dune is thus gradually converted
into a fixed dune, which, if left to itself, finally becomes forested.

Similar dunes are often formed along the larger rivers or on interior
sandy wastes such as are found in the central portions of the Nether-
lands and Denmark. It not infrequently happens that a fixed dune
becomes converted into a wandering dune. This occurs through the
removal of the vegetation, either by natural means or as the result of
man’s carelessness. The result in the first case is usually brought about
by changed conditions, such as the direction of the wind, whereby the
vegetation dies in certain spots and *‘ blowouts” are formed. Such
cavities or blowouts gradually enlarge as the surrounding vegetation
is undermined and the result may be the birth of a wandering dune.
But from an economic standpoint by far the greatest harm has come
from the removal of forests from fixed dunes. The Kurische Nehrung
in Prussia and the coast dunes of the Netherlands were at one time
covered with forest and gave no trouble. Other cases are known
where dunes held permanently by a covering of grass have been con-
verted into wandering dunes by the pasturing of cattle upon them,
thus cutting up the sod.

Sand dunes of any considerable extent are rarely found along the
seacoast in warmer regions, because the long growing season is more
favorable to vegetation. The forest, or at least a scrubby growth of
shrubs, usually comes down close to the high-water mark. The severe
winter storms of the high latitudes are chiefly responsible for the great
dune areas of the north.

FORMATION OF DUNES. vt

In many cases the wandering dunes encroach upon arable land, upon
forest, upon valuable property such as railroads and buildings, or
upon rivers, harbors, or other water ways. This usually indicates
that there has been a recent change of conditions resulting in the
formation of active dunes. Seaside resorts upon sandy beaches are
often seriously damaged by the formation of dunes and blowouts upon
various portions of the property.

In addition to the trouble arising from the encroachment of sand
at points where it does damage, it should be understood that there are
large areas of sandy land consisting of dunes in various stages of fixa-
tion, interspersed with portions of level and sometimes arable land.
These level spots represent portions where the wind has swept away
the sand down to moist soil, which usually has a definite relation to
the water level. Such areas of dunes may include many square miles
and are useless for agricultural purposes. It is thus seen that the
_ fixation of dunes may be for two purposes—to protect property in the
lee or to convert a useless area of waste land into a productive forest.

ACTION OF THE WIND UPON DRIFTING SAND.

When the wind sweeps over a free surface of drifting sand it acts
about equally throughout; but an obstruction of any kind, such as
a log or a bunch of grass, at once modifies the action of the wind.
A solid object increases the force of the wind around the sides, and
hence the sand is excavated. In the lee of the object the sand will
accumulate. If two such obstructions are near together a channel is

formed between them and once formed deepens with astonishing
yvapidity. The carrying power of the wind increases much more
rapidly than the increase in the velocity.” Consequently, any increase
in the velocity is immediately noticeable in the increased erosive
power. The erosive power of the wind is not identical with the
carrying power, for in the first case the wind overcomes cohesion and
in the second case it overcomes weight. If the velocity of the wind
decreases, the sand previously held in suspension is deposited.

If a solid fence is placed upon the sand at right angles to the wind

«Theoretically the transporting power of the wind varies as the sixth power of the
velocity—that is, if the velocity is doubled the carrying power is 64 times as great.
It is clear that the force exerted by the wind upon a fixed surface increases as the
square of the velocity, for if the velocity of the wind is doubled there will be twice
as much air striking the surface with twice the velocity. Furthermore, if the velocity
remains the same the force exerted increases with the surface—that is, with the square
of the diameter. The moving power then varies as the product of the square of the
velocity and the square of the diameter. But the force or work done, which is the
same as the weight of the object transported, varies with the cube of the diameter;
or, putting it all in terms of velocity, the force varies as the sixth power of the
velocity.

12 METHODS USED FOR CONTROLLING SAND DUNES.

the sand is excavated in front (fig. 1). The wind, unable to proceed,
is divided into currents in all directions. Those going downward
scoop out the sand, thus forming a drift a short distance in front.
This increases until its height equals that of the fence, when the wind,
no longer meeting with the obstruction, allows sand to be deposited

Fie. 1.—Drifting sand as affected by a solid fence.

in this channel, and it fills up, covering the fence. Similarly at the
ends of the fence the wind currents are increased and the sand is
scooped out. If the fence is raised so as to allow a space beneath, the
sand is rapidly scooped out below. The same result occurs beneath
buildings, trestles, or other works which allow a space beneath,

Fic. 2.—Drifting sand as affected by an open, inflexible obstruction.

through which the wind rushes with increased force. If, however,
the obstruction is not solid, but more or less open, as a pile of brush
or a bunch of grass, the action is entirely different. The wind passes
through the obstruction, but with decreased velocity; hence, sand is
deposited within the obstruction. No excavation takes place in front

Fic. 3.—Drifting sand as affected by an open, flexible obstruction.

or around the sides. If the obstruction is stiff and inflexible like a
sand fence, the sand is deposited on both sides (fig. 2), the windward
slope being gradual and the lee slope more abrupt. If the obstruc-
tion is flexible like a bunch of grass, most of the sand is deposited in
the lee (fig. 3). Of course there are all gradations between the two
classes, and various circumstances may modify the usual action.

It may be further stated that when the wind is blowing up an

a oe

FIXATION OF DUNES. 13

incline, the surface velocity increases with the steepness. A small
object is easily blown uphill. But when the wind blows down a slope,
eddies form which usually produce a current uphill at the surface.
Thus it happens that while small bodies can be blown uphill easily it
is not often that they are blown downhill, but must fall from their
own weight when the slope is steep. ‘The fact that the velocity of the
wind at the surface on the windward side of a dune increases with the
slope results in producing a normal incline, which represents a_bal-
ancing of forces. Usually this incline is quite gradual compared with
the lee side of the dune, where the slope is the greatest at which the
sand will remain in place—about 30°.

Sand can be removed from one place to another farther on by placing
a suitable obstruction above, with a space. between it and the surface
of the sand, which will increase the wind velocity at this point. Sand
may be filled in at any point by interposing an open obstruction, such
as brush or a sand hedge, or by planting grass. The practical appli-
cation will be referred to farther on.

ARTIFICIAL FIXATION OF DUNES.

The fixation is most permanent when the dunes are covered with
forest; hence, forestation is the ultimate aim wherever possible. But
there is a narrow strip of territory just back of the strand where
trees will not grow on account of the exposure to the severe winds
and the action of the ocean spray. The width of this strip depends
upon local conditions and may vary from one to several rods. The
force of the wind is influenced by the character of the coast. Expe-
rience soon demonstrates how near to the strand a forest may be
produced.

When the work of fixation is completed there will be a forest over
the greater part, but a strip along the coast remains which must be
permanently held in place by some other method, usually by the plant-
ing of grass. When the forest is once established it is cared for and
preserved according to the usual methods of forestry. Usually it is
impossible to establish a forest directly upon the sand dunes either by
sowing the seed or setting out young trees, because the drifting sand
cuts the leaves and bark or uncovers or buries the young plants.
Sowing the seed has been tried several times, but there remain of this
work only a few scattered patches of trees in protected places. It is
therefore necessary to hold the sand in place by some kind of a cover-
ing until the trees can obtain a start, when they form a covering
themselves.

The work of fixation is thus divided into two rather distinct stages:
(1) Preliminary; holding the sand in place. (2) Permanent; establish-
ing a forest. Upon the coast strip the work does not proceed beyond
the first stage, but the maintenance of the covering in a satisfactory
condition requires constant care.

14 METHODS USED FOR CONTROLLING SAND DUNES.

BINDING THE SAND.

There are many methods which have been employed at various times,
but those now in successful use on a large scale may be considered
under three heads: (1) Transplanting sand-binding plants upon the
dunes, sufficiently thick to form a living cover; (2) covering the entire
surface with some inert material which prevents the wind from reach-
ing the sand, and (3) covering the surface with a network of brush
fence which, while not preventing the wind from reaching the sand,
lessens its velocity and prevents drifting. It may be remarked that
numerous experiments have demonstrated the futility of sowing the
seeds of any plant directly upon the unprotected surface of the bare
sand.

These methods, as they have been finally elaborated, will now be
described. For the historical development and the description of
special methods to meet unusual conditions, the reader is referred to
Gerhardt’s book previously mentioned.

BINDING BY MEANS OF GRASSES.

Various plants for binding the sand have been tried, but none have
been found so successful as grasses. Willow cuttings have been
employed in afew cases, but their use has not proved satisfactory. Of
the grasses the species used almost exclusively is beach grass (Am-
mophila arenaria Link), shown in Plate I, frontispiece. A kind of
wild rye (Zlymus arenarius Li.) has been used occasionally. Beach
grass grows naturally on the dunes all along the north Atlantic
coasts of both Europe and America as far south as Morocco and North
Carolina. It grows in clumps to the height of one to three feet and
spreads by means of extensively creeping underground stems or
rhizomes.

An important character of beach grass is that it grows with most
luxuriance where the sand is drifting. In quiet sand it persists fora
few years but gradually dies out. The drifting sand seems to supply
the conditions for continued rejuvenation of the growth as the sprouts
force their way up through the accumulating sand.

Transplanting.—Beach grass may be transplanted in the autumn or
spring ; in the autumn from the time it is mature, which may be as
early as September, until the ground freezes, and in the spring from
the time the ground thaws until growth starts. The grass is usually
transplanted in the autumn, because at this time the requisite labor is
more easily obtained, and furthermore it is then easier to pick out the
individuals that are at the right stage of growth. It is best to choose
moist or foggy weather, as the plants are more certain to grow, the
danger of desiccation is less, the sand being damp it is more easily
manipulated, and the work can be performed much more comfortably,

Se

BINDING SAND WITH GRASSES. 15

as the flying sand seriously interferes with planting during dry
weather.

The plants chosen for transplanting should be two years old and
have at the base one or two nodes. The roots spring from these nodes;
consequently at least one node must be present. More than two are
not necessary and would be a waste of material, though they do no
other harm than to interfere with planting in proportion to their num-
ber. One-year-old plants are not strong enough and have not devel-
oped the nodes sufliciently for transplanting. Plants more than two
years old are proportionately lacking in vitality and do not throw out
roots with sufficient vigor. With some experience laborers are able
to distinguish at sight plants of the right age. If the grass is grow-
ing in loose sand and has not been covered deeply, it
may be pulled up by hand. But usually it is neces-
sary to cut the rhizomes below the surface of the
sand, after which the plants can be easily pulled up.
The method of procedure is for the workman to seize
a suitable clump of the grass with the left hand and
with a spade held in the right hand strike into the
sand in such a manner as to cut off the rhizomes below
having one to three nodes at the lower end (Pl. VII,
fig. 1). The bunch is then pulled up and placed in a
pile or under the leftarm. When a bundle has accum-
ulated, it is tied up and is ready for use. The spade
used is a light tool specially made for the purpose,
with a sharp edge or point and a short handle.
Sometimes an ordinary spade, such as is used in dig-
ging, is put to this service.

If the grass for transplanting is taken from the
dunes that are to be fixed, care should be taken not to
remove too much from one place and allow the wind ric. 4.—spade used
to make a blowout. It should be chosen from places oe mere
where the grass is growing too thickly. The arrange-
ments should be such that the grass can be planted soon after being
dug or the roots may dry out too much. For the same reason it is
best to dig the plants near the place where they are to be set out,
thus reducing the distance of transportation.

The grass may be set out in various ways, but the method which
seems to be most satisfactory is as follows: The planting is done by
two persons working together. One prepares the holes and the other
inserts the grass. The holes are made with a spade specially con-
structed, as shown in the illustration (fig. 4). The blade is rather heavy
and has a sharp edge below. The operator lifts the spade by the cross
bar or handle with both hands, and allows it to drop into the sand
mostly by its own weight. He moves the handle back and forth once

17170—No. 57—04—_2

aa = upl
f

“

w-- eo nennnee ee 22

Beery, ae

16 METHODS USED FOR CONTROLLING SAND DUNES.

or twice, or until the blade has been worked down through the sand
to the required depth. This makes a V-shaped opening in the sand 8
to 12 inches deep. The sand must be moist enough to retain its posi-
tion or this method can not be used. The second worker now takes a
portion of grass sufficient for one planting and places it in the hole,
flattening out the bunch properly. The first worker puts the spade in
the sand just behind the bunch, pushes the sand up tightly against the
grass, and the operation is completed (fig. 5). The grass can be set
out quite rapidly in this manner (PI. VII, fig. 2).

Arrangement of the plantation.—lf the dunes are already partially
covered with beach grass, it may be necessary to plant only here and
there in the bare places to prevent excavation by the wind or the
formation of blowouts. If the sand is bare or covered with only a
scattering growth, it is necessary to plant systematically. The most
common method is to set the plants in rows. In Germany they are
set in squares, the quadrat system, which will be
described under methods used in the Kurische
Nehrung. When the grass is set in rows, the
bunches are placed so that they alternate in adja-
cent rows. Ordinarily the rows are fairly straight
and perpendicular to the prevailing direction of
the wind. In an extended area, where there is a
succession of dunes and depressions, the rows may
follow the contour lines. Rows in the direction
of the wind should be avoided, as a channel will
be formed between. In broken dune areas the
plantings are made between the dunes and along their slopes, but
leaving the tops bare (PI. LV, fig. 1).

Usually there is no preparation of the dunes in the way of leveling
or filling, as it is found more economical to allow the wind to do this
work. The idea is to accumulate sand in the channels and hollows and
allow the wind to blow off the tops of the hills. To aid in leveling
the high places the grass is removed from these so that the wind can
have free access. No planting may be necessary in the low places
where the sand has been blown off down to moisture, as such situa-
tions support considerable vegetation. The planting is begun at the
base of the slopes and proceeds toward the top, as it is the lower por-
tions that are eroded the most rapidly, for the reasons stated when
discussing wind velocity.

The thickness of the planting depends upon local conditions. If it
is necessary to accumulate sand rapidly, as in filling a channel, the
grass is planted in large bunches placed closely together; but where
the sand is easily accumulated, the grass is set thinly to prevent its
being covered. Under average conditions the rows are 15 to 18
inches apart and the plants about a foot apart in the row. The amount

Fie. 5.—Method used in
planting beach grass.

2 pate

—

FORMATION OF BARRIER DUNE. Me

of grass in a bunch is about what can be easily taken in the hand and
may consist of four or five stalks.

Formation of the barrier dune.—The grass planting previously
described applies particularly to the large dune areas near the coast,

: eee eS ef
. : Ness

Fic. 6.—Diagram showing in cross section the successive steps taken in forming a barrier dune. The
strand is at the left.

where this process is preparatory to the planting of trees. The

function of the grass has been fulfilled when the forest is established.

As stated in an earlier paragraph, there is a strip of sand along the

18 METHODS USED FOR CONTROLLING SAND DUNES.

coast just back of the strand which presents conditions unfavorable to
forest growth. Here it is necessary to hold the sand in place perma-
nently by means of the grass. To do this requires constant super-
vision. Through various causes bare spaces are likely to occur which
must be replanted to prevent the formation of blowouts. Sometimes
the bunches must be thinned, as the presence of two large adjacent
bunches may cause the wind to draw through between them and form
a channel,

Fic. 7.—Repairing a small breach in a barrier dune by planting grass.

On the Kurische Nehrung in Prussia and along the southwest coast
of France it has been found advisable to form an artificial protecting
dune extending all along the sea in front of the forest (Pl. VI, fig. 1).
This dune is produced by accumulating the sand rapidly so as to form
a long ridge (fig. 6). For this purpose brush fences, which consist of
rows of brush or rough branches driven into the sand firmly but rising
above the surface about 30 inches, are used. The tops should be on a
level. Two such rows are placed about 6 feet apart. These fences
allow the wind to pass through, but reduce its velocity, and hence sand
is deposited within and on both sides. When the sand has reached the
top of the fences, a second pair is placed above. When a ridge has
been formed, beach grass is planted in rows parallel to the crest. At
first, plantings are made along the slopes and a short distance in front
toward the strand. As the sand accumulates, the grass is planted far-
ther to the windward. Finally the protecting dune assumes a com-
paratively permanent form, with a long slope to windward (toward

Fic. 8.—Repairing a larger breach by means of sand fences. The diagram represents a cross section
of a dune with two rows of sand fence parallel to the dune and cross rows extending from the
outer row to the broken face.

the sea) of 4 to 5 degrees, or about 1:9, and a-steep slope on the. lee
side of about 1:2 (Pl. V, fig. 1). As a matter of fact, the windward
slope is often much steeper—as much as 1:6 or even 1:4.

In practice this protecting dune must be established upon an area
more or less broken by dunes of irregular shape. The ground line
for the ridge is laid out to follow the coast in a general way, but to
avoid all sharp bends or indentations of the shore line. The hollows
and channels are filled up to the desired height, while the peaks and
any small dunes lying in front are denuded of grass so that they are

|
.

= Le CRE eee ee

TEN

BINDING SAND WITH HEATHER. 19

ultimately removed by the wind. Such a ridge protects the forest or
arable land lying in the lee, but requires constant supervision to keep
it in repair. The danger is from encroachment of the sea during
storms, especially in winter. A single severe storm may break
through and destroy several rods of well-built dune. Such a breach
must be repaired as soon as possible, or the wind will still further
erode the unprotected sand and enlarge the opening. These breaks
are best filled in by means of sand fences (figs. 7 and 8 and Pl. IV,
fig. 2).

It may be mentioned here that reclamation of sand dunes on a large
scale is carried on in Europe by the general governments, as private
individuals lack the necessary unity of purpose. This will be touched
upon under the head of the particular regions visited.

BINDING BY MEANS OF HEATHER.

As stated previously, it is necessary to hold the sand in place while
a forest is being established. Near the seacoast this is usually done by
planting the beach grass, which is found growing wild upon the dunes.
There are, however, vast stretches of inland dunes where beach grass
does not grow, and the cost of transportation renders this method less
economical than others. When fixing the sand is but preliminary to
planting trees the method used depends upon the relative cost. Along
the coast, where the fixation is permanent, the planting of beach grass
is the only method which meets the requirements, and hence it is used
even when it becomes necessary to import the plants.

For a temporary covering any cheap inert material which meets the
condition, such as brush, straw, or sawdust, may be used, but by far
the most satisfactory material in northern Europe is the heather ( Ca/-
luna vulgaris Salisb.). As it is a common plant in the sand-dune
regions this method is used in the central portion of the Netherlands
and in the interior regions of Denmark (PI. II], fig. 2). The heather
can be used also in areas near the seacoast, as in western Denmark.

Laying the heather.—The heather is cut off with secythes, spread
over the surface, and held in place by a little sand. The scythe used
for mowing is short and somewhat resembles American brush scythes.
The heather is then tied in bundles and carried to the place where it
is tobeused. Sometimes it may be necessary to transport the bundles
some distance, as the heather grows usually only in the low places
between the dunes, or at least it is here that it grows in suflicient
luxuriance to be cut profitably. Since the heather is not planted, it is
not necessary to use it immediately after gathering, as in the case of
the grass. The plants are spread out flat upon the surface, overlap-
ping each other in the rows, and are held in place by being partially
covered with sand: The surface is not prepared, except that small
inequalities are leveled so that the wind can not get beneath the layers
of heather (Pl. 1, fig. 1).

20 METHODS USED FOR CONTROLLING SAND DUNES.

The heather is also used in road making. The roads through the
dunes are laid out and graded in the usual manner, after which heather
is laid thickly in courses upon the surface, thus preventing the wheels
of vehicles from sinking into the sand (PI. I, fig. 2).

BINDING WITH SAND HEDGES.

Sand hedges are used for binding when other methods are not prac-
ticable, or where the sand is drifting with especial force, or where it
is desired to accumulate sand with rapidity. In general this method
involves the use of some inert material, like brush or rows of stakes or
reeds, which projects above the surface of the sand and reduces the
velocity of the wind without causing deflecting currents, which erode
the sand. The entire surface of the sand is not covered, but the action
of the wind is hindered sufficiently so that the sand present remains in
place and additions from the strand or from neighboring unprotected
areas are accumulated (PI. LX, figs. 1 and 2).

The sand fences or hedges are made from brush obtained in the
forest. The branches are cut into pieces from 18 inches to 2 feet long,
with sharp ends. The ends are sharpened by the slanting stroke which
severs the stick. The side twigs are cut off roughly. These stakes
are driven into the ground in rows, or, still better, in squares, thus
catching the sand from all directions. The stakes project above the
surface about a foot and should be on a line at the top, parallel with
the general plane of the dune surface. The size of the squares depends
on the tendency to drift, and varies from 9 to 12 feet. The rows
should be at right angles to the direction of the prevailing wind. On
dunes near the shore the rows should run parallel to this, with the
short rows perpendicular. In covering a surface the long rows are
first placed and the squares made by inserting crossrows between.
The stakes should be close enough together in the rows so that the
average width of the space is about equal to the average diameter of
the stakes. The size of the stakes varies from half an inch to 2 inches
(PIPEX fie 1).

The common reed of Europe is utilized in the same manner. It is
cut into the proper lengths and the pieces are set out in rows by about
the same methods used in grass planting (Pl. LX, fig. 2).

As previously stated, sand fences are used to repair breaks in proteet-
ing dunes, to fill channels previous to planting grass, or wherever it is
necessary to accumulate sand. In these cases it may be advantageous
to have the fences higher than when they are intended primarily to
bind the sand. Sand fences are sometimes used along the base of dunes
near the strand, where grass will not grow on account of occasional
high tides (Pl. VIII, fig. 1).

In place of sand fences heather or brush placed in rows or squares
and held in place by a little sand thrown over one edge is sometimes
used.

ESTABLISHING A FOREST. 21
FORESTATION.

The processes previously described are as a rule only preparatory to
establishing a forest. When the dunes are covered with trees they are
permanently fixed, and the trees being cared for according to the usual
regulations pertaining to forest management become a source of revenue
to the Government. It appears that most of the large and troublesome
dune areas along the coast were at one time covered with forest, not-
ably Holland and the Kurische Nehrung, but
through lack of foresight these areas were de-
nuded of forest and ere long were converted into
wastes of drifting sand. Some attempts were
made in the early part of the last century to re-
forest these areas by sowing the seed of forest
trees. These trials all resulted in failure,
although there are here and there in protected
situations small and stunted groves which sur-
vived. It has been proved that the only satisfac-
tory method of establishing a forest in the north-
ern dune areas is by setting out young trees, after
the sand has been fixed by one of the methods
described in previous paragraphs. In Gascony
on the southwest coast of France, however, the
forest has been successfully established from seed
under conditions which will be described when
speaking of the methods used in that country.

The trees used are mostly conifers, the species
depending upon the locality. In the Netherlands
Pinus austriacaand P. laricio are most successful Fre. 9.—spade used in Prus-
on the coast and P. sy/vestr/s on the interior dunes; fs ie Pea ans yonEe
in Denmark Pinus montana on the coast and
Picea excelsa (preceded by Pinus montana) on the interior ‘* heide;”
Pinus sylvestris and P. montana on the Kurische Nehrung; and Pinus
maritima in Gascony. Deciduous trees, such as birches, alders, and
oaks, are used along the roads and serve as fire guards.

The seedlings are raised in nurseries located at convenient points
near the area to be planted. These nurseries are often surrounded by
wire netting to keep out rabbits and other harmful animals, and may
also be protected from the wind by wind-breaks of reeds or cut
branches of pine.

The young trees are transplanted when one or two years old (fig. 9).
The growth is often quite slow at first and the young forest needs
much attention. Some of the trees die and these must be replaced.
But on the whole these operations have been very successful, and now .
there are several areas of forest that are producing an income to the
Government.

22 METHODS USED FOR CONTROLLING SAND DUNES.

FIXATION AS OBSERVED IN EUROPE.

For the purpose of observing the details of the European processes
of dune reclamation as actually practiced, the Netherlands, Denmark,
Germany, and France were visited. Below are given the details of the
methods used in the countries mentioned, caiiclah may be taken as fairly
typical of the work throughout Europe.

THE NETHERLANDS.

Through the kindness of the American minister at The Hague, Mr.
Newel, and Mr. Van Marez Oijens, the minister of the department
of waterworks, a detailed examination of the dunes near Alkmaar and
in the vicinity of Barneveld was made.

COASTAL DUNES.

A line of dunes extends all along the coast of the provinces of North
Holland and South Holland. These are two of the richest provinces
in the Kingdom, and it becomes of great importance to prevent the
encroachment upon the agricultural lands which lie just back of the
coast. The dunes were visited in company with Mr. Van Dissel, who
has charge of this portion of the work, and who explained the details
of the methods used at that point. The particular portion of the dunes
visited was near the little town of Schoorl. The land to be reclaimed
was the property of the General Government. At an earlier period
this region was covered with forest trees, but these were cut off to be
used for fuel and other purposes. The result was disastrous. The
covering of vegetation was broken through, allowing the wind access
to the sand, and finally the whole area was converted into a series of
shifting dunes. About forty years ago an attempt was made to reforest
these dunes by sowing the seed of pines. These seeds seem to have
germinated quite readily, but the seedlings were unable to withstand
the severe conditions, and now all that remain to show for the work are
a few isolated groves in protected places. The Government has now
planned an extensive system of reclamation which in time will convert
all of this waste into a productive forest.

The preliminary fixation is done by planting beach grass, as indi-
vated in a previous paragraph. (See Pl. VII, fig. 1.) In this region
there is no inert covering that can be economically used, but beach
grass grows abundantly all along the coast. As it is easier to obtain
the necessary labor in the autumn, the planting takes place at this
season rather than the spring. Furthermore, it is easier in the autumn
for unskilled laborers to choose grass of the proper age for planting,
as in the spring the portion above ground is dried and brown, thus
making it difficult to distinguish between the shoots of. different
ages. Care is taken to gather grass for planting from places where
it is growing thickly, so as not i. rob the sand of its covering to an

:

vt 4
>

~~

FIXATION IN THE NETHERLANDS. 23

injurious extent. In gathering the grass a short-handled spade is used.
The little bunches are tied in bundles of 72, this being a convenient
armful and also a convenient number for calculation, six dozen. The
planting is done by two persons working together, as already described.
Sometimes the sand is pressed back upon the transplanted grass by
means of the foot instead of the first worker using the spade. While
a handful is more than necessary, experience has shown that some of
the grass fails to grow. Even though it does not grow, the dead grass
acts as a barrier to the sand for some time, at least one year. The
grass is planted in rows about 40 centimeters (16 inches) apart and
30 centimeters apart in the row, the bunches in successive rows
alternating. If the sand is not entirely bare, the bunches are planted
here and there where they are needed. Ordinarily no attempt is made
to level or alter the ground and in many places steep hillsides are
planted. However, there are cases where the land is somewhat pre-
pared, especially by leveling sharp points that rise above the general
surface. In the region visited there is no protecting dune along the
strand, and such a method of protection seems not to have been used
in Holland.

After the sand has been planted to grass to prevent its drifting, the
trees are set out. The young trees are grown in nurseries from seed
planted usually in April. Trees are set out when one or two years old
in spring or fall, according to conditions. Several species have been
tried, such as Abies balsamea Mill., Pinus austriaca Link, P. laricio
Poir., P. maritima Lam., P. rigida Mill., P. sylvestris L., Quercus
pedunculata Ehrh., Q. rubra L., and Robinia pseudacacia L.

It has been found that the species best adapted for exposed situa-
tions are Pinus austriaca and P. laricio. Some other pines, especially
P. sylvestris, are good for the more sheltered places.

The cost of setting the grass is 50 to 75 guilders” per hectare, and
the total cost of reforesting is about 150 guilders per hectare (about
$22 per acre). It must be remembered, however, that labor, the most
important item of expense, costs much less than in the United States.

INTERIOR DUNES.

In company with Mr. Jager-Gerlings, an interior dune area in the
Province of Gelderland, east of the town of Barneveld, was next vis-
ited. This is known as heath land because heath or heather ( Cald/una
vulgaris) is abundant here. The Government has purchased a quan-
tity of this waste land and proposes to convert it into forest. The
land is sterile and the country almost uninhabited.

Here the preliminary fixation is by means of covering the sand with
layers of cut heather. The heather is cut with a short, thick scythe

@A guilder, gulden, or florin is worth about 40 cents in American money. A hec-
tare is equal to 2.471 acres.

24 METHODS USED FOR CONTROLLING SAND DUNES.

with a straight handle, tied in bundles about 1 meter in circumference,
and carried to the place of use in carts or wagons The hills are coy-
ered with the layers of heather described in the first part of this article
(BL aie):

The region consists of dunes more or less bare and shifting, alter-
nating with lower moist areas where there is a covering of vegetation,
mostly heather. These low areas are sufficiently moist to keep the
sand from drifting. Experience has shown that over much of this
area trees do not thrive when set out in holes, as is customary. This
seems to be due to the lack of air in the soil. It has therefore been
found necessary to spade up the soil before the trees are planted.
This is done by digging up the soil to a depth of 0.56 meter (about 22
inches). It is unnecessary to spade up the soil over the entire surface,
the digging being confined to strips 1.2 meters wide, with an unspaded
space of 0.8 meter lying between.

The trees are planted in rows, one near each margin of the spaded
strip and 0.75 to 0.80 meter apart. Heather is laid between the rows
to hold the sand. On the hills where the heather has been laid the
trees may be planted in holes among the heather. The planting takes
place in autumn or spring, but it is customary to plant the hills in the
fall, leaving the low places till spring, when it is drier (Pl. II, fig. 1;
Pl EI vise; A),

After the planting it is necessary to watch the growth of the trees
and to stir the ground around them in proportion to their needs. If
the growth is poor and the trees remain stunted the ground is stirred
with a stout four-tined rake. If the soil is moved too much the trees
may make too vigorous a growth and the wood will not ripen suffi-
ciently in the fall.

The tree best suited to the greater part of this region is the common
pine or, as it is called in America, the Scotch pine (us sylvestris).
It was stated that the trees from Scottish seed grew better than those
from Norway seed.

On the more sterile portions of the area better results are obtained
from Pinus rigida and P. divaricata Gord. (P. banksiana WLam.).
The black or Austrian pine (/%nus austriaca) does not succeed well,
its growth being too slow. Pinus laricio promises well.

About one-fourth of 1 per cent of the trees die from various causes,
and these it is necessary to replace. Various insects prey upon the
trees. In this connection it is noteworthy that bird houses are placed
at intervals in the forest to attract birds that devour harmful insects
or their larve. <A bird called the ‘*birkhuhn” nips off the young
buds. Rabbits and other small animals gnaw the bark. <A root fun-
gus (Agaricus melleus) kills many individuals. ‘These are.replaced by
choke-cherry (Prunus virginiana).

FIXATION IN DENMARK. 25

The cost of the work per hectare at this point is approximately as
follows:

Guilders.
Dene hVIn ihe Menten) f aoe o no a ela ko See ane ne be ye ene ik
SS aS neg) 07 3022 2 0 1.5
DE CEENE CESS ESOS) a eo Se a ane 16
Segre oie ts id SR Se Se ee ee Se 57
(EV Ev VESEN GS CRE 2 2 SES 2 Des os OS ree es ae 25

This makes the total cost about 100 guilders per hectare, or about
$16 per acre.

The different parts of the plantation are reached by means of roads
placed at convenient distances. There is usually a strip of deciduous
trees, mostly of birches, planted along these roads as a protection in
case of fire, since conifers burn with ease, while the birches do not. In
passing through the higher dunes, it is necessary to have the roads
curve between them in order that the wind may not sweep through
and cause serious erosion.

DENMARK.

Through the kindness of Prof. Eugene Warming, director of the
botanical garden at Copenhagen, letters of introduction to the dune
inspectors at Aar and Skagen were obtained. Dune areas extend all
along the coast of western and northern Denmark, but these two
points were selected as being typical of the entire region.

> OXBOL.

The first point visited was in the southwestern part of Denmark in
the Province of Ribe. Mr. R. P. F. Bang, the inspector of this dis-
trict, lives at Aar, near Oxb6él, which is reached via Esbjerg and
Varde. The method used here for fixing the sand and planting frees is
similar to that used in Holland; the conditions are also very similar.
The region consists of a series of sand dunes, with low places inter-
spersed, and extends some distance back from the coast. There has
been no attempt in this region to form a barrier dune. As the
heather grows abundantly throughout most of the dune region this
plant is used for the purpose of fixation except near the coast. The
young forest consists for the most part of Pinus montana and Picea
alba. In addition, Mr. Bang has experimented with Picea sitchensis
and P. nordmanniana, both of which promise success. nus austriaca
is injured by the cold winters, and Picea excelsa does not successfully
withstand severe winds. On certain portions, where the soil is com-
paratively rich, Picea pectinata succeeds.

About fifty years ago an attempt was made to establish a forest in
this region, and in certain isolated and protected places portions of
this forest are now in evidence. The trees, according to the situation,

26 METHODS USED FOR CONTROLLING SAND DUNES.

may be 3 to 15 feet high, but for the most part present a very stunted
growth.

The heather is laid at any time of the year when it can be most con-
veniently done.“ Near the coast, where beach grass is used, the plant-
ing takes place as in Holland except that on account of the broken
nature of the country and the strong winds it is found that the
bunches of grass must be smaller, consisting only of one or two
pieces. The pines are planted when they are 3 years old and the
spruces at 4 years. The plantation showed a very marked differ-
ence in the condition of the trees, depending on the richness of the soil
and the exposure. The stunting of the trees is very noticeable in the
native forest near the coast. The trees nearest the coast are small and
scrubby, and for some distance inland they bear very few branches on
the windward side, therefore appearing very lopsided. The entire
cost of laying the heather, planting and raising the trees, is 300 crowns
per hectare,’ or about $32 per acre. The usual compensation for
planting the grass is about 8 cents per square rod, the work being done
at a fixed price (4 Gre) per 4 square meters.

SKAGEN.

The investigation of the dunes around Skagen at the north end of
Denmark was made in company with the inspector, Mr. C. F. Dahlerup.
The whole peninsula above Frederikshavn is one vast sand area con-
sisting mostly of dunes. Between the dunesare more or less extended
areas of flat land where the soil contains more humus. These lower
portions can be used for grass and to a limited extent for other crops,
but they must be fertilized and limed. For this purpose kainit and
Thomas slag are used, and lupines are grown to supply nitrogen. The
distance to the ground water determines the availability of the soil for
crops, the most favorable distance being about 18 inches. If the
ground water lies lower than this the soil is too dry and if above this
it is too wet for cultivation. The land around Skagen and for about
two miles south is owned privately, but a large area south of this is
owned by the Government. The latter is carrying on asystem of recla-
mation upon this area, and also upon some of the land owned privately.
Upon the private land the cost is divided as follows: One-half is paid
by the General Government, one-sixth by the province, one-sixth by
the township, and one-sixth by the owner.

The preliminary fixation is by means of beach grass planted in Octo-
ber or November. Although in the more quiet portions of the dune
the beach grass lives only from five to ten years, yet as it gradually
dies out its plac e is taken by various native plants which serve to

«The reenida used in pianene ieee been = ribed in Tidskrift for shaven 12,
Om de Nord-og vestjydske Klitters Beplantning.
>A crown equals 26.8 cents in American money.

ae

“*,

Nal ont 24

te
a

on Se RT INI ema Oo Pr

FIXATION IN GERMANY. oF.

hold the sand effectively. Heather also lasts about the same time,
but the native plants tend to take its place as it disintegrates. One
of the common plants found as a native covering is reindeer moss.
Salix repens, one of the willows, is an excellent plant for holding the
sand, but thus far there has been no success in its artificial propaga-
tion. On the large areas of beach-grass plantations the rows follow
the contour lines and the planting extends from the base toward the
apex of the hills, but the tops of the dunes are not planted. The cost
of planting and gathering the grass is about the same here as around
Oxbol. It is customary to hire one workman at a fixed price per
square yard, and this man provides the necessary helpers.

The trees used here upon the plantation are mostly Pinus montana
and Picea alba. Picea sitchensis has been used to some extent and
seems to do well, especially in wet places, but it has not yet been sufli-
ciently tested. Picea alba withstands wind but will not endure
drought. The seed of the trees is planted in seed beds in May. The
following spring, when the seedlings are one year old, they are trans-
planted to the nursery rows by an ingenious machine. It was said
that by means of this machine 1,000 plants could be transplanted at a
cost of about 6 cents. The trees are finally set out upon the dunes
when they are three years old. Besides the conifers mentioned, oak
(Quercus sessiliflora) and birch are employed as fire guards. It is
interesting to note that the heather comes in naturally in the birch
plantations, but does not appear in the oak plantations. Alder is
planted on low places for the purpose of enriching the land, the nod-
ules upon the roots having the same function as those upon fhe roots
of legumes. Mr. Dahlerup stated that there are in all about thirty-
five plantations in Denmark along the west coast of Jutland, one of
the largest being this one at Skagen. Concerning the interior plan-
tations in the ‘*‘heide” region, he said that the preliminary fixation is
by meansof heather, while the young forest is composed of Pinus mon-
tana and Picea excelsa. The latter is the best tree for the purpose,
but it can not be grown successfully directly upon the heather land.
It is therefore necessary to plant first Pinus montana. This kills the
heather and Picea excelsa can be made to grow in the shade of the pine.
Although Pinus montana can be successfully grown, it is inferior to
Picea excelsa so far as its usefulness for timber purposes is concerned.

GERMANY.

The most extensive work to be found in Europe in the reclamation
of sand-dune areas has been done along the north coast of Germany.
The coast of the North’Sea, and especially the North and East Friesian
Islands, are continually subjected to the erosive action of wind and
water, which requires not only extensive work in the protection and
reclamation of dunes but much in the way of mechanical obstruction.

28 METHODS USED FOR CONTROLLING SAND DUNES.

The coast and harbors are protected in various ways by masonry and
piles. Sand-dune works also extend in various places all along the
coast of the Baltic Sea, which, however, are fully described in Ger-
hardt’s book, previously mentioned. Therefore, for the purpose of
inspecting the methods which are typical of the whole coast, a visit
was made to only one of the important sand-dune regions of Ger-
many—the Kurische Nehrung in northeastern Prussia.

This is one of the most wonderful sand spits in the world, consist-
ing of a narrow peninsula which extends northward from the region
of Kranz for about 60 miles. To the west lies the open ocean of the
Baltic Sea and to the east the bay called the Kurisches Haff. The
opening to the bay lies just to the north of this sand spit. On the
opposite shore is located the somewhat important town of Memel,
and there are three or four towns or villages situated in various places
along the peninsula. The strip of land is quite narrow, varying from
1 to 5 miles in width. At one time this peninsula was covered with
forests, but later the trees were removed and the region was soon
converted into a series of shifting dunes. Besides the necessity for
protecting the villages and arable land upon the peninsula it is neces-
sary to prevent the increased encroachment of the sand upon the
harbor to the east. For these reasons the Government undertook the
reclamation of the whole peninsula.

So much attention is given to this region in Gerhardt’s work that
it is unnecessary to do more than note a few points in which the
methods differ from those used in the Netherlands and in Denmark.
In the first place, a long barrier dune, the entire length of the peninsula
on the west side, has been produced. This is kept in repair by means of
beach grass and the necessary sand fences. The beach grass is planted
upon this dune ina much more exact and methodical manner than that
seen elsewhere. The surface is first carefully laid off with a line in
squares called *‘quadrats,” and the plants are placed with almost
mathematical precision. The forest consists for the most part of
Pinus montana. In the vicinity of Rossitten there are several large
wandering dunes which have not been planted. These dunes are in-
deed hills, being from 200 to 300 feet in height. As the general
course of these shifting dunes is from the west toward the east, they
will finally disappear in the waters of the Kurisches Haff. For this
reason it has been thought inexpedient to make plantations upon them
except where it has been necessary to protect villages and other val-
uable property.

Through the kindness of Prof. Christian Luerssen, who gave a letter
of introduction to the dune inspector of this region, the venerable Mr.
Epha, a veteran in the service of sand reclamation, every pains was
taken to render the inspection of the dunes easy and satisfactory.
The success of the work in this region is impressive. The conditions

FIXATION IN FRANCE. 29

are certainly as adverse as on any of the dune areas along the European
coast; yet the vast sandy waste has been converted into a productive
forest, which, with a comparatively small amount of attention, can be
protected from further encroachment of the ocean.

The cost of holding the sand by planting grass upon the wandering
dunes of the Kurische Nehrung is said by Gerhardt to be from 170 to
220 marks“ per hectare, or $17 to $22 peracre, This includes gather-
ing the grass, transporting it to the plantation, and the setting The
gathering costs from 2 to 2.50 marks, while the transportation costs
about 2 marks per 100 bundles for distances not exceeding 3 miles
and about 3 marks where the distance is 3 to 5 miles. Planting is
usually done by the day, the wages paid being 1.30 to 1.80 marks for
men and from 1 to 1.20 marks for women. The laborers are mostly
women (Pl. VII, fig. 2). According to circumstances the cost of
planting 100 bundles may be 3 to 8 marks. Where the grass to be
used is obtained in the vicinity by thinning the dense bunches the
total cost of planting may be 5 to 10 marks per 100 bundles.

The cost of the brush fences, where this method is used, is about 0.20
mark (5 cents) per running meter. This includes gathering the brush,
preparing the stakes, and setting the fence. As the material is obtained
from the waste brush in the neighborhood, no charge is estimated for
this. The amount of material is at the rate of 0.05 cubic meter per
running meter. At this rate one cord of the prepared brush is sufh-
cient to set about 80 yards of fence.

The cost of establishing a forest is given by Gerhardt as 1,200 marks
per hectare ($120 per acre). This is the average of ten years’ experi-
ence upon the Kurische Nehrung and includes items as follows:

Cost per | Cost per
hectare. acre.

| Marks. | Dollars.
Fixation of the shifting sand by means of sand or reed hedges...-....----------- | 700 70. 00
0 oie 1g gt Ee eae Pe eee = 300 30.00
Ercnarailono: ihe Holes for planting... -202..-22--J----ccenccesccceses eoesessess 50 | 5. 00
Pinniine tbe youns trees, 400'to the hectare :... -. 2.2 -2-s2c- se. sacqaainen sn siaie sec 125 12.50
emir Re MMs CMC HSC sees sees seater Go win ae ee ines elnino ome se asi ot eel 25 2.50
TR AS ee es ere eS Re ARID Y Bp Bi Rdg Pe aos Lead BOS cas Be | 1, 200 120. 00

FRANCE.

The most important dune region in France is that along the south-
western coast from the vicinity of Bordeaux to the Spanish line.
Through the courtesy of Mr. Poisson, a botanist in the Jardin des
Plantes, a letter of introduction to Mr. Emile Durégne, a civil engineer
living in Bordeaux, who has been oyer the greater part of the dunes

«A German mark is equal to 23.8 cents in American money,

30 METHODS USED FOR CONTROLLING SAND DUNES.

in his capacity as surveyor, was provided. Mr. Durégne is very
familiar with the whole region and with the methods which have been
used to reclaim it, and has published some important papers upon the
subject. The particular region visited was a few miles south of
Arcachon. This is a part of the general dune system extending from
the mouth of the Gironde River to Bayonne. Before this land was
reclaimed a considerable portion lying back of the dunes was unfit for
agriculture, as it consisted of alternating sand hills and marshes.
Since the reclamation the conditions have so changed that the popula-
tion has very materially increased. A barrier dune, similar to the one
found in the Kurische Nehrung, extends all along the coast (Pl. VI,
fig. 1). This is held in place in the same manner; that is, by means of
beach grass and brush fences. The most marked difference in the
method of reclamation is in the fact that a forest was established by
sowing the seed. The seed of Pinus maritima is sown on the sand in
October or November or in the spring during March and April, and
the whole is then covered with brush or conifers. The seed soon
germinates, and, protected temporarily by the brush, grows into a
forest.

The total cost of covering the area with forest, including the plant-
ing of the trees and the covering of the land, is about 320 franes per
hectare, or about $26 per acre. The grass for planting the barrier
dune is dug up by means of a small mattock, and is set with a conical
instrument having a horizontal handle. The grass is planted in rows
parallel to the course of the dune. Breaches are repaired by means of
sand fences (Pl. IV, fig. 2), usually by placing two lines of fence
about 6 meters apart and extending above the surface of the sand 60 |
or 70 centimeters. As soon as these are covered a second line of fence
is placed on top. The fence which was used in establishing the
original barrier dune was placed about 2 meters high. Where ravines
are to be filled with sand it is common to use these fences in a net-
work of squares. Some portions of this protecting dune reach the
extraordinary height of 200 feet or even more. ‘There is evidence to
show that in former times some of these dunes had encroached upon
the inland forest, killed the trees, and then passed over them, as stumps
are to be found on the windward side along the shore (PI. V, fig. 2).

Mr. J. Poisson“ has described the method used upon the dunes of the
Coubre, a peninsula which lies just north of the mouth of the river
Gironde. The seed of Pinus maritima was sown at the rate of about
54 pounds to the acre, mixed with one-half pound each of furze,
broom, and beach grass. The total cost of covering 2,100 hectares
was 766,142 francs, or » vout $29 per acre.

@Sur la fixation des dunes dans l’ouest et dans Je nord de la France. Extrait des
Comptes Rendus de I’ Association Fran¢aise pour l’ Avancement des Sciences. Paris,
1900.

FIXATION IN FRANCE. ob

Mr. John Gifford, who has examined the dune region of the Landes,
gives an account” of the methods used in the original work of recla-
mation, which is here appended:

A littoral dune was constructed straight along the shore from the mouth of the
Gironde to Bayonne. This dune is the secret of all success in the fixation of shift-
ing sand. It is simply a bank of sand of certain dimensions, with a certain slope
suited to the condition of affairs. This protective, or littoral, dune is formed as fol-
lows: A double fence is constructed of brush, or of palisades driven in the sand.
This stops the sand which comes from the ocean. Soon a ridge of sand forms, equal
in height to the fence. A double fence is used, as it gives breadth to the dune and
stops the sand which blows through the fence on the ocean side. As soon as a ridge
of sand is formed as high as the fence, the old fence is pulled up or a new one built
on top, and so on until a dune of the height desired is formed artificially. The
proper height of a protective dune is 33 feet. It should slope 25 degrees toward the
sea, and may be 60 degrees ® on the land side. The dune must be at least 300 feet
from high-water mark. After the dune has reached the proper size, it is kept in
shape by the sea marram (Psamma arenaria).¢ This peculiar plant, called gourbet
in France, is exclusively used for fixing the sand on the littoral dune. It has long,
much-divided rhizomes, and will grow well only when covered with fresh sand. The
dune must always be kept in shape. If sand accumulates in any one spot in undue
amount, a draft is formed, which may end in a breach of the littoral dune. ‘‘Gardes
cantonniers’’ are stationed along the dune to watch it closely, and here and there on
this long, straight sand bank groups of men and women may be seen digging up the
gourbet in places where it is too thick and planting it where needed. Constantly
the dune is watched and mended; the forest, villages, and fields in its lee are depend-
ent upon it, and it in turn is dependent upon the humble but persistent gourbet.

After the formation of the littoral dune comes the work of planting in its lee. The
surface of the sand is covered with brush arranged like the slates on a roof, with a
shovelful of sand here and there to hold it down. Then the seeds of Pinus maritima
are sown, with seeds of other plants to shade the young pines, and seeds to attract insec-
tivorous birds. The pines usually come up welland grow quickly, although close to the
littoral dune they are gnarled and stunted by the salt winds. Thus the sandsare fixed,
and, although the forests do not yield a good interest in cash, they are of incalculable
value to a large proportion of the people of Gascony; in fact, indirectly, to the whole of
France. Fire lanes have been constructed across the dunes, and, thanks to the watch-
fulness of the guards and the rigid enforcement of laws, fires are almost impossible.

Very little cutting is done in these forests, the revenue coming mainly from the
resin industry. Owing to a lack of roads and insufficient means of transportation
on these dunes, only the most valuable timber is marketed, after being tapped for
resin. If it is desirable to remove a tree, it is bled to death before being cut. All
other trees are tapped very carefully, and are in no way injured by the process. In
fact, bled timber is considered superior to unbled in France. The Hague method of
orcharding is used, a system which does not injure the tree, but gives a resin of bet-
ter quality and more abundant turpentine. Another article, however, could be
written on the French method of turpentine orcharding.

Other industries have started, the people have improved, and the country is more
fruitful and beautiful, so that through the agency of trees a new province has been
practically added to France.

@The Control and Fixation of Shifting Sands. J the Engineering Magazine,
January, 1898.

> There is some error here in the angles given for the slope. The windward slope
is from 4 degrees to 14 degrees, and the lee slope about 30 degrees.

¢ Another name for beach grass (Ammophila arenaria).

17170—No, 57—04 3

32 METHODS USED FOR CONTROLLING SAND DUNES.

SUMMARY.

Extensive and systematic work is done by various governments in
Europe for the purpose of reclaiming waste dune areas. he object
may be to convert this waste into a productive forest, or to prevent
the encroachment of the sand upon valuable property.

The sand is first held in place by some inert covering or a plantation
of grass, and afterwards a forest is established by transplanting young
trees.

Trees will not grow in the immediate vicinity of the ocean; hence
a narrow strip along the coast must be permanently held in place by
means of a sand-binding grass.

The best grass for this purpose is beach grass (Ammophila arenaria),
which grows naturally along the sandy seashores of the North Atlantic
coast. The same species grows along the shores of the Great Lakes
and on the Atlantic coast of the United States as far south as North
Carolina.

The grass is transplanted in rows or squares in autumn or spring.
Satisfactory results can not be produced by sowing the seed of this or
of other plants directly upon the unprotected sand.

Where heather grows in sufficient abundance this is cut and laid upon
the surface of the sand.

The third important method for preventing drifting is the use of sand
fences. These consist of rows of rough stakes or pieces of brush driven
into the sand and projecting above the surface from 1 to 3 feet. For
holding the sand the shorter stakes are placed in squares of 9 to 12 feet,
forming a network. For accumulating sand in hollows or repairing
breaches in a protecting dune the high fences may be used. Solid
fences are not used,

The drifting of the sand having been prevented by one of the above
methods, young trees are set out to form the permanent covering of
forest. In northern Europe no satisfactory results have been obtained
in establishing a forest by sowing the seed, but in southwestern France
a forest was produced by sowing the seed of Pinus maritima upon the
sand and covering it with brush.

The trees used are: In the Netherlands, Pinus austriaca and P. laricio
near the coast, P. sy/vestris on the interior dunes; Denmark, Pinus
montana near the coast and Picea excelsa (preceded by Pinus montana)
on interior heath land; Germany, Pinus montana; France, Pinus
maritima.

On the Kurische Nehrung and in other parts of Prussia, and in
Gascony, a long barrier dune has been formed artificially to protect
the land lying back of it. This is kept in repair by planting beach
grass and by the use of sand fences when necessary.

Pee ES.

33

—-_

a

DESCRIPTION OF PLATES.

Piate I. Frontispiece. Beach grass (Ammophila arenaria Link). Drawing from her-
barium specimen.

Puate II. Fig. 1.—Inland dunes near Barneveld, the Netherlands. Inthe background
the dunes have been covered with heather to prevent drifting and afterwards set
out with Pinus sylvestris. In the foreground the pines have been planted without
a covering of heather, as the sand is here moist enough to prevent its drifting.
Fig. 2.—Inland dunes near Barneveld, the Netherlands, showing road in process
of construction through the plantations. In the background the dunes are
covered with heather. In the foreground is the road, the sand being ridged up
with ditches at each side. Upon the sand is placed heather in a thick layer.
This prevents the wheels of vehicles from sinking into the loose sand.

Prate III. Fig. 1.—Inland dunes near Barneveld, the Netherlands, showing a plan-
tation of Pinus sylvestris on a covering of heather. The sand is first covered with
a layer of cut heather to prevent its drifting. Fig. 2.—Unreclaimed sand dunes
near Alkmaar, the Netherlands. In the foreground is a low area partially
covered with heather. In the interior such areas furnish the heather, which is
cut and laid upon the surface of the sand to prevent its drifting.

Puate lV. Fig. 1.—Plantation of beach grass upon the dunes near Oxbdl, Denmark.
This shows how the plantations are made along the lower places and part way
up the slopes of the dunes, the tops remaining unplanted. The grass will be
planted somewhat higher on the slopes as opportunity permits, but the tops will
be denuded of grass to facilitate the removal of the sand by the wind. Fig. 2.—
Barrier or protecting dune south of Arcachon, France. To the left beach grass
has been planted in rows parallel to the beach. In the center is a sand fence,
placed to repair a breach, which is now nearly covered with sand. To the
extreme right is the forest in the lee of the dune.

Puate V. Fig. 1.—Lee slope of a portion of the barrier dune south of Arcachon,
France. Since the dune has been fixed on the windward slope, the advance of
the sand inland has been very slow, as shown by young trees growing along the
slope. Fig. 2.—Unreclaimed sand dunes south of Arcachon, France. The
stumps are the remains of a forest which has been covered and again uncovered
by an advancing dune.

Puate VI. Fig 1.—General view of the barrier dune south of Arcachon, France.
This dune stretches along the coast from Arcachon to Bayonne, about 75 miles,
and protects the forest. of Pinus maritima in its lee at the right. The ocean is
seen at the leit. This dune was formed artificially with the help of sand fences
and beach grass and is now held in position by the same means. [From a pho-
tograph by Mr. E. Durégne.] Fig. 2.—Unreclaimed sand dunes south of Arca-
chon, France. The sand is drifting badly at this point. Here and there a small
hillock is held in place by a bunch of beach grass.

Puate VII. Fig. 1.—Laborers digging beach grass near Alkmaar, in the Netherlands.
The instrument used for this purpose here is a spade with a rounded point. The
grass is obtained upon the dunes where it is growing naturally, by thinning out
the bunches. In the background may be seen the unreclaimed dunes partially
covered with vegetation. Fig. 2.—Laborers setting out beach grass upon the barrier

35

36 METHODS USED FOR CONTROLLING SAND DUNES.

dune at Rossitten, on the Kurische Nehrung. At theright is the overseer. The
grass is set in squares or ‘‘ quadrats.’’ The position of the rows is determined quite
accurately by stretching a line between two poles, one of which appears in the
illustration. One laborer makes the holes with a planting spade, while another
sets the grass. At the left may be seen a bundle of the grass ready to be set.

Puate VIII. Fig. 1.—Protecting the base of a harrier dune by means of two rows of
sand fences. Storms had eaten away the face of the dune and the fences are
placed to accumulate sand, after which grass will be planted. [From a cut in
Gerhardt’s Diinenbau.] Fig. 2.—Protecting a road through the dunes, on the
Frische Nehrung, Prussia. The road is curved and the slope is held by cover-
ing with a layer of reeds and placing poles upon these. [Froma cut in Gerhardt’s
Diinenbau. |

Puate IX. Fig. 1.—Shifting dunes held by sand fences on the Kurische Nehrung,
Prussia. The fences are of brush placed in squares. Nearer the strand the
brush is in rows parallel to the beach. [From a cut in Gerhardt’s Diinenbau. |
Fig. 2.—Shifting dunes held by means of sand fences of reeds, on the Kurische
Nehrung, Prussia. Next to the strand the reeds are placed in rows parallel to
the beach. Farther up on the dunes they are placed in squares. A roadway
passes through at this point. [From a cut in Gerhardt’s Dinenbau. ]

O

Bul. 57, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE II.

Fig. 1.—DUNES HELD BY COVERING OF HEATHER.

Fic. 2.—MAKING A ROAD IN THE DUNES.

‘s 4 ‘ ‘ !
2 4 f y { ,
a ie Arty, i 4 ey - ;
\ . Pei ” : rn i
: t
j i F \
' ; j i =
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7 7 » -

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Bul. 57, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE III.

Fic. 1.—PINE PLANTATIONS IN COVERING OF HEATHER.

FiG. 2.—HEATHER AMONG THE DUNES.

4 Bul. 57, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE IV.

:
.
j

Engen

Fic. 1.—BEACH GRASS PLANTATION ALONG BASE OF DUNES.

Fia. 2.—BEACH GRASS AND SAND FENCE ON BARRIER DUNE.

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Bul. 57, Bureau of Plant Industry. U. S. Dept. of Agriculture. PLATE V.

Fic. 1.—LEE SLOPE OF BARRIER DUNE.

Fig. 2.—REMAINS OF ONCE BuRIED FOREST.

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—-—

,

Bul. 57, Bureau of Plant Industry, U. S. Dept. of Agriculture.

Fic. 1.—GENERAL VIEW OF BARRIER DUNE.

Fig. 2.—UNRECLAIMED SHIFTING DUNE.

PLATE VI.

Bul. 57, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE VII.

Fic. 1.—DIGGING BEACH GRASS FOR PLANTING.

Fic. 2.—TRANSPLANTING BEACH GRASS.

.

Bul. 57, Bureau of Plant Industry, U. S, Dept. of Agriculture. PLATE VIII.

Fic. 1.—SAND FENCES PROTECTING BASE OF DUNE.

Fig. 2.—PROTECTING A ROAD THROUGH THE DUNES.

ares
ind oe :

* 7

alt ; —e
pea 0. ee Se are

Bul. 57, Bureau of Plant Industry, U. S. Dept. of Agriculture.

Fic. 1.—SHIFTING DUNES HELD BY BRUSH FENCES.

Fic. 2.—SHIFTING DUNE HELD BY REED FENCES.

PLATE IX.

~

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