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UNIVERSITY OF B.C. LIBRARY

3 9424 05123 513 0

NRY S. GRAVES

U.S.C. LIBRARY

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Fig. I. — A Virgin Forest in Idaho.

THE PRINCIPLES

HANDLING WOODLANDS

HENRY SOLON GRAVES

FORESTER, UNITED STATES DEPARTMENT OF AGRICULTURE

FIRST EDITION
FOURTH THOU3AND

NEW YORK:

JOHN WILEY & SONS

London: CHAPMAN k HALL, Limited

1914

PKFSS OH THH Pl'BI.ISHEKS PKINTINd COMPANY, N KW YORK, V. S. A.

To My Father

PREFACE

During the last few years there has been a rapid ex-
tension of the work of practical forestry in the United
States. The Federal government has set aside as Na-
tional Forests about 190 million acres, on which to-day
all work is conducted under the principles of forestry.
A number of States also have established reservations
which have been placed under systematic forest admin-
istration. Forestr}^ is being practised on a considerable
number of private tracts, and there are many owners
who -are seeking information regarding forestry with a
view of practising it if found to be commerciallv practi-
cable.

The literature treating of forestry as applied in this
country is still very meager. Much of it is fragmentar\'
and scattered in various Government and State publica-
tions, and the information most desired b\' an owner or a
forester is often not available. There is a great need of
systematic works covering the different branches of for-
estry, for the use of owners of woodlands, for practising
foresters, and students in the forest schools. As a con-
tribution to this greatly needed literature of forestr\-, I
have prepared the present volume covering the sihicul-
tural treatment of woodlands.

VI PREFACE

The book deals primarily with the principles of cut-
ting mature stands of timber with a vaew to their replace-
ment by new growth; cuttings in immature stands made
for their improvement; and forest protection, with par-
ticular reference to forest fires. The book is not intended
as a complete treatise on silviculture, but deals only with
the treatment of woodlands. The methods of artificial
seeding and planting are not included at all. This is an
extensive subject in itself and is left to be handled by
another author.

I have endeavored to present the subject primarily
from the standpoint of conditions as they obtain to-day.
The book is designed to serve a present purpose. In
most parts of the country the methods of forestry first
used are necessarily primitive in their application. We
are using to-day methods in vogue in Europe many years
ago, when market conditions were similar to those now
common in this country. With the increasing value of
timber and larger returns from forestry, better and more
intensive methods will be used. In the long run the ap-
plication of forestry in this country will resemble very
closely that in Europe, with such modifications as are re-
quired by the peculiar characteristics of our species and
our climate. I have laid special emphasis on some of
the more primitive methods of forestry because these are
often the only methods which can be applied under con-
ditions of poor markets and difficult logging. Thus a
prominent place is given to the selection system in its
first application to virgin forests; some of the clear-cut-

PRKFACE VI 1

tin^ systems, which will necessarily later he replaced hy
hetter methods, are descrihed in considerahle detail; and
more space is given to the primitive application of the
shelterwood system than to its fully developed practise
in Europe. A number of the European modifications
of the various silvicultural systems have not been men-
tioned at all, as they would have at present only a very
limited application in this country.

So far as possible I have endeavored to use such tech-
nical terms as have been already established. The ter-
minology has been made to conform in most instances to
that given by Mr. O. W. Price in Bulletin No. 61, U. S.
Forest Service. There has, however, been some devia-
tion from that list, and several new terms have been used
where those in common usage seemed inadequate.

I am indebted to the Forest Service for the majority
of photographs used in the book.

Henry Solon Graves.

CONTENTS

Chapter I. — Introduction

The American forest .

The march of forest destruction
Damage by fire
Damage by insects
Reduction of supplies .
Unregulated cutting
Disturbance of stream flow"

Definition of forestry .

Definition of silviculture

Objects of silviculture
Quick reproduction
Desirable species .
A full stand
A valuable product
Rapid growth

Measure of production

Purpose of the owner .

Objects of public forests
Objects of private forests

The cost of silviculture

Financial returns from forestry
Returns from public forests
Problem of private owners
Profits of planting
Investments in immature forests

FAGE

2
3
3
3
5
5

21
11

CONTENTS

.ln\cstinents in natural reproduction
Progress of private forestry

Reproduction cuttings .

Classification of the trees in a forest

Age-class ....

Size-class ....

Crown-class , . , .

The stand ....

Origin of stands ,

Form of the stand

The silvicultural systems
Classification of silvicultural systems
Systems depending on reproduction by seed
Systems depending on reproduction wholly or

from sprouts ( coppice j
Combination of silvicultural systems
Application of silvicultural systems
Choice of species
Pure and mixed stands contrasted .

Chapter II. — The Selection System
Origin of tlie selection system
Theory of the selection system
Principles of limiting the cut
The diameter limit
Application of a diameter limit

Marking
Defects of a rigid diameter limit .
Provision for reproduction
■ Protection from windfall

Cutting small trees for improxement
Influence of market conditions

partly

PAGE

24
25

27
28
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.^0
M)
30

32
35
35

38
38
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42

41
44
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48
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57
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64
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CX)NTENTS

Cost of the system ....
Increased cost of logging
Cost of pr(3tecting young grovvtii
Increased cost of construction work
N'alue of seed-trees
Cost of improvement work

Intensive development of the selection system

Results of the selection system

Choice of the selection system

Example in the spruce forests of the Northeast

PAGE

67
68
68
69
69

69
71
72
74

Chapter 111. — Systems of Clear-Cutting

Definition of clear-cutting .

Conditions requiring clear-cutting

Disadvantages of a clear-cutting .

Methods of reproduction

Advantages of artificial reproduction
Advantages of natural reproduction

Clear-cutting with artificial reproduction
Use of the system in this country
Use in National forests
Use in State forests
Use in private forests
Clear-cutting the whole stand
Clear-cutting in strips .
Clear-cutting in patches

Clear-cutting with natural reproduction
Conditions of success
Iniiuence of market conditions
Clear-cutting the whole stand
Reserving blocks of trees
Reser\ ing scattered seed-trees

87
88
88

89
90
90
93
95
96
97
97

98
98
100
101
103
107

Xll

CONTENTS

Reserving groups of seed-trees
Reserving thrifty standards
Clear-cutting in two or more operations
Alternate cleared strips .
Irregular cleared strips .
Progressive cleared strips
Use in this country
Clear-cutting in patches

PAGE

116
118
121
123
128
132
134
135

Chapter IV. — The Shelterwood System . .137

Underlying principles of the shelterwood system . 137

Advantages of the system . . . .137

Disadvantages of the sj^stem .... 140

Variation in application .... 140

Primitive application of the system . . . 141

Application in the longleaf pine forests . . 142

The first or seed-cutting .... 144

The second cutting ..... 145

Results 146

Application in the Black Hills .... 147

The first cutting ...... 149

The second cutting ..... 150

Progress in the development of the shelterwood

system ........ 150

Intensive application of the shelterwood sjstem . 152

Shelterwood system with uniform cuttings . . 153

The preparatory cuttings .... 153

The seed-cutting ...... 156

The remo\'al cuttings ..... 161

Shelterwood cuttings in strips .... 162

Shelterwood cuttings in groups . ... . 164

The two-storied svstem ..... 166

CONTENTS

Xlll

Chapter V. — The Coppice Systems

Simple coppice

Age of cutting
Season of cuttirn^
Care in cutting
The cutting .
Maintenance of density
Arrangement of cutting
Holding over reserves .

Pole-wood coppice

Use in the hardwood region of the East
The reproduction cuttings
. , The second cutting

Coppice with standards

Chapter VI. — Improvement of the Forest

Improvement cuttings .
Cleanings .
Liberation cuttings
Thinnings .

Need of thinnings

Results of thinnings

Theory of thinnings

Principles governing the severity of thin

Time of first thinning

Repetition of thinnings

Application in Europe

The French method

Practical application of thinnings in
country
Accretion cuttings
Impro\ement work in irregular stands

nines

thij

PAGE

170

172
17S

n.^

174
174

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177

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181

184

189

189
190
194
196
198
200
201
202
204
208
208
210

212
Z\b
21'^

XIV

CONTENTS

Improvement work in selection forests
Damage CLittinj2;s ....
Pruning .....

PAGE

220
221
223

Chapter MI. — Protection of Forests from Fire . 225

Character of forest fires . . . 226

Surface fires ....... 226

Inflammable material ...... 227

Topography ....... 229

Character of the soil ...... 230

Condition of the atmosphere .... 230

Rapidity of surface fires ..... 230

Grass fires . . . . . . . .231

Brush fires . . . • . . . .231

Ground fires ....... 232

Crown fires ....... 233

Damage by fires ....... 235

Death of standing trees . .... 235

Injury to trees ...... 238

Injury to the soil ...... 240

Reduction of density ..... 241

Influence on reproduction .... 242

The prevention of fires ..... 244

IClimination of the causes of fires . . , 245

Organization of the forest .... 246

Disposal of slash ...... 247

Disposal of brush and debris .... 249

Piling and burning brush as logging proceeds 249

Piling and burning brush in separate operations 251

Lopping the tops . . . . 260

CONTENTS

Broadcast burniiiti;

Annual or periodic hurninn ot litter

Fire-lines

Roads .

Trails .

Special fire-lines

Location of fire-lines

Artificial fire obstructions

Supervision and patrol .

Aids to supervision and patrol

Supervision of small tracts

Supervision of large tracts

Patrol along railroads

The methods of fighting fires
Quick access to fires
An adequate force of fighters
Proper equipment for fighting fires
Organization of the fighting crew
Methods of fighting surface fires
Methods of fighting ground fires
Methods of fighting crown fires
Back-firing ....
Patrol after a fire is extinguished

Chapter VIII. — Protection from Other Injurious

Agencies

Protection from Insects
Death of trees
Injury to trees
Injury to reproduction
Control of insects

Protection from fungous diseases

Protection against other agencies

Index . ...

PAGE

262
265
267
268
270
271
281
284
284
285
290
291
294

297
297
297
299
300
301
305
305
306
308

309

309
310
312
314
314

318
319

321

LIST OF ILLUSTRATIONS

FIG. PAGE

1. A Virgin Forest in Idaho Frontispiece

2. In the California Redwoods 4

^. The Devastating Effect of a Forest Fire in AJinne-

sota 11

4. A Forest Destroj^ed b^' Fire in the Cascade Moun-

tains of Washington 16

5. A Virgin Forest of Douglas Fir, Cedar, and Hem-

lock in Oregon 23

6. A Forest of American White Pine in Germany 26

7. Natural Arrangement of Crown Classes in an I^ven-

aged Stand 29

8. A Selection Stand. Spruce in the Mountains of Aus-

tria 33

9. An Even-aged Stand. Mature Beech in Germany.. })^

10. Profile of an Ideal Selection Stand Before First

Cutting 46

11. Profile of an Ideal Selection Stand Twenty Years

after Cutting 46

12. Trees Designated for Cutting under the Selection

System. Engelmann Spruce, Arapahoe National
Forest, Colorado 51

13. After a Selection Cutting. Logs not yet Removed

or Slash Disposed of. Missoula National For-
est, IVIontana 55

14. Marking Axe 5(S

15. A Stand of P^ngelmann Spruce after a Selection Cut-

ting. Arapahoe National Forest, Colorado. ... 06
xvii

XVIU LIST OF ILLUSTRATIONS

FIG. PAGE

16. A Group of J^alsam I'irs Marked for Cutting in a

Selection I^Orest. Their Removal will Favor
the More \'aluable Spruce. Arapahoe National
Forest, Colorado 66

17. Trees Designated for Cutting under the Selection

System. Arapahoe National Forest, Colorado.. 73

18. A Stand in the Adirondacks in which there has been

a Selection Cutting 76

19. A Stand of Douglas Fir and Cedar of Great Size and

Age. A System of Clear-Cutting is Required.
Washington 84

20. A Heavy Douglas Fir Stand in Washington, Calling

for One of the Systems of Clear-Cutting 91

21. A Dense Stand of Tall Lodgepole Pines, Calling for

some System of Clear-Cutting on Account of the
Danger from Windfall 99

22. Application of a System of Clear-Cutting with Large

Blocks of Timber Reserved for Seed. A Quar-
ter Section in the Kaniksu National Forest,
Idaho 105

23. Thrifty Standards Reserved to Grow through a Sec-

ond Rotation. Scotch Pine in Europe 109

24. Reserving Scattered Trees to Distribute Seed after

Lumbering. Minnesota National Forest 109

25. Cjroups of Trees left to Distribute Seed over Clear-

ings. Lodgepole Pine. Deer Lodge National
Forest, Montana 117

26. A Stand of Western Yellow Pine, with Scattered

Old Irees, Showing the Results which May
be Obtained by Reserving the Thrifty Standards
for Growth through a Second Rotation. Hlack
Hills, South Dakota 122

LIST OF H.LUSTRATIONS XIX

FIG. PAGE

27. Clear Cuttin^r as Applied in a Scotch Pine Forest in

Germany. The Clearing will be Restocked by
Planting l.U)

28. Clear-Cutting in Strips as Applied in Lodgepole Pine.

Deer Lodge National Forest, Montana 1S0

29. Cutting Series 1 ^^

30. Reproduction of a Stand by the Shelterwood System.

The Sheltering Trees will be Removed in the
Next Ten Years, Black Forest, Germany ].V)

31. Primitive Application of the Shelterwood System,

after the First Cutting. Lodgepole Pine. Big
Horn National Forest, Wyoming L^9

32. After a Cutting under the Shelterwood System.

Western Yellow Pine. South Dakota 148

33. Just Before the Removal of the Last Trees under the

Shelterwood System. Young Growth has been
Secured over the \\ hole Area. Austria 160

34. After the First Work in an Open Irregular Stand.

The Cuttings Followed the Principles of the
Shelterwood System. Western Yellow Pine.
Black Hills National Forest, South Dakota. . . . 160

35. The First Cutting in an Irregular Open Stand of

\\ estern Yellow Pine. In Places it is Neces-
sary to Make Small Clearings; P^lsewhere the
Shelterwood System is Followed 107

36. Simple Coppice on a very Short Rotation, Illustrated

by Willow C\ilture J 71

M. Distribution of Annual Cutting Areas in a Forest
Managed under the Simple Coppice System on
a Rotation of 1 wenty Years. A C\)mnuinal
Forest in Northern Germany 176

XX LIST OF ILLUSTRATIONS

FIG. PAGE

38. A Stand of Hardwoods, Composed of Trees of Sprout

and Seedling Origin, after the First Cutting un-
der the Polevvood Coppice System. Southern
New York 180

39. Coppice with Standards. Germany 185

40. Another Example of Coppice with Standards. Ger-

many 185

41. Inferior Trees which Should be Removed from over

a Stand of Young Trees. A Liberation Cut-
ting 192

42. A Spreading Tree which Should be Cut for the Bene-

fit of the Younger Surrounding Trees. A Lib-
eration Cutting 192

43. A Stand of Loblolly Pine after a Thinning. Mary-

land 197

44. A Stand of White Pine after a Thinning. New

Hampshire 205

45. A Stand of Hardwoods after a Thinning. Massa-

chusetts 213

46. A Thinning in Progress in a Shortleaf Pine Stand.

Biltmore, North Carolina 222

47. Example of a Damage-Cutting. Trees Removed

Because Infected by Insects. Black Hills Na-
tional I'orest, South Dakota 222

48. A Eire Burning in the Rocky Mountains 228

¥\ A Surface Eire in a Longleaf Pine Eorest in the

South 228

50. Brush Piled and Ready for Burning. Missoula Na-

tional Eorest, Montana 248

51. Cjood Work in Piling Brush. Coconino National

Eorest, Arizona 254

LIST OF ILLUSTRATIONS XX i

FIG. PAGE

52. A Favorable Condition for l>urninn; Piled Brush.

Missoula National Forest, Montana 259

53. A Spruce 'Fop Improperlj' Lopped 263

54. The Same Spruce Top Properly Lopped 263

55. A Well-Developed System of Roads and 1 rails, Used

for 7 ransportation and Fire Protection. Black
Forest, Germany 269

56. A Plowed Furrow that Stopped a Surface Fire 274

57. A Fully Cleared Fire-Line in the San Gabriel Moun-

tains, California 274

58. A Fire-Line in the Chaparral. Angeles National

Forest, California 279

59. A Mountain Trail Built for Fire Patrol. Angeles

National Forest, California 283

60. Location of Fire-Lines in the Angeles National For-

est, California 283

61. A Lookout Station. Cabinet National Forest, Mon-

tana 287

62. A Watch Tower in the Tusayan National Forest,

Arizona 295

63. Fighting a Ground Fire by Trenching 304

THE PRINCIPLES OF
HANDLING WOODLANDS

CHAPTER I

INTRODUCTION
The American Forest

At the time of the first settlement of America the
forests were unexcelled anywhere in the world. They
stretched practically unbroken from the Atlantic Ocean
half across the continent to about the ninetieth meridian.
They covered a large portion of the Rocky Mountains
and a broad strip on the Pacific coast. In the aggregate
these forests comprised about 850,000,000 acres.

The original forests of this country were remarkable
not only for their vast extent, but also for the great num-
ber of valuable species composing them. The richness
of our forest flora is due in part to the fact that the coun-
try includes several climatic zones, in part also to the fact
that the climate and physiography have favored the devel-
opment and continuance of tree life.

Another characteristic of the original forests in this
country was the enormous yield in \'al Liable material.
The greater part of the country is comprised within the
temperate zone, whose climate favors rapid growth and

I THE PRINCIPLES OF HANDLING WOODLANDS

large development of trees. The original forest con-
tained trees of great age and enormous size. Nature,
working through centuries, had provided a vast store-
house of timber, fully grown and ready for use when
required. It is on this supply that the American people
have been drawing for four centuries. It has constituted
a source of great wealth, and has been an important
element in the internal development of the country and
in the extension of its commerce.

The March of Forest Destruction

When the country was first settled, the effort was to
clear the land for agriculture. With the increase of pop-
ulation there naturally arose a demand for forest products,
and the timber was cut for use, and not merely destroyed.
The first lumbering for use took only the choicest trees
in the forest. Timber was so plentiful that the ordinary
grades had no value. The selection of a tree here and
there had little effect on the forest. In fact, the cutting
was beneficial, for it removed the mature trees, and the
openings which were made induced new growth, and
thereby increased the increment of the forest. As the
demand for timber increased for export and for local con-
sumption, and the supply of the best grades became more
remote, the forests near the settlements were cut over a
second time; and this process went on until the modern
systems of lumbering were introduced, which make very
heavy inroads into the forests, in some cases removing
practical Iv every tree.

INTRODUCTION 3

Damage by Fire. — It was soon after lumbering for use
began that forest fires became a common occurrence, and
these increased in number and severity, burning over the
majority of lumbered lands, and usually at the same time
enormous areas which had not been cut, and destroying
millions of dollars worth of timber. It is estimated that
since 1870 an average of 50,000,000 acres has been
burned and a damage of fully 1 50, 000, 000 done each
year, aside from the injury to young trees and to repro-
duction.

Damage by Insects. — The American forests have
suffered, further, incalculable injury by insects. In some
instances whole forests have been killed by bark-beetles.
Sometimes the damage attributed to fire has been in the
first instance due to beetles; and the dead trees and
debris were later consumed, or practically consumed, by
fire. In the Black Hills of South Dakota and Wyoming
there has been a damage from beetles of J2, 500,000
within a decade.

Reduction of Supplies. — Taking together the vari-
ous causes of destruction of forests, such inroads have-?
been made into our resources that a conservative esti-
mate shows that the bulk of our virgin supplies will be
exhausted in less than a generation. The supply of
forest products will then come entirely from what is
now classed as second growth.

Heretofore, the only idea in the minds of the Ameri-
can people has been to utilize the great store of timber
which they found already at hand. The Government and

THE PRINCIPLES OF HANDLING WOODLANDS

Fig. 2. — In the California Redwoods.

INTRODUCTION 5

States disposed of their lands as rapid I \' as possit)le to
private owners and for prixate exploitation. IVivate
owners, in handling their forest lands, had no other idea
than to cut the accumulated stock withoLit any regard
whatever for future growth. While a few far-sighted
lumbermen in Maine, and in some other sections,
began 30 or 40 years ago to restrict their cuttings to the
oldest timber, and to reserve the intermediate and young
growth, and while a few individuals planted trees and
otherwise practised forestry in a small way, it is only
within a decade that there has been any wide-spread
conception of the management of timberlands on a large
scale with a view to perpetuating the forest.

Unregulated Cutting. — Ordinary lumbering, even
when not accompanied by fire, results in a steady deteri-
oration of the forest. The best individuals are taken
out and the crooked and defective trees, which the lum-
bermen do not want, are left. In mixed forests, the poorer
species are usually left, and these seed up the ground.
The soil is often exposed, trees are blown over, and at
best the production is very much lowered. So great has
been the damage to our forests that the annual growth
upon them is less than one-third of what is actuallv used
by the country. To meet the future demands of the
country, with the ever-increasing population, waste and
destruction must be stopped and the productive growth
of the forests increased from 300 to 400 per cent.

Disturbance of Stream Flow. — One of the most seri-
ous effects of destructive lumbering, followed by fires,

b THE PRINCIPLES OF HANDLING WOODLANDS

has been the disturbance of stream flow and the erosion of
the soil. Forest destruction has already caused a damage
of many millions of dollars, by silting up navigable rivers
and reservoirs, by causing an increase of spring floods
and a deficiency of water in the summer, by deposits of
rocks, gravel, and sand on agricultural land, by the
drying up of the sources of water used for irrigation
and for domestic purposes, etc. This damage in the
aggregate is so large as to constitute one of the principal
causes of the present demand for forestry.

If the United States is to have an adequate supply of
timber in the future, and if the headwaters of the rivers
are to be properly protected, the practise of forestry is
required not only on the public forests, but also on lands
now in the hands of private owners.

Definition of Forestry

The underlying idea of forestry is continuity of use.
Forestry aims to utilize the present product of the forest
with the greatest possible economy, and with profit to the
owner, and at the same time to provide for the continu-
ance of the forest, and for the production of timber and
other forest products in the future.

Heretofore, lumbering has been the exploitation of a
ripe crop of timber, with no intentional provision for the
future use of the land for forest growth. The forester
regards a forest as a property capable of yielding repeated
crops of timber. When a merchantable crop is cut, the
forester aims to replace it by a new growth, to protect the

INTRODUCTION /

young, middle-aged, and merchantable trees, which by
the old methods would often be destroyed, and to secure
from the forest the highest possible yield in the long run.
The highest possible utilization of the present product
requires only the application of ordinary modern business
principles. Forest production requires of the manager
not only practical business capacity but also knowledge
of the life and characteristics of the trees and forests, and
the methods of carrying out the objects of forestry in a
practical way. The forester, therefore, must be a man
trained and experienced both in modern lumbering and
also in the art of forest production, which, in technical
language, is called silviculture.

Definition of Silviculture

Silviculture is the art of establishing, developing,
and reproducing forests. It comprises:

1. The establishment of forest stands, by natural
reproduction or by artificial seeding or planting.

2. The improvement of woodlands, including thin-
nings for the betterment of their composition and the
enhancement of the quality and growth of the trees,
pruning, and all other work of improvement.

The protection of woodlands from lire, insects, and
other damage is not always dealt with in books on silvi-
culture. The need of protection is so urgent in this
country, however, and the successful handling of wood-
lands depends so much on securing their safety, that the
subject is given a place in this volume.

8 THE PRINCIPLES OF HANDLING WOODLANDS

Objects of Silviculture

The ultimate goal of all silvicultural work is to secure
on a given area a high production of valuable material,
in order that the owner may secure the largest possible re-
turns in the long run. More specifically the objects are:

1. To secure quick reproduction after the removal of
timber.

2. To produce valuable species instead of those hav-
ing little or no market value.

3. To secure a full stock, in contrast to stands of
small yield.

4. To produce trees of good form and quality.

5. To accomplish the most rapid growth compatible
with a full stand and good quality.

Quick Reproduction. — When forests are abused by
unregulated cutting and by fire, reproduction is very
slow, and sometimes, when the abuse continues, entirely
prevented. Thus, for example, areas in Pennsylvania
cleared by lumbering and repeated fires, are in many cases
entirely covered with low brush and weeds, and years
will be required for natural reproduction to take place.
The great plains in the Lake States, w^hich have been
devastated by fire, are capable of producing as good tim-
ber as formerly, but the trees needed for seed have been
destroyed. It will require a long period, amounting in
some cases to many tree generations, for the reestablish-
ment of the forest by natural means. There are, in this
countrw millions of acres of devastated forest land, on

INTRODUCTION

which it will he impossihle to estahlish a stand hy natural
reproduction in less than a centur\'. This represents the
worst conditions of forest destruction. But even where
fire has not played so important a part, hut where lum-
bering has been conducted in the usual way, reproduction
is generally slow and meager. This means loss of growth.
To the owner it means that the soil is idle for a long
time, and that the period between removing the timber
and the maturing of the new crop is much longer
than is necessary. To the country at large it means a
great loss which, in the aggregate for a single State, may
amount to millions of dollars each year.

Desirable Species. — Nature does not discriminate
against the inferior species. In the struggle for existence
between two species, the one which has the least market
value often w^ins. In any forest left to nature a great
deal of ground is occupied by trees which do not have as
high technical value as some others. This is particularly
true in a country like America, where the number of
species is large. Thus, in southern New England the
ground is often occupied bv birch, soft maple, ironwood,
or other species of relativeh' little value, where chestnut
and oak might be growing. Lumbering and fire are often
followed by a deterioration of the soil and a growth of
species inferior to those in the original stand. The pur-
pose of silviculture is to improve the composition of the
forest, so that a given area will be occupied b\ the most
valuable species which are capable of growing under the
giv^en conditions.

10 THE PRINCIPLES OF HANDLING WOODLANDS

A Full Stand. — There are relatively few forests in
America which are producing a maximum amount of
timber. Thus, it is estimated that the second-growth
woodlands of Connecticut do not yield much over 60
per cent of what is possible under good methods of
forestry. This refers merely to the actual quantitative
production, without regard to the quality of the product.
The production from the standpoint of value is probably
less than 60 per cent, of the possible. The reason for this
small production is the fact that the stands are very irreg-
ular. Frequently the trees are straggling and spreading,
and occupy a great deal of space to the exclusion of other
trees, and there are many openings occupied by valueless
shrubs or entirely bare, which might be growing trees.
The loss to the country through this reduced productive
power of the forests is very great. In Connecticut alone
it probably amounts to at least $400,000 per annum.
The purpose of silviculture is not only to produce the
trees best adapted to the soil, but as many trees per acre
as is compatible with good quality.

A Valuable Product. — In the American forests a
large number of the trees are crooked or forked, or have
low branches which destroy their otherwise high techni-
cal value. Frequently these trees are suitable only for
fire-wood, though they are large enough, and of the right
species, to furnish high-priced timber. Thus, frequently
one sees a stand of oak, 75 years old, with trees of such
poor form that the timber is worth onlv 1 cent per cubic
foot, whereas within this period it would have been

INTRODUCTION

fct

>
<u

12 THE PRINCIPLES OF HANDLING WOODLANDS

possible to produce a stand worth 3 cents per cubic
foot. One purpose of silviculture is, therefore, to pro-
duce trees of high technical value.

Rapid Growth. — It is a proved fact that the growth
in a natural forest is very much lower than in a cultivated
forest. In the fierce struggle for existence trees are, in
the majority of cases, retarded in growth, and those which
live and come to maturity have usually grown relatively
slowly. In the Adirondacks, for example, it requires on
an average 180 years for a spruce to reach a diameter of
12 inches. Under favorable conditions, it is possible for
spruce to reach 12 inches in from 80 to 100 years. One
object of silviculture is to give each tree which is likely
to come to maturity the requisite amount of light and
growing space, in order that it may grow at its maximum
rate. Trees standing in the open grow more rapidly than
those in the forest, but this rapid growth is obtained at a
sacrifice of form and quality of wood. A certain amount
of crowding is necessary, in order to secure natural
pruning and good form of trunk. The forester has,
therefore, to sacrifice increment in a certain measure to
form and quality, but by judicious silviculture he can
secure the maximum rate of growth that is compatible
with the production of valuable material.

Measure of Production

There is for every type of forest a maximum of pro-
duction. By the expenditure of enough labor, it is pos-
sible in time to bring a forest to th5s high condition of

INTRODUCTION 13

productiveness. All open lands may he planted with
good species of trees; ruined stands may be cleared and
restocked artificial!}' or naturally; stands containing weed-
trees, or overcrowded, may be thinned and their compo-
sition and growth improved. The measures necessary
to secure the maximum production may, however, involve
a very large inv^estment, and one which might not yield
an interest return at all satisfactory to the owner. While
the forester aims to secure a continued high production,
he does not handle his forest with this alone in view, re-
gardless of business considerations. His design is to
make the forest serve the highest possible use to the
owner as a piece of productive property. If any land
is more valuable for agriculture or other purposes than
for producing trees, it is put to its best use. If it is best
suited to forest growth, the aim is to secure from it re-
peated crops of timber. Investments are made in forestry
when it can be shown that there will be adequate returns
in money or in some other desired form. It is a rule of
silviculture that no investments are made unless there
will be such returns. Under our present conditions it is
usually not possible to secure the maximum productive-
ness of the forest and at the same time meet the financial
requirements of the investment.

How much, then, must one produce from a forest in
order to practise legitimate forestry? In other words,
what is the minimum of forest production which may be
established as the dividing line between forestry and
destructive lumbering? The simplest principle is that

14 THE PRINCIPLES OF HANDLING WOODLANDS

those areas which are to be held permanently for forest
use should be managed in such a way that the production
by yearly growth will not be progressively reduced, but
will at least be maintained. If by failure to provide for
replacement, or through destructive fires, the productive-
ness of the forest is constantly decreasing, there will ulti-
mately be little or no forest at all; and that is exactly what
is happening in many places under the present methods.
If, on the other hand, there is a provision for new growth
and a conservative handling of growing timber, so that
the growth equals that which produced the present stand,
the forest's prociuctiveness is not decreasing, even if it
does not approximate what might be secured by a larger
outlay of money.

This measure of production is a very easy matter to
determine if it is based on the mean annual growth of the
forest. If, for example, the first forest is 200 years old
and yielcis 10,000 board feet to the acre, the annual
growth is 50 board feet. In this case, if the forest is
handled so that the mean annual growth of the next
crop will be 50 feet, it falls within what may be called
the dividing line between forestry, or a system of main-
taining forest production, and exploitation, in which
there would be a constant lowering of the yield. It may
be said, however, that on account of the small yield of
the virgin forest compared with what might be produced
under forestry, such a return is exceedinglv low. Any
system that does not produce at least 100 feet per acre
per annum is decidedly poor forestry. But between this

INTRODUCTION IS

mininumi rate of growth and the possible niaxiimiin
growth lies the range of timber production under legiti-
mate forestry. Just what point will be reached within
that range depends entirely on the object of the owner
in handling his forest. The application of forestry to
secure a high production, involving as it does a consid-
erable outlay of labor, is called intensive forestry.

Purpose of the Owner

The management of a forest depends on what returns
are sought by the owner. The object of management
varies w idely among different owners, and there is a cor-
responding variation in the application of forestry. The
first consideration in organizing a forest is the purpose
of management. Every investment is made to secure
some definite return desired by the owner.

Objects of Public Forests. — In the case of public for-
ests the financial returns, measured in actual interest on
the invested capital, are ordinarily not the first considera-
tion. National forests and State forests are set aside, to
be managed for the permanent benefit of the public. In
some cases these forests serve primarily to protect the
slopes of mountains, to conserve moisture, and to control
the run-of? of water. The accomplishment of this object
must be regarded as one of the returns from the forest.
In case of some National Forests located in high moun-
tains at the headwaters of important streams, the cost of
administration anci protection will exceeci the returns
which may be obtained from the sale of timber and from

THE PRINCIPLES OF HANDLING WOODLANDS

-T3

'4-

INTRODUCTION 17

Other sources. I^uhllc interest demands the protection of
these forests, and this itself is an ample return on the
investment necessary in forestry.

Some public forests serve as great recreation and
health resorts. Thus the State forests in the Adirondack
Mountains of New York are held primarily for these
purposes, as well as for their value in protecting the
headwaters of rivers. The constitution of the State pre-
vents any cutting of timber whatever, and hence there
are no returns in money at all. The public desires the
forest to remain, at least at present, untouched. Large
sums are spent each year for acbninistration, protection,
and improvement, and the indirect value to the public is
regarded as a satisfactory return. In this particular case
it would be possible to make the forests more than self-
supporting by judicious cuttings, and at the same time
meet all the protective and esthetic purposes of manage-
ment. Without doubt, such apolicv of treatment wdll be
introduced on these forests in a few ^•ears.

One of the greatest purposes of public forests is the
continuous production of wood and timber for use. The
object of management is not onl\' the production of as
large a quantity as possible, but also of the grades needed
by the people dependent on the forests for their supplies.
Oftentimes the public owner will aim to produce in its
forests trees of large size and high qualitv, in order to
secure grades of timber which private forests are not likelv
in the future to yield. The best grades of lumber can be
obtained only from very old trees. Most private owners

18 THE PRINCIPLES OF HANDLING WOODLANDS

will cut their trees as soon as merchantable. The cost
of producing very oki trees is high because of the interest
accumulating during a long period of years on the initial
investment, and the annual expense of taxes, protection,
and administration. The interest returns will be corre-
spondingly lower than when there is a short rotation.^
The public owner alone can afford to produce timber of
this character. The return will be in part the public
advantage of having a certain amount of high-grade tim-
ber on the market.

Objects of Private Forests. — Private forests are, for
the most part, managed for profit. On some large private
estates of wealthy individuals and clubs, held as hunting
and fishing preserves or pleasure parks, the questions
of timber production and money returns are secondary.
The protective principle enters strongly into the policy
of the management by water companies of the forests
about their reservoirs. Farmers frequently aim to pro-
duce timber of a certain class for local use. The essential
object of most private owners in forestry is financial.
Forestry with them is strictly a business problem.

The Cost of Silviculture

The objects of silviculture cannot be secured without
cost. There is alwa\s required an outlay in some form
or other, an investment made for the purpose of securing
greater returns in the long run. Sometimes the invest-
ment is in the form of actual expense for planting, protec-

' By rotation Is meant tlic a^e at which it is planned to cut the mature trees.

INTRODUCTION 19

tion from fire, inspection and supervision, or nuirkini; (A
trees; or it may he represented by increased cost of hog-
ging, and, hence, reduced profits of present cuttings; or
it may he in the retention of seed trees and small timher
left for growth, which might he utilized now; or per-
haps, in the case of a farmer doing his own cutting, in
the extra trouble necessitated by the application of far-
sighted, intelligent methods of treatment in his woodlot,
as opposed to the thoughtless, haphazard methods usually
employed. It is difficult to give any general average
figures of cost of silviculture, because different measures
are used under different conditions, and the cost of any
given measure varies widely. In the discussion of the
different methods of silviculture, the cost of the various
operations is discussed. In general, it may be said that
the extra cost of operating in the lumber woods bv for-
estry methods, compared to the ordinary methods, is
from 25 cents to Jl per thousand board feet; that the
cost of reproduction varies from $2 to |10 per acre; and
the annual cost of protection, supervision, and adminis-
tration varies from 2 to 1 0 cents per acre.

If a large lumber company were to practise forestrv,
the cost expressed in terms of the annual cut would be
about from 50 cents to $i per thousand.

Financial Returns from Forestry

It is obvious that the practise of forestrv in public
forests is of great value. The indirect protective influ-
ences of the forest, the continued supply of a certain

20 THE PRINCIPLES OF HANDLING WOODLANDS

amount of useful products, the maintenance of certain
industries which could not otherwise continue to exist in
a given region, are all of great advantage to the people,
and contribute largely to the actual creation of wealth
and prosperity. They justify public forestry even if
they involve a continued outlay of money.

Returns from Public Forests. — As a matter of fact,
public forests pay financially in the long run, in addition
to furnishing many indirect advantages. The forests of
Prussia yield a net revenue of over 1 16, 000, 000 a year,
or about $2. SO per acre. The forests of Saxony yield
more than $S per acre per annum above all expenses of
protection, administration, and operation.

Public forests in this country will also pay financially
in the long run. In some cases the forests have been so
badly damaged by destructive lumbering that there will
be no revenue from them for a long time. Thus Penn-
sylvania purchases cut-over forests. No timber can be
cut on many of them for a long time. But ultimately
there will be a large financial return to the State. A
typical public forest in Europe yields about 2}^ per
cent, per annum compound interest on the value of the
investment.

Problem of Private Owners. — The question asked by
many private owners of forests is whether it w^ill pay
them from a business standpoint to practise forestry.
Thus, for example, a lumber company owning 100,000
acres, has the problem of whether it shall cut everything
from the tract that can be sold, or cut only the mature

INTRODUCTION 21

timber and handle the forest with a view to repeated
crops.

It cannot be said that forestry will be a profitable in-
vestment for all private owners. There are a ^reat many
cases where the returns will not be satisfactory, compared
to other investments. I'he reason wh}' forestry fre-
quently is not an attractive investment is on account
of the danger from forest fires and burdensome taxation.
Where a forest can be successfully protected from fire at
reasonable cost, and where the annual taxes are not
excessive, forestry will certainly pay, and in many cases
yield a return fully equal to that which could be ob-
tained in other lines of business.

Profits of Planting. — The question of the possible
profit from forestry is usually based on the cost of pro-
ducing timber from the seed. The value of the land, the
cost of establishing the stand of trees, the annual expenses
of taxes, protection, and administration are considered,
the interest on all is compounded, and the aggregate
costs are compared with the possible returns from the
sale of the timber. When the land is cheap, the
taxes are reasonable, the risk of damage In fire is not
great, and the market is certain, a sure profit can be
shown. Thus, in New Kngland forest planting has
yielded over 6 per cent., and in the Prairie States, where
small trees are valuable, an even higher return has been
secured.

Under the present conditions confronting man\-
timberland owners, forest planting is not an attractive

22 THE PRINCIPLES OF HANDLING WOODLANDS

investment, because of the risks from fire, possible bur-
densome taxes, and uncertainty of markets.

Investments in Immature Forests. — On the other
hand, forests in such a condition that there are not only
merchantable trees but younger trees which will reach
merchantable size in a reasonable period, of^er a splendid
opportunity for profitable forestry. During the few years
required for the }^oung growth to reach merchantable size,
there will be a very rapid increase in value. Thus, for
example, a purchaser may in some sections secure second-
growth chestnut and oak at $5 per acre; in otner words,
to obtain land well stocked with second growth up to 75
years old for the same amount as it would cost to buy a
denuded land and plant a new crop, or even less.

A lumber company which has purchased a tract on
the basis of the value of its mature timber, frequently
acquires an enormous supply of young trees, for which it
really pays nothing. The operation of the forest so as to
protect and bring these to maturity will result in produ-
cing timber at exceedingly low cost, and with consequent
high profits.

Those large producers who will require stumpage
after the present abundant supply is depleted will find
it very profitable to grow their own timber, purchasing
young forests already well stocked and partly grown while
these are relatively cheap. The virgin timber in the East
will be largely cut in 25 or 30 years. The timber cut
after that time will be that which is now called second
growth. For example, after the old southern pine is cur.

INTRODUCTION

Fig. 5. — A Virgin Forest of Douglas Fir, Cedar, and Hemlock in Oreiion.

24 THE PRINCIPLES OF HANDLING WOODLANDS

the lumbermen will use the stands which are now from 6
to 12 inches in diameter. Far-sighted owners who hold
and protect these stands will furnish the stumpage of the
immediate future. Their profit will be high, partly
through the growth of the trees and partly through the
increase in the stumpage value of trees of moderate
size.

Investments of this sort should attract capital, even
under our present conditions. The original investment
called for is comparatively small, and both sure and early
profits are clearly in sight. The forestry which will
most generally appeal to private owners now is of this
class, where thrifty and rapidly growing trees can be
reserved as a basis for later cutting at the same time that
renewal of the forest for an entirely new crop is pro-
vided for.

Investments in Natural Reproduction. — One serious
objection which may be raised to the foregoing presenta-
tion of an opening for private forestry is that it is fores-
try with forestry left out; for earlier in this chapter it was
shown that reproduction is necessary in order to have true
forestry. The average American lumberman has not been
much more interested in natural reproduction than in
plantations. He is interested in a conservative forest
policy, which will mean a return in 10, 15, or 2S years.
It is hard for him to interest himself in returns one
or two generations hence. Nevertheless, the question of
reproduction is well worth his attention on practical
grounds, evx^n though he has not the interest of the

INTRODUCTION 25

owners who arc planninijja heritage for their children antl
p;randchilch*cn, or of coq^orations orij^ani/cd on such a
perfnancnt basis that they can h)()k far into the future.

Already in the best settled portions of the country
land well stocked with young growth brings a higher
price than denuded land. Even the land speculator who
has no interest in permanent forestry ma}' well take this
into account. Reproduction can be secured naturally in
most cases where a second cut is contemplated. If there
is enough rapid-growing timber of medium size to make
holding it for a second cut good business, natural repro-
duction can be secured from the reserved trees, provided
fires are controlled. The holding of inmiature timber
necessitates a certain amount of protection, which, with
comparatively little additional outlay, will suffice to
secure reproduction sufficient to maintain the required
minimum of production.

Progress of Private Forestry. — In progressive States
which have inaugurated a system of fire protection, the
hazard from forest fires is already under way to be re-
duced to a minimum, making it worth while for for-
est owners to look beyond the cutting of trees now
half-grown, and to replace the old stands by natural re-
production or planting. Farmers are beginning to prac-
tise forestry in order to produce wood and timber for
their own use and for sale, and also in order to increase
the sale value of their property. Large prixate owners
are now considering this question from the standpoints
of the actual returns from the increased value of the

26 THE PRINCIPLES OF HANDLING WOODLANDS

I'K;. (}. A i' ort'bt ot American White I'liie m Germany.

INTRODl ("I'lON 2*!^

land, the continuance of the hiniher trade, and theii
responsibilities to the jMihlic.

Already in a number of the States, as for example in
Idaho and Washington, large owners are forming partner-
ship associations for fire protection and the practise of
forestry. In the author's judgment, the time is n(3t far
distant when the States will fulfil their responsibilities in
the matter of aid to the private owners in fire protection,
taxes, and other ways, w^hich will make it possible for
private owners to practise forestry, and that there will
then be carried out, on such private lands as are not
better suited for agriculture or other purposes, a system
of forestry which will at least maintain the minimum
of production. This will be conducted voluntarily or
under the guidance of the State.

Reproduction Cuttings

Prompt reproduction after cutting constitutes one of
the important objects of forestrv. Whenever a stand or
portion of a mature stand is cut, the design is to establish
new growth in its place, as soon as possible. Cuttings
made with the expectation of replacement are called re-
production cuttings. They are in contrast to improvement
cuttings^ whose object is primarily to improve a growing
stand and not to remove it and restock the area with new
trees.

Classification of the Trees in a Forest

It is customarv, for v^arious purposes in forest work, to
group the trees into classes. There are three different

28 THE PRINCIPLES OF HANDLING WOODLANDS

principles of classifying trees: First by age, second by
size, and third by development of crown and position in
the stand.

Age-Class. — It is customary to classify the trees in a
forest in arbitrary age-classes. Usually the range of a
single age-class is 20 years. Thus, if the oldest trees are
120 years, there would be 6 age-classes, 1-20, 21-40,
41-60, 61-80, 81-100, 101-120 years. Sometimes, in
our forests, age-classes of SO years are used. In Europe
10-year age-classes may be used, but the 20-year age-class
is most common, both here and abroad.

Size-Class. — In a great deal of forest work it is more
convenient to classify the trees by size than by age.
The simplest classification is by inch-diameter groups.
Two-inch or 4-inch or other classes are used, according
to convenience. In certain work in forest mensuration
height-classes are also used.

Crown-Class. — Trees are classified also with reference
to the development of the crowns and their position in
the canopy of the forest. If the trees in an even-aged
stand are examined, it will be seen that there is a wide
variation in the development of the crowns. Some trees
are distinctly the leaders, with crowns well developed,
and occupy the principal position in the canopy. Other
trees, crowded from the side by their more thrifty neigh-
bors, lag behind in their growth, are shorter, and have
a smaller crown and a smaller diameter than the leaders.
Still other trees are entirely overtopped and after a time
are killed. Five crown classes are recognized, as shown

INTRODUCTION

30 THE PRINCIPLES OF HANDLING WOODLANDS

in the following list, and as illustrated in the sketch on
page 29.

1. Dominant trees — the ordinary leading trees with
full crown.

2. Co-dominant trees — those beginning to lag behind
the dominant trees in height, crowded from the side, and
having narrow crowns.

3. Intermediate trees — those with crowns retarded
by crowding of the upper as well as of the lower part of
crown, but still vigorous and usually capable of recovery
if released.

4. Suppressed trees — those entirely overtopped.

5. Dead trees.

The Stand. — The term stand is a general expression
applied to any given portion of a forest having a distinct
character. The characteristics distinguishing a given
stand may be age, form, density, quality, value, growth,
yield, etc. Thus, such expressions are used as a 20-
year-old stand, a selection stand, a dense stand, a broken
stand, etc. A forest is made up of a multitude of stands.

Origin of Stands. — Stands are distinguished according
to whether the trees have originated from seed or from
sprouts, or from both combined. The stand originating
from the seed is usually called a //(^// forest: that from
sprouts a coppice ox sprout forest; if both classes of trees are
represented it is a composite forest.

Form of the Stand. — The result of the competition
between trees m the forest under a given set of conditions

INTRODUCTION 31

is a stand of characteristic form. The form of a stand
has reference to the arrangement among the different tree-
classes. The form depends primarily on the distribution
of the age-classes. Trees of different ages may mingle
together promiscuously; the age-classes may be in groups;
the trees may be all of about the same age; or there
may be a more or less complete canopy of crowns, and
underneath this a separate story of smaller trees, whose
crowns form a secondary canopy. The forms most com-
monly recognized are the following:

A. High Forest Fo

RMS.

1. Selection Form. — Trees of different ages, from the
seedling to maturity, are represented, mingled individ-
ually or in small groups.

2. Regular or Even- Aged Form. — The trees are ap-
proximately even-aged. The term is not confined to
stands in which the trees are exactly even-aged. If the
majority of the trees have nearly the same age and their
crowns form a clearly defined, regular canopy, the stand
is classed as regular. In a virgin forest a stand is regular
if the majority of the trees are of merchantable size.

3. Irregular Form. — Through unregulated cuttings or
accidental injuries the stand has been broken and there is
an irregular representation of two or more ages. The
age-classes are not all at hand, and therefore it is not of
the selection form. The n-reguhn^ form necessaril\ \'aries
enormousK .

4. Two-Storied For)}!. — I'here are two distinct stands

32 THE PRINCIPLES OF HANDLING WOODLANDS

of regular form on the same area, one growing under-
neath the other.

5. The Reserve Form. — In a regular stand there are
scattered older trees remaining over a second rotation.

B. Coppice Forms.

1. Regular Coppice Form. — The sprouts are approxi-
mately of the same age.

2. Irregular Coppice Form. — As a result of bad treat-
ment, various ages are irregularly represented.

C. Composite Forms.

1. Regular Composite Foi'm. — Sprouts and seedling
trees of approximately the same age are growing together.

2. Irregular Composite Form. — Through abuse, an
irregular mixture of ages occurs, with both sprouts and
seedling trees represented.

3. Coppice with Standards. — Upon a given area there
is a regular coppice stanci, and also scattered trees, origi-
nating from the seed, which are allowed to grow over
several sprout rotations.

The Silvicultural Systems

A silvicultural system is a broad plan of management
under which a forest is reproduced and developed.
In order to handle forests with a view to continued
production of timber, ordinary lumbering must be modi-
fied or supplemented by special measures. To justify
such investments as these measures involve the forester

INTRODUCTION

Fig. 8. — A Selection Stand. Spruce in the Mountains of Austria.

Fig. 9. — An Even- Aged Stand. Mature Beech in Germany.

34 THE PRINCIPLES OF HANDLING WOODLANDS

must have clearly in mind the results which may be
secured, what kind of forest will be produced, what
species will compose it, what form it will have, and the
yield in salable products.

Definite results can only be secured under a system-
atic procedure. There have been developed by experi-
ence certain principles of handling forests of different
character. These principles have been brought together
and systematized, and are expressed as silvicultural
systems. These systems do not, however, represent
conventional rules for cutting, as often supposed, but
rather are principles enabling the forester to systematize
and control his work, and definitely to accomplish the
purposes of management.

The silvicultural systems differ primarily in the man-
ner of cutting and reproducing the stand. A given
method of reproduction cutting results in a new stand,
which has a characteristic form. Under systematic for-
estry, stands of a given form are given a specific treat-
ment later. In forests thoroughly organized, therefore,
the silvicultural system has a broader significance than
merely a method of reproduction, and comprises also the
development of the stand. In a new country, where the
forests are irregular and the market conditions often poor
or uncertain, it may be impossible to foresee the later
handling of the forest. For American foresters the
essential idea in a silvicultural system is, therefore, the
method of cutting and reproducing the stand. '

INTRODUCTION 35

Classification of Silvicultural Systems

In the following pages are enumerated the silvicultural
systems of most importance to the American forester.
These are essential h' the same as those used in other
countries. In Europe, there are some systems represent-
ing modifications of those in this list, and adapted to
the special conditions obtaining abroad. Some of those
given prominence here are no longer considered of im-
portance abroad, but were formerly used when the forest
and market conditions were similar to those which are
now found in this countr\'. As the markets improve,
the systems used in this country will, in their applica-
tion, be more and more like those of Europe.

The list of systems differs in arrangement slightly
from that found in most text-books. The present
arrangement has been chosen as the one which has
seemed to the author to be most helpful to the ordinary
student, in view of the prevailing literature and the cur-
rent ideas and practise of forestry in this country.

The silvicultural systems of chief importance to the
American forester may be grouped under the following
heads:

I. Systems Depending on Reproduction by Seed.

A. The Selection Svstem.

Applicable to stands in which trees of all age. are
represented. The old trees, scattered or in groups, are
selected for removal; the immature trees remain standing.

36 THE PRINCIPLES OF HANDLING WOODLANDS

B. The Clear-Cutting Systems.

1. Clear-Cutting with Artificial Reproduction,

a. Clear-Cutting the Whole Stand. — The whole stand

is clear-cut in one operation, and the area re-
stocked by artificial seeding or planting.

b. Clear-Cutting iyi Strips. — The stand is removed

gradually by a series of clear-cuttings in strips.

c. Clear-Cutting in Patches. — The stand is removed

gradually by a series of clear-cutting opera-
tions, at least the hrst cuttings having the form
of irregular patches cut in the stand.

2. Clear-Cutting with Natural Reproduction.

a. Clear-Cutting the Whole Stand. — 7'he stand is

clear-cut in one operation, and the surround-
ing stands are relied upon for reproduction.

b. Reserving Blocks of Trees. — The stand is cut

clear, except for large blocks of trees left stand-
ing for seed, the latter usually constituting
not over 15 to 2S per cent, of the area.

c. Resei'ving Scattered Seed-Trees. — The stand is cut

clear, except for scattered individual trees left
standing for seed.

d. Reserving Groups of Seed-Trees. — The stand is

cut clear, except small groups left here and
there for seed.

e. Reserving 'Thrifty Standards. — All trees are cut,

except a limited number of thrifty individuals
left to furnish seed, and to grow with the new

iNTRoincnoN .^7

stand over a second rotation. This differs from
the scattered seed-tree system m that the trees
) left standing are much more luimerous and

are of a character to live through a second
rotation.

f. Clear-Cutting in Strips. — The stand is removed

in a series of strips, and reproduction secured
from the uncut portions of the stand.

g. Clear-Cutting in Patches. — The stand is removed

by a series of clear-cuttings in irregular patches
of limited size, and reproduction secured from
the side.

C. The Shelterwood System.

1. Cuttings Distributed Uniformly. — The stand is re-
moved gradually by a series of thinnings; each thinning
extends throughout the stand, and gives it a uniform
character. The new stand starts under the shelter of the
trees left stanciing, which act as a protection. The whole
stand is usually removed within a period of twenty to
thirty years.

2. Cutting in Groups. — The stand is removed grad-
ually by a series of thinnings which are not uniform
over the whole area, but concentrated on groups from
which, as centers, the reproduction is progressiveh' se-
cured.

3. Cutting in Strips. — The stand is removed gradually
by a series of thinnings, the work proceeding in progres-
sive strips rather than uniformly over the whole stand.

38 THE PRINCIPLES OF HANDLING WOODLANDS

II. Systems Depending on Reproduction Wholly or
Partly from Sprouts (Coppice).

a. Simple Coppice. — A stand of hardwoods is cut

clear and reproduction from sprouts almost
entirely relied upon. This system is usually
managed on a very short rotation.

b. Coppice with Standards. — The bulk of the area

is occupied by sprouts cut on a short rotation.
Mingled with them are thrifty trees allowed to
grow through one or more rotations of the
coppice.

c. Pole-Wood Coppice. — An even-aged stand of

sprouts and trees from the seed, combined, is
allowed to grow to pole-wood size (40 to ^0
years of age), and then reproduced in part bv
sprouts, in part by natural seeding.

Combination of Silvicultural Systems

The various systems are very frequently combined.
It is particularly common to combine systems of natural
reproduction and systems of clear-cutting with arti-
ficial reproduction. Thus, a portion of the stand may
be reproduced naturally, and then the balance clear-
cut and replanted; or patches may be clear-cut and
restocked with certain species, and then the rest repro-
duced naturally. The forester uses that method, or
combination of methods, which will best meet the
requirements of the forest and its management.

INTRODUCTION 39

Application of Silvicultural Systems

If the conditions of the forest and those affecting kim-
bering are iniiforni, the forester may use a giv^'n system
over the whole forest. Thus, for example, in the Minne-
sota National Forest the land is flat and the logging
conditions are fairly uniform. The forest is also suffi-
ciently uniform to enable the application of one system
— the scattered seed-tree system — over most of the area.

Usually conditions are variable, and a system applic-
able in one place is not suitable on other areas. hWen
in the regular forests of Europe there are usually in each
forest several difiFerent silvicultural systems in operation.
In this country the forests are so irregular and the
logging conditions so variable that often in a single
logging operation more systems than one are used. For
example, in a forest chiefly of the selection character and
requiring the selection system, there may be patches of
even-aged timber which must be handled under one of
the other systems. In every case, the forester applies the
system best adapted to meet the special conditions under
which he works.

Not only does the choice of a system of cutting de-
pend on local conditions, but the application of a given
system is subject to great variation. The application of
a given silvicultural system is dependent on the character
and condition of the stand and on the market and log-
ging conditions.

Every species has its peculiar requirements for repio-

40 THE PRINCIPLES OF HANDLING WOODLANDS

duction and growth, and these are subject to great va-
riation under different conditions of soil and climate.
Stands vary enormously in composition, form, density,
and thriftiness. The forester must know the habits and
requirements of the different species, and must be able
to diagnose the needs of any given stand, in order to
handle it in such a way as to secure the results desired.

Every measure of practical silviculture is, however,
subject to local conditions of markets and logging. The
owner desires as high a production as possible, but the
question of cost will always shape the method of apply-
ing his operations. Not only may the market and log-
ging conditions determine the system of silviculture;
they will always be a great factor in determining the de-
gree of intensity of the work, and govern the details of
operation.

In the discussion of the various systems of silviculture,
repeated references will be made to the different factors
which modify the working out of details on the ground.

Choice of Species

In reproducing a forest, one aims to establish the
species which will best meet the objects of management.
In artificial reproduction there is, theoretically, a choice
among all species adapted to the local climate and soil.
In practise, it may be possible to secure trees or seed of
only a limited number of species.

When natural reproduction is used, choice is restricted
to the species already growing on the ground. In a mixed

INTRODUCTION 41

forest there are always some species more desirable than
others. Poor forestry results in the decrease of the bet-
ter species. In making cuttings for natural reproduction
the better species are favored, with the aim of securing as
large a proportion of them as possible in the new crop.

Successful forestry results, in the long run, in the
gradual reduction in the proportion of the less valuable
species, and their replacement by the more desirable
ones.

In determining the most desirable species, the follow-
ing points are considered:

1. The Intrinsic Value. — Ordinarily the tree whose
wood is of the greatest intrinsic value is preferred.

2. The Rapidity of Growth. — Often a rapid growing
tree is preferred, even if its wood is less valuable than
that of some other species.

3. Suitability to Market. — The future market must be
considered, as well as the present. Frequently, foresters
regard certain species as undesirable because there is no
present market for them, when their intrinsic qualities
indicate that ultimately they will be valuable.

4. Logging Conditions. — The problem of handling and
transporting the logs must be considered. In the moun-
tains conifers are usually preferred to hardwoods, because
they are more easily handled; and if there are streams,
they can be driven. It is not merely the probable mar-
ket which is considered, but also the cost of placing the
product on the market. The profits, rather than the
market value, may determine the desirability oi a species.

42 THE PRINCIPLES OF HANDLING WOODLANDS

5. Cost of Reproduction. — Some species cost more than
others to reproduce, both artificially and naturally.

6. Resistance to Injury, — Species subject to damage by
wind, insects, disease, or other damage may be rejected,
even though otherwise desirable. A species may some-
times be favored primarily because of its ability to resist
fire.

7. Silvicultural Value. — A species may be of special
value in its influence on the growth of its neighbors or
in conserving the factors of site. Thus, hemlock in
mixture with pine helps the development of the latter,
and furnishes an excellent soil cover.

8. Esthetic Value. — Sometimes a species is chosen
because of its peculiar value from the esthetic or senti-
mental standpoint. This question becomes of impor-
tance on private estates, and those public forests which
are used as recreation resorts.

Pure and Mixed Stands Contrasted

A pure stand is one composed of a single species.
As the terms are used in this country, the stand is called
pure if 80 per cent, of the main crop is composed of one
species. If there are two or more species, and no one of
them comprises over 80 per cent., it is a mixed stand.
The aim of forestry is to reduce the proportion of the
less valuable species in the forest. Ultimately the un-
desired species will be represented only as scattered,
accidental specimens. The tendency in forestry is
constantly toward pure stands. This is especially true

INTRODUCTION 43

where stands are established by artificial seeding, or
planting. The forester is apt to choose the species
which give promise of the highest returns, and to
establish pure stands of it. Then again, the seeding
or planting of a single species is simpler and often
cheaper than if two or more species are in mixture.

There are, however, certain advantages in producing
mixed forests, and these should be considered when a
new stand is established. They are as follows:

1 . Mixed crops form a denser leaf-canopy, and hence
cast a heavier shade than pure stands. This is due to
the overlapping of the crowns of trees w'hose natural
crown development and ability to bear crowding differ.

2. In a judicious mixture of species there are a lar-
ger number of trees than in pure stands. This is the
result of differences in ability to endure crowciing, dif-
ferences in crown development, and differences in root
development.

3. It has been actually demonstrated that a larger vol-
ume of product can be obtained in mixed than in pure
stands.

4. IVIany species are less subject to damage from fire,
insects, disease, and windfall when in mixture than when
grown pure.

5. By a judicious mixture certain trees develop a bet-
ter form, and hence higher quality of wood, than in pure
stand.

6. Mixed stands have a higher esthetic value than
pure stands.

CHAPTER II

THE SELECTION SYSTEM

Origin of the Selection System

As a rule, the original forest is composed of trees of
all ages mingled together promiscuously, as individuals
or in groups. In the early days in this country the
smaller trees were not cut, because they could not be
sold. The first lumbering, therefore, consisted in select-
ing here and there a tree or group of trees and leaving
the remainder in the forest. No attempt was made to
prevent damage to the younger trees, but so few trees
were taken that comparatively little damage was done
and the forest was left in fairly good condition. As the
market improved and smaller trees became salable, the
cuttings were progressively heavier. In the Adiron-
dacks, for example, the first lumbering removed only
the larger pine and the choicest spruce; later, spruce was
taken down to 10 inches in diameter, and still later spruce
down to 6 or 5 inches was cut, with any of the choicest
hardwoods in addition. To-day, in sections where nearly
all trees are merchantable, lumbering practically results
in clear-cutting.

It is natural that the first conception of forestry under
the primitive conditions in a new country is to cut only

THE SELECTION SYSTEM 45

the larpjest trees and to reserve and protect the middle-
sized and youn^ trees, which will reach merchantable size
in a comparatively short time and will furnish the basis of
the future cuts. This is the fundamental principle of the
selection system. As far as the selection o{ the trees to be
cut was concerned, the earliest lumbermen practised it as
a matter of course. The forester takes the principle and
applies it systematically, with the object of reproducing
and so perpetuating the forest. By the system, as the
forester uses it, the old trees and others which have passed
their effective growth are cut, the immature trees are pro-
tected and encouraged, and reproduction is secured in the
openings made by the cuttings. A given cutting never
clears an entire stand, but makes only small openings.

Theory of the Selection System

The selection system is applicable to selection stands;
that is, those in which trees of different ages are repre-
sented. An ideal selection stand is one in which trees
of all ages, from the seedling to the mature tree, mingle
together in full proportion. Kven in the best selection
forests, however, every year in the rotation would not
be represented. If the rotation were 100 vears, there
would never be trees of every age, from 1 year up to 100
years, because seed is only produced at intervals. It is
an ideal selection forest if all age-classes are proportion-
ately represented. Thus if the rotation were 100 \ears
and the age-classes comprise 20 \cars each, the oldest
age-class should occupy in the aggregate about 20 per

THE PRINCIPLES OF HANDLING WOODLANDS

i. (L. wrtVcrtQ.

Fig. 10.

Fig. 11.

Profile of an Ideal Selection Stand. Fi^. 10. Stand before First Cutting
I'iy;. 11. Stand Twenty Years later, and ready for Second Cutting.

THE SKLKC'IION S\ S TKM 47

cent, of the area, and the other classes should have
enough trees so that, as each comes to maturity, it will
occupy 20 per cent, of the area.

In making selection cuttings in this ideal forest, the
oldest age-class would be removed during the first 20
years. Then the trees in the next age-class would begin
to come to maturity, and would be cut during the fol-
lowing 20 years. If successful reproduction were se-
cured, this process might be continued indefinitely.

The theory of the selection system is illustrated on
page 46. Fig. 10 represents a fragment of a selection
forest just before cutting. The trees designated as *T"
are mature, imd are therefore removed. Fig. 11 shows
the same stand after 20 years. The trees marked *TI"
in Fig. 11 are now grown into the mature class, and
are ready for cutting. All trees have grown both in
height, diameter, and crown surface. Several trees have
disappeared as a result of the mutua) crowding. Small
groups of young seedlings are found growing in the
openings made by cutting.

In some cases a stand is cut through every year. In
the theoretical example this would mean cutting each
year one-twentieth of the oldest age-class. Usually it is
impracticable to make annual cuttings, and the stand
is cut through periodically. The interval between
cuts may be called the cutting cycle. In Kurope, the
cutting cycle is usually about 10 years. In this counrry
the interval between cuts will more often be from 20
to 50 years.

48 THE PRINCIPLES OF HANDLING WOODLANDS

Principles of Limiting the Cut

In making selection cuttings the design is to remove
primarily trees in the mature age-class. Even where all
age-classes are well represented, they are usually not so
clearly differentiated as in the theoretical example shown
on page 46. When the market conditions are at all
favorable, not only the trees in the oldest age-class, but
also those in the younger classes are merchantable. The
restriction of the cut to the oldest class would mean then
that many trees for which there is a -market are left
standing as the basis of the next cut. There is always a
temptation to increase the cut as much as possible, in
order to show a large return and to reduce the cost of
logging. It is obvious that there must be some definite
principle of restricting the cut to prevent the removal of
such a large proportion of the tre^s of intermediate ages
and sizes that succeeding returns will be greatly dimin-
ished, and to prevent disturbing the arrangement of the
age-classes to such a degree that the continuance of
the selection system is impossible.

There are two fundamental principles which must
never be lost sight of: (1) The maintenance of the rate
of growth of the stand, and (2) the continuance of a
proper representation of age-classes.

If the age-classes are all represented in proper pro-
portion, the problem is simple. The growth is deter-
mined in advance, and the cut limited to this amount.
The trees removed are selected primarily among the

THE SELECTION SYSTEM 49

oldest trees. If a given stand is cut through each year,
there is removed an amount equal to the annual growth
of the whole stand. If the stand is cut every 1 0 years, each
cutting removes an equivalent of 10 years' growth. As all
age-classes are at hand, there are continuously trees grow-
ing into the merchantable class as a basis for the next cut.

The theory may be illustrated by a concrete exam-
ple. Suppose that the stand comprises 100 acres, the
annual growth is found to be 250 board feet per acre,
and the cutting cycle is 10 years; then 2, SOO board feet
per acre, or 250,000 feet on the whole tract, may be
removed at each cutting, provided there are no special
conditions to modify this amount. In a stand in which
the age-classes are well represented, the proportion of the
total area uncovered by a given cutting, that is, the
aggregate of all openings taken together, ic approximately
equivalent to the rotation divided by the cutting cycle.
Thus, if the rotation is 150 years, and the cutting cycle
is 25 years, each cutting uncovers in aggregate of all
small openings one-sixth of the area.

In the continued operation of a selection forest it is
exceedingly desirable to have the different age-classes
represented in their proper proportion. Obviously, if a
given age-class is not represented or is deficient it is not
possible to cut at regular intervals an amount of timber
equivalent to the full growth of the stand. Suppose, for
example, that in a selection forest handled on a rotation
of 100 years the oldest age-class, namely from 80 to 100
years, is represented in full proportion, while there are

50 THE PRINCIPLES OF HANDLING WOODLANDS

no trees at all from 60 to 80 years of age, and the place
which would normally be occupied by this age-class is
covered with trees less than sixty years old. It is clear
that after the expiration of 20 years and the oldest age-
class is removed, there would be no trees at all from 80
to 100 years old, and it would be necessary to wait another
20 years before cuttings could be made. Unless, there-
fore, all age-classes are normally represented the cuttings
must be at irregular intervals.

The selection system is applied in this country chiefly
in virgin forests. The normal form of a virgin forest is
of a selection character; that is, it consists of trees of dif-
ferent ages mingled together promiscuously. The forests
of the United States, fiowever, have in the past been seri-
ously damaged by destructive fires. It is common, there-
fore, to find in virgin forests stands of great age which
have a regular or even-aged form. This occurs where
past fires have cleared the ground and a new stand has
come in on the clearing. Even in forests where there
have been no destructive fires in the past, frequent small
clearings have been made by windfall, insects, and other
destructive agencies, and the distribution of age-classes is
therefore irregular.

The range of age-classes in most virgin forests is very
great. In northern Idaho, for example, the oldest trees
may be over 400 vears old. In such forests, if there
have been no disturbances by fire or otherwise, all ages
may be represented. But in classif\'ing the trees with a
view to practical management ail the mature trees would

THK SKUX'TION S^'S'^l:M

Fig. 12. — Trees Deslp^nated for Cuttiiiij under tlie Selection System
Engelmaim Spruce, Arupalioe Mutional Forest, Colorado.

52 THE PRINCIPLES OF HANDLING WOODLANDS

be grouped together in the oldest age-class as trees which
have ceased productive growth and ought to be cut.
Thus, in northern Idaho this age-class might comprise all
the trees over about 150 years of age. It is evident that
under these conditions the oldest age-class would far
exceed in number of trees any other age-class, and might
occupy in the aggregate 50 per cent, or more of the area.
The rest of the area would be occupied by trees belong-
ing, in more or less varying proportion, to the age-classes
below 150 years. In handling a virgin forest this unde-
sirable representation of the age-classes cannot be helped.
The mature trees should be cut and used, even if their
removal disturbs the arrangement of ages. In the sub-
sequent treatment of the forest, however, the gradual
establishment of the proper proportion between the age-
classes is kept in view.

Very commonly in this country it is necessary to
make cuttings before complete working plans have been
developed, and it is not possible to determine what
system of management will be best to use in the long
run. The first cuttings are therefore made conservatively
on the selection system. In some cases without question
the second cuttings will be comparatively heavy and will
practically be shelter-wood cuttings, which transform the
stand in a comparatively short time into an even-aged
form. If, on the other hand, at the second cutting it
seems desirable to continue the s lection system, cuttings
are made with a view to bringing about a proper repre-
sentation of different ages.

THE SELECTION SYSTEM S3

The Diameter Limit

While theoretically one aims to select trees for cutting
on a basis of age, in actual practise the decision whether
a tree is to be cut or left standing for a later cut depends
more on its size, condition, and capacity for growth than
on its age. For this reason it is usually customary to
restrict the cut on a basis of size rather than of age. The
size set as a minimum for cutting is called the diameter
limit.

The purpose of a diameter limit is to aid in restrict-
mg the cutting to those trees whose growth no longer
represents a return satisfactory to the owner. The trees
which are thrifty and growing rapidly are left standing,
regardless of their age, as a basis for a later cut.

It is, of course, impossible to investigate the growth
of each tree before cutting. It is, therefore, customary
to determine in advance of cutting the average diameter
at which trees cease to yield a satisfactory growth. Un-
less there are some special silvicultural reasons for modi-
fying it, this limit is used in planning the work of
cutting, and as a guide and check in selecting the trees.

When possible, the diameter limit of satisfactorv
growth is determined by a thorough local investigation.
Such a study will show the rate of growth of stands cut to
a number of different diameter limits, and will enable
the owner to fix upon that limit which will result in a
return most satisfactory to him. In making the stud\-
the forest is first analyzed, to determine the average num-

S4 THE PRINCIPLES OF HANDLING WOODLANDS

ber of sound trees of different diameters. It is then
assumed that all trees above a fixed diameter will be cut,
and those below it left standing. In practice, the limit
is somewhat elastic, but usually the trees left standing
above a limit about equal in volume those cut below it.
An inspection of the forest shows that the limit will
fall within a comparatively narrow range. Thus in
Maine it is readily seen that the average diameter limit
of spruce will be somewhere between 8 and 14 inches.
Accordingly, a computation of growth is made on the
basis of cutting to 8, 10, 12 and 14 inches. The limit
which shows the most satisfactory returns in volume or
in interest on the investment, according to the owner's
wishes, is selected as the guide for the cutting.

This limit may be modified slightly by special sil-
vicultural considerations, such as danger from windfall,
reproduction, etc. These points have usually a greater
bearing on the actual selection of the trees than on the
fixing of the average limit. A limitation of cut, based
on this method of study, maintains the rate of growth
of the forest and guarantees succeeding cuts at short
intervals.

Sometimes it is necessary to begin cuttings before an
adequate study of growth can be made. This happens
very commonly in the National Forests when time,
money, or men have been lacking to make the investiga-
tions, and the sales of timber cannot wait for possible
later appropriations for such work. In this event the
forester aims to cut only those mature trees which are

THi: si;i,i;cTioN system

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56 THE PRINCIPLES OF HANDLING WOODLANDS

obviously no longer making a satisfactory growth, and

he leaves the thrifty trees for a later cut. Thus, while

no growth study is made, the limitation of cut is really
based on growth.

Application of a Diameter Limit

In selecting the trees for cutting, one takes all trees
above the diameter limit determined upon, unless there
is some reason for leaving them, and leaves all trees
below it, unless there is some reason for taking them.
The reasons for leaving trees above a chosen diameter
limit may be the following:

1. Where it is necessary to leave one or more trees
for the distribution of seed in an opening.

2. Where the removal of a tree would expose a
group of trees below the limit to damage by windfall.

3. Where a tree is very thrifty and increasing in vol-
ume and value very rapidly.

4. Where the removal of a tree, or group of trees,
would result in erosion or serious damage to the soil
from drying.

5. Where it is desirable to leave a tree, or trees, for
esthetic reasons, as, for example, near roads of other
public places.

6. Where the policy of management requires the
leaving of a few prime trees for the production of ex-
ceptionally high grades.

The circumstances under which trees below the limit
are cut are as follows:

THE SELECTION SYSTEM 57

1. Where trees are defective.

2. Where trees are growing very slowly, and are
unlikely to remain sound till the next cut.

3. Where trees are of poor development, and are
retarding the growth of others of greater promise.

4. Where the removal of trees of poor promise will
aid reproduction.

5. Where it is necessary to cut patches clear, because
the trees, if left, would not withstand the wind.

6. Where trees will inevitably be injured by the fell-
ing of larger trees.

Marking. — The selection of the trees to be cut should
not be left to the judgment of the loggers. It has usu-
ally been the custom of lumber companies cutting to a
diameter limit to issue instructions to the sawyers to cut
only trees above a certain diameter on the stump. Even
when a diameter limit is the only basis for selecting the
trees the best results are secured by marking in advance
each tree which is to be cut. The ordinary logging crew
cannot be expected to measure the trees with care and
accuracy. The marking should be done by a special
crew of men skilled in this work.

In selecting the trees the chosen diameter limit is used
as a check. Accordingly, the marker carries a measuring
rule of some sort. Some mark oH rough graduations on
the handle of the marking axe to measure diameters.
Others carry calipers. Where only one limit is used, as
when a single species is being marked, a set caliper or a
simple gage may be used.

THE PRINCIPLES OF HANDLING WOODLANDS

Diameters are best measured at breast-height, because
the diameter limit is based on breast-high diameter
classes. A diameter limit based on the stump measure-
ments has no value, on account of the varying height of
stumps.

The trees are markeci with a special axe. A conspic-
uous blaze is made on the tree for
the convenience of the sawyers, and a
check-blaze and mark made at the
butt, below where the stump-cut will
be made. In making the check-blaze a
chip of bark is removed and the blaze
stamped with the **die" on the head
of the marking axe. Means are thus
afforded to determine whether any
unmarked trees have been cut.

There are numerous types of mark-
ing axes. One type used by the U. S.
Forest Service is shown in Fig. 14.
The mark consists of the raised letters
U. S. When a special axe is not avail-
able a substitute may be made from, a
shingle hatchet by cutting a letter or
other mark on the hammer.
In marking timber one works over a given stand in
progressive strips. The blazes are made on the side of
the trees facing the outside edge of the strip. Thus, if
the strips run north and south and progress east, the
blazes nre on the east side of the trees. This enables the

Fif7. 14.— Mark-
ings Axe.

THK SELECTION SYSTEM 59

marker to see the trees already blazed. Sometimes the
trees are blazed on two sides.

A very rapid and convenient method of marking is to
use a crew of three men, with one man to indicate the
trees and the other two to make the marks. Frequently
two or more men work together in a line, each selecting
and marking trees. This method requires that each
be a skilful marker, and is ordinarily more expensive
than that of using one expert with one or more un-
skilled blazers.

The cost of marking varies enormously. The first
work of marking in a forest is more expensive than later
marking, done after the markers have been trained to
the details of the work. At first the marking must be
done by an experienced forester. Frequently, he can
later turn the work over to a competent ranger and
direct the work by occasional inspection, and thus reduce
the cost.

In this country the cost of marking, in selection
forests, has so far varied from 2.5 to 10 cents for each
thousand board feet marked.

The cost of marking depends on the following factors:

1. Size of the Operation. — In general, the average
cost per unit of volume of timber cut for marking is in
inverse ratio to the size of the area marked.

2. Yield. — The larger the yield per acre and the
larger the contents of the individual trees, the smaller
the unit cost of marking.

3. Skill of the Marker. — An experienced marker can

60 THE PRINCIPLES OF HANDLING WOODLANDS

select the trees more rapidly and hence mark more
cheaply than an unskilled man.

4. Simplicity of Silviculture. — The simpler the prob-
lem, the more rapid the selection of the trees.

5. Kase of Mechanical Work. — A marking crew can
work faster when travel is easy, when the trees can be
readily seen at some distance, and when the trees are
easily blazed, than under the opposite conditions.

Defects of a Rigid Diameter Limit

In the northeastern woods it has been for a good
many years customary for lumbermen to restrict their
cuttings to the largest trees. They set a diameter limit,
and instruct the cutting crews to take only trees above
that size. All merchantable timber above the limit is
cut, anci none below, except such as may be required in
the logging operations. It is assumed that there is a
supply of medium-sized timber which will constitute the
next cut. As a matter of fact, there is often a deficiency
of thrifty trees just below the diameter limit capable of
growth, and not uncommonly a large number of these
are cut for skids, bridges, and other purposes in log-
ging the mature timber.

Cutting to a fixed diameter limit disregards entirely
the condition of the trees from the standpoint of health
and possibilities of growth. The theory of the whole
plan is that there are half-grown trees which will in a
short time grow to full merchantable size. Th-ere are,
however, in every virgin forest many trees below the

THE SELECTION SYSTEM 61

diameter limit which are old, and will produce little
growth, and may not live or remain sound till the next
time the area is cut over. Naturally these trees ought
to be cut and utilized. On the other hand, there are
many trees just above the diameter limit which are grow-
ing very rapidly, and which it would be good business
policy to leave standing.

Those practising this rigid method assume that repro-
duction will take care of itself. Under the scheme of
cutting to a rigid diameter limit, this will not be the
case. In a great many openings reproduction of the
species desired will fail entirely, because of the removal
from the neighborhood of all trees capable of bearing
seed. As the work is usually conducted, a large amount
of the small growth is injured through carelessness in
logging. Some of this damage is necessary, but much
of it is the result of thoughtlessness. The limitation
of the cut, as the rigid limit is applied, itself is often a
farce. Formerly, when only large trees were merchant-
able, there was little temptation to cut small timber.
The stumps were ordinarily cut very high, and a rough
rule was sufficient to prevent the choppers from taking
trees below, say, 12 inches on the stump. Under present
conditions a 12-inch limit measured on the stump is a
different matter, because the trees are sawed and, with
good logging methods, the stump-cut is well within
the root swelling. A 12-inch limit now is equivalent
to about a 10- or 11-inch Hmit under the old regime.
It is seldom that the felling crew is required to measure

62 THE PRINCIPLES OF HANDLING WOODLANDS

the trees before cutting, while inspection is very lax, so
that even when a company has the best intentions the
plan fails to be properly carried out.

Another defect of the rigid diameter limit plan is
that the limit itself is detc^rmined very largely by
guesswork and tradition. A 12-inch limit under certain
conditions may be conservative, from the standpoint of
leaving the forest in a fairly productive state. In other
conditions an owner may be deceiving himself as to the
rate of production after cutting. As a matter of fact,
this is exactly what is constantly happening. In many
cases the owners have entirely overestimated the yield
capacity of the forest under their method of treatment;
and in the case of large corporations which are counting
on an indefinite production this will be a serious matter.
It would be wise business policy for such owners to deter-
mine what their forests can produce under a proper selec-
tion system, and then practise that system in the manner
indicated in the foregoing section, so as actually to secure
the production desired.

Provision for Reproduction

In the management of a selection forest the aim is to
secure prompt reprodtiction of a suitable species in the
openings made in lumbering. In some forests, trees of
intermediate size, capable of bearing seed, are so well
distributed that it may not be necessary to leave any large
trees for this special purpose. In other cases the inter-
mediate seed-bearing trees are scanty or not always prop-

THE SELECTION SYSTEM 63

er!y located, so that some provision for seed distribution
must be made from among the old timber.

Then, again, in mixed forests the intermediate trees
near an opening may not be of the species most desired.
The forester must endeavor to secure a distribution of
seed by leaving seed-trees properly located. In leaving
a seed-tree above the diameter limit, one must bear in
mind that it involves an actual investment, for the tree
might otherwise be taken out and sold. If the tree is
salable now, but will not be so at the next cut, one in-
vests its value in reproduction. If it is sound now, and
likely to remain so till the next cut, it is merely a ques-
tion of deferred profits. In any case, one must be cer-
tain that a special seed-tree is required, and that it will
answer the purpose for which it is left.

Successful reproduction depends not only on a prop-
er distribution of seed, but also on the conditions for
germination, and for the development of seedlings. The
problem is very simple WTth tolerant^ species, for these
are able to grow in very small openings, and often a good
reproduction is already established where the openings are
to be made. With intolerant species, on the other hand,
special measures often have to be taken if they are to be
reproduced successfully. If such measures are not taken,
other more tolerant species mav occupv the opening to
their exclusion. The opening must be large enough not
only to give the trees a start, but also to allow them to
make straight and thrifty growth. It is, therefore, some-

^ Tolerant species are those capable of enduring more or less neavy shatle.

64 THE PRINCIPLES OF HANDLING WOODLANDS

times desirable to enlarge an opening beyond what is
necessary to remove a single mature tree. In such a
case one would aim to cut several trees in a group;
and in so doing it would often be necessary to cut trees
under the diameter limit. Usually, however, this can
be done without cutting medium trees of large promise.

Protection from Windfall

Very commonly a selection cutting would result in
windfall among the trees left standing unless this point
is regarded in the location of the trees to be cut. Some-
times it is necessary to cut whole groups clear, often as
large as an acre, because they cannot be thinned without
windfall. In many cases a tree, or group of trees, above
the diameter limit must be left standing to protect the
surrounding stand.

Cutting Small Trees for Improvement

The struggle for space in a selection forest is very
great. The old trees overtop and crowd those coming
up between and below them; the middle-aged trees
crowd and suppress the younger ones, while all the
competing trees are crowding one another. A poorly
developed tree of small promise may often injure
several trees of better form and species, llie removal
of such poor trees greatly increases the total growth
of the stand.

THR SELECTION SYSTEM 65

Influence of Market Conditions

The principles giv^en in the foregoing are subject to
restrictions in their practical application imposed by poor
market conditions.

In the first place, it may happen that only a certain
number of the species are merchantable. Thus, for ex-
ample, in the Adirondacks there are certain areas where a
number of the hardwood species cannot be marketed at
all. Sometimes the best individuals of a species can be
cut at a profit, but the crooked and defective trees are
not merchantable. Ordinarily it is the merchantable
species which the forester desires to reproduce. If he
cannot cut the less desirable kinds, he is forced to leave
the ground practically in their possession for reproduc-
tion. This will result in a reduction in the proportion
of the best species. There is, however, no alternative
except to wait for a market, and this is often, if not usu-
ally, impracticable. When such is the case the forester
leaves the forest in the best condition for reproduction
possible under the circumstances, but he must expect
that there will be certain areas on which the poor species
will gain the upper hand.

The larger trees which cannot be sold — because they
are either of poor grade or of poor species — usually inter-
fere with the growth of trees of better character. Their
removal would increase the growth of the forest by re-
leasing the trees which they crowd, and replacing them
with reproduction of valuable species. But this would

66 THE PRINCIPLES OF HANDLING WOODLANDS

Fig. 15. — A Stand of Engelmann Spruce after a Selection Cutting.
Arapahoe National Forest, Colorado.

Fig. 16.— a Group of Balsam Firs Marked for Cutting- in a Selection
Forest. Their Removal will Favor the more V'aluahle Spruce. Arapa-
hoe Natio: al Forest, ColoiaJ;)

THE SELECTION SYSTEM 67

be an actual outlay which often would not he justified.
The experiment has sometimes been tried of girdling
these trees. Doubtless this expedient would be practi-
cable in certain instances in public forests, but there are
usually more important cultural operations which demand
the use of whatever money there is to devote to such
purposes. Sometimes the danger of injury to young
growth from the windfall of girdled trees would fully
offset the aci vantages secured. As a rule, therefore, the
cutting or girdling on a large scale of large, mature trees
which cannot be sold is not advisable.

A poor market means that small individual trees can-
not be sold. It would be impossible, \yith a poor mar-
ket, except at considerable expense, to cut all the trees
below a diameter limit which are defective, unpromising,
or interfering w ith reproduction and with the growth of
other better trees. The amount of money which can be
spent on cutting small trees for these purposes depends
on the returns which w^ould result. The question must
be worked out in the same way as any other proposed

investment.

Cost of the System

The cost of forestry with the selection system de-
pends on the following factors:

1. Increased Cost of Logging. — In any selection for-
est, like most of our virgin forests, the lumberman has to
go over a good deal of ground for the timber. If there is
a further restriction of the amount cut by limiting the
size to only the largest trees, and by leaving seed-trees.

68 THE PRINCIPLES OF HANDLING WOODLANDS

the cost of logging per unit of volume is increased. As
a matter of fact, most of the merchantable trees left stand-
ing are small, and the profit from them is insignificant.
Often there is no profit from them at all, or there may
even be actual loss in logging them. Thus the increase
in cost of logging under the selection system is so slight
that it may practically be disregarded.

Lumbermen usually contend that the trouble to the
choppers in looking for marked trees adds to cost. As
soon as the crews become accustomed to the work, there
is no increased cost due to this cause.

2. Cost of Protecting Young Growth. — The felling
crew has to be careful not to injure small trees in felling,
and the skidding crew must avoid breaking down small
trees and barking those of medium growth. A careful
chopper does not in any case throw his tree into groups
of young growth; and an intelligent swamper always
avoids small trees, to save himself needless labor. An
unintelligent crew will do a great deal of damage. A
careful crew is able to hold down the damage to a mini-
mum, without extra cost.

3. Increased Cost of Construction Work. — Ordinari-
ly, a logger uses for skids, building bridges and skidding
roads, etc., the straight, well-formed trees of medium
growth which happen to be most convenient to his
work. These are exactly the trees which the forester
would save. If the logger must go to a greater distance
to secure this material, and if it is less easily handled,
there is a cost which adds to the total cost of lumbering.

THE SELECTION SYSTEM 69

While this item is difficult to estimate, it is never
large.

4. Value of Seed-Trees. — If seed-trees are left which
have a value now, but will deteriorate before the next
cut, there is an item of cost. Ordinarily, such trees are
not left. Their total would be so small as to be insig-
nificant in a large operation. If thrifty trees are left
which will live till the next cut it is an investment com-
parable to that of leaving the small merchantable trees.
The increase of stumpage price will often more than
cover the investment, even if there should be no increase
in volume by growth.

5. Cost of Improvement Work. — Under this head
are comprised special measures to aid reproduction, and
to improve the condition of the small trees. Usually this
investment is not made at all. In case of valuable species,
improvement work is often desirable and profitable.

Intensive Development of the Selection System

It has been shown that the selection system is usually
the first development of forestry in a newly developed
country. With a virgin forest of selection form and with
a market only for the largest and best trees, the lumber-
man's first cutting resembles a conservative selection
cutting, even though not designed by him to be such.
With unfavorable market conditions, the system mav
thus be applied in a crude or primitive manner. On the
other hand, with good market and logging conditions it
may be developed into one of the most highly inten-

70 THE PRINCIPLES OF HANDLING WOODLANDS

sive of all systems, as illustrated in certain forests of
Europe.

In the primitive application of the selection system,
as described in the foregoing pages, the handicaps of mar-
kets and transportation prevent more than a rough pro-
tection and care of the young growth. If there is a
market for all products and a system of permanent roads,
the cutting cycle may be reduced even to a single year.
The aim is then to make provision, as fast as the forest
permits, for a proper representation of age-classes; repro-
duction of the right species is secured, if necessary, by
planting; improvement work is done throughout the
given stand, so as to give each tree the right amount of
space for its best development; deteriorating trees, those
of poor form, and injured trees are cut at the proper
time. In other words, instead of handling the forest
under long cutting cycles and large logging units, the
management is intensified, the units are reduced in size,
and each stand is cut over at frequent intervals.

This intensive development of the selection system
finds its expression in a number of special forms of appli-
cation in Europe. In general, the tendency is to trans-
form the forest into the group-selection form, in which
each age-class occurs in groups instead of in the single-
tree arrangement. The groups vaiy in size from fifty
feet to several hundred feet across, are irregular in form
and area, and their location in relation to each other is
irregular; but the aim is to secure an equal aggregate
area of each age-class in each stand. This develop-

THE SELECTION SYSTEM 71

ment is really a series of even-a^ed groups, instead of
larger, even-aged stands, which means a much more
intensive management if each group is carefully handled
for its best development. A prominent European for-
ester. Dr. Ney, has carried out this idea still further, and
has merged the various groups of each age-class together
in the form of regular or irregular strips.

Results of the Selection System

The selection system results in a many-aged form of
forest which is well adapted to the protection of moun-
tain slopes, because in the management of selection forests
clearings are never made, and a permanent soil cover is
maintained. It is a form most admired from an esthetic
standpoint, and hence well adapted to public forests used
as recreation grounds.

Comparing two forests, of which one has separate,
even-aged stands of difiFerent ages, and the other is
managed on the selection system, with trees of different
ages mingling together singly or in groups, it is usually
held that the growth of the latter is the less. In the
former, trees grow in even competition w ith each other,
and without cover overhead. In the selection forest the
growth of individual trees is retarded, because of the
shade either overhead or on the side during a large part
of the tree's life. In the selection stand there are a
very large number of trees, because the crow ns overlap,
but usually this advantage is not enough to equal
the retarding of the growth by shading. There is no

72 THE PRINCIPLES OF HANDLING WOODLANDS

question that with Intolerant species the growth Is the
greatest under one of the even-aged systems. With tol-
erant species and Intensive management it is probable
that as great an increment can be secured by the selection
system as by any other.

The development of the individual trees in a selection
stand is somewhat different than in an even-aged stand.
They are apt to have larger crowns and larger diameters
than those produced in even-aged stands. Because of the
larger crowns, there is less clear bole and the knots are
larger. The trees pass through periods of retarded and
full growth, and hence the grain of the wood is less even.

Choice of the Selection System

The selection system is used in forests where the mar-
ket conditions are such that only a limited class of trees
can be cut at a profit. It is used in those all-aged forests
in which the various sizes are represented, and the re-
moval of the medium trees would be less profitable than
vSaving them for growth and later cutting. It is an ex-
cellent method for the handling of a woodlot which is
culled frequently for fuel, poles, posts, rails, and occa-
sional sawlogs for home use and for sale. It is the ideal
system for forests on ridges and slopes, where it is im-
portant to keep a continuous forest cover to control run-
off or to prevent erosion. It is particularly applicable to
forests composed of tolerant species; it may, however, be
used successfully with intolerant species, provided that
in making cuttings the openings are made large enough

THK SELECTION S\'STEM

Fig. 17. — Trees Designated for Cutting- under the Selection System.
Arapahoe National Forest, Colorado.

74 THE PRINCIPLES OF HANDLING WOODLANDS

to secure reproduction and to permit the new stock to
develop.

It is not applicable to even-aged stands. As the
market in a given region improves, and as the smaller
sizes of trees and those of inferior species become mer-
chantable for fuel and other purposes, the tendency is
away from the selection system. As intensive methods
become practicable, the tendency is to use one of the
systems resulting in a clearing and an even-aged new
stand, rather than to use the intensive application of
the selection system. This is well seen in continental
Europe. There, the selection system is most widely used
in the protection forests and the less accessible regions of
the mountains, in which the market is still very poor.
In regions in which all of the products have commercial
value and the markets are good, it is the clear-cutting
systems and the shelterwood system which are most used,
and, as a result, the common form of forest is even-aged.

In this country the better-settled regions have an
increasing proportion of even-aged stands on the cut-
over lands. This is partly because of the prevalent
method of cutting, but partly because fires have followed
cutting and made clearings. The second growth has
more the character of an ev^en-aged forest than otherwise,
particularlv among the conifers.

Example in the Spruce Forests of the Northeast

The spruce forests of northern New England and
New York contain extensive areas to which the selection

THE SELECTION SYSTEM 7S

system is admirably adapted. This is particularly the
case in the rolling plateau regions, such as most of north-
ern Maine and the Adirondacks. In these regions the
forest is almost altogether of a selection character, and
trees of dif^^erent ages are mingled together individually
and in small groups. The natural form of the forest is
due to the fact that the majority of species are tolerant of
shade. These are spruce, hemlock, fir, beech, and hard
and soft maple. The birches are very abundant species
and, though less tolerant than the other trees, they can
still hold their own in the selection forest. The intol-
erant species, like pine and larch, occur localized, and
usually come up on new-made land, on the borders of
lakes, and on clearings made by windfall and fire. On
certain types of land where windfall has been extensive
in the past, like swamps and steep slopes, there are
groups and often w^hole stands of an even-aged character;
but the forest is mainly all-aged.

Suppose that a privately owned tract in the western
Adirondacks is to be managed under the selection svs-
tem. In organizing it, the first step is to analyze the
stand to determine for each species the representation
and distribution of the different size-classes. This analv-
sis shows the number of soimd trees of different diame-
ters, and makes it possible to cietermine what can be cut
at a profit at once, and what will be left for the formation
of a merchantable cut in the near future.

The next step is to determine the rate of growth or
increment of the forest. It is not the present growth

76 THE PRINCIILES OF HANDLING WOODLANDS

Fig. 18. — A Stand in the Adirondacks in which there has
been a Selection Cutting.

THE SFLF.CTION SYSTEM 77

which is desired, hut the growth of the stand after
hinihering. The forester therefore makes a study of
growth, which enahles him to predict the rate of growth
of the middle-sized trees; that is, those which will be the
merchantable trees at the next cutting. In calculating
the number of trees which will be standing after the lum-
bering, it is necessary to assume that the lumbering will
take all trees above a diameter limit. Of course, the
rigid diameter limit will not be used in the cutting, for
the reasons already explained. The trees cut below the
limit about offset in volume those left standing above
the limit.

But it is not known in advance what general average
limit is desirable. The forester therefore makes trial
calculations of growth on the basis of several limits.
Thus, in the case of spruce a superficial study show's that
the limit may be below 14 inches, breast-high. The
trees above this size are old and mature, and should
be cut and utilized as soon as possible. Moreover, a
higher limit w-ould ordinarily not )'ield a profitable cut.
One can readily see that a cut below 10 inches would
deplete the pole-class so sev^erely that the production of
the forest would be reduced by an excessive amount.
Hence the forester makes trial computations of the
rate of growth, assuming a cut hrst to 10, then to 12,
and then to H inches.

A comparison of the various possible limits, and the
possible present and future returns, together with a con-
sideration of the problem of reproduction, enables the

78 THE PRINCIPLES OF HANDLING WOODLANDS

forester to fix the most desirable limit. In the supposed
case in the Adirondacks, all conditions show that 12
inches is the desirable average limit for spruce. This
corresponds to an average age limit of about 185 years.
The growth after cutting will be approximately 110
board feet per acre per annum, compared with about 70
feet if 10 inches had been chosen as the diameter limit.

The other species are studied in the same way, and
an average diameter limit is determined which will meet
all requirements.

If all species are merchantable, one makes selections
in accordance with the principles explained on page 56.
Trees above the established diameter limit would be cut,
except where needed for seed or some other special pur-
pose. Trees below the limit would be left standing,
except when they are defective, or interfere with better
individuals, or have reached their limit of growth, or are
of poor species likely to seed up openings, or for any
other reason would benefit the stand by their removal.

Unfortunately, at the present time some species are not
merchantable. In the Adirondacks it is often the case
that only the spruce and the best individuals of hemlock,
of fir, and of some of the hardwoods are merchantable.
There is no market for the defective and crooked hard-
woods, or for those small trees whose removal would
benefit the stand.

The forester is therefore in the position of having to
restrict his cuttings to the choicest trees in the forest.
Many poor species are left which will distribute seed in

THE SELECTION SYSTEM 79

the openinpjs, and thereby compete in the next crop with
the better species. Defective trees occupying the ground
prevent reproduction by their shade, or they may be
crowding and injuring valuable individuals. The result
is that in some instances the poorer species will increase
in the reproduction. In some types of forest the hard-
woods will crowd out the spruce, while occasionally soft
maple or beech replace the better birch and hard maple.
Not only will the reproduction be of poorer quality than
would be the case if the markets were favorable, but, on
account of the impracticability of releasing crowded trees,
the growth in the immediate future, as well as in the
long run, will be less.

Under these conditions there are two alternatives:
first, to defer cutting altogether and wait for better mar-
kets, when the cuttings under the selection system or
some other one can be conducted in a better wav than at
present; second, to carry out the cuttings in the best
manner possible under the present unfavorable condi-
tions, with the full realization that the future returns will
be somewhat less than would be obtained by more inten-
sive w^ork. In some cases it would be wise on State land
to defer the cuttings for a better market. The State is
not obliged to pay interest on investments, and can afford
to hold the timber for later realization.

Most private owners, however, cannot afford to hold
their valuable timberlands without returns for a long
time. They wish to realize something now, and to
reduce the investment in the forest, which, even under

80 THE PRINCIPLES OF HANDLING WOODLANDS

our best conditions, is exposed to considerable risk from
fire. The policy is, then, to cut among the merchant-
able trees, with a view to leaving the forest in as good
condition as possible for increment and for reproduction.

Under the conditions assumed, the forester has in
mind the following general principles in marking the
trees for cutting:

1. The following average diameter limits are used as
a guide in the marking:

For spruce 12 inches

Forfir , 10 ''

For hemlock 12

For birch, beech, and hard maple ... 16

For soft maple 12

2. All trees above these respective limits are cut,
except those needed for seed or for some other special
purpose.

3. All trees below the limit are left standing, except
such merchantable trees as are growing very slowly and
will not live till the next cut.

4. Trees which are not over 3 inches larger than
the diameter limit, and which are growing very rapidly
and obviously increasing in value at a rapid rate, should
not be marked.

5. Very old and slow-growing trees which are below
the limit, but are incapable of increasing their growth
after release, should be marked, unless needed for some
special purpose.

THE SELECTION SYSTEM SI

6. All trees certain to he blown down should he
marked.

7. Trees likely to he destroyed or seriously injured
in lumhering should he marked.

8. It is occasionally necessary to leave trees ahove the
limit, if their removal would result in serious windfall.
This is particularly true of the hardwoods.

9. In leaving special trees for seed, spruce and white
pine should be favored over all the other species, and
hard maple and birch should be favored over hemlock,
beech, fir, and soft maple.

10. A seed-tree should never be left where it will
not serve its purpose. Thus, on hardwood land where
abundant birch and maple seed-trees stand, there is little
use in leaving for seed a spruce above the diameter limit.

11. In selecting seed-trees, only such as have a well-
developed crown and are now capable of bearing seed
should be left.

12. In choosing between trees for seed, each of which
will serve the purpose equally well, the smallest should
be chosen.

13. Do not leave seed-trees —

a. Which will be blowni down.

b. Which will be broken or destroyed in log-

ging-

c. Which are likely to be cut for lumbering pur-

poses.

d. Which must be cut to make way for a logging

road or skid way.

82 THE PRINCIPLES OF HANDLING WOODLANDS

14. Seed-trees above the limit are left only where
there are none below the limit to answer the purpose.

15. One or more trees of the species capable of bear-
ing seed should be left on the border of every opening
1 5 feet or more in width.

16. In openings resulting from the cutting of a group
of trees, and 50 feet or more wide, seed- trees should be
located on the side toward the prevailing wind.

17. In case an opening is on a slope, the seed-trees
should be located above rather than below the opening.

CHAPTER III

SYSTEMS OF CLEAR-CUTTING

Definition of Clear-Cutting

A CLEAR-CUTTING occLirs Oil a giveii area when all of
the trees are removed, or at least such a large proportion
of them that those which remain do not materially affect
the growth and development of the new stand. A clear-
cutting may be contrasted to those systems of cutting in
which at any given time the stand is culled by the re-
moval here and there of a tree or group of trees, and
there remains after the cutting a sheltering cover which
influences, advantageously or otherwise, the new stand.

A given stand may be cleared either in one operation
or gradually in a series of operations, each of which has
the character of a clear-cutting. In the latter case a short
period usually elapses between the cuttings. The whole
stand is, however, cleared wathin a limited time, usuallv
not over 20 years. There are certain exceptions to this
principle, which are described imder the different meth-
ods of clear-cutting with natural reproduction.

Conditions Requiring Clear-Cutting

The popular impression is that the practise of forestry
consists of thinning the forest in the manner described

THE PRINCIPLES OF HANDLING WOODLANDS

F,G 19 -A Stand of Douglas Fir and Cedar of Great Size and An:e.
■ A System of Clear-C\itting is Requn-ed. Waslnnp:ton.

SYSTEMS OF CLKAR-CUrjI \G X5

for the selection system. The method of culling only
the largest trees and leavinojthe smaller ones is, howcxer,
applicable onl\' to stands havnn^ trees of different ages
mingled together. In handling a stand in uhich all, or
nearly all, the trees are mature, the design is to remove
the whole stand, and replace it with new growth in as
short a time as is feasible. This is accomplished either
by one of the clear-cutting or one of the shelterwood
systems.

The conditions requiring a clear-cutting are the fol-
lowing:

1. Where there is danger from wincifall. Such a con-
dition is found in mature coniferous forests which are
growing on steep slopes and ridges in the mountains.
For example, the .spruce stands growing on the exposed
slopes in the mountains of northern New England and
New^ York cannot, as a rule, be heavily thinned, because
the trees left standing woidd be almost certain to be up-
rooted by the wind. In most cases, however, a very light
thinning, such as coulci safely be made, would not pay,
so that some system of clear-cutting is necessary. .

Conspicuous examples of the same principle are found

in the mountains of the W est. The lodgepole pine in

the Rocky Mountains grows at high deviations in exposed

situations. The stands are usual I v regular in form and

the trees long and slender, with shallow lateral roots.

Attempts to thin mature stancis of lodgepole pine have,
in many cases, resulted in heavy windfall.

2. W here all the trees are large and mature, and j")rac-

86 THE PRINCIPLES OF HANDLING WOODLANDS

tical considerations of logging require a concentration of
cutting.

3. Where the trees are so large that their removal
after reproduction is established would result in destruc-
tion of the young growth.

4. \\"here the trees are so large and valuable that their
retention for seed would involve a greater investment
than artificial planting.

5. Where a clearing is necessary to remove trees of
undesirable form or poor species, in order to establish
artificially better species.

6. Where a clearing is necessary to secure good nat-
ural reproduction of some species which cannot thrive
under shelter.

Frequently a clear-cutting is required by a combina-
tion of the conditions just enumerated. Thus, for exam-
ple, in the Cascade Mountains of Washington a stand of
red fir, cedar, and hemlock from 400 to 800 years old,
with trees from 4 to 10 feet in diameter, and from 200
to 250 feet high, presents the conditions of overmatu-
rity of all trees, great expense of logging, and the im-
possibility of removing trees without injury to young
growth. It is obvious that under such conditions a
clear-cutting is necessary.

Disadvantages of a Clear-Cutting

There are certain disadvantages attendant on the clear-
cutting system, as follows:

1. In any clear-cutting system there is necessarily a

SYSTEMS OF CI-KAR-CUTTING X7

period in which the soil Is exposed to the action of the
elements. Even if the new stand is started at once after
cutting, a number of years must elapse before the canopy
is closed and the soil shaded. There may be a deteriora-
tion which influences, at least temporarily, the growth of
the stand.

2. On slopes the exposure of the soil after the clear-
ing may result in more or less serious erosion.

3. Grass, brush, and weeds spring up readily on
clearings to a greater extent than under the shade of
trees. This undesired vegetative cover interferes with
reproduction, and competes with the young growth.

4. The young trees are exposed to drying by sun and
wind.

5. In certain localities the young growth suffers from
frost.

6. The young growth is apt to be more damaged by
insects than when it starts under shelter.

The disadvantages of clear-cuttings are in direct ratio
to the size of the clearings. Many of the evils of clear-
cutting can be obviated by reducing the size of the area
clear-cut. Intensive forestry avoids large clearings; and
when a given stand of considerable size is to be removed
under an intensive management, it is cut in a series of
operations, each confined to only a portion of the stand.

Methods of Reproduction

Reproduction after clear-cutting may be accomplished
artificially by planting young trees, or by sowing seed; or

88 THE PRINCIPLES OF HANDLING WOODLANDS

it may be accomplished by natural seeding from seed-
trees, properly located for the purpose. Very com-
monly, natural and artificial reproduction are both used;
a stand is reproduced as far as possible by natural
means, and the areas incompletely stocked are filled by
planting.

Advantages of Artificial Reproduction. — Contrasting
the two methods, artificial reproduction has the following
advantages:

1. The new stand is established at once. Natural
reproduction often requires from 5 to 10 years to stock
an area with young trees.

2. Artificial reproduction is more certain of success.

3. The forester is able to establish the species best
adapted to the soil and best suited to the requirements
of the market.

4. The trees may be given the right amount of grow-
ing space for their best development. Natural reproduc-
tion is often too dense or too open.

5. For the reasons already given, the yield of high-
grade material is usually greater from artificial than from
natural reproduction.

Advantages of Natural Reproduction. — On the other
hand, natural reproduction has the following advantages:

1. It is usually cheaper than artificial reproduction.

2. With certain of the methods of natural reproduc-
tion there is a continuous partial shelter over the ground,
and consequently less danger of soil deterioration.

3. Natural reproduction follows nature more closely,

SYSTEMS OF CLKA R-CM rnXG 89

and is apt to producr a niixrd forest, w ht'i-cas tin- tt-n-
dency of artificial reproduction is toward pure stands,
which are less desirable over lar<2;e areas than the former.

4. Natural reproduction is peculiarly adapted to rough
conditions, like those in this country, where intensive
methods are often not practicable.

Artificial reproduction is necessary when it is desired
to establish a species difiFerent from any that occurs nat-
urally on the ground. It is necessary where seed-trees
are not present in proper location.

Artificial reproduction requires large initial outlay;
often, therefore, it is impossible, even when it would ob-
viously be the more profitable in the long run.

In general, natural reproduction will, for the present,
be used chiefly in operating forests on a large scale in
this country.

Clear-Cutting with Artificial Reproduction

Under this method a specified stand is cut clear, and
the area is restocked by planting or by artificial seeding.
Ordinarily the planting or seeding is done after the cut-
ting, and not in advance of it. The logs and other mate-
rial are removed as soon as possible, anci the slash is dis-
posed of by burning or otherwise. The ground is then
clear, and may be restocked by setting out )'oung trees or
by sowing seed.

It is desirable to start the new stand as soon as possi-
ble, in order that there may be no loss of growth, and
also in order that the new trees may izain sufficient head-

90 THE PRINCIPLES OF HANDLING WOODLANDS

way to compete with the weeds and brush which inevit-
ably spring up on clearings.

Use of the System in this Country. — The systems of
forestry which will be practised in the United States in
the immediate future will, for the most part, be those
which depend on natural reproduction. The clear-cut-
ting system with artificial reproduction will, however,
be used under certain circumstances, and the use of the
system will increase rapidly in the future, as the oppor-
tunities to practise intensive forestry become more com-
mon. The conditions under which it will be practised
fall under the following groups:

Use in National Forests. — Without doubt, there will
be in the immediate future many areas of public forests
in which natural reproduction of a desired species will be
exceedingly difficult. At the present time, planting on
public lands is largely confined to barren areas. As the
organization of the planting becomes more complete,
and as the knowledge of the methods of planting is
perfected, the system will undoubtedly be used in re-
placing mature stands where now natural reproduction
is chiefly relied upon. It will find an extensive applica-
tion in certain forests of the West, where the trees are
very large and valuable, and where any system of natural
reproduction involves an investment comparable to arti-
ficial reproduction. Already in certain instances this sys-
tem is being used by the Forest Service in cutting the
overmature forests of the Northwest.

Suppose, for example, that there is a block of over-

SYSTEMS OF CLEAR-CUTTING

Fig. 20.— a Heavy Douglas Fir Stand in W'asliine^ton, Calling- for
One of the Systems of Clear-Cutting.

92 THE PRIXCIPLES OF HAXDLIXG WOODLANDS

mature old fir, hemlock, or cedar covering; an area half a
mile wide. Suppose, further, that it woidd not pay to
log in strips and patches, but only to cut clear the whole
area; and suppose, further, that the onlv feasible way
to secure natural reproduction were to leave as seed-
trees large trees containing at least 2,500 feet each — very
common conditions on the Coast. There is no question
that the best method would be to cut clear and restock
artificiallv. The Forest Service is using this method
more and more. It has been frequently possible to rely
on natural reproduction, but as the sales of timber in-
crease and the areas cut over become larger, the artificial
restocking will be increasingly used.

It is probable that this system will be applied in cer-
tain portions of the semiarid region of the West. For
example, in the Southwest there are certain types near
and at the edge of the forest where reproduction comes
exceedingly slowly. Frequently the present forest is ma-
ture, and it is desirable to make cuttings to utilize the
timber while it is sound. There are, for instance, hun-
dreds of acres of Western yellow pine in which the ma-
jority of trees are mature, with very little young timber,
and where the conditions for reproduction are such that
it is exceedingly doubtful whether the removal of the
trees will be followed by young growth within any reason-
able length of time. It may be that not less than from
50 to 75 years will have to be allowed for securing
adequate reproduction. A period of 50 years amounts
to fully one-half or two-thirds of a tree generation.

SYSTEMS OF CLEAR-CrTTIN'G 93

We may well sav that under such circumstances tor-
estr\' would he unsuccessful, and that it would be bet«
ter policy in a public forest of this character to resort to
artificial reproduction. It is probable, therefore, that
under these difficult circumstances certain areas will be
designated upon which natural reproduction is so difficult
and hazardous that a system of restocking bv artificial
means will be adopted.

The actual conduct of the work would be governed
by local conditions. Under the circumstances just de-
scribed extensive clear-cuttings would be dangerous, for
if it is difficult to secure natural reproduction it will also
be difficult to protect the voung trees from the drving
influences. There has been little experience in planting
such a tree as Western vellow pine under the conditions
in question. The methods must be learned bv ex-
periments which will also determine how much shelter is
required bv the trees in vouth. it mav be necessarv
to restrict clear-cuttings to patches not over 10 or 15
acres in extent, or it mav be found necessarv to leave a
portion of the stand as a shelter during tlie earlv life of
the voung trees. In the latter case the svstem of forestry
would no longer be clear-cutting, but one of the methods
of shelterwood cuttings described in a later chapter.

Use in State Forests. — There will be in the near
future man\ areas within State Forests w here an intensive
svstem of forestry can be practised. In practically all
States there will be developed State nurseries and an
organization for planting. At first, just as in the Xa-

94 THE PRINCIPLES OF HANDLING WOODLANDS

tional Forests, the planting will be confined largely to
waste areas. Cuttings will, however, be made in the
mature portions of the forest, and in some instances
a clear-cutting will be necessary or desirable. Suppose,
for example, that there is a stand of 2S acres of ma-
ture pine of even age. This may be located so that a
system of thinning and gradual removal of the trees can
be used. It may happen, however, that much better
results would be obtained by cutting the stand clear, and
restocking the area by planting. Under the present
conditions of the market such a system might be finan-
cially the best plan. Again, the timber might be so lo-
cated that any system of thinning would be followed by
windfall. In such a case it would be necessary to make
the clear-cutting and restock the area either by a natural
reproduction from seed-trees on the edge of the clearing
or by planting.

It frequently happens that the areas acquired by the
State have been badly damaged through unintelligent and
reckless lumbering in the past, and are covered with
undesirable species or an open stand. Under such con-
ditions natural reproduction might result in a stand of a
species which never would ha\^e nuich value. Thus, for
example, the State forester might be operating on land
suitable for white pine, and \et be unable to secm-e
through natural rej^rodiiction an\thing btit imdesirable
hardwoods. Kxactl)' this condition was met in the Adi-
rondacks on certain portions of the tract opera^ted by Cor-
nell Universit\- from 1899 to 1902. The tract had been

SYSTEMS OF CI.KA R-Cl 'ITIN'G 9S

cut over and most of the softwoods removed, and the
land was capable of producnig pine and spruce; hut nat-
ural reproduction would yield only hardwoods. A larijje
part of the stand was of poor qualit\ , and it was found
that cuttings could he made profitable only by removing
most of the stand. It was therefore decided that the
best interests of the State lay in cutting clear and replacing
the forest by a new one of softwoods. This system in-
volved a large initial expenditure, with a view to large
future returns in the form of a large yield of valuable
timber. The experiment in the Adirondacks was the
first instance of clear-cutting and planting on a large scale
in this country, even in public forests.

Use in Private Forests. — It is probable that the sys-
tem of clear-cutting with artificial reproduction will not
be practised on a large scale by private owners in the
United States for a long time. It is not imlikely that
some owners may supplement the work of natin-al repro-
duction by planting, but this, like other intensive sys-
tems of forestry, will be chiefly confined to public ow ners
and to small owners.

The system will, however, be used commonly on a
small scale. Owners of small tracts who are interested
enough to practise forestry at all, are impatient to see
results. The\ are not willing to wait 10 or JO \cars
for natural reproduction to take place on a clearing.
The area cleared is usually small, and the cost of restock-
ing l)\' planting not large. Not uncomniotilv the clear-
cut area would not be over S or 10 acres. W hen, for

96 THE PRINCIPLES OF HANDLING WOODLANDS

example, a private owner has patches of matured trees of
a few acres each, much the simplest plan is to clear-cut
and replant. An example of this condition is found in
the lands owned by the New Haven Water Company,
and operated by the Yale Forest School. An area of 2
acres of old hardwood timber was cut clear and restocked
artificially with white pine. The total cost of planting
was about J 16. The ground had run wild, and it would
have been impossible to secure anything more than a
meager stand of hardwoods through natural reproduc-
tion. In 40 years the resulting stand of hardwoods would
have yielded about 20 cords per acre, with perhaps 10
per cent, of the material suitable for ties, and a money
value of perhaps $30 per acre. A pine plantation will
yield in 40 years material worth at least $150 per acre.
Such an investment is worth while for a permanent
concern like a water company.

In many woodlots there are stands composed of poor
species, or of trees of poor form and quality. Where
the material can be utilized, the best system of forestry is
to clear-cut such stands and replace them artificially by a
new growth of valuable species.

As the knowledge of tree planting progresses, and as
private owners can secure seed and young trees at reason-
able rates, clear-cutting with artificial reproduction will be
used more and more.

Clear-Cutting the Whole Stand. — Under this method
a whole stand is cut clear and the area restocked arti-
ficially. It is the method of clear-cutting which will be

SYSTEMS OF CLEAR-CUTTING 97

most commonly used in this countn'. \n many cases the
stand comprises a restricted area, which is cleared in one
year's operation. In other cases there may be a ver}'
large stand of mature timber to be cleared, requiring
several years* consecutive work to finish. In the latter
case, the area cut in a single year is large, and is not
comparable to the strips or patches described in the suc-
ceeding sections.

Clear-Cutting in Strips. — It has been explained (page
86) that extensive clearings are attended with certain
dangers. In order to reduce these dangers, the strip
clear-cutting was devised. This consists of removing a
stand by a series of clearings in progressive strips, each
relatively narrow. After cutting a given strip the new
growth is established, and then several years are allowed
to elapse before the next strip is cut. The new stand
is in a measure protected by the neighboring trees, and
at no time is there a very large clearing in any one
place. This method is common in Europe. Its appli-
cation in this country will for the present be confined to
second-growth woodlots.

Clear - Cutting in Patches. — Under this method
small clearings, more or less irregular in size and shape,
are cut in the stand and restocked artificially. These
patches are usually not over one-quarter to three acres in
extent. After several years the clearings are enlarged
by strips entirely surrounding them; and these are
promptly restocked by planting. The process continues
until the stand is entirely cleared. This is another

98 THE PRINCIPLES OF HANDLING WOODLANDS

European method which will not be used very much
by us.

The principle of this method is used in combination
with other systems. Thus, sometimes it is desired to
introduce a valuable species which has some difficulty in
competing with the species in mixture. Patches are clear-
cut as above described, and the valuable species planted.
When the young growth has made a good start, the rest
of the stand is then removed by some one of the systems,
and reproduced to the other species. This modified plan
is used in Europe in mixed oak and beech woods when
oak has to be favored against the competing beech. The
oak is introduced in the cleared patches and the beech
reproduced naturally after the oak is well established.

Clear-Cutting with Natural Reproduction

Under this system a stand, or part of a stand, is cut
clear, and the area is restocked by natural reproduction
from trees standing on the border. The system is used
where a clear-cutting is necessary, and where natural
reproduction from the side is possible and can be accom-
plished cheaper than by artificial seeding or planting.

Conditions of Success. — The system under considera-
tion depends, for reproduction, on natural seeding from
the sides. It is, therefore, applicable to species having
light seed that is distributed by the wind. Inasmuch as
the new stand must be established in the open, reproduc-
tion can be secured onlv from species capable of germi-
nating and developing without shelter. It may happen

SYSTEMS Ol' CLKAR-CUTTING

100 THE PRINCIPLES OF HANDLING WOODLANDS

that a given species reproduces itself best on a clearing,
but this is not by any means always the case. If a clear-
ing is necessary, and a new stand of a desirable species
cannot be secured upon it by natural reproduction, plant-
ing must be resorted to, or the area sacrificed to inferior
and undesired species.

In the past, where the trees are all merchantable, lum-
bermen have usually cut clear, without regard to repro-
duction. It is a common opinion among them that
reproduction will take care of itself, no matter how the
stand is cut, provided the land is protected from fire. It
is true that some large clearings made by haphazard cut-
ting have been reproduced in a marvelous manner,
even where fire has followed. These cases are, however,
exceptional. Ordinarily, good reproduction will not
take place unless there are seed-trees near at hand to pro-
vide the seed, and the conditions for germination are
favorable. This means that where clearings are made
and reproduction from the side is relied upon, there must
be a restriction of the area cleared, based upon the distance
to which seed may be carried in abundance. The loca-
tion of the clearing, its form and size, and the work of
preparing the ground for reproduction must necessarily
vary enormously under different conditions.

Influence of Market Conditions. — With this system a
distinction may be made between its application in virgin
forests having a large amount of overmature stock, with
unfavorable market and logging conditions, and its appli-
cation under such favorable economic conditions as exist

SYSTEMS OF CLEAR-CUTTING

in Kuroj'yc and in tin- hcttcr-scttlcci portions of this coun-
try. Apph'ing this s\'stcni is often the first stcj) toward
organized silviculture in a forest, and the methods used
in the he^^inning may have to be very crude in compari-
son with the intensive work done in Europe.

The first factor determining the manner of using the
system is whether the timber in a given stand can be
taken oH in a series of clear-cuttings, each taking only
a part of the stand, or whether the conditions are such
that it is necessary to cut the bulk of the timber in one
operation.

There are many areas on which the conditions of log-
ging are such that, in order to make a profitable opera-
tion, a large part of the timber must be removed at one
cutting. The cost of road construction, installing the
logging equipment, and transporting the logs, mav be
so great that it would not pay to restrict the cutting in a
given stand to only SO or 60 per cent, of the timber.

Clear-Cutting the Whole Stand. — The principle of
this system is to cut an entire stand clear, and rely for
reproduction on seed which may be distributed from
the trees in the surrounding stands. It is presupposed
that the area of the stand to be cleared is small enough
to enable a generous scattering of seed upon it. It verv
commonly happens that there are blocks of old, valuable
timber, rec|uiring a clear-cutting, which are surrounded
by younger timber that should be left standing and that
will furnish an abundance of seed. This is a very com-
mon occurrence in the forests of the extreme Northwest.

102 THE PRINCIPLES OF HANDLING WOODLANDS

A Specific illustration may be taken from northern
Washington. A given area was swept by a fire about
50 years ago. Portions of the forest were destroyed,
and natural reproduction filled them with excellent stands
of Douglas fir. There are to-day blocks of the old for-
est, separated by the young stands. This old forest con-
sists of Douglas fir, cedar, and hemlock. The trees are
from 3 to 6 feet in diameter, and from 150 to over 200
feet high. There is a large amount of defect in all the
species, the fir being especially unsound. A clear-cut-
ting is demanded for the following reasons:

1. The trees are deteriorating, and public interests
demand that they be utilized and the ground restocked
with a new, growing stand.

2. The timber is so large that donkey and cable
logging is required, necessitating a large yield per acre
for a profitable operation, and making it impracticable
to return a second time for a few trees per acre.

3. The trees are so large that their subsequent
removal from among young growth would result in
extensive destruction.

4. The old trees are so large and valuable that the
leaving of over two trees per acre would equal the cost
of artificial planting.

5. Natural reproduction of Douglas fir on the coast
takes place best on openings where the mineral soil is
exposed.

The case is, therefore, simple. The blocks of old
timber are restricted m size. About them are stands of

SYSTEMS OF CLK AR-CUTTING 103

Douglas fir already bearing seed. The merchantable old
timber is, therefore, cut clear, and the ground burned
over to prepare the soil for the reception of the seed.

If the area were so large that natural reproduction
could not be relied upon, it would be necessary to resort
to planting. Very often both natural and artificial repro-
duction are used. The old stand is cut clear, and a rea-
sonable area near the edge of the clearing is left for natu-
ral reproduction, while the center — that part beyond the
zone of good seed distribution — is planted. A good
example of this method may be found in a Government
cutting in Montana. The stand covers a valley bot-
tom and the surrounding slopes. The timber on the
bottom and the lower slopes is very heavy white pine,
spruce, larch, Douglas fir, hemlock, white fir, and
other species. On the main slopes there is a more or
less irregular stand of the same species. The bottom
and lower slopes must be clear-cut; the central and upper
slopes may be culled, partly on the selection and partly
on the shelterwood plan. For a distance of about 250
feet from the seed-trees left on the central slopes, the
lower slopes will be left to natural seeding. The bot-
toms will be planted.

Reserving Blocks of Trees. — Where extensive areas
of very old timber require clear-cutting, and under con-
ditions which at present make artificial reproduction im-
practicable, a portion of the stand must be left for the
distribution of seed. Verv frequentlv it is impracticable
to leave single trees, or even groups of trees, for seed,

104 THE PRINCIPLES OF HANDLING WOODLANDS

because they would he certani to he damaged hy wind-
falL

The hest methods are those of cleared strips de-
scribed in later sections. But there are cases where,
on account of the logging conditions, it is not feasible
to leave standing 40 or SO per cent, of the stand, as is
required by those systems. In this event the stand
is cut clear, except that solid blocks of timber, aggre-
gating from 15 to 25 per cent, of the stand, and well
located with reference to the distribution of seed, are
left standing.

Where it is desirable to operate in this manner, it is
usually the expectation that it will not be possible to
return in a few years — after reproduction is established —
to cut the standing blocks. If this were possible, a better
system of cuttings would usually be feasible.

In some instances no cutting will probably be made
before the nev/ stand is ready. By that time a portion of
the timber left for reproduction will have died or become
defective. In such a case the timber which cannot be
used is a sacrifice to reproduction, and its original value
represents the investment for that purpose.

Location of the Blocks. — The blocks to be left
standing are located with the care and skill that would be
used in selecting single seed-trees in the other systems.
In locating these areas the following considerations are
kept in view:

1. They must be large enough to withstand the wind.

2. They are located so as to distribute seed as far as

SYSTEMS OK CLEAR-CUTTING

105

Fig. 22. — Application of a System of Clear-Cutting with Large Blocks of
Timber Reserved for Seed. A Quarter Section in the Kaniksu National
Forest, Idaho.

106 THE PRINCIPLES OF HANDLING WOODLANDS

possible. Usually they are located on ridges or upon
slopes.

3. They are sufficiently close together to insure a
distribution of seed between them. The intervals vary
from 200 to SOO feet.

4. The youngest timber is selected which will an-
swer the purpose from the standpoint of reproduction.
The younger the trees the greater the proportion of
living trees at the next cutting in the area.

5. One selects trees having as small a value as pos-
sible, but which will meet the needs of reproduction.
The purpose is to reduce the investment to a minimum.

An Illustration from Idaho. — An illustration may
be taken from the forests of northern Idaho. Here the
forest is composed of white pine, larch, hemlock, Douglas
fir, cedar, and white fir. An area of mature forest is to
be cut, on which nearly all the trees are old and many
are deteriorating. The stand is past maturity; there is
loss of growth, anci the timber should be utilized at an
early date. It is believed that the pine, larch, and
Douglas fir will reproduce themselves readily on the clear-
ings, and that the cedar, hemlock, and white fir will come
up underneath them. A clear-cutting is made, with
carefully located blocks left untouched, where they will
accomplish the most good. The arrangement of the
clearings and the blocks is shown in Fig. 22. The
blocks of timber are left chiefly on the upper slopes and
ridges. Care is taken to select such areas as will be safe
from windfall, and will distribute seed. There is also

SWSTKMS Ol" (^f.KAR-ClfTTINC; 107

the aim to select, w hen possible, stands containing thrifty
trees, which are likeh to li\e for from 25 to 50 years.
In the ciittinijj it is desired, as far as possible, to remove
the declining trees and those attacked by fungus.

Characterization of the System. — The system just
described is one of temporary expediency. As a measure
of silviculture it has serious defects, and it should be
used only where necessary. The chief defects are as
follows:

1. A considerable amount of excellent timber is
sacrificed to reproduction, with a loss in the plan of
close utilization.

2. While reproduction will occur, it is problematical
whether it will be in the amount and of the form desired.
Thus, in the example cited another species might seize
on areas planned for white pine. The area cleared is so
large that in many cases the density will not reach the
degree hoped for.

3. The system necessitates the clearing in one place
of a very extensive area. An ordinary operation would
cover two or three sections — from 70 to 85 per cent,
clear. Such a clearing is not desirable.

Reserving Scattered Seed-Trees. — This system in-
volves the removal of all trees in a merchantable stand,
except a small number left scattered on the clearing for
the distribution of seed. The essential characteristics
which distinguish the method are:

1. There are only a very limited number of trees.

2. The trees are isolated and scattered.

108 THE PRINCIPLES OF HANDLING WOODLANDS

3. The tiees are left primarily to provide seed.
Required Conditions. — The conditions under which
this method is applicable in practise are:

1. In mature stands, where a clear-cutting is de-
sirable.

2. With species whose seed is distributed by the
wind.

3. Where seed-trees may be found which will not be
overturned by the wind after lumbering.

4. Where the ground may be left in such a condition
that the seed will germinate, and a new stand become
established.

The system cannot be used, therefore, with hard-
woods which have heavy seed — like oak, beech, hickory,
chestnut, walnut, etc. It cannot be used in very dense
regular stands of trees growing in exposed situations, like
many areas of lodgepole pine, of spruce, and of Douglas
fir.

Future of the Seed-Trees. — In projecting a cutting
under this plan, one must consider whether it will be
possible to cut and utilize the seed-trees after reproduc-
tion has been secured, or whether the conditions are such
that it would be impossible to make a second cutting for
them. The character of trees selected would depend
very largely on this point. The leaving of merchantable
seed-trees represents an investment. If they can be cut
at a second operation, after they have performed their
function in furnishing reproduction, the investment is
represented in a higher cost of logging at the second

SYSTEMS OF CLEAR-CUTTING

109

Fig. 23. — 1 hntty btandards Reserved to Urow through a Second Rota-
tion. Scotch Pine in Europe.

Fig. 24. — Reserving Scattered I'rees to Distribute Seed after Lumbering.
Minnesota National Forest.

110 THE PRINCIPLES OF HANDLING WOODLANDS

operation, and a loss of Interest on their value during the
period of reproduction. This may be compensated by
increase in market value, and in some cases by the growth.
If one cannot return for the seed-trees after reproduc-
tion is secured, and if the seed-trees are necessarily old
and mature, it is probable that they will not live until
the new stand is ready for cutting. The trees are then
sacrificed for reproduction, and their value represents
the principal item of investment for that purpose. It is
obvious that one may leave better trees, and more of
them, in the first than in the second case.

Number of Seed-Trees. — This depends on a variety
of conditions. There must, in the first place, be enough
trees to secure an abundant distribution of seed. Ordi-
narily the principle is to leave just as few trees as possi-
ble. This is especially important when it is likely that
the trees will not be utilized by a second cutting. The
forester determines the required number by a local study
of reproduction. He determines how far abundant seed-
ing will take place from individual trees of the species
in question, taking into consideration their height and
crown development, as well as the conditions of site and
exposure to wind. The conditions of germination must
also be considered; for, where these are not favorable, a
larger number of seed-trees should be left than under
the better conditions.

In general, the seed-trees should stand not farther
apart than their average height. Under the best condi-
tions, they may sometimes be reduced to an average of

SYSTEMS OF CLKA R-CUTTING 1 1 1

from 3 to 5 trees per acre. More often, from S to 10
trees per acre are necessary for good reproduction.

Character of Seed-Trees. — Seed-trees are chosen
for reproduction, and they must be capable of performing
that function. A satisfactory seed-tree Is a wind-firm
tree, with a full, thrifty crown. Generally the tree with
a full, thrifty crown is the most wind-firm of the stand,
since root and crown develop in harmony. A good
working rule is to select, when possible, trees whose
crowns take up at least 50 per cent, of the full height of
the tree.

In selecting seed-trees one must consider constantly
the question of the Investment. If the trees are to be
sacrificed to reproduction, and probably will not be util-
ized later, one chooses the least valuable trees which will
serve the purpose. The forester, therefore, selects the
smallest trees which will be satisfactory distributers of
seed. They must, however, have full, thrifty crowns.
Suppressed trees, trees with long boles and short crowns,
or dominant trees with dying crowns, will not answer the
purpose. If small seed-trees are wanting, larger and more
valuable ones must be left in proper locations.

There are certain defects which unfit a tree for high-
grade lumber, but do not affect Its reproductive power.
A knotty or a crooked tree may be fully as good a seed-
tree as a straight one. In fact, a knotty tree may be the
best possible seed-tree, because It usually has a full
crown. Other defects, like cat-face, seams, sun-scald,
etc., do not injure a tree for reproduction.

112 THE TRINCIPLES OF HANDLING WOODLANDS

It may be safe in some cases to leave trees affected
with rot. Sometimes those trees will be left anyhow, as
there is no practical method of disposing of them. If
the crowns are still thrifty, they will be good seed-trees.
It may be dangerous, however, to leave seed-trees affected
with diseases that are likely to spread. In some forests,
for example, a disease may have become so prevalent that
the majority of trees of certain species are infected. An
illustration is the diseased condition of the fir, hemlock,
and pine in some areas of northern Idaho. It is certain
that diseased seed-trees will be liable to infect the new
growth, through rapid propagation. Where possible,
therefore, one avoids leaving trees inflicted with a disease
which is likely to spread to the new crop.

Distribution of the Seed-Trees. — The design is to
have the trees distributed regularly over the cutting area.
The more regularly spaced the trees, the less the required
number. It is not always possible, iiowever, to find a
suitable tree in the precise location most desired. It is
much more important to have suitable trees than a regu-
lar distribution.

The Cutting. — The whole stand is cut clear, except
for the reserved trees. The slashings are disposed of as
described in Chapter VII — either piled and burned, or,
where the conditions demana it, cut up and scattered.
Any individuals or groups of small trees which have
started as advance growth are carefully protected in the
operation.

Preparation of the Soil. — It is essential that the

SYSTEMS OF CLKAR-CUTTING 113

soil he in a condition for the ready germination of the
seed and for the growth of the seedlings. Frequently
there is a heavy layer of litter which retards germination,
or a dense growth of weeds and brush which interferes
with the development of the young seedlings. Ordi-
narily the best plan is to destroy this material by surface
burning. The ground is burned over preferably during
a seed year. This gives an opportunity for the seed to
germinate, and for the young seedlings to gain headway
and compete successfully with other vegetation.

Results. — The scattered seed-tree method produces
excellent results in reproduction where there is little com-
petition for the occupancy of the ground by other species,
where there is little injury to young growth by competing
brush and weeds, and where the soil conditions are favor-
able for the germination and continued life of the young
seedlings. There is no difficulty in securing an adequate
distribution of seed over the cleared ground, for that is
merely a matter of properly locating a sufficient number
of seed-trees. The difficulty is entirely in securing the
germination of the seed and the protection of the seed-
lings. Where the conditions are unfavorable for the
germination and growth of the seedlings, the svstem
inevitably yields poor results. In some situations a
heavy opening in the forest is followed by a drying out
of the soil. This is particularly true in the- semiarid
regions of the West. In the same way, reproduction
under this system is apt to be a failure where there is
danger of damage by frost. In a mixed forest other

114 THE PRINCIPLES OF HANDLING WOODLANDS

species are apt to compete in the new growth, and retard,
or in some cases entirely prevent, reproduction of the
desired species. Thus, in a mixed forest of white pine
and hardwoods, hardwood trees very commonly form the
bulk of the second growth after a clearing, even where
abundant seed-trees of white pine have been left standing.

If good reproduction is secured, the new stand is
essentially even-aged. If the seed-trees are not cut after
reproduction, they are so scattered that they do not inter-
fere in a material way with the development of the new
stand.

The investment is usually small. The value of the
trees left standing is under most circumstances not over
$2 to $S per acre. Sometimes, however, the system is
used in a virgin forest where the only adequate seed-trees
have considerable merchantable value. If the trees are
very valuable, the probabilities are that it will pay to
come back for them in a second cutting after they have
accomplished their reproductive function. If it is im-
possible to return for them, and they are very valuable, it
would not pay to use the system at all. In general, the
results in reproduction are so uncertain that it would not
pay to .use this system where the investment in securing
reproduction would be over $J> to $5 per acre.

Practical Application. — The system has already
been used in this country in a number of instances. The
work conducted on the largest scale is that on the Min-
nesota National Forest. I'his area formerly belonged to
the Chippewa Indians. When the land was relinquished

SYSTEMS OF CLEAR-CUTTING 1 1 5

by them and ceded to the United States, provision was
made by statute that in cutting the pine timber 5 per
cent, was to be left standing as seed-trees. A later statute
required that the amount left for seed be 10 per cent.
The forest was by no means regular, and in some places
the cutting has left several seed-trees to the acre, and in
others only one seed-tree to from three to five acres.
There was no special preparation of the soil and the
cuttings were made without regard to seed years.

The results have not been very satisfactory, first, be-
cause there are not enough seed-trees, and second, because
the ground has been covered with a growth of brush which
interferes w-ith reproduction. A clearing of the brush
by carefully regulated burning just before a seed year
would enormously aid reproduction.

The value of the seed-trees would probably not be
over one or two dollars per acre.

This system has also been used in the white pine
forests of the Northeast. Where it has been applied, the
forest has been usually a second growth from 50 to 100
years old. From 2 to 5 seed-trees have been left per
acre, and these have been of comparatively small value,
averaging ordinarily not over $3 per acre. In certain
sections, as, for example, in southern New Hampshire,
very good reproduction follows this method, for there
is very little competition with other species in mixture,
and the conditions for germination are excellent. In
Massachusetts, on the other hand, there is a distinct
tendency toward the replacement of white pine, after

116 THE PRINCIPLES OF HANDLING WOODLANDS

cutting, with oak, maple, and other hardwoods. If the
original stand was a mixture of white pine and hard-
woods, many of the latter send up vigorous sprouts,
which practically maintain the proportion of hardwoods
in the future stand, and, it becomes difficult to increase
the proportion of pine. In pure white-pine stands there
is also a tendency toward a replacement by hardwoods
because of the great abundance of seed on the ground,
and of young seedlings already started under the pines.
This tendency can partly be overcome by burning over
the ground. Where, however, the hardwoods are estab-
lished as the principal growth, pine creeps in underneath
them in a few years, provided there are trees to furnish
the seed.

The system of scattered seed-trees is applicable also
to the second-growth stands of loblolly and other yel-
low pines in the South; in certain instances to second-
growth Douglas fir stands on the Pacific Coast; and,
where the conditions of moisture are favorable, to cer-
tain stands of pure Western yellow pine.

It is a system more commonly applicable in second
growth than in a virgin forest, because in the former the
investment in securing reproduction may be brought
within a reasonable amount, while in the virgin forest it
is difficult to find seed-trees of the right character which
do not represent so great an investment as to make the
system impracticable.

Reserving Groups of Seed-Trees. — In exposed sites it
is often not practicable to leave isolated seed-trees, because

SYSTEMS OF CLEAR-CUTTING

117

If*/ • , »

118 THE PRINCIPLES OF HANDLING WOODLANDS

of the danger from windfall. In many instances a clump
of trees will resist the wind where single trees will not.
This is particularly the case when one or two fairly wind-
firm trees are in the clump. Suppose, for example, that
a forest is composed of two species, one subject to wind-
fall and the other fairly wind-firm; and suppose that it is
desired to reproduce the former. It might often be the
case that a clump of trees composed of both species would
resist the wind and accomplish the reproduction, even
if only a few of the trees in the clump were of the wind-
firm species.

The clumps would ordinarily comprise from three to
thirty trees, and would be located and spaced on the
same principles as under the system of scattered seed-
trees. The only difiPerence between the two systems is
that in the latter a group of several trees would usually
be left instead of single isolated trees.

Reserving Thrifty Standards. — In the two systems
described in the foregoing pages, the purpose of leaving
reserves is for reproduction, and for that only. Under
the method now to be described, trees are left standing
for two reasons, reproduction and growth.

The system is applied in regular, relatively even-aged
stands of moderate age; that is, to stands in which there
are many trees still capable of living a long time, and
capable of rapid growth. It is not applicable in very old
stands in which the trees have all reached their limit of
profitable growth. Usually the system is not applicable
to stands over about 100 years old.

SYSTEMS OF CI.KAR-CUTTING I 19

The design is to leave scattered over the cutting area
trees which are thrifty, capable of producing abundant
seed, and capable of living through a second rotation.
Suppose that a stand is cut when 100 years old. Selected
reserves are left standing, and these restock the ground.
The reserves, then, are designed to stand during the
entire rotation of the new crop. If this new stand is cut
at 100 years of age, there will be scattered throughout it
a certain number of trees about 200 years old. The re-
serves will have stood for fully half a century practi-
cally isolated, and for another half century as the leaders
in the stand. With the advantage of full light they will
have made a maximum growth. With a rotation for
the stand of only 100 years, a certain amount of timber
of large size and high grade will be produced.

Selection of the Standards. — The trees selected to
remain standing are from among the dominant trees of
moderate development. The aim is to select trees of as
little present commercial value as will meet the require-
ments of reserves. The trees must, however, be from
the dominant class. Suppressed trees and ordinary inter-
mediate trees would not be suitable for purposes of re-
production or growth. The trees must be wind-firm,
since they will stand isolated for many years. Thev
must have thrifty crowns capable of responding to the
new conditions of light and space, and capable of produ-
cing rapid growth. They must be likely to develop
into good seed producers, even if thev are not so at pres-
ent. Ordinarily, their crowns should take up at least 3S

120 THE PRINCIPLES OF HANDLING WOODLANDS

or 40 per cent, of the tree's length. They should be
thoroughly sound, and as straight as can be found. In a
stand having trees from 6 to 16 inches in diameter, they
would usually have a diameter of from 9 to 12 inches.
Trees with large, spreading crowns are avoided, in order
that there may be as little interference with the new crop
as possible.

Number of Standards. — In determining the number
of reserves, it must be borne in mind that they must
stand far enough apart for a new stand to develop among
them. It is necessary, therefore, to consider the size of
the crowns of the reserves. The reserves are evenly
distributed, so far as this is compatible with the selection
of proper trees. Since the method is most commonly
applied with intolerant trees, the number of reserves
must be comparatively restricted. A good rule is to aim
to have an average interval between the crowns of fully
30 to 40 feet. This would usually mean about from IS
to 2 S reserves per acre.

Results. — This system yields better reproduction
than the scattered seed-tree system. There are from
15 to 2S seed-trees, and though they are not so large
as those left under the other system, and each would
not yield so much seed, they are so much more numerous
and so much nearer together that the results are better.
The trees are near enough together to give a certain
amount of shade that is very beneficial in checking exces-
sive drying of the soil, and in reducing damage to the
seedlings bv frost. The presence of 15 or 25 reserves

SYSTEMS OF CLEAR-CUTTING 121

cannot help interfering to some extent with the de-
velopment of some of the young trees. About 10
or 20 per cent, of the area will be shaded from above,
and this proportion of the new crop will be prevented
from making normal growth. In case of loblolly pine,
this would result in reducing the yield from the new
crop by about from 1,000 to 2,000 board feet. On the
other hand, if 20 of the reserves lived through the
second rotation successfully, they alone would yield at
least from 5,000 to 10,000 feet of lumber of the highest
grade.

Application. — There are no instances in this country
of the systematic use of this system. In Europe, the
plan of reserving certain trees for growth over a second
rotation has long been in practise. The purpose of these
reserves has, however, been chiefiy for growth. Re-
production has generally been accomplished by planting.

The system may well be applied to many even-aged,
comparatively young stands in this country, such as lob-
lolly and other yellow pines in the South, white pine
occasionally. Western yellow pine, and Douglas fir.

Clear-Cutting in Two or More Operations. — The con-
dition requiring the clear-cutting of an area in one opera-
tion is temporary. The advance in values will before
long permit the cutting in a single operation of a smaller
amount in a given logging unit than is now practicable.
Already in many stands that require clear-cutting, it is
possible to restrict the first cuttings to strips or patches
occupying not over 40 or 50 per cent, of the area, and

122

THE I'RINCII'LES OF HANDLING WOODLANlJ^i

Fig. 26.- a Stand .1 W extern Yellow Pine, with Scattered Old Trees,
Showing^ the Results which May be Obtained by Reserving the Thrifty
Standards for Growth through a Second Rotation. Black Hills, South
Dakota.

SYSTKMS ()l rF,r.AK-(M riFNC; 12.^

then return and cut the remainder in one or several
operations.

The clear-cutting s}'stenis which involve more than
one operation may be classed under three heads:

1. Alternate Cleared Strips.

2. Irregular Cleared Strips.

3. Progressive Cleared Strips.

Alternate Cleared Strips. — In the first operation, the
strips are cut at more or less regular distances, leaving
alternating bands of standing timber between them. The
design is to cut from 40 to 60 per cent, of the area clear
at the first cutting. It is expected that the clearings will
become restocked by seed from the standing timber.
When reproduction has taken place on the cleared strips,
a second operation is made for the timbered strips be-
tween them.

Location of the Strips. — A regular arrangement of
alternate strips is possible wherever the topography
permits it. In general, the conditions must be such that
the logs may be conveniently taken out of the strips to
the road. The simplest conditions are where the ground
is level or gently sloping. Logging is then eas\-, and
the strips may be laid off uniformly, and with main
reference to reproduction.

Under these conditions the strips are laid off at right
angles or diagonally to the prevailing winds, unless some
special considerations require a different arrangement.
This manner of cutting insures the best possible distribu-
tion of seed over the clearings. It may happen that the

124 THE PRINCIPLES OF HANDLING WOODLANDS

area is so situated that the necessary location of the roads
will not permit the laying off of the strips at right an-
gles to the direction of the prevailing wind. It is usu-
ally possible, however, to make them run in such a way
that seed will blow across them. This may necessitate
making the strips narrower than would be proper if their
location were the best.

If the timber is situated on a long, even slope, the
method of alternate strips can be used, provided that
a profitable logging operation can be conducted. Ordi-
narily under such circumistances, the strips are run up and
down the slopes. On broken, rugged topography the
method of regular alternating strips cannot be used at all.
The clearings are then located according to the topogra-
phy, and are arranged very irregularly in the manner
described on page 128.

Width of Strips. — The width of the strips depends
on the distance to which seed will be distributed in suffi-
cient quantity to insure reproduction. It depends also
on the conditions for germination. If these are good,
the strips may be wider than when they are poor, for in
the latter case more seed is necessary to insure repro-
duction. No rule can be given, because every case
must be judged on the ground with a knowledge of
the reproductive habits of the species in question. In
general, the best results are secured when the strips are
not wider than the height of the bordering trees. Seed
is carried to considerably greater distances, but usually
not in quantities sufficient for a full reproduction. In

SYSTEMS OF CLEAR-CUTTING 125

this country, logging conditions may often require strips
wider than the standard. The wide strips are cut with
full knowledge that the reproduction will not be so good
as on narrow strips.

In most forests where this method is likely to be
used, and with species growing in their optimum region
of development, fair reproduction can be secured at a dis-
tance of about three times the height of the seed-trees.
Under especially favorable conditions even a greater dis-
tance can be safely used. Thus, it is believed that in
Douglas fir stands in the foothills of the Cascade Moun-
tains, where the trees are from ISO to 175 feet or more
in height, strips may be cut from 500 to 600 feet wide.

In this country, the general rule has been to make the
strips as wide as possible. In Europe, the rule has been
to make them as narrow as possible. The effort to make
a w^ide strip is designed to cheapen the cost of lumber-
ing; the aim is to reduce the present investment, ev^n
at a sacrifice of future returns. The advantages of a nar-
row over a wide strip are as follows:

1. A quicker, surer, and denser reproduction is
secured.

2. A smaller, continuous area is exposed, and there is
less damage by drying of the soil.

3. The newly established trees have a measure of side
shade, and suffer less from drought.

4. On steep slopes the danger from erosion is less.

5. The damage to small growth by insects is in the
long run less.

126 THE PRINCIPLES OF HANDLING WOODLANDS

The distance between the strips is ordinarily about
the same as the width of the clearings. This is deter-
mined on a basis of the percentage of timber to be re-
moved at the first cutting. If 50 per cent, is to be cut,
then the strips and bands of standing timber are the same
in width. If more than 50 per cent, is to be cut, the
intervening bands of timber are correspondingly narrow-
er than the areas cleared. Ordinarily, the strips are
of uniform width. There will, however, be many spots
where a strip will run through a site with an exception-
ally shallow or soft soil, and danger of windfall would be
great. In that case, a widening of the strip is made, to
comprise the endangered area. In the same way other
special conditions will often require a departure from
uniformity in the width of the strips.

The Second Cutting. — When the cleared strips have
become stocked with young growth, the bands of standing
timber may be removed. Sometimes reproduction takes
place promptly in the first seed-year succeeding the cut-
ting. More often several seed-years are required. This
is particularly true when wide strips are cut. Ordina-
rily, with w4de strips the second cutting may be made
within 10 or 15 years; with narrow strips in from 5 to 6
years.

The second cutting cannot, like the first, be a clear-
ing, for there would then remain no seed-trees for natural
reproduction. The simplest silviculture w^ould be to
clear-cut and plant, but that is often out of the question.

If these second strips must be practically all taken oflF

SYSTEMS OF CLEAR-CUTTING 127

in one openition, and single trees and groups cannot be
left because of danger from windfall, blocks must be left
comprising as large a percentage of the stand as the c(jn-
ditions permit — say from IS to 25 per cent. These
blocks would not insure very good reproduction when
they could not be properly located. Under poor market
conditions at the time of the second cutting, there is,
therefore, no method of securing adequate natural repro-
duction.

Frequently, in this country, the question of how
the second strips of timber are to be removed is not
decided when the first strips are cut. The forester has
usually located the first cuttings, and, knowing that some
10 years or more will elapse before the seconci cutting,
has left the problem of how to reproduce the balance for
some one else to solve. This is not good practise, and
is justified only under the stress of being obliged to cut
in a given stand when a clear-cutting system is necessary,
and when a clearing of over about 50 per cent, would be
a misfortune. Good reproduction on half the area is
better than very poor reproduction on the whole.

Operation. — The strips are cut clear. Theoretically
this means the removal of every tree. In practise, even
with the good market conditions, there are some small
inciividuals which it is too expensive to remove. Such
trees would not, however, interfere in any serious way
with reproduction or with the development of the stand.
Yet it is desirable not to have any such trees if it can be
helped, unless they are likely to live and constitute legiti-

128 THE PRINCIPLES OF HANDLING WOODLANDS

mate reserves. If any groups of young growth occur,
they are carefully protected, unless they are so small and
scattered that this would involve an unwarranted expense.
The logs are removed just as soon as practicable, and the
slash is destroyed. In some cases it is desirable to burn
over the surface of the ground to prepare for the recep-
tion of the seed.

Irregular Cleared Strips. — Where the topography is
uneven and rugged, a regular arrangement of alterna-
ting strips is impracticable. Such cuttings would usually
increase the difficulties and cost of logging; the regular
strips would result in windfall on many exposed points;
the location of the strips with reference to the bordering
seed-trees would often be unfavorable for good reproduc-
tion; the bands of standing timber would in many cases
be poorly located with reference to reproduction at the
time of the second cut; and one could not take full ad-
vantage of the condition of the timber to locate the cut-
tings where most needed.

On rough topography the clearings may be irregular-
ly arranged, and be irregular in size and form. Just as
in the case of the regular cleared strips, the design is to
remove the stand in two or more operations. The first
cuttings comprise from 40 to 60 per cent, of the area, and
take the form of clearings restricted sufficiently to permit
a distribution of seed from the bordering trees.

The forester determines in advance the proportion of
the area which will be cleared. This is based on consid-
erations of logging, reproduction, windfall, protection

SYSTEMS OF CLEAR-CUTTING 129

from fire, the condition of the timber, and the succeeding
operations which will remove the balance of the stand.
The clearings are located with reference to the same con-
siderations. Their location is a matter of careful and
skilful selection in contrast to a conventional arrangement
of cleared strips of uniform width at regular intervals.

Location of Strips. — In locating on the ground the
areas to be cut, the forester should keep in mind the
following considerations:

1. Logging. — The question of practical logging must
be considered first of all. The location of the cutting
areas, which would be most advantageous from the
silvicultural standpoint, might, under some circum-
stances, be entirely impracticable on account of the dif^-
culties and cost of logging. Under a given set of condi-
tions of forest and topography, the required method of
logging is pretty clearly defined. The method of log-
ging, the location of roads, and the cost of constructing
them, the cost of installing the appliances, the cost of
cutting the logs and transporting them to market, and
their market value, must determine the general arrange-
ment of the clearings and their approximate size. Their
precise location depends, in addition, on the considera-
tions discussed below.

2. Reproduction, — The clearings are sufficiently nar-
row to enable the distribution of seed over them from the
seed-trees standing on the border. The form of the
cleared areas is a matter of no importance as far as repro-
duction is concerned. For the reasons explained on page

130

THE PRINCIPLES OF HANDLING WOODLANDS

Fig. 27. — Clear-Cutting as Applied in a Scotch Pine Forest in Ger-
many. The Clearing will be Restocked by Planting.

Fig. 28.— Clear-Cutting in Strips as applied in Lodgepole Pine.
Deer Lodge National Forest, Montana

SYSTEMS OF CLK AR-CUTTIX(/ 131

125 the clearings should he as narrow as is compatihlc
with practical requirements of logging. They must n(;t
be wider than the distance of abundant seed distribution.

The clearings are so located that there will be nu-
merous seed-trees on the border, especially on the side
toward the prevailing wind. Where there is danger of
injury to the soil and to the reproduction by drying
winds, the cuttings are as far as possible located so that
the remaining stands act as shelter belts and reduce the
winds' unfavorable influence.

In general, the cutting areas are located more on the
lower than on the upper slopes, when this is compatible
with the proper operation of the second cutting. There
are several advantages, as follow-s:

a. The present logging is facilitated — at the time of
poorest market conditions.

b. The location of seed-trees above a clearing is bet-
ter than below it, and such a location enables a larger
opening to be made.

c. The steepest part of the slopes are kept under for-
est at a time when market conditions only permit a clear
cutting.

d. Very commonly, as a result of old clearings by
fire, the trees on the upper slopes are younger than those
below; and the greatest amount of unsound timber is
usually on the lower ground.

3. Condition of the Forest. — The irregular arrangement
of clearings enables the forester to cut just those stands
which are most in need of attention, namelv, the patches

132 THE PRINCIPLES OF HANDLING WOODLANDS

which are mature, deteriorating, diseased, insect-infested,
or damaged by fire or other agency.

4. Windfall. — The cuttings may be made so as to
reduce to a minimum the damage to the remaining stand
by windfall. In a broken topography the irregular loca-
tion of cuttings is the best method of making clearings
so as to avoid this danger.

The Second Cutting. — The problem of reproduc-
tion at the time of the second cut is taken into account
in locating the first clearings. In some instances the
location of a clearing may be determined entirely by this
consideration. Suppose, for example, that there is a
choice between locating the cutting on a site exposed
to windfall and on a sheltered site. This might occur
where a strip is to be cut on one side of a ravine and
not the other. The exposed side is cut at the first
operation, and the sheltered side left for the second cut.
When the second cut is made, reproduction may be
accomplished by leaving seed-trees, or by some other
system applicable where the danger from windfall is
removed.

On the other hand, there are many instances in every
operation where the problems of logging and present
reproduction do not permit locating the cutting primari-
ly with reference to the second operation. In this event
the situation is precisely that of the conventional alter-
nate strips.

Progressive Cleared Strips. — This method provides
for the gradual clearing oItF of a stand of mature timber

SVSTEiVfS OF CLEAR-CUTTING

]^^

by a series of strips beginning on one side and pn;-
gressing across the area until the whole is cleared.

It is a niethod which requires a number of separate
operations in the same stand. After the first strip is cut,
an interval is allowed to elapse until the clearing is
restocked by natural reproduction. Then a second strip,
bordering on the first, is cut, and this in turn is repro-
duced, and then successive other strips are cut at inter-
vals until the timber is cut off.

It is at once obvious that if this method were applied

III

I III II I III

Fig. 29. — Cutting Series.

to a large block of timber and the strips cut even moder-
ately wide, it would take a long period to cover the area,
and that a very small yield would be obtained at a single
operation.

Cutting Series. — To meet this difficulty, it is cus-
tomary to constitute in a single block several cutting series.
Instead of beginning at one side and progressing across
the area in a single series of strips, the stand is divided
into several approximately equal divisions, and a series

134 THE PRINCIPLES OK HANDLING WOODLANDS

of Strips established in each. Suppose, for example,
that a tract 900 feet long, such as that represented in
Fig. 29, is to be cut, and it is desired to remove the
timber in 12 years. Suppose, further, that reproduction
of the cleared strips can be secured in about 4 years.
The aim should then be to cut over a single division
in three operations indicated in the figure as I, 11 and
III. The first cutting then removes 3 strips, each 100
feet wide, separated by a distance of 200 feet. After
about 4 years, the second operation removes the second
strips bordering on the first. At the end of the next
period of 4 years, the final strips are ready for repro-
duction. This last strip cannot be cut clear and
reproduced naturally, for there would be no seed-trees
left standing. It is, therefore, either reproduced nat-
urally by some other system, or cut clear and restocked
artificially.

Use in this Country. — This system is not used very
commonly, even in Europe. It has not been used in
this country in a systematic way, as far as the author is
informed. It is probable that it will occasionally be used
in a small way in cutting woodlots under certain condi-
tions. Thus, it is sometimes customary to cut off the
even-aged stands of white cedar in New Jersey by strips.
The owner cuts a strip each year and gradually works
over the swamp. He does not cut in this way in order
to secure reproduction, but because it is the most con-
venient way for him to operate. 7^he result, however, is
a series of strip reproduction cuttings. Probably the

SYSTEMS Ol' (IJ'.AR-Cr'rriN'G \M

plan would work \'cry well in the small holdings of
second-growth loblolly pine in the central Atlantic
Coast region, and in other coniferous stands where
reproduction is simple.

Clear-Cutting in Patches. — This system ordinarily
involves the gradual removal of a giv^en stand by a series
of clearings, each covering only a restricted part of the
area. In the first operation, patches of irregular form
and limited size are cut. These patches, which are
usually not over 100 to 200 feet across, are located here
and there through the stand at points requiring the
most immediate attention. As a rule, they do not
aggregate over 40 per cent, of the area. They are skil-
fully located with reference to reproduction. When a
new growth has been established, each patch is enlarged
by a second cutting in the form of a cleared strip
running entirely around it. After this strip is repro-
duced, another cutting is made, still further enlarging
the opening. This is continued until the clearings
merge together. The last cutting will leave no seed-
trees standing, so that natural reproduction cannot be
secured. Unless there has been natural reproduction
under the trees as advance growth, the final clearing must
therefore be planted artificially.

This plan of successive enlargements of patches is sel-
dom carried through to its logical completion. In prac-
tise, the patch system is applied only in making the first
cuttings, and some other method is used for the repro-
duction of the balance. Thus, the first cuttings mav be

136 THE PRINCIPLES OF HANDLING WOODLANDS

in the form of patches cut clear, while reproduction is
secured naturally from the bordering trees. The portion
of the stand left standing may be cut under the shelter-
wood system, or it may be cut clear and the area planted.
An illustration may be taken from a case in southern
Europe that once came under the author's observation.
The forest was composed of beech and spruce. It so
happened that the natural reproduction of beech in that
district was better than that of the spruce. The use of
the shelterwood system would have resulted in an increase
of beech in the new stand. Accordingly, the first cut-
tings were in the form of patches, made about as wide as
the tree-height. Care was taken to leave abundant seed-
trees of spruce on the border. The light seed was read-
ily distributed over the area, while beech-seed is scarcely
carried beyond the periphery of the crowns. Good
reproduction was secured on the plots, and a certain pro-
portion of spruce in the new crop was thus guaranteed.
The balance was then reproduced by the shelterwood
method, the beech predominating in the new repro-
duction.

CHAPTER IV

THE SHELTERWOOD SYSTEM

Underlying Principles of the Shelterwood System

KxPERiENCE has shown that the systems of clear-cut-
tings with natural reproduction have certain disadvan-
tages which in many cases render their results uncertain
and unsatisfactory. The exposure of the soil often re-
sults in retarding reproduction through drought or frost,
or through competition with brush and weeds, which
spring up in abundance on clearings. A disadvantage
of the clear-cutting systems wdth natural reproduction is
that they cannot be used with trees having heavy seed.
All of these difficulties are in a measure overcome by
the application of the shelterwood system.

The principle underlying this system is to remove
a given stand gradually by a series of thinnings. The
opening of the canopy results in reproduction ov^er the
ground under the protective shelter of the trees left stand-
ing. These trees are then removed at one cutting, or
gradually, in accordance with the neecis of the new crop
and the special requirements of market and logging.

Advantages of the System. — Fhe special advan-
tages of the system are the following:

1. The cuttings for reproduction leave a large num-

137

138 THE PRINCIPLES OF HANDLING WOODLANDS

ber of seed-trees, evenly distributed and comparative-
ly close together. In consequence, a relatively large
amount of seed is produced, and is regularly distrib-
uted over the area.

2. The system may be used with trees having heavy
seed, for the distribution of seed may be entirely con-
trolled by the number of seed-trees and their distance
apart.

3. The shade of the remaining trees retards the
growth of grass, weeds, and brush, which would interfere
with the young growth of trees.

4. The shelter acts as a protection to the soil, pre-
venting excessive drying and baking.

5. The shelter protects the seedlings from drought
and frost.

6. During the period of reproduction the trees left
standing are more or less isolated, and grow at a maxi-
mum rate, adding substantially to the fmal aggregate
yield and value.

7. The new stand is established in advance of clear-
ing. As a result, there is not only a gain of several
years' growth, but the interval between removing the
cover of old trees and the formation of a close canopy by
the new trees is much shorter than in the clear-cutting
operations. The soil is, therefore, exposed for a mini-
mum length of time.

8. The gradual clearing of a forest bv successive thin-
nings is always less objectionable from an esthetic stand-
point than a clear-cutting.

THE SHKLTERWOOD SYSTEM

Fig. 30. — Reproduction of a Stand by the Shelterwood System. The
Sheltering Trees will be Removed in the Next Ten Years. Black
Forest, Germany.

Fic. 31. — Primitive Application of tlie Shelterwood System, after the First
Cutting. Lodgepole Pine. Big Horn National Forest, Wyoming.

140 THE PRINCIPLES OF HANDLING WOODLANDS

Disadvantages of the System. — As compared with
the clear-cutting systems, the shelterwood system, there-
fore, gives to the forester means of better controlling
reproduction, protecting young growth, and conserving
the quality of soil, as well as the appearance of the forest.

The chief disadvantage, from a silvicultural stand-
point, is that the system cannot be applied when there
is great danger from windfall. During the period of
cuttings the trees are isolated, and, therefore, exposed to
danger from windfall. This disadvantage is partly over-
come in European practise by opening up the forest in
the first instance by a series of light thinnings, and thus
gradually rendering more windfirm the trees that are
chosen to stand. Even this measure is of no avail where
the danger from windfall is extreme. In this country a
series of light thinnings is often not feasible, and this
fact excludes the system not only from the more exposed
sites, but also from many areas where it would be practi-
cable if it could be intensively applied.

A second disadvantage touches the problem of log-
ging. The conditions must be such as to permit the
restriction of the first cutting and the removal of only
a part of the stand in the form of a thinning; then a
return for one or more subsequent cuttings.

Variation in Application. — This system, like all
others, must be applied with wide variations in different
forest types, according as the forests vary in age, density,
and reproductive capacity. But the application of the
system is mainly affected by the market and logging

THE SHELTERWOOD SYSTEM 141

factor. Upon this factor depends the number of thin
nings which may he made during the process of remov-
ing the given stand. The best work is done where it is
possible to dispose of any and all products of the forest —
cord wood as well as logs — and where there are permanent
roads. Under these conditions one may make a thin-
ning in the forest whenever needed, and may cut just
those trees whose removal is required in each given case.
The other extreme is found where the market and
logging conditions permit only two cuttings; one thin-
ning to open the stand for reproduction, and a final cut-
ting after reproduction is secured. The better the condi-
tions of market and transportation the more thinnings
will it be feasible to make. The greater the number of
thinnings, the more intensive will be the application and
the better will be the final results. The most intensive
application is found in Germany; the most primitiv^e, in
America and in other countries just inaugurating the
practise of forestry.

Primitive Application of the System

The simplest use of the system is when it is designed
to remove a given mature stand in two cuttings. The
first is a thinning intended to secure the conditions re-
quired for reproduction. This is called the seed-cutting.
The next cutting is made after the reproduction is se-
cured, and removes the trees left after the first cutting.
This is called the final cutting. Usually the final cutting
is made from 10 to 20 years after the seed-cutting.

142 THE PRINCIPLES OF HANDLING WOODLANDS

The method Is applicable to stands in which the tim-
ber is all, or nearly all, mature, where the trees are fairly
windfirm, and where the market permits the cutting of
a part of a stand in the form of a thinning. Precisely
these conditions are found in many of our original forests
which have an even-aged form of stand. The best illus-
trations are the old yellow pine stands in the South, and
many stands of Western yellow pine in the West.

The application differs so w-idely in different forests
that the principles are best illustrated by a discussion of
several practical examples.

Application in the Longleaf Pine Forests

The ordinary longleaf pine forest is composed of
stands and groups of regular form. The old stands and
groups are composed chiefly of mature trees. These
usually are not continuous, but are broken by stands,
patches, and groups of younger trees, each of which is
also of regular form. The average forest in which the
lumberman to-day is operating is composed chiefly of old,
mature stands. Usually about 75 per cent, is mature.
A cutting of all mature trees would, therefore, constitute
a series of clear-cuttings. The younger trees would re-
main as stands, patches, and groups standing by them-
selves. The reason why the forests are in this condition
must be sought in the effect of the forest fires which have
doubtless occurred for countless years, and in the de-
structive tornadoes which periodically sweep certain sec-
tions of the longleaf pine region.

THE SHi:i;n:RW()oi) system 143

The mature stands require a system of silviculture
which will remove the timber in a restricted pericxl, and
replace it with a new even-aged stand. The selection
system is out of the question. Heretofore, it has been
the custom to clear-cut without reference to reproduction.
Many foresters anci lumbermen agree that the best meth-
od is to remove the timber in two cuttings, separated
by a period of from 10 to 20 years. This is in real-
ity the shelterwood system, though a very primitive
example in comparison with the practise in Europe. It
is the best, and indeed often the only, method which can
be used under the given conditions.

The advantages to the owner in using this system are
as follows:

1. The forest is cut over rather rapidly, and the ma-
ture, deteriorating timber is utilized.

2. The trees left standing are thrifty. Thev will
grow rapidly and add materially to the amount which
may be taken out at the second cut, thus prolonging the
supply on the tract.

3. Since the trees left standing are the smaller diam-
eters, the average grade of the present cut is raised.

4. The increase of stumpage, and particularlv the in-
crease for the lower grades, should result in a much
greater return from the trees left standing than could be
realized from them if cut now.

5. A good reproduction may be secured, which will
undoubtedly increase the v^alue of the land for future
sale, at least that portion not designed for cultivation.

144 THE PRINCIPLES OF HANDLING WOODLANDS

The First or Seed-Cutting. — In making the first cut-
ting, the forester has in mind present utilization, a
profitable logging operation, the securing of a maximum
growth between cuts, a profitable second cut, and
reproduction before the time of the second cut. The
special points considered in selecting the trees for re-
moval are as follows:

1. Cut all deteriorating trees, such as those infected
with red rot and those with burned butts, cat-face, or
similar defects likely to affect their value before the
next cut.

2. Cut mature trees which have reached their limit of
ef^^ective growth, except where absolutely needed for seed.

3. Cut trees with suppressed and broken crowns.

4. Cut all trees liable to be blown over before the
second cut, such as certain leaning trees, tall, slim trees
with small crowns, and those weakened by boxing.

5. The trees left standing must be:

a. Windfirm.

b. Sound.

c. With well-developed and thrifty crowns.

d. Capable not only of living till the second cut,

but of adding substantial growth.

6. Provision is made for the distribution of seed-
bearing trees, so that seed will be scattered in abundance
over the entire area.

7. If the trees which should be left for growth
are not sufficient in quantity, or not properly located,
special seed-trees from the mature class are left standing.

THE SHELTERWOOI) SYSTEM 145

8. In leaving special seed-trees, the ones of least
present commercial value are selected.

9. Defective trees may sometimes be left as special
seed-trees, but only if they will produce seed in abun-
dance, and will stand long enough to secure reproduction.

10. All groups and patches of immature timber and
young growth are carefully protected.

11. Of no matter what size, trees attacked by insects
should be cut, even at extra expense, since this is the
only way to prevent the spread of insects to the rest
of the forest.

In operating on these principles, care must be taken
not to injure the trees left standing. This applies to the
work of felling and of skidding out the logs. The for-
est is usually so open that there is no excuse for damage
in felling trees. Nor is there any reason for injuring the
standing trees and the young growth, especially if logs
are taken out by horse power.

The Second Cutting. — After reproduction has been
successfully secured, the forest is cut over a second time,
and the timber left from the first cut is removed. Theo-
retically, this cutting should take place as soon as the
young growth is thoroughly established. In actual prac-
tise, however, the second cutting cannot be accurately
timed with reference to the needs of the new growth.
This is particularly the case in extensive forests operated
on a large scale. Usually the second cutting will not
be made until the first cuttings have been completed
through the whole forest. Then the operations will

146 THE PRINCIPLES OF HANDLING WOODLANDS

commence all over again, beginning at the same point as
the first cuttings. Frequently, however, the second cut-
tings will not follow precisely the same cutting areas, and
they may progress at a different rate. Often, therefore,
the interval between the cuts must depend on the length
of time it takes to work over the forest the first time.
This will ordinarily vary from 10 to 20 years.

When the second cut is made, the ground will pre-
sumably be covered with young growth. A certain
amount of damage to the new growth will be inevitable.
If reproduction has been successful, the new growth will
be very dense; there will be so many trees that a certain
amount of loss by breakage will not materially affect the
final crop. The small openings made in getting out the
logs will be covered by the closing together of the neigh-
boring trees as they grow older. If the reproduction is
not complete, but in patches, the logs can be taken out
with very little damage to such young growth as has been
secured. In any case, the loggers must exercise a great
deal of care not to injure this growth. At that cutting it
is probable that the use of a steam skidder would have
to be discontinued.

Results. — It is estimated that, on an average, about
65 per cent, of the merchantable trees are taken out
at the first cutting, and that this amounts approxi-
mately to 70 or 80 per cent, of the volume and 60 or 70
per cent, of the crown cover. The trees left standing
are capable of fair growth, and this materially increases
the yield of the second cut.

THi: SHKf/rFRWOOD SYSTEM 147

If fires are kept out, reproduction ma)' he secured in
large amounts. It may happen, however, that a full
stand cannot he ohtained. The necessity of confining
the operations to only two cuttings, the heavy openings
and rather extensive exposure of the soil, the competition
of weeds which cannot be controlled, atid the damage at
the second cut, are factors likely to reduce the reproduc-
tion below what could be secured under an intensive sys-
tem of management. If, however, the work is carried
out as indicated, there is no reason why a stocking of 60
percent, of the maximum should not be secured. Under
the circumstances, this should be considered very good;
it is enough most amply to repay the expense and trouble
incurred.

Application in the Black Hills

The forest of the Black Hills of South Dakota and
Wyoming is chiefly composed of one species — Western
yellow pine. From time immemorial the area has been
swept by forest fires, which have made clearings of
greater or less size. On these clearings stands of rela-
tively even-aged pine have come up, so that to-dav the
forest is composed of stands, patches, and groups, each of
regular form. There are, to be sure, many very broken
and irregular stands with individuals and clumps of trees
of different ages intermingling; but the prevailing form
is regular. The mature stands of this regular character
are very well handled by the shelterwood method, and
the Government is now adopting this plan of cuttings.

148

THE PRINCIPLES OF HANDLING WOODLANDS

THE SHKI/rERWOOI) SYSTI-M 149

The First Cutting. — Suppose, for example, that a
stand has an age of 100 to 1 SO years, a range of diameters
from 8 to 16 inches, and a yield of 12,000 feet per acre.
The trees for the first cutting are selected with the fol-
lowing considerations in mind:

1. The cutting is restricted to about 60 per cent, of
the present merchantable stand.

2. The trees selected for cutting are primarily:

a. The largest trees.

b. Defective trees which will not live till the next

cut.

c. Trees with suppressed, badly broken, or un-

healthy crowns.

d. Insect-infested trees.

e. Trees likely to be blown over or otherwise dam-

aged before the next cut.

f. Trees with the long slender boles and small taper.

g. Fire-scarred and otherwise injured trees which

are in danger of becoming defective before the
next cut.

3. The trees left standing are primarily dominant
trees of moderate diameter, with crowns of moderate size.

4. The trees left standing should be sound, thrifty,
and capable of responding to the new conditions of
light and space, and of producing an effective growth.
They should be windfirm, and capable of bearing seed
now or in the near future.

5. When the stand is dense and regular, the trees left
standing can usually be spaceci at fairly regular intervals.

150 THE PRINCIPLES OF HANDLING WOODLANDS

When the stand is broken and irregular, this is impossi-
ble. Care is taken to leave trees capable of bearing seed,
at least every 50 feet. If there are no trees of the
moderate diameters which will serve as seed-trees, larger
trees, properly located, must be left.

6. All thrifty individuals and groups of immature
and young trees are left standing.

7. The trees standing over good reproduction are cut
freely.

The Second Cutting. — The second cutting will prob-
ably take place in from 10 to 20 years. By that time
there should be ample reproduction over the whole
area and in fairly uniform distribution, under the trees as
well as between them. The damage to this growth in
taking out the trees in the final cutting will be con-
siderable. But the trees left standing are those with
moderate crowns, which will do less damage than large
veterans with sprawling crowns. The damage should
not reduce the real density of stocking in the new stand
over 10 per cent., because the young growth will usually
be denser than is necessary, and the loss of a few small
trees will not materially impair the development of the
new stand.

Progress in the Development of the Shelterwood System

The removal of a stand in two successive cuttings
represents the most primitive application of the shel-
terwood system. As was said, the time of making a
given cutting is dependent more on the conditions of

'j'HK sHKF.'rKRWooi) s^'s'^l•:M ISl

market and lo^^ging than on the requirements for repro-
duction.

The next step in the dev^'lopnient of the system is
the remoN al of the trees left after the first or seed-cutting
in two cuttings instead of one cuttin<^. The additional
cutting is a thinning made after reproduction has been
started, in order to admit more light for development of
the seedling growth. It is made when the condition of
the new crop requires it; and the amount of timber to
be removed and the selection of the trees depend on the
needs of the young growth. It is a thinning, and there-
fore leaves standing a certain number of trees which still
act as a partial shelter and seed up blanks not reproduced
after the first thinning. This second thinning is called
the Removal Cutting.

The two-cutting plan was used in Europe as early
as 1720. In the early part of the 19th century the
idea of three cuttings was fully developed. W ith the
improvement of market conditions, still greater attention
was given to reproduction and the development of the
new stand. It became more and more possible for the
forester, from first to last, to direct all cuttings so as to
secure a full and thrifty new crop, and at the same time
to meet the requirements of logging. The result of
experience in reproduction and of the development of a
good market is the modern shelterwood system, as ap-
plied in Kin-ope, which consists of a series of cuttings,
from three to ten or more, according to the needs of a
given case.

152 THE PRINCIPLES OF HANDLING WOODLANDS

In this country we are passing through the same
process of development. The two-cutting plan is used
in certain virgin forests under difficult market condi-
tions. With improved conditions the stand left after the
first cut may be taken off in two cuttings. It is probable
that this is about as far as we shall go in operating old
forests from 150 to 300 years old.

The further development and more intensive applica-
tion will come with the second-growth regular stands,
which do not exceed 100 years of age. Already in
many parts of the East the market is such that the
system can be applied in much the same way as in
Europe. This condition is reached when there is a
market for all wood products, including cordwood, and
when there is a permanent road system — conditions which
enable the forester to make a thinning just when it is
needed, and to cut just what is required for the good of
the forest.

Intensive Application of the Shelterwood System

It is necessary to look to Europe for the best illustra-
tions of the shelterwood system intensively applied.
The description which follows is drawn entirely from
European practise. It holds equally good, however, in
the intensive application of the shelterwood system in
this country.

The use of the shelterwood system varies to some ex-
tent. The individual cuttings may be made uniformly
over the whole stand, or they may be concentrated in

THE SHELTERWOOD SYSTEM 1 53

Strips or groups; and in the latter case a given cutting
affects only a part of the stand. There are recognized in
Europe three methods of application:

Cuttings distributed uniformly.

Cutting in strips.

Cutting in groups.

Shelterwood System with Uniform Cuttings

This is called the uniform system because the va-
rious operations extend over the whole stand, and the
thinnings are designed to secure a regular and uniform
reproduction over the area, rather than in groups or in
strips.

In order to make the description concrete, let us sup-
pose that the stand in question is pure spruce, even-aged,
about 100 years old, and fully stocked. The design
is to cut and reproduce the stand within a period of 20
years. This is done by a series of thinnings which fall
into the following groups:

1. TJie Preparatory Cuttings ^ designed to prepare for
reproduction.

2. A Seed Cutting, which accomplishes the reproduc-
tion.

3. The Removal Cuttings, which are made to help the
seedling growth and which include the Final Cutting.

The Preparatory Cuttings. — The objects of the pre-
paratory cuttings are:

1. To prepare the soil for the reception and germina-
tion of the seed. A dense spruce forest is characterized

154 THE PRINCIPLES OF HANDLING WOODLANDS

by little or no undergrowth, and by a deep layer of litter
and humus. This forest floor is a very poor germina-
ting bed, and the first requisite for reproduction is to has-
ten the decomposition of the vegetable material. This is
accomplished by the preparatory cutting, which admits a
free circulation of the air. The object is to open up the
forest enough to bring about this rapid disintegration of
the humus, but not enough to allow the soil to run wild
with weeds and brush.

2. A second object is to stimulate seed production.
The first thinnings admit more light to the crowns and
stimulate assimilation, and hence seed reproduction.

3. Still another object is gradually to accustom the
trees to isolation, and make them more vvindfirm.

These purposes may sometimes be accomplished by
making a single thinning. If, however, the forest is very
dense, it may be necessary, on account of danger from
windfall, to open up the forest gradually by two or, in
some cases, three thinnings.

The preparatory cuttings are thinnings which open
the canopy uniformly throughout the stand. The trees
taken out in the preparatory cutting are primarily of the
following character:

1. Trees infected with disease.

2. Trees with suppressed, broken, or otherwise de-
fective crowns.

3. Trees with overdeveloped, spreading crowns.

4. Very tall, slender trees likely to be overthrown. by
the wind.

THE SHELTERWOOD SYSTEM 155

5. Species not desired in the next crop.

The aim is to leave thrifty dominant trees of moder-
ate size regularly distributed over the area. It is often
necessary to leave standing trees with overdeveloped
crowns, as well as undesired species, when their removal
would open the canopy so much as to induce a growth of
weeds and brush before the stand is ready for the seed-
cutting.

The preparatory cutting removes from 25 to 40 per
cent, of the trees, which amounts to from 20 to 30 per
cent, of the volume. The crown canopy is reduced 20 or
25 per cent. The aim is to isolate the trees very moder-
ately, leaving them spaced from 3 to 5 feet between the
peripheries of their crowns.

The number of cuttings needed, the severity of each,
and the aggregate opening made, depend on the follow-
ing factors:

1. Danger from Windfall, — The greater the danger,
the more gradual must be the opening.

2. Character of the Forest Floor. — The thicker the
vegetable cover, the heavier the cuttings. The slower
the natural processes of decomposition, the heavier the
cuttings.

3. The Character oj Canopy. — The thicker the can-
opy, the denser is the shade, and, consequently, the
heavier are the openings required.

4. Height of Canopy. — The higher the canopy, the
denser is the shade cast, and hence the larger are the
openings required.

156 THE PRINCIPLES OF HANDLING WOODLANDS

S. Soil. — The richer the soil, the greater the tendency
to growth of weeds.

The preparatory cuttings are successful when the soil
is in good condition for the reception of the seed about
the time when it is designed to make the seed cutting.
When the humus and litter are so far decomposed that
here and there mineral soil appears, the ground is in
receptive condition. Usually there is at the same time
a light growth of grass and tolerant annuals.

In a forest in which there is a deep humus to begin
with, the time required to bring about the desired con-
dition of the forest floor varies greatly with different
soils, and with humus derived from different species.
Roughly, from three to ten years may be required.

The Seed-Cutting. — As soon as the soil is ready to re-
ceive the seed, the seed-cutting may be made. This is a
heavy thinning, made through the stand, and designed
to establish the conditions necessary for the start of re-
production and for the life of the seedlings during the
first few years. It is the aim to make this cutting during
a seed year, in order that these new conditions may imme-
diately follow the fall of seed. If the soil has duly bene-
fited from the preparatory cuttings, and the seed-cutting is
made during a good seed-year, one cutting for seed is all
that is necessary. The seed-cutting removes from 2S to
SO per cent, of the volume of the stand. It reduces the
density of cover to 30 or 50 per cent.

The principles of selecting the trees for cutting are
similar to those governing the preparatory thinning,

THE SHELTERWOOD SYSTEM 157

except that the seed-cutting is a much heavier thinning.
The aim is to cut such defective, malformed, and sup-
pressed trees as are left from the preparatory cuttings.
The larger trees with spreading crowns are taken, because
of their possible danger to the reproduction if left for
later cutting. Trees of undesirable species, likely to re-
produce themselves in competition with the good species,
are also cut. Just as in the preparatory cuttings, the
trees to be left are of moderate size, and chosen from the
dominant class. They should be thrifty and capable of
rapid growth during the remainder of the period of re-
production. They should also be capable of producing
seed, since they not only must produce the greater part of
the seed for the first reproduction, but are also counted
on to seed up any gaps that may occur.

In general character, the thinning is uniform — that is,
it extends over the whole stand. Usually, however, it is
not necessary to be very precise in spacing the trees at a
uniform distance. It may happen that a given site is
subject to danger from frost, and that protection of the
small trees in the earliest period requires a uniform cover.
Even if the trees are not regularly spaced, a uniform
distribution of seed may usually be secured. If the seed
is distributed by the wind, small openings here and there
would be readily covered with seed, as well as the ground
under the trees. With trees having heavy seed, a good
distribution is obtained if the seed-cutting is made after
the ripening of the fruit in a seed-year. There is then a
production by all seed-trees left from the preparatory cut-

158 THE PRINCIPLES OF HANDLING WOODLANDS

tings, and the ground should be amply covered in a uni-
form manner. A slightly irregular thinning would not
be unfavorable to the young growth from the standpoint
of protection from drought, for there would usually be
enough side shade to meet the requirements of the seed-
lings. With trees of only moderate tolerance an irregu-
lar thinning might often be better than a uniform one,
because it would admit a certain measure of side light to
young growth standing under slightly too heavy shade.
The best rule is to make the thinning uniform so far as
the conditions permit, but not to make undue sacrifice to
uniformity where, for one reason or another, certain trees
ought to be removed.

In judging how heavy to make the seed-cutting, the
forester has in mind the distribution of seed, and the
maintenance of such a degree of shade as is necessary to
protect the new crop from drought and frost, and to hold
in check the growth of weeds. The usual rule is to
leave only as much as is necessary to accomplish this pur-
pose, in order that the uncovering of the crop later on
will be attended by the least possible danger.

If the preparatory cutting has been successful and
reproduction is pretty certain, a heavier cutting would be
made than when reproduction is uncertain. Just how ex-
tensive an opening of the canopy is best for establishing
and for protecting reproduction must depend in each case
on the species, the site, and the condition of the ground.

In Europe, it is often customary to aid the reproduc-
tion by artificial measures., Thus, if there is a growth of

THE SHELTERWOOD SYSTEM 1 59

grass and weeds which will interfere with germination
and the establishment of the reproduction, the soil is
sometimes broken up to expose the mineral soil. One
method is to break the ground cover with mattocks at
intervals of 5 or 6 feet, exposing about a square foot
of soil in each place. Another method, used when the
soil and topography permit, is to plow furrows among
the trees; and yet another in common use is to turn hogs
into the w^oods before the seed-year, to work up the soil.

In some instances a certain amount of planting is
done after the seed-cutting. This would be done when
natural seeding is uncertain, and the species requires shel-
ter during youth. If no shelter w^ere needed, the stand
would be cut and the trees planted on the clearing. The
planting in advance of cutting usually has for its object
the maintenance of a certain species in mixture. It is
a common measure in mixed beech and spruce forests,
where the natural reproduction of beech is better than
that of spruce. The young spruce-trees are planted near
stumps and rocks, w^here there will be the least possible
damage by the later logging.

When a seed-cutting fails to yield good reproduction,
and the ground is beginning to be covered with weeds
and brush likely to retard reproduction from later seed-
years, planting is commonly used to complete the new
stand. If the young growth requires shelter, the planting
is done as soon as the fail-spots are located; otherwise
the stand is cleared rapidly, and the planting done after
the final cutting.

160 THE PRINCIPLES OF HANDLING WOODLANDS

Fig. 33.— Just before the Removal of the Last Trees under the Shelter-
wood System. Young Growth has been Secured over the Whole
Area. Austria.

Fig. 34. After the First Work in an Open Irregular Stand. The Cut-
tings Followed the Principles of the Shelterwood System. Western
Yellow Pine. Black Hills National Forest, South Dakota.

THi: SHELTERWOOD SYSTEM 161

Very frequently there are at the tune of the seed-
cutting groups of advance growth. Any such groups
as are thrifty and will develop well after releasing, are
carefully protected. The shading trees are cut, so far as
there is need of more light; and, if desirable, a group
is entirely uncovered. Useless advance growth which is
likely to interfere with the new crop is cut out. Such
useless advance growth consists of poor species, poorly
formed and unsound trees, and trees so much suppressed
that they cannot recover and become of value.

The Removal Cuttings. — Just as soon as the young
growth is well established and no longer needs protection
from drought and frost, the shelter-trees are removed.
Sometimes this can be done in one cutting without dan-
ger to the seedlings from the sudden exposure; but it
is usually better to remove the shelterwood by a series
of cuttings.

The first removal cutting is made as soon as the seed-
lings begin to need a greater amount of light. As a rule,
this is wdthin three or four years after the seed-cutting.
The forester must watch the young growth to see if it is
sufiFering from shading. If the seedlings are stunted,
weak-looking, and unhealthy of color, and hav^e a sparse
foliage, or if they are found to be bending to one side in
their search for light, this is an indication that a thinning
must be made.

The removal cuttings are not made uniformly over
the whole stand, but are necessarily irregular, because
some portions of the new crop require more light than

162 THE PRINCIPLES OF HANDLING WOODLANDS

Others, or some are in a position to stand a greater
amount of exposure. Ordinarily three or four removal
cuttings are required in the best practise. These are
made at intervals of from 2 to 4 years.

Just as soon as the young trees have entered the stage
of rapid growth and are out of danger from exposure, the
final cutting is made. The last trees are usually taken ofiF
in about ten years after the seed-cutting.

The rapidity of the removal of the shelterwood neces-
sarily depends on the species and on the site conditions.
The operation progresses more rapidly with intolerant
than with tolerant species, with drought-enduring than
with moisture- loving species, with frost-hardy than with
frost-sensitive species, and more rapidly on favorable than
unfavorable sites.

The most serious problem in the removal cuttings is
the damage to the young growth. With hardwoods, this
is very small, because the young trees bend over under
the weight of the falling trees, and many of them recover
when released. The damage is greatest with conifers.
If the reproduction is abundant and the logging done
with care, this damage may be kept down to an amount
so small as not to materially affect the final crop. In
Europe, it is customary to plant up the blanks made by
damage in the final cuttings or by other causes.

Shelterwood Cuttings in Strips

This is a luodification of the method just described,
used principally when the uniform opening of a large

THE SHELTERWOOD SYSTEM 163

Stand endangers the trees from windfall. The cuttings
at a given time are made in narrow strips, instead of over
the whole stand. Beginning on the lee side and progres-
sing against the wind, successive strips are worked over
and reproduced until the whole stand is covered. The
first operations are the preparatory cuttings in the first
strip. After a few years the second strip is taken in
hand, and preparatory cuttings are made about the time
the first strip is ready for the seed-cutting. When the
first strip is ready for the removal cuttings and the second
for the seed-cutting, a preparatory cutting is made in the
third strip, and so on.

The conduct of the cuttings in this manner has cer-
tain advantages, as follows:

1. Since each operation is in a narrow strip in the
lee of an uncut block of timber, the danger from wind-
fall is less than when the whole stand is opened at
one time. This permits the use of the shelterwood
system under conditions which would otherwise pro-
hibit its use.

2. The protection from the wind gives a freer hand
in conducting the cuttings; in many cases, fewer opera-
tions in the series are required, and heavier individual
cuttings may be made.

3. The side shade is beneficial, while the protection
from the wind lessens danger from drought.

4. When used with species having light seed, as is
usually the case, there is an abundant distribution of seed
over a given strip from the bordering trees. This is

164 THE PRINCIPLES OF HANDLING WOODLANDS

particularly valuable in filling gaps, especially after the
final cutting.

The width of the strips varies with conditions, and
depends chiefly on the danger from windfall. The greater
this danger is, the narrower must be the strips. They
usually range in width from 100 to 600 feet. The period
of reproduction with a given stand is the same as in the
uniform system, namely, from 20 to 30 years, usually the
former. If a stand is so long that a series will not be
complete within the assigned period of reproduction,
two or more cutting series are made in the same man-
ner as described on page 133. The result is an approxi-
mately even-aged stand, with the trees at the side where
cutting began somewhat older than at the other side.
The difference in age would be hardly noticeable when
the stand reaches maturity.

Shelterwood Cuttings in Groups

This is a further modification of the principles of the
shelterwood system, by which the cuttings are concen-
trated at special points in the stand, and reproduction is
secured in groups, instead of in strips.

The system is used in mountain forests where breaks
have occurred and groups of advance growth have been
established. These groups are used as centers of repro-
duction. The cuttings begin about them and progress
radially from them. Ultimately, all groups are merged
together.

To illustrate concretely, suppose that in a given ma-

THK SHELTERWOOI) SYSTEM 165

ture stand of spruce and fir, there are a number of p^roups
of advance growth, from 20 to SO feet in width, of
the character shown in Fig. 30. The center of a given
group stands under an open or broken canopy, and there
the trees are the tallest. The group extends under the
denser portion of the canopy, obtaining enough side
light from the central opening for life.

The first cutting, which may be called the primar}^
cutting, is designed to uncover the larger of the young
growth, to give more light to the less vigorous trees near
the edge of the group, and to induce an extension of the
group in all directions.

It might happen that an actual clearing would be
made over the center of the group, while over the border
trees there would be a heavy thinning, and still beyond
there would be a lighter thinning. In fact, one w^ould
actually be making a final cutting over the center of the
group and a removal cutting over the remainder of it,
while immediately beyond the edge of the group the
thinning would resemble in severity a seed-cutting.
One could go farther, and if the forest were dense
immediately beyond this point, a thinning resembling
a preparatory cutting could be made in a still wider
circle.

All the groups are thinned as just described. Sup-
pose that the thinnings have been successful, and that
reproduction has taken place beyond and around the sev-
eral groups. They will then be extended a distance of
from 50 to 100 feet. A secondary cutting is then re-

166 THE PRINCIPLES OF HANDLING WOODLANDS

quired to continue the operation which has already
been started. In the secondary cutting more trees are
taken from over the existing groups, according to their
need, and the newly reproduced circle is opened up by
a heavy removal thinning. The portion which was in-
cluded in the previous preparatory cutting is thinned for
seed, and if necessary a preparatory cutting is made still
farther into the woods. These secondary cuttings are
made not necessarily in all groups at the same time, but
in any groups whose condition requires treatment. The
result of the gradual extension of these groups is that
they ultimately are merged together, and the whole stand
is reproduced.

As a rule, a long period of reproduction is used to
work over a whole stand — usually from 30 to 40 years.
The result is a stand much less even-aged than that ob-
tained by the other methods. The advance growth is
often from 20 to 30 years old, thus making a total varia-
tion in age in the new stand of from SO to 60 years. In
spite of the wide difference in the age of the trees, the
new stand is essentially regular in character, and is in no
sense a selection forest.

The Two-storied System

This is an intensive system used in Europe, having
for its object the isolation of the best trees during the last
half of the rotation in order to secure a maximum growth
in diameter and volume. It is applied to even-aged
stands of species which are windfirm and which have

THE SHELTERWOOD SYSTEM

167

168 THE PRINCIPLES OF HANDLING WOODLANDS

light or moderately light foliage, such as pine, oak, and
larch. When a given stand has reached its main height-
growth and the boles are well cleared by natural pruning,
a heavy thinning is made which removes from 40 to 60
per cent, of the trees. This thinning takes out the sup-
pressed, partially suppressed, and defective trees. Those
left standing are the best dominant trees in the stand.
Each tree is isolated, and will produce its greatest pos-
sible growth. Usually there is only one thinning, but if
the trees all tend to be slender and subject to possible
danger from windfall, two thinnings are made, the first a
light one and the second establishing just the conditions
desired. This thinning is made in pine stands at an age
of from 40 to 50 years, in oak at from 50 to 60 years, and
in larch at from 35 to 40 years.

The stand is then underplanted with some tolerant
species like birch, hornbeam, spruce, or fir, according to
the requirements of site. This constitutes an under-story
which protects the soil from deterioration. The lower
crop is of tolerant species, and is able to live under the
open stand of the older trees. Usually the crowns of the
upper story spread rapidly, and it is necessary, about once
in ten years, to make a further thinning to sustain rapid
growth and prevent excessive injury to the under-story
by crowding. At the end of the rotation of the upper
story, the whole stand is cleared, including the lower
story, and restocked artificially to a stand of the species
composing the upper story. If the rotation is 120
years, the trees of the upper story contain material of

'j'Hi: siir.L'i'i.Kwooi) s^'s'I•l:M 169

high grade and vaUic, of a size which would he pro-
duced under other systems only in about 1 50 years.
The understory niay be about 60 years old, more or
less crippled, and of small dimensions. It is used
for cordwood.

CHAPTER V

THE COPPICE SYSTEMS

Simple Coppice

Under this system a stand is cut clear, and reproduc-
tion takes place by sprouts from the stumps. It is ap-
plicable only to species which sprout vigorously after
cutting, such as chestnut, oak, maple, hickory, ash, tulip,
basswood, locust, birch, and certain other hardwoods. It
is not applicable to conifers, since, with a few exceptions,
these do not sprout from the stump at all.

The simple coppice system has for many years been
used in a rough, haphazard way by the farmers of the
hardwood region of the Northeast. Conspicuous illustra-
tions of its use are found in southern New England,
southern New York, and northern New Jersey. For-
merly many iron mines were operated in this region, and
consequently there was a demand for charcoal. The
hardwood forests were cleared off. The stands which
took their place were again cleared off as soon as large
enough for use, reproduction taking place by sprouts.
As the population increased, demand for fuel succeeded
that for charcoal, after the mines were closed, so that in
many sections it is still the custom to clear off the wood
at intervals of from 25 to 40 years.

]70

THK COl'I'in: SYSTEMS

It is a very simple system to practise, for there is no
skill to he exercised in selecting trees for cutting, and
reproduction takes place promptly and abundantly hy
natural means, and without expense. There are, how-
ever, certain principles governing sprout reproduction

Fig. 36.— Simple Coppice on a very Short Rotation, Illustrated by-
Willow Culture.

which must be observed in the continued practise of the
system. If these are ignored, the forests will deteriorate
and their productiveness will steadily diminish. Exactlv
this has happened in Xew Kngland. No attention has
been paid to the condition of the forest when cut, the
season of cutting, or the manner of cutting the stumps.
Fires have run through the woods repeatedlv and injured

172 THE PRINCIPLES OF HANDLING WOODLANDS

the trees, reducing their vitality and sprouting vigor.
The result has been that many stumps fail to sprout, the
density of stocking by good species is reduced, and the
growth and final yield are greatly diminished.

Willow culture is an example of simple coppice, han-
dled on a small scale and on a very short rotation.

Age of Cutting. — There is an age of maximum sprout-
ing vigor, which varies with diflFerent species and under
different conditions of site. It occurs in early life, and
ordinarily under 25 years. There is also a maximum
age limit of sprouting. This may, in individual cases, be
over 100 years. It is later with trees from the seed than
with trees that have originated from sprouts. There is
a point in the life of a stand of sprouts when certain indi-
viduals become defective and weakened, and reach the
limit of their power to send up vigorous shoots. If a
stand is cut after this period, some stumps fail to sprout,
and reproduction by this means is incomplete. This
period is usually from 25 to 40 years of age.

In simple coppice management the stands must be
cut young enough to insure sprouting from practically all
stumps, and the cutting should take place as near the age
of greatest sprouting vigor as practicable. In Europe,
oak coppice is often cut on a rotation of from 10 to
1 5 years. Experiments have shown that oak at this age
sprouts most vigorously and consistently, and that the
coppice system of regular cropping can be maintained
more successfully, and with less work of replacement and
fewer failures, than with a longer rotation. In some

THE COPPICi: SYSTEMS 173

cases the trees are allowed to grow to be 25 or 30
years old, but where larger timber is required one of the
modified coppice methods is commonly used.

In this country the market is seldom good enough to
cut trees below 25 years old. In certain places there is
a market for small material at brick-yards and lime-kilns,
and for domestic fuel. Under these conditions the trees
are cut on a rotation of about 25 years. More often, it
does not pay to cut the stand until at least ties and poles
can be obtained from the largest trees. This means a
rotation of 40 years or more. At so late an age the
simple coppice method is uncertain of reproduction, and
the pole-wood or system of holding over reserves is
preferable.

Season of Cutting. — The trees should be cut during
the season of vegetative rest. In general, in the climate
of New England, any time from September 15th to
April 1st is favorable. Cutting in April results in good
reproduction, but at this time there is danger of injury to
the stumps by the peeling of the bark and bruising in
removing the wood.

Care in Cutting. — The best sprout reproduction is
obtained by cutting low, smooth stumps. Where a verv
short rotation is used, as in Europe, the manner of sur-
facing the stump is even of greater importance than under
the conditions in this country. The European forester
takes care that a smooth cut is made on a slant, to shed
off the water. A ragged or cup-shaped surface tends to
hold water and hasten decay. A short rotation means the

174 THE PRINCIPLES OF HANDLING WOODLANDS

production of small trees and saplings. The stumps are
so small that they are rapidly covered over by the new
growth. If the stumps are cut properly they are covered
before decay sets in. With larger trees, such as are cut
in this country, it is often not possible for the new growth
to cover the whole stump; but low stumps mean vigor-
ous sprouting, little hindrance to individual development
by the sprouts, and much less danger from decay than
is apt to occur after careless cutting.

The Cutting. — It is important to remove the wood
from the clearing as soon as possible. Where the wood
is piled and left in place for a season, a good many
stumps are inevitably covered by the stacks, and thereby
prevented from sprouting. Moreover, when the wood is
taken, it is usually done by driving on the area with
a team and heavy wagon. Large numbers of one-year
sprouts are broken ofiF and otherwise damaged in this
way.

One of the serious problems in this country is the dis-
posal of the brush. Ordinarily the farmer throws the
brush in windrows. They may actually cover about 2S
per cent, of the whole area cut over. These piles cover
a large number of stumps, and either prevent them from
sprouting or cripple the sprouts enough to make them
useless.

Maintenance of Density. — If the stand is in healthy
condition when cut, the stumps sprout vigorously and
a full stand is the result. It often happens that certain
stumps have failed to sprout, or through previous abuse

THE COPPICE SYSTEMS 175

the stumps are too far apart. Sometimes new stock
creeps in by natural seeding. But under the simple
coppice method the rotation is short, and the trees do
not bear much seed. Therefore such seeding as occurs
comes largely from neighboring lots containing old seed-
bearing trees.

In Europe, where the rotation is very short, natural
seeding is never relied on to fill gaps in the reproduction,
but resort is had to artificial replacement. When a
sprout stand is cleared, it is closely examined with ref-
erence to the condition and vigor of the trees. Spots
where there are no stumps, and where stumps are likely
to fail, are filled by planting. In oak coppice, for exam-
ple, it is customary to plant in spaces as large as 15
feet square. The custom is to plant oak transplants
which have stood two years in the nursery. Ordinarily
these are cut back when planted. That is, the seedling
is planted, and then cut off at the ground. It throws up
a vigorous sprout and grows up with the remainder of
the stand. Such a plan naturally presupposes a regular
organization, with a nursery and with men in charge
of the property who are trained in such work.

Arrangement of Cutting. — In this country owners of
sprout forests cut a lot here and there as the trees come
to marketable size. In Europe, the system is extensively
used in the management of communal and government
forests. In such conditions the forests are so organized
that an approximately equal yield is secured each year.
This is accomplished by dividing the forest into as manv

176

THE PRINCIPLES OF HANDLING WOODLANDS

lots as there are years in the rotation. If the trees are to
grow twenty years, there will then be twenty divisions,
one of which is cut each year. After the work has been
in operation one rotation, there are 20 ages represented,
and one lot is coming to the rotation age each year. If
the quality of site is about uniform over the whole for-

FiG. 37. — Distribution of Annual Cutting- Areas in a Forest Managed under
the Simple Coppice System on a Rotation of Twenty Years. A Com-
munal Forest in Northern Germany.

est, these lots are made about equal in size. If there are
difiFerent types of land, with different qualitiep of site,
and hence with different yield capacities, the lots are
made somewhat larger on the poor soil than on the
good soil, so that the yield in material will be about
the same each year. The diagram above shows a
German communal forest divided into 20 annual cut-
ting areas.

THE COPIMCi: SYSTEMS 177

Holding Over Reserves

Under this system all trees in a sprout stand are
cut, except a certain number of selected individuals left
scattered over the area to remain during a second rota-
tion. Take, for example, a stand of oak, chestnut, hick-
ory, and maple sprouts 25 years old. Certain straight,
thrifty trees are designated to be left, and the remainder
cut clear, as in the simple coppice method. At the
end of the next rotation, the main stand will be com-
posed of 25 year old sprouts with scattered individuals
50 years old.

The purpose of this system is to use the land chiefly
for the production of small wood, and at the same time to
obtain a certain amount of large timber. It is the same
principle as the system of reserving thrifty standards,
described on page 118, applied to sprout forests. The
rotation is short, returns are frequent, and there is se-
cured a measure of the higher and more v^aluable grades
of timber.

When the stand is ready to cut, the forester marks the
reserves. He aims to leave, regularly distributed over
the area, as many trees as possible without interfering
with the reproduction from the stumps of those cut. As
sprouts do not thrive under cover, there must be no sem>
blance of a canopy of reserves, but the individuals must
be scattered. The number left depends on the toler-
ance of the coppiced trees, which necessarily varies w ith
different species and under different conditions. This

178 THE PRINCIPLES OF HANDLING WOODLANDS

number varies, further, with the age at which the sprouts
are cut. If 25 years is the rotation, more reserves can
be left than with a 40-year rotation, because the trees
have a much smaller spread of crown. As a general rule,
the number of reserves varies from 20 to 40 per acre.

The trees chosen for reserves are well-formed, domi-
nant trees with a moderate crown development. They
must be sound, thrifty, and windfirm. Trees standing
singly are better than those growing in clumps, though
it is often necessary to leave some of the latter class.

Under this system the returns are greater than under
the simple coppice. The total amount of wood produced
would not differ materially in cubic volume. The vol-
ume of coppice would be somewhat less because of the
space occupied by the reserves and the retarding of the
growth of shoots affected by their shade. It is probable,
however, that the loss of growth of the coppice would
be fully counterbalanced by the yield of the reserves in
cubic volume, and more than equalled in value. The
reserves are isolated, and have a maximum growth.
They reach a size in 50 years what it would take in a
closed stand 60 or more years to secure.

Pole-Wood Coppice

In most hardwood forests the simple coppice system
on a short rotation is not practicable, on account of the
lack of market for small material. The rotation is then
extended until the trees, or a portion of them, are large
enough for piles, poles, ties, or lumber. The age of

THE COPPICE SYSTEMS 179

cutting in this case is considerably later than the period
of best sprouting capacity. Reproduction by sprouts
alone cannot, therefore, be relied upon, but this must
be supplemented by establishing many seedlings, nat-
urally or by planting. The production of the pole class
of timber and the reproduction partly by sprouts and
partly from the seed, may be called the Pole-Wood Coppice
System.

Use in the Hardwood Region of the East. — This is
the method by which farmers' woodlots in southern New
England are often treated; there, however, it is practised
without design and with a poor degree of success from
the standpoint of forest production. It is customary to
cut the forest clear when a profitable sale can be made.
The large trees are used for lumber or ties, the straight
trees for poles, piles, and posts. The small, defective,
and crooked trees, and the tops, are used for cordwood.

The trees are cut when from 40 to 80 years old.
Some of the stumps sprout vigorously, some throw up
weak shoots, and some do not sprout at all. It usually
happens that a stand of second-growth hardwoods over
40 years old does not have a complete canopy. This
is especially true of stands originating largely from
sprouts. The small, scattered breaks in the canopy admit
light, heat, and a free circulation of air to the soil. As a
result, there may be started some advance reproduction
from the seed. If this advance reproduction is plentiful
at the time of cutting, and there are no fires to destroy
it, the reproduction by sprouts will be largely supple-

180

THE PRINCIPLES OF HANDLING WOODLANDS

mented by seedlings. In this way, many hardwood
staads, which are cut at an age when sprout reproduction
is uncertain, are followed by surprisingly good second
growth. Usually, however, fires run over the ground
at frequent intervals, or cattle are allowed to graze

Fig. 38.— a Stand of Hardwoods, Composed of Trees of Sprout
and Seedlings Origin, after the First Cutting under the Polewood
Coppice System. Southern New York.

through the woods; and at the time of cutting there are
very few seedlings, or none at all, so that the succeeding
stand is composed chiefiy of the shoots from such stumps
as may retain their sprouting capacity. There are wide
gaps between the clumps of sprouts, and the stand is
inferior in form, quality, and yield to the previous one.

THK coimmcm: SVSTKMS 1(S1

Continuance of such treatment results in steady deteriora-
tion of the forest.

The Reproduction Cuttings. — Tlie poor results of
this careless and haphazard way of treatinpj second-growth
stands are avoided by the systematic application of the
pole-wood system. The aim of the method is to secure
an advance reproduction of seedlings wherever there is a
possibility that sprout reproduction will not be complete.
This is accomplished by making a thinning to open the
canopy sufficiently for natural reproduction. When the
seedlings have become established, the rest of the timber
is removed in one or more operations.

This system is in reality, therefore, the shelterwood
system wdth a short rotation and the use of both seedling
and sprout reproduction. Ordinarily there is no need
of a preparatory cutting. Most of the hardwoods with
which it will be used are intolerant of shade, and do not
form a heavy canopy. Usually there is not a heavy layer
of litter and humus. Since the trees are windfirm, a
preparatory cutting as a precaution against windfall is
not needed. The first cutting is, therefore, a seed -cut-
ting.

The selection of the trees in this seed-cutting de-
pends primarily on how far reproduction by sprouts can
be counted on. If there is uncertainty as to the sprout-
ing of most of the stumps, the effort should be to get a
fairly general distribution of seed over the whole area.
Thus, in the case of a mixed stand of oak and hickory
from 60 to 70 years old, the period of greatest vigor of

182 THE PRINCIPLES OF HANDLING WOODLANDS

sprouting has already been passed, and it is difficult
to tell which trees will and which will not sprout.
The procedure, under these circumstances, is to make
a uniform seed-cutting; that is, the stand is thinned
throughout, instead of only in patches. The principles
governing the cutting are the following:

1. The thinning removes about 35 per cent, of the
volume.

2. The cutting takes the suppressed and defective
trees, and those with large spreading crowns, especially
any overgrown individuals which are older than the
main crop.

3. In choosing between two trees, the least vigorous
is cut, for the other will bear most seed, be most likely
to sprout after the seed-cutting, and grow most rapidly
before the final cutting.

4. In case of clumps of trees which have originated
from sprouts, only defective and suppressed trees are
taken. The dominant thrifty trees in a clump are
treated as one tree. If, on account of defect, one or more
large, dominant trees in a clump must be cut, the entire
clump should be removed. If there is not space for a
healthy development of sprouts the opening should be
enlarged, so as to secure straight and vigorous sprouts.

5. All scattered individuals of undesired species are
removed. Such sprouts as appear will be checked by
the shade of the remaining trees.

6. If there are good groups of advance seedling or
sprout reproduction, trees which are shading them should

THE COPPICE SYSTEMS 183

be cut, and in removing the trees, the groups should be
carefully protected.

7. If for any reason the cutting takes healthy, domi-
nant trees which are likely to sprout, the development of
the sprouts is guaranteed by making an adequate opening
in the canopy — cutting the neighboring trees if neces-
sary.

As soon as there is a sufficient amount of seedling
reproduction fully to supplement the sprout reproduc-
tion, the remainder of the stand is cut clear.

In many hardwood forests of the Northeast, there is
a mixture of chestnut which sprouts vigorously even
when the trees are 60 or 80 years old. Chestnut grows
very rapidly, and usually has the largest yield of ties,
poles, and lumber. The best results are obtained, in
applying the pole-wood system, when the seed-cutting
is confined chiefiy to species which are less likelv to
sprout, like oak and hickory. It often happens that the
chestnut occurs more or less in groups of from 5 to 10
clumps together, though individual clumps and trees
occur scattered among the other species. The chestnut
should be cut as little as possible at the seed-cutting,
on the same principle that in an oak stand the individuals
most likely to sprout well are left until the final cutting.

It may happen that an owner may wish to cut the
chestnut, or a part of it, at the first cutting. In that
event, whole clumps should be cut and not individuals
from a clump, and in all cases openings should be made
large enough for good sprout development.

184 THE PRINCIPLES OF HANDLING WOODLANDS

The presence of young chestnut sprouts here and
there in the stand will necessitate care in taking out the
wood at the second cutting, in order not to injure them.

The average well stocked stand of hardwoods 50
years old, in New England, yields from 25 to 30 cords
per acre. The first cutting removes from 6 to 12 cords.

The Second Cutting. — The final cutting may be made
after an interval of from 5 to 10 years. Usually, the
second cutting is a clearing. This is the best plan, for
if there were more than one final cutting, there would be
a great deal of damage to the sprouts in felling and
removing the trees left standing. In many cases, how-
ever, it may be desirable to leave scattered reserves to
remain during a second rotation.

In making the seed-cutting the cost of cutting and
piling the wood is S to 10 cents per cord more than if
the stand were cleared. The cost of removing the wood
is also increased 5 to 10 per cent. The cost of marking
is about 3 cents per cord. The total added cost of the
method, including the burning of the brush, over that
of the old method of general clearing, is from 20 to 40
cents per cord for the wood taken out at the first or
seed-cutting.

Coppice with Standards

The principles of the system of coppice with reserves
described on page 177, may be extended still further in
what is known as coppice with standards (also called
stored, or storied, coppice). This differs from the sys-

THE COPPICi: SYSTEMS

183

Fig. 39. Coppice with Standards. Germany

Fk;. 40. — Another Kxaniplc of Coppiic with Standards. CTerniany.

186 THE PRINCIPLES OF HANDLING WOODLANDS

tern described on page 177 in two particulars; first,
the reserves are left over several rotations for the pro-
duction of very large trees, and second, the reserves are
chiefly trees from the seed, and not sprouts.

This is a svstem long in vogue in Europe, and now
practised there very extensively, especially on private
and communal forests. As yet the method has not been
used systematically in this country, but it will be un-
doubtedly as soon as there is a market for the products
of coppice cut on a short rotation. The description given
below necessarily applies to the practise in Europe.

This system is most simply understood by following
its development from the simple coppice. Suppose that
there is a simple coppice managed on a 20-year rota-
tion, and it is decided to develop a system of coppice
with standards in which the latter will have a rotation of
100 years.

When the sprouts are cut, a certain number of re-
serves are chosen from among the best trees in the
stand. Seedling trees are used if they occur; otherwise
the best sprouts are used. If there are likely to be no
seedlings in the reproduction, some are established by
planting. Twenty years later, at the time the coppice is
again cut, new reserves are chosen among the best trees,
preferably seedling trees, of the 20-year-old wood. After
cutting there will then be standards 20 and 40 years old.
After the following 20 years, the oldest standards are 60
years, the next 40 years old; and then some 20-year-old
standards are chosen as before. This process is continued

THK coiMMci: systf:ms 187

until the first standards reach the hnal age designed for
them; in this case, 100 years. There will then be on the
ground standards 100, 80, 60, and 40 years old, \n addi-
tion to the 20-year stand composed of sprouts and such
seedlings as were established at the last cutting. The
oldest standards are then cut, and new seedlings started
in their place.

There is no rule regarding the number of standards.
Sometimes in European practise the main stress is laid
on the coppice production, and only a few standards are
held over at each cutting. In this case the production
of sprouts would be but little interfered with. In other
cases the main stress is on the overwood. The system
then approaches the selection system, combined w ith the
production of a coppice crop. The form and condition
of a compound coppice forest may be illustrated by the
number of standards of different ages per acre. Drawing
from a European stand in which the standards are oak,
there might be the following at the time of cutting:

Number of Standards

100 years old, 1

80 " 2
60 " 3

40 '' 12

20 " 20

In this table it is seen that the number of standards is
progressively smaller with increase of age. Theoreti-
cally, it is designed to have all classes of standards occupy
equal areas. Enough standards are held over in the be-

188 THE PRINCIPLES OF HANDLING WOODLANDS

ginning to allow for loss through accident and for thin-
nings.

When a cutting is made, the spaces formerly occupied
by the old standards are filled with seedlings by planting.
The younger standards are inspected carefully, and thin-
nings are made when desirable, so as to benefit the best
standards and to maintain the area occupied by each age-
class at about the normal.

The species used as standards are those which have a
relatively light foliage, such as oak and ash. The under-
wood is best composed of comparatively tolerant species,
such as (in Europe) alder, hornbeam, beech, elm, and
maple.

The standards are crowded from the side only during
the life of the sprouts, and consequently have only a
comparatively short stem cleared of branches. Since
they stand isolated for most of their life, they develop
broad, spreading crowns. The diameter growth is at a
maximum, and they produce one or two very large logs.

CHAPTER VI
IMPROVEMENT OF THE FOREST

Improvement Cuttings

Under this head are comprised those cuttings which
are made in immature stands to improve their character
and growth. Their specific objects are:

1. To improve the composition of the stand.

2. To improve the form of the trees.

3. To increase the rate of growth of the trees.

4. To increase the yield and value of the final
product.

Improvement cuttings are thinnings designed to give
to the best trees the amount of light and growing space
most favorable for their best development. Their pur-
pose is entirely to benefit the existing stand. As far as
possible, the openings are made small, with the expecta-
tion that in a few years the crowns of the surrounding
trees will close together. They thus differ from repro-
duction cuttings, in which permanent openings in the
canopy are made with the ijitention of establishing re-
production.

189

190 THE PRINCIPLES OF HANDLING WOODLANDS

Improvement cuttings may be classed in the follow-
ing groups:

1. Cleanings.

2. Liberation cuttings.

3. Thinnings.

4. Damage cuttings.

Cleanings

This term is applied to cuttings in young, even-aged
stands which remove the undesirable trees likely to
overtop and injure those of greater promise. In nearly
every young stand there are a certain number of indi-
viduals of poor species or of poor form which grow taller
than the surrounding trees; and if these are allowed
to stand, they will interfere w-ith or actually kill trees of
prospective value. These undesirable trees are removed
by the cleanings while the stand is still very young, and
before they have done any appreciable damage. The
small openings made by their removal are quickly closed
together.

The material which most commonly requires atten-
tion is advance growth of poor species or of poor form.
A tree from 5 to 10 years older than the main stand
may develop an open-grown form, overtop and injure
the surrounding trees of good form, occupy a proportion-
ately large space where a number of much better trees
might be growing, and itself produce knotty, inferior
wood. Often this advance growth is composed of infe-
rior species. If, however, a stand is poorly stocked, and

IMPROVEMENT OF THK FOREST 191

an advance tree is more or less isolated, it really consti-
tutes an integral part of the crop, and is allowed to stand.

In reproducing a forest naturally, the species most
desired often do not establish themselves as quickly as the
poorer kinds, or, during early youth, the inferior species
may be the more rapid growing. If the stand is left
untouched, a large number of the most promising trees
may thus be killed or crippled, and the value of the crop
may be much reduced. A good illustration of this
condition is found in New England. After a pine stand
is cut, the first species to spring up are hardwoods.
Later on, young pines creep in abundantly under the
hardwoods, but many of the pines are killed in the com-
petition. A cleaning would release the best pines, and
thus maintain the species in the next crop.

The application of this method may be seen also in
the mountains of Europe, where beech and spruce in
mixture are reproduced naturally. The two species come
up together in the reproduction, but the beech grows
the more rapidly, overtopping and injuring the spruce.
The latter is maintained in proper proportion onlv bv
cleanings in which those beeches which are likely to in-
jure the spruce are cut back.

In hardwood regions one of the problems is to pro-
tect young seedling trees from sprouts. The latter grow
very rapidly during early youth, and in some cases over-
top seedling trees which are of special value. This is
illustrated where pine is planted after the clear-cutting of
hardwoods. There are inevitablv a certain number of

192

THE PRINCIPLES OF HANDLING WOODLANDS

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IMPROVEMENT OF THE FOREST 193

fast-growing sprouts which overtop and injure the pine
trees. Unless the stand is cleaned in early life, there
may be a very large percentage of loss to the pine. The
author is familiar with one plantation of pine which was
practically destroyed in this way.

There is often a considerable growth of brush which
competes with valuable young trees. Thus, in Penn-
sylvania such shrubs as scrub oak, sweet-fern, blueberry,
etc., injure an immense amount of valuable young tree
growth. This damage can practically be eliminated by
cleanings.

Cleanings are made in young stands as soon as the
overtopping trees begin to be injurious. The first cut-
ting is usually made within the first 10 years after the
establishment of reproduction. The best plan is to make
a cleaning within the first five years, and then go over the
ground a second time within the next five years.

The trees are either cut down at the base or they are
lopped. Sometimes the lopping of a single branch is
sufficient to release a crowded tree permanently. It may
occasionally be the best plan to lop off the head of a tree,
leaving a high stub. This is done when there w^ould be
danger of rapid sprouting from low stumps and the over-
topping of the released trees.

In making cleanings, the forester must make it a point
to remove only that which is absolutely necessary for
accomplishing the purpose of the operation, and in this
way to hold down the expense of cutting. There is a
temptation to cut more than is necessary, and hence to

194 THE PRINCIPLES OF HANDLING WOODLANDS

increase the cost beyond what is warrantable. The work
does not require much skill, and can be conducted by an
intelligent foreman after some instruction. The part
requiring the greatest exercise of judgment is the deci-
sion as to how much should be cut in a given case.

In making cleanings one ordinarily uses a bill-hook
or a heavy hunting knife. One of the most satisfactory
tools is a plain straight Rogers steel hunting knife of
the largest size, with a 10-inch blade and weighing
about 2 pounds.

The cleaning is a cultural operation, and usually yields
no immediate money return. The cost necessarily varies
under different conditions. It is commonly between 2S
cents and $2 per acre, and averages about 50 cents. An
outlay in cleanings may be distinctly profitable in the
long run. An expenditure of 50 cents per acre may pre-
vent the injury of 30 or 40 per cent, of the valuable trees

in the stand.

Liberation Cuttings

It frequently happens that in immature stands there
are scattered trees much older than the main crop which,
by their wide-spreading crowns, overtop and retard the
development of the younger trees. The removal of
these trees may be called a liberation cutting. This
operation should not be confused with a cleaning in
which the trees removed comprise advance growth only
a few years older than the average. In the liberation
cuttings there is a wide difference between the age of the
trees to be cut and of those in the main stand.

IMPROVEMENT OF THE FOREST 195

There are two problems of liberation cuttings: first,
in vounp: stands where the crowns of the old trees are
well above the ) oung trees ; and second, w^here the
crowns of the young trees have reached the crowns of
the scattered older trees.

The first problem is exactly analogous to the removal
and final cuttings in the shelterwood system of natural
reproduction. There has not yet been any material in-
jury to the young growth, and the overtopping trees may
have been a benefit from the standpoint of shelter. In
removing the overtopping trees care is taken to do as
little damage as possible to the young trees. If the
young stand has a good density, the openings will be
rapidly filled by the meeting of the crowns. If the
opening is too large for this, it is often possible to plant
some young trees, which will then grow up with and
form a part of the main stand, even though a few years
younger.

In the second problem the stand is older than in the
case just described, and the scattered old trees have al-
ready retarded the development of the trees immediately
under and near their crowns. This is the situation very
frequently encountered in second-growth forests. Usu-
ally these trees are large, with short boles and broad,
spreading crowns. They will not increase appreciably
in value, and their continued presence in the stand
means further injury to the trees near them. They are,
therefore, cut for the benefit of the stand. It often hap-
pens, however, that the opening made by cutting one o^

196 THE PRINCIPLES OF HANDLING WOODLANDS

these trees is too large to be filled by the closing of the
crowns. In other words, a permanent opening is made,
in which reproduction of trees, brush, or weeds will
take place. Such reproduction as comes in will probably
not be thrifty, because the opening is too small to permit
normal development of the new growth. But even if it
is not possible to secure in these openings reproduction
that will thrive, the stragglers should be cut for the bene-
fit of those trees which surround the opening.

Sometimes the scattered older trees are well formed,
middle-aged, thrifty trees. These are not cut, but rather
are treated as reserves, and allowed to stand for the pro-
duction of large timber.

Usually the trees cut are large enough for the market.
The operation yields a good return. The liberation cut-
ting is frequently made at the same time as a thinning.
The large size of the trees may sometimes increase the
general grade of the product, and thus make possible
a thinning where this would by itself bring so small a
return that the owner would be unwilling to make it.

Thinnings

This term is applied to cuttings made in immature
stands with the object of reducing the density of canopy,
and of giving to the most vigorous trees that space and
light needed to secure most quickly the product desired
in the management.

The word thinning is an unfortunate term, because
any cutting other than a clearing is in a sense a thinning.

IMPROVEMENT OF THE FOREST

197

198 THE PRINCIPLES OF HANDLING WOODLANDS

The term has, however, come to have a restricted techni-
cal meaning, both in British and American practise, and
for that reason the author has chosen to retain it rather
than to undertake the establishment of a new and unfa-
miliar expression.

Thinnings are made chiefly in even-aged stands.
When used in even-aged groups in irregular stands,
the principles are the same as where the whole stand
is even-aged. Therefore the discussion in the follow-
ing pages will be confined chiefly to the application of
thinnings in stands which are even-aged or approxi-
mately so.

Need of Thinnings. — For the purposes of forestry it
is desirable for trees to grow in crowded stands. The
mutual crowding results in the natural pruning of the
stems and the production of high-grade lumber. In
planting forests the trees are set from 4 to 6 feet apart, or
from 1,200 to 2,800 trees per acre, and successful natural
reproduction often results in an even greater density of
stocking. As soon as the crowns of the trees meet, and
their growth is consequently restricted, the struggle for
light, space, moisture, and nourishment begins. One
of the first manifestations of this competition between
the trees is their difference in crown development.
Some trees forge ahead and take their place as leaders,
with strong, dominant crowns; others fall behind, with
crowded crowns, and take an intermediate place, while
the weak trees are suppressed and overtopped. As the
stand grows older and the trees must have more space

IMPROVEMENT 01 THK FOREST 199

for growth, the differences between the development of
the individual trees are intensified. It is always the
leaders which are best able to spread their crowns, so
that many trees that are only partially crowded at first are
later on suppressed, and those at first suppressed are at
last actually killed. There is, therefore, a rapid reduc-
tion of the numbers of trees by the natural struggle for
existence.

The development of a stand in this manner is at-
tended with both advantages and disadvantages. The
chief advantage is that the crowding results in the death
of the lower branches and the production of clear stems.
On the other hand, the restriction of the crowns, in both
length and width, results in a reduction of the diameter
and volume growth of the individuals. While the trees
are young, the retarding of growth is relatively small,
because only a small crown is required for growth and
the natural vigor of the trees is at a maximum. Later
on, there is a progressively greater relative difference
between the actual and possible growth through the
reduction of the crown. In some cases the crowns are so
reduced that they do not occupy more than 1 5 per cent,
of the total length of the stem. Such a tree is lankv, and
exposed to damage by the wind; it is incapable of good
seed production; it is weak and subject to insect attacks
and to damage by excessive droughts; and its product,
though of high quality, is quantitatively much less than
it might be. The crowding of a stand is, therefore,
beneficial in youth, as it contributes to the production

200 THE PRINCIPLES OF HANDLING WOODLANDS

of clear-boled trees; but excessive crowding in later life
results in a great reduction of growth.

In a crowded stand left untouched, the struggle for
space sometimes results in injury to the form of good
trees. Most trees tend to grow straight, and the crook
or sweep in a stem is often due to its bending and reach-
ing for light, through being crowded on one side by
another tree. This is particularly true in coppice stands,
where a clump of sprouts all start straight, but through
mutual crowding may all develop crooked stems.

Then, again, poor species will often take a dominant
place and crowd those of more value.

Results of Thinnings. — The practical results of thin-
nings are as follows:

1. Rapid growth of individual trees. It is possible
to bring a stand to merchantable condition 10 or 20
years sooner than without thinnings.

2. Increased total yield. In Europe, about 30 per
cent, of the total aggregate yield of a stand during the
rotation is from thinnings. This amount is really a sur-
plus, because the final yield is not less, and is sometimes
even more, than if there had been no thinnings.

3. Improved quality of product. The forester has
the opportunity to develop trees of specially high quality,
clear stems, and even grain. By timely thinnings he can
prevent the distortion of valuable trees through side
crowding, and thus reduce the percentage of crook.

4. If there is a cordwood market, decadent and de-
fective material can be utilized.

IMPROVEMENT OF THE FOREST 201

5. By the prompt removal of diseased and insect-
infested trees further injury from these sources can be
prevented.

6. The amount of inflammable debris on the ground
is less than where there are no thinnings.

7. The trees are more windfirm.

Theory of Thinnings. — The objective point is the
development of the dominant trees of good form. The
aim is to give them the space required for their proper
growth, with a view to a larger yield per acre, and the
maintenance of a degree of density of cover which will
maintain the soil in good condition.

In making thinnings, therefore, the forester studies
the crowns of the trees and their position in the canopy.
He does not consider the number of trees per acre, or
the spacing between the trunks; his principal attention is
directed to the requirements for crown space of the trees
he seeks to develop. In order clearly to understand the
principles of thinnings, the reader should keep in mind
the distinctions between the different crown-classes, as
outlined on page 28, and illustrated in the diagram on
page 29.

The methods of thinning most common in Europe
are those developed in Germany and to-day most exten-
sively practised in that country. The theory is to re-
move, first, the suppressed stand, and then such of the
intermediate and co-dominant trees as are required by
the local conditions and objects of management Dom-
inant trees are not cut, except in the case of indi-

202 THE PRINCIPLES OF HANDLING WOODLANDS

viduals which are defective, injured, dying, or dead, or
have exceptionally poor form.

The characteristic of the method is that the trees pri-
marily chosen for cutting are in the subordinate part of
the stand; and then such others are taken as are required
by the special objects of management. Normally, the
suppressed trees are not left standing at all, unless it is
necessary to remove one of the larger trees because of
some defect, and in that case subordinate trees are left as
a ground cover.

The selection of the trees for cutting depends on how
severe a thinning is required. For convenience in sys-
tematizing the work, thinnings are classified into the fol-
lowing grades, based on the severity of the cutting:

Grade A. Lighty removing the dead and dying trees.

Grade B. Moderate, removing all suppressed and,
in addition, the lower of the intermediate trees.

Grade C. Heavy, removing, in addition, the re-
maining intermediate trees.

Grade D. Very Heavy, removing, in addition, many
of the co-dominant trees.

A heavier cutting than Grade D is called an accretion
cutting. (See page 216.)

Principles Governing the Severity of Thinnings. —
The grade of thinnings to be used in any given case de-
pends on a variety of circumstances, of which the follow-
ing are the most important:

1. Purpose of management.

2. Condition of the stand.

IMPROVEMKNT OF 'IHK lOREST 20J

3. "Folerance of the species.

4. Danger from windfall.

5. Site.

Purpose of Management. — The character of the
product depends on the density of the stand. If the aim
is to secure rapid growth in diameter, the stand must he
opened sufficiently to permit the development of a full
crown. The long, full crown means, however, a shorter,
clear-length and coarser logs from the upper stem. The
largest trees and the greatest yield in log measure are ob-
tained by the heavier grades of thinnings. On the other
hand, for the production of trees of high qualitv mod-
erate thinnings are made. In general, the best results are
obtained by making the thinnings during the first half of
a stand's life moderate, in order to secure good iorm of
trees, and then, after the main height growth is reached,
thinning heavily, in order to secure rapid growth in diam-
eter and volume.

Condition of the Stand. — The considerations in the
previous pages are necessarily subject to modification, if
a stand is not regular or does not hav^e a uniform densitv.
In many stands — in this country, most of them — there
are undesirable individuals in all crown classes. There
are dominant trees of poor species, trees of poor form,
defective trees, etc., which are cut whenever their removal
will benefit the stand. In a thinning designed to be of
the B grade, there might be taken out co-dominant or
even dominant trees, of imdesirablc character. So, also,
in a thinning designed to be of the D grade, there

204 THE PRINCIPLES OF HANDLING WOODLANDS

might be such a small density that intermediate or even
suppressed trees should be left to fill gaps.

Tolerance of Species. — Tolerant species suffer from
overcrowding less than intolerant species. To maintain
a full crown and rapid growth, the latter must be thinned
the more heavily. Conversely, to secure wood of high
quality, the stand must be kept denser with the tolerant
species.

Danger from Windfall. — If there is danger from
windfall, the stand is thinned early and heavily in order
that there may be developed trees with strong roots. If
an older stand is dense, and there is danger from wind-
fall, the thinnings must be very moderate.

Site. — On good soil the trees are vigorous and the
differentiation into crown-classes is more rapid and
sharply defined than on poor soils. The trees respond
quickly and energetically to thinnings, and fill very rap-
idly any gaps that have been made. Heavy thinnings
may be made on good soils without danger of exposing
the soil to drying influences. The poorer the soil,
usually the greater is the need of thinnings to secure
good growth, but the greater is also the danger of ex-
posing the soil.

Time of First Thinning. — The best results are ob-
tained if thinnings are begun early in the life of the
stand. It would be a benefit if light thinnings were made
as soon as the active crowding and sharp separation into
crown-classes begin. This would ordinarily be when
the trees are between 10 and 20 years old. In some

IMPROVEMENT OK THE FOREST

205

Fig. 44. — A Stand of White I^ine after a Thinning. New Hampshire.

206 THE PRINCIPLES OF HANDLING WOODLANDS

instances in Germany, Scotch pine stands are thinned
as early as at 12 years. Unless, however, there is a mar-
ket for very small sapling wood for fuel, a very early
thinning would bring no return whatever. The general
rule is that thinnings shoulci begin as soon as returns
from the sale of the material covers the cost of the
operation.

In most cases it will not pay to make thinnings in-
volving an actual outlay. There are millions of acres of
second-growth, even-aged timber in this country which
need thinning, and neeci it badly, but are so situated with
reference to the market that the product of the thinnings
could not be disposed of at all. In the better popu-
lated districts, where there is a market for fuel, thin-
nings may often be made without loss, even at an early
period in the stand's life.

Often a farmer is able to spend some of his own time
or that of his regular employees in such work, without
sacrifice to other work, and hence without a real loss.
An owner may have in charge of his property a forest
ranger who can devote part of his time to thinnings with-
out interfering with his main work. Under such cir-
cumstances it certainly pays to make early thinnings, even
before the product is salable. Therefore a rule based on
market conditions does not answer the question as to
when thinnings should be begun.

In some instances when the prospective value of the
timber is large, it will pay to make thinnings, even if this
entails an actual outlay of money. When such thinnings

IMPROVEMENT OF THE FOREST 207

would mean the protection of the valuable trees against
the crowding of less valuable ones, and the stimulation of
growth in a stanci which is stagnating from overcrowd-
ing, an investment in thinnings is warranted.

The owner of a forest is interested in knowing
whether there is not a critical period before which thin-
nings should be made if they are to be of any real benefit.
There is such a critical period, which differs with differ-
ent species and with different conditions, and which
ciepends also on the object of management. The forest
should be thinned before the crowns of the dominant
trees are so far reduced that the trees cannot respond
to the improved conditions and accomplish the objects of
management. If, for example, the purpose is to produce
a maximum of large trees and a large v^olume of timber
measured in board feet, the thinnings must be begun
while the crown is relatively long. If the crown is per-
mitted to become verv small and short, occupying only
10 or 15 per cent, of the stem, the trees are not capable
of much benefit from thinnings. In managing white
pine for the production of box boards, the aim should be
to begin the thinnings before the crow^ns of the dominant
trees are on an average reduced below 40 per cent, of the
total height of the trees. If for convenience the ratio be-
tween the crown length and that of the full stem is called
the crown-ratio, the critical period in white pine managed
for box boards is when further postponement of thinnings
would be likely to reduce the crown-ratio to less than 40
per cent.

208 THE PRINCIPLES OF HANDLING WOODLANDS

The critical period would be later if the aim of man-
agement were the production of wood of high quality.
In that case it might depend on a crown-ratio of 20 to
30 per cent., according to the species and site conditions.

The experience in thinnings in American species is
so limited, and the markets are so poor for the products
obtained from them, that no data can be given as to the
time of beginning the work of thinnings with the various
forest types.

Repetition of Thinnings. — Thinnings make small, \
temporary openings in the canopy which grow together
in a few years. Theoretically, the thinning is repeated )
as soon as the crowns close over these openings. The '
interval between thinnings would depend, then, on the
severity of the cutting and size of the openings. The old
rule in Germany was to thin early, moderately, and often.
Frequently in Europe thinnings are made at intervals
of from 3 to 5 years. That is, of course, a very in-
tensive application of thinnings. More often from S
to 10 years represents the interval between thinnings.
The interval is shorter in youth and middle life, when
the growth of the crowns is rapid, than later, when it
takes longer for the crowns to meet.

Application in Europe. — The principles outlined in
the preceding pages may be illustrated by the policy of
thinnings recommended bv Dr. Heinrich Mayr, of Mu-
nich, Germany, and by Dr. Flury, of Zurich, Switzerland.
Dr. Mayr's program for the treatment of the average
even-aged stand in Germany is as follows:

IMPROVEMENT OF THE FOREST 209

The cleanings are begun before the canopy is closed.
From that point until it is from 30 to 40 years old, the
stand is kept as dense as possible. During this period
the death of the lower branches takes place over a satisfac-
tory proportion of the stem. Then regular thinnings
begin. The first thinning removes the dead and the
suppressed trees. About 5 years later a second thinning
removes suppressed trees, and also cuts into the lower
intermediate class. Some 5 five years later a third thin-
ning is made, comprising, in addition to the above, many
of the intermediate and some of the co-dominant trees.
This brings the stand up to about the 50th year. The
main object up to this point has been the development
of form and quality. After this period the stand is
thinned much more heavily for the production of vol-
ume. The design is then to give the crowns the advan-
tage of full light. These cuttings occur every 5 years
till the stand is about 80 years old. During this period
the distance between the crowns is kept at about a meter.
After the 80th year the cuttings are made every 10 years,
and the crown distance is increased to about 2 meters.
Dr. Mayr classifies these last cuttings — from 50 years
on — as accretion cuttings, and assigns the term '*thin-
nings" to those from the cleanings to the 50th year.
The planting of an under-story, preferably of beech, as a
ground cover during the period of accretion cuttings is
recommended.

Dr. Mayr estimates that ordinarily there would be
approximately 400 trees per hectar, or 160 per acre, at

210 THE PRINCIPLES OF HANDLING WOODLANDS

the end of the rotation. He estimates that the aggre-
gate yield of the thinnings and the accretion cuttings
will be about equal to the volume of the final cuttings,
and that the latter will be fully equal to the final cut-
tings under other methods of treatment.

This program is somewhat more drastic than that
recommended by some other European foresters. It may
be compared with that of Dr. Flury, whose proposals are
the result of a series of experiments in stands subjected
to different grades of thinning.

Dr. Flury's conclusions for the management of spruce
are that the thinnings should begin early and be con-
ducted regularly. During youth and up to about middle
age — 50 to 60 years — they should be between grade B
and C, approaching C. After middle age they are in-
creased to a full C grade. At the beginning of the last
third of the rotation, the stand is in a condition to
require no more real thinnings. From that time further
openings would be of the character of accretion cuttings.
He recommends an early beginning of reproduction
cuttings under the shelterwood system and a long pe-
riod during which the trees would grow rapidly in an
isolated position, with the grounci protected by the young
crop. This plan differs from that of Dr. Mayr chiefiy
in extending the period of real thinnings, and thus
holding the stand dense for a longer time.

The French Method. — Somewhat in contrast to the
principles just described, is a method of thinnings used
very extensively in France,

IMPROVEMENT OF THE FOREST 211

The objective point in this method is to assist trie
growth and development of a certain number of the best
individuals in the stand. The trees chosen are those
most suited to form the final dominant stand, and the
number is fully equal to what may stand on the area at
maturity. These trees are given the right amount of
light and space required for them to produce the class of
timber desired. This is done by removing the upper
intermediate, co-dominant, and, sometimes, even the
dominant trees that are crowding them. The subordi-
nate stand is not cut, except to remove dead and dying
trees. Most of the lower intermediate and suppressed
living trees are retained. Their removal would have
practically no effect in helping the growth of the selected
leaders, and they act as a soil cover, thus permitting
greater freedom in cutting in the upper classes without
fear of exposing the soil. The presence of the subordi-
nate trees results in excellent natural pruning of the
trees in the main stand, particularly by hastening the
decay and fall of the dead branches.

Comparing this method with that used in Germany,
it is in substance a thinning in the main stand of the
grade D, and a thinning in the subordinate stand of the
grade A. From the standpoint of practical operation,
the method has the advantage that the trees cut are almost
all in the upper classes; their average size is larger than
in the other method, and hence the returns are greater.
This would sometimes warrant a thinning when market
conditions are too poor for the German method. On the

212 THE PRINCIPLES OF HANDLING WOODLANDS

Other hand, the presence of a great number of small trees
increases the difficulty of felling the trees and making up
the wood, and offers a distinct hindrance to removing
the logs and wood.

Practical Application of Thinnings in this Country.
— The principles outlined in the preceding pages serve
as a guide for practise. In actual application they are
necessarily subject to considerable variation. The exact
measures to be used and the details of selecting the trees
must in every case depend on the requirements of the
given stand. The forester must diagnose the stand and
make the cuttings according to its peculiar needs.
Knowing the specific life characteristics and requirements
of the species and their capabilities under the given site
conditions, he makes his thinning so as to accomplish in
the highest measure the objects of management.

As regards the time at which to begin the real thin-
nings Dr. Mayr specifies from the 30th to the 40th
years in the life of the stand. The statement means,
however, that this is an average for a stand well estab-
lished, in which the necessary work of cleaning in early
youth has already been made. It means also that this is
the period when thinnings ought ordinarily to begin. It
often happens even in Europe that it will not pay to make
thinnings even at 30 or 40 years of age, on account of
poor market and logging conditions.

There are many instances of young mixed stands
in which valuable species are being badly crowded and
injured by those less valuable, and in the long run the

iMiMU)\'i:Mi:\'r oi thi: iokkst

21J

Fig. 45. — A Stand of Hardwoods after a Thinning, Massachusetts.

214 THE PRINCIPLES OE HANDLING WOODLANDS

prospective value of the stand and the final yield will be
very much reduced. A thinning will save the trees of
value, and there are certainly a great many instances in
which an actual outlay will be not only fully justified but
necessary if the purpose of management is to be accom-
plished.

In applying the principles relating to the grade of
thinnings, the forester often finds it necessary to depart
widely from the normal. This is particularly true in
mixed forests, and those not perfectly regular. A stand
which has been established under management, and
cleaned at the right time, presents a quite different prob-
lem from a volunteer stand which has developed on an
area cleared by fire or windfall and has never been treat-
ed at all. In the latter there are great irregularities.
In spite of these irregularities the principles of thin-
nings may be applied in our even-aged stands.

In this country the forests in which thinnings are
practised are now for the most part privately owned.
Private forests will, in the main, be handled on a rela-
tively short rotation. The object will be to raise as
large trees as possible within a given time. Usually the
grade of the trees will not be so important as the size.
The general policy will be to keep the forest dense dur-
ing the first half of the rotation so as to produce reason-
ably good form, and to thin rather heavily during the
last half of the rotation.

In thinnings at all ages the forester should mark for
removal all the dead, dying, and defective trees that can

IMPROVEMENT OF THE FOREST 21 5

be disposed of. During the first half of the rotation the
aim is to improve the form of the good trees, and to pre-
vent a too great reduction of the crown. Trees of poor
form, with spreading crowns, and those of poor species
which are crowding better ones, are therefore cut. If no
thinning is made until after middle life, the spreading
trees will have done their principal damage. Such trees
are cut only when the trees crowded by them are capable
of prompt recovery and rapid growth.

During the first half of the rotation the aim should be
to thin to about a C grade, and then to increase to a D
grade, or sometimes even a heavier cutting. Thinnings
are repeated when the crowns close together over the
openings.

There are frequently overcrowded groups among the
dominant trees. These are usually thinned by cutting the
co-dominant trees, or such of the dominant trees as have
the shortest crowns. Sometimes, however, the removal
of one dominant tree will stimulate the growth of several
co-dominant trees which, in the long run, would be over-
topped and crowded out by the former. If these trees
are released, their aggregate value will ultimately be
greater than that of the single dominant tree. This
principle is used in thinnings at all ages.

In a great deal of work in this countrx the thin-
nings will tend toward the French principle, and leave
the subordinate classes standing. This will usuallv be
because the small material is not merchantable, rather
than because it is desirable to leave it for silvicultural

216 THE PRINCIPLES OF HANDLING WOODLANDS

reasons. Wherever there is danger from windfall, a
stand must be opened gradually by moderate and fre-
quent thinnings. In the same way, stands of trees with
thin bark must be opened gradually to prevent sun-
scald, which frequently occurs, for instance, with second-
growth white pine.

It is often necessary to make openings in the canopy
which will be more or less permanent. This occurs
when groups of damaged trees have to be removed.

Accretion Cuttings

It is a well-known fact that when stands are heavily
thinned the trees usually show a marked increase in
growth. This is due to the greater amount of light, and
the stimulation this gives to the activity of assimilation.
The increased growth may be called light growth. It
takes place after thinnings v^^hen, by crowding, the crowns
have been prevented from receiving as much light as
they could utilize; when the trees are vigorous enough to
respond to the new conditions; and when there is enough
moisture and nourishment in the soil to meet the require-
ments of the increasingly active crowns.

The endeavor of modern forestry is to obtain the
greatest possible light growth, particularly during the
last half of a stand's rotation. Practically all foresters are
agreed that during the first part of the rotation the forest
must be kept dense to produce trees of good form. The
principal difference in methods concerns the handling
of the stand to secure the maximum light growth.

IMPROVEMENT OF THE FOREST 217

The various methods developed to secure this object
are called accretion methods, or methods of accretion
cuttings.

The two-storied system of management is really an
accretion method; but since it involves the reproduction
of a stand to be grown with the main trees, it was de-
scribed under the silvicultural systems. In like man-
ner, the systems of reserves involve the same principle of
giving individual trees full light.

One method of taking advantage of an accelerated
growth is to make a long period of reproduction under
the shelterwood system. The reproduction cuttings are
begun earlier than usual. When the seed-cutting is
made, the trees left standing are chosen primarily with
reference to their ability to produce a more rapid
growth. During the lengthened period of reproduc-
tion there is thus secured a large growth. This method
is employed only where the rotation is relatively short,
as, for example, in spruce 100 years of age or under.
With old stands there would be little response to the
changed light conditions, and hence very little or no
light growth.

Probably the most common method used in Kurope
is that of underplanting. When the trees have reached
their main height-growth and have developed the form
desired, the stand is thinned very heavily and under-
planted. The aim is to give to the best dominant trees
in the stand just the amount of light thev can fullv utilize
in making growth. In order that there may be as many

218 THE PRINCIPLES OF HANDLING WOODLANDS

trees per acre as possible, and hence a maximum total
yield, no more space is given than is necessary to accom-
plish this purpose. The accretion cutting is made be-
tween the 50th and the 80th years.

The purpose of the underplanting is to protect the
soil from deterioration. The rank growth of grass,
weeds, blueberry-bushes, and the like, is a detriment
rather than a benefit. An understory of a favorable
tree species conserves and improves the quality of the
soil.

Underplanting is most needed with intolerant spe-
cies, which usually have a light foliage. The understory
must be composed of a species capable of living in the
shade of the old trees. Under a light canopy of Scotch
pine, ash, or larch, trees of moderate tolerance can be
planted. Under species with dense foliage, tolerant
species must be used. Naturally, the species must be
one adapted to the given site. In Europe, beech is re-
garded as the best tree for underplanting. Other species
used are hornbeam, linden, maple, and sometimes toler-
ant conifers.

The function of the underwood is soil protection. It
is not expected to produce a merchantable crop, except
when the two-storied system is used. The cuttings in
the overwood are made without regard to it. The aim
is merely to keep it alive, regardless of its form. Crip-
pled, spreading trees may make as good cover as straight
ones.

The underplanting is purely a ctdtural operation.

IMl'ROVKMKNT OF THE FOREST 219

The returns from it must be sought In the maintenance
or improvement of the soil conditions and in the sus-
tained rapid growth of the trees. Without underplanting
the soil often suffers from loss of moisture and nourish-
ment, and the growth of the tree drops off.

Underplanting Is an intensive operation. So far as the
author is Informed, it has not yet been practised in this
country. Such underplanting as has been undertaken
here has been for advance reproduction or for esthetic
purposes.

Improvement Work in Irregular Stands

In this country there are a great many second-growth
stands which are uneven-aged and irregular. Some of
these stands have resulted from very slow natural repro-
duction on old clearings. Others are the result of hap-
hazard cutting and irregular reproduction. Competing
with the best trees there are many trees of poor form and
of poor species, and manv defective trees. Such stands
require thinnings to Improve their composition and
growth.

The stand Is essentiallv immature. If there are old,
straggling trees which Interfere with the stand's develop-
ment, they are cut. The thinning further removes de-
fective trees of all classes, together with malformed trees
and poor species, except when the density Is so poor that
they constitute an important part of the canopy. Crowded
groups are thinned bv cutting intermediate and co-domi-
nant trees, and oftentimes a domliKUit tree is taken for

220 THE PRINCIPLES OF HANDLING WOODLANDS

the benefit of two or more co-dominant or intermediate
trees.

Frequently the removal of an old straggler or of de-
fective trees makes openings of a permanent character, in
which natural reproduction takes place. Nevertheless,
this is an improvement cutting, not a reproduction cut-
ting. The whole aim is to improve the immature stand.
If the defects and irregularity of the stand result in open-
ings large enough for reproduction, this cannot be
helped; and in that case the cutting is so made as to get
as good natural reproduction as possible. In most of the
thinnings only temporary openings are made.

Improvement Work in Selection Forests

In selection forests, thinnings are sometimes made —
provided there is a market for the product — for the bene-
fit of the immature trees. Such thinnings are made at
the time the mature trees are cut. In principle, they are
of the same character as those just described for irregular
second-growth stands. The good specimens of all ages
are protected by removing undesirable crowding indi-
viduals. Seedling growth is aided by cutting away poor
specimens over it, and sometimes even by cutting advance
growth and brush, just as in a cleaning in an even-aged
group. In such work, the principles of practically every
kind of cutting are employed — cleanings in young
groups, thinnings in even-aged patches, and damage-
cuttings in injured young groups.

IMPROVEMENT OF THE FOREST , 221

Damage-Cuttings

In nearly every forest there is some damage by wind,
lightning, ice, snow, insects, disease, or fire. Good for-
estry calls for the removal of damaged material as soon
as practicable, not only to utilize what is still fit before it
deteriorates beyond usefulness, but also to prevent the
spread of insects and disease.

If a mature forest is badly damaged, it is cut and
reproduced as soon as practicable.

It frequently happens that an immature stand is dam-
aged, and a large number of trees are so injured that they
ought to be cut. Their removal involves a heavier
opening'of the'stahd'than if theforest were thinned, and
often makes permanent openings in the canopy. Such a
"heavy" cutting in an immature stand, required by fire,
windfall, or otherwise, may be called a damage-cutting.

When a stand has been so damaged, the forester must
determine whether it will pay to leave the uninjured trees
standing. If the stand is approaching maturity and a con-
siderable portion is injured, it is usually reproduced, ahead
of the normal time. If the damage is localized, that por-
tion may be reproduced. If the damage is confined to
only a few patches, the injured material is removed, and
the openings are left to natural reproduction or, in the
case of intensive practise, are filled by planting.

Sometimes a surface fire runs through an immature
stand, killing from 40 to 60 per cent, of the trees. The
remainder are rapid-growing, and the loss of growth

112

THE PRINCIPLES OF HANDLING WOODLANDS

Fig. 46. — A Thinning in Progress in a Shortleaf Pine Stand. Biltmore,

North CaroHna.

Fig. 47. — Example of a Damage-Cutting. Trees Removed Because
Infected by Insects. Black Hills National Forest, South Dakota.

IMPROVEMENT OK THE FOREST 223

through their removal would be large. When possible,
the good trees are retained, either as reserves or as an
upper-story, or brought to merchantable size as an in-
complete stand.

Pruning.

The pruning of forest trees is confined chiefly to cut-
ting off the lower branches, in order to have as much of
the stem as possible clear of knots, and so raise the grade
of the lumber produced. As a rule, forest trees are not
pruned at all, but there is a natural cleaning of the stem,
called natural pruning, by the loss of the lower branches
as a result of the crowding of the trees. Often, however,
natural pruning fails to give satisfactory results. With
many species the branches remain on the tree long after
they die, and their stubs produce loose knots in the lum-
ber. The branches of white pine, even in crowded stands,
persist for many years after their death; but after a time
they drop off, and the wood subsequently made yields
lumber clear of knots. Very old white pine-trees, there-
fore, yield a good proportion of clear lumber if they have
grown in crowded stands. But if this species is managed
on a short rotation very little clear material is ordinarily
obtained, unless the trees are pruned. An unpruned
stand, cut at from SO to 60 years of age, yields but little
clear lumber; whereas, if the trees had been pruned when
from 20 to 30 years old the wood produced during the
last half of the rotation would have been free from knots.

Pruning is a relatively expensive operation. It in-

224 THE PRINCIPLES OF HANDLING WOODLANDS

volves an investment whose return appears in the in-
creased value of the final product. It is practised only
when stands are intensively managed, and even then the
work is confined to a limited number of the most valuable
and promising trees in the stand. Usually not over 100
trees per acre are pruned, and these are selected individ-
uals which are of good form, thrifty, and most likely to
be the choicest trees in the final stand.

The aim is to clear off the branches for a distance of
about 16 or 18 feet, enough to include one saw-log. This
is about as high as it is practicable to prune, even with
the help of ladders and long-handled saws and hooks.

The period for pruning is usually when the stand is
from 20 to 40 years old. In most cases only dead branches
are cut, though a live branch may be cut here and there.
The work is not undertaken until the branches are dead
for a distance of from 16 to 20 feet above the ground.
Some of the limbs can be knocked off by a blow from a
stick, or pulled off with a hook. The larger limbs have
to be sawed off. Care is taken to make the cut close to
the trunk.

The cost of pruning conifers from 20 to 40 years old
is about 2 cents a tree.

Forest pruning will not be extensively practised in
this country for some time. For the most part, it will
be confined to comparatively small tracts which are inten-
sively managed, and to valuable individual trees here and
there in the forest.

CHAPTER VII

PROTECTION OF FORESTS FROM FIRE

The first measure necessary for the successful practise
of forestry is protection from forest fires. As long as
there is any considerable risk from fire, forest owners have
little incentive to make provision for natural reproduc-
tion, to plant trees, to make improvement cuttings, or to
do other work looking to continued forest reproduction.

In many localities great progress has lately been made
in forest protection. Organized fire protection has been
established in the National Forests and in most of the
State forest reservations. A number of States have begun
to develop systematic fire protection on private lands,
through the organization of State fire wardens. In some
instances private owners have formed cooperative associa-
tions for fire protection and employ a regular force of
rangers for patrol during the fire season. The most con-
spicuous and successful associations are those formed bv
certain lumber companies in Idaho and Washington.
Throughout the country there are here and there in-
stances of serious effort toward thorough fire protection
by individual private owners. In spite of all that has
been done, however, the fact remains that most of the
forests of the country, particularly those privatelv owned,

225

226 THE PRINCIPLES OF HANDLING WOODLANDS

are inadequately protected from fire. It is probable that
in fully 75 per cent, of the private forests there is no
attempt whatever at systematic protection.

Character of Forest Fires

It is customary to distinguish three classes of forest
fires, as follows:

1. Surface fij'es, which burn the surface layer of dry
leaves and other litter, dry grass, brush, and small trees.

2. Ground fires, which occur where the mineral soil is
covered with a deep accumulation of vegetable mold, and
which, on account of the peaty character of the material,
burn much more slowly than surface fires.

3. Crown fires, which burn through the crowns of the

trees.

Surface Fires

Nearly all forest fires start as surface fires. The dry
litter on the surface of the ground is ignited by a spark,
perhaps from a locomotive or a camp-fire. At first the
fire burns in a small circle, gradually eating out in all di-
rections. If there is a wind, the fire burns with greatest
intensity on the leeward side, and quickly assumes an
oval form. If the wind is very strong, the fire may die
out entirely on the windward side, but it burns intensely
on the other side, soon developing a distinct front or
head, with side wings running diagonally with the wind.
At first the front of the fire is very narrow, but it gradu-
ally widens and takes the form of a broad, irregular line.
The front may reach indefinite proportions, from a few

PROTECTION OF FORESTS FROM FIRF. 227

hundred feet to a tuniiher of miles i?i width. Irregular-
ities of topography and differences in the amount of
inflammable material cause the fire to burn more rapidU'
in some spots than in others, so that the entire front be-
comes scalloped and irregular.

Ordinarily a surface fire simply burns along the
ground and does not get into the tops of the trees.
Sometimes, however, the flames reach up into the crowns
and scorch them, or even ignite them here and there; but
such a fire still has the character of a surface fire, unless
it actually burns through the crowns.

The manner of burning, the form of the fire area, the
rapidity of burning, and the intensity of the fire depend
upon the following conciitions:

1. The character and c]uantity of inflammable mate-
rial.

2. The topography.

3. The character of the soil.

4. The condition of the atmosphere.
Inflammable Material. — The severity of a surface fire

depends largely on the quantity of dry material in the
forest. If there is an accumulation of leaves represent-
ing the fall of a number of years the fire is much more
severe than if the litter is the residt of the fall of only
a year or two. The quantity of accumulated litter is
greatest with species having large leaves and large crow ns.
Maple and red oak, for example, niake a heavier litter
than ash or birch; white pine makes a heavier litter than
pitch pine. The severity of a fire depends further on

0 0 0

2z8 THE PRINCIPLES OF HANDLING WOODLANDS

Fig. 48. — A Fire Burning in the Rocky Mountains.

Fig. 49. — A Surface Fire in a Longleaf Pine Forest in the South.

PROTECTION OF FORESTS FROM FIRE 229

the character of the leaves. A layer of resinous softwood
needles burns more rapidly and with a hotter fire than
does a layer of hardwood leaves.

The amount of dry wood on the ground influences
largely the severity of a fire. In some t)'pes of forest
there are a great number of fallen dead trees, which litter
the ground, and thus increase the fire danger. This is
well illustrated in the lodgepole pine forests of the Rocky
Mountains. In localities subject to windfall there is
likely to be a large amount of fallen timber, while fires,
disease, and insects leave standing dead trees and snags,
which are easily ignited. After lumbering in the old-
fashioned way, the ground is covered with a mass of tops
and rejected logs, which soon become dry and highly
inflammable.

Again, the condition of the litter and debris governs
largely the character and severity of the fire. The most
severe fires occur where the material is thoroughly dried
to the mineral soil. When the material is only partially
dry the fire is slow, and the litter is not completely
burned.

Since the ground litter is, as a rule, unevenly dis-
tributed, a surface fire burns very irregularlv. Still
another cause of the irregularity of surface fires is the
varying soil moisture.

Topography. — A fire runs uphill with great rapidity,
because the heated air-currents draw the flames upward.
If the litter is evenly distributed, the velocity with which
a lire will run up a slope is in direct proportion to the

230 THE PRINCIPLES OF HANDLING WOODLANDS

Steepness of the slope. After passing the crest, a fire
travels more slowly in its descent on the other side.

Mechanical obstructions, such as abrupt walls, narrow
ridges, outcropping ledges, and so on, tend to check a
fire and to prevent its gathering volume. On extensive
level ground, fires burn more uniformly, gather a greater
volume, generally do more damage, and extend over a
larger area than in rugged topography.

Character of the Soil. — Any influence which tends to
dryness increases the intensity of a fire. Thus on sand
and limestone soils, which warm up and dry out readily,
fires are likely to be very severe. Southern and western
slopes are apt to be more severely burned than others,
because they are the warm and dry exposures.

Condition of the Atmosphere. — The character of a
fire is influenced, further, by the condition of the atmos-
phere. Roughly, the greater the velocity of the wind,
the more rapid is the progress of the fire. A fire burns
more severely when the wind is constant than when it is
gusty. It is the steady high wind which makes the most
intense fire.

A fire burns most fiercely when the atmosphere is
dry. Fires are, therefore, most severe during the hot
part of the day, and when fanned by a dry wind. A
moist atmosphere retards a forest fire. The well-known
fact that the night is the best time to fight a fire is thus
explained; for at night there is usually little or no wind,
while the air is comparatively heavy and damp.

Rapidity of Surface Fires. — No reliable estimate of

PROTECTION OF FORESTS FROM FIRE 231

the rapidity of surface fires can be made, because it varies
SO greatly under different conditions. In the hardwood
regions of the East a surface fire seldom travels more than
5 miles a day, but in the coniferous forests of the West
instances are known where this rate of speed has been
more than doubled.

Grass Fires. — In nearly all open forests there is a cer-
tain quantity of grass which, when dried, carries fire very
rapidly. In many forests the presence of grass consti-
tutes one of the important problems connected with sur-
face fires. This is particularly true in the Southern pine
forests.

A grass fire is more influenced by the density of the
grass than by its height. Where the grass is in separated
patches, with no leaves or other inflammable material
between, it is difficult for a fire to spread. Uniformly
dense grass burns with the greatest intensity. High
grass burns with greater intensity than low grass, but the
fire does not usually run so rapidly. Grass a foot high,
if dense, may produce such a hot fire as to start a crown
fire. In short grass, with an ordinary wind, a fire will
run from 3 to 4 miles an hour; with a high wind, twice
as fast. The chief factors affecting the burning of grass
are its dryness and the force of the wind. Other factors
have their influence, however, just as they do in the
burning of litter.

Brush Fires. — Bushes and small trees frequently
retain many dried leav^es late into the fall, and in some
cases even into the following spring. This is particular-

2?^2 THE PRINCIPLES OF HANDLING WOODLANDS

ly true of some of the oaks. A fire will sometimes run
through such brush and do an immense amount of dam-
age. Such a fire is called a brush fire. It is carried
along in part by the burning of the litter, but, wherever
the opportunity offers, it runs up through the dried
leaves, remaining on the brush. In the eastern United
States a brush fire is most likely to run during the late
fall. Under ordinary circumstances it has rather the
character of a surface fire than that of a crown fire

Fires running through young stands of conifers con-
sume the foliage and readily kill the trees. In a very
young stand, in which the trees stand isolated and the
crowns have not yet grown together, the fire has the
nature of a surface fire, intensified by the burning crowns.
If the crowns meet, and there is a more or less complete
canopy, a true crown fire is developed.

A special class of brush fires are those in the chaparral
of the Southwest. The brush is dense and there are
many species with inflammable foliage. In many places
a thick layer of litter and humus is formed on the
ground, just as in a dense forest. Fires in this class of
scrub forest are very fierce and destructive. They are
analogous to fires in dense stands of young conifers.

Ground Fires

This term is applied to the slow fires that burn in the
deep accumulations of vegetable matter common in many
of our damp Northern forests. Here the fallen leaves,
needles, and other offcastings of the trees decompose

PROTECTIOM ()|- lORKSTS FROM J I RE 2JJ

very slowh, and a deep la\c'r of partially decayed organic
matter accunudates, often to a depth of from 2 to 3 feet.
This material absorbs moisture with avidity and retains
it tenaciously. Consequently, in moist seasons it is not
readily ignited. In some seasons, however, it becomes
thoroughly dry and will burn. A fire in this peaty sub-
stance burns slowly, but with very intense heat, and is
exceedingly ciifiicult to extinguish. Ground fires in the
Adirondacks have been known to burn all winter, creep-
ing along under a deep layer of snow.

Ordinarily a ground fire does not cover more than a
few acres in a day. Frequently, however, there is upon
the surface a large amount of dry debris or small coni-
ferous trees so that there accompanies the ground fire
a surface fire or a brush fire, or both, and occasionally
a crown fire.

Crown Fires.

Crown fires are those which burn through the crowns
of the trees. They almost invariably start from surface
fires. Occasionally, however, they are started w^hen light-
ning strikes and ignites a dry stub or resinous tree sur-
rounded by a dense stand of conifers. If the crowns
are of such a character that they will burn, they may be
easily ignited by the flames which rise from a surface
fire. Sometimes a crown fire is started by the flames
from a burning clump of young growth, and where the
trees have exuded resin or there is loose inflammable
bark, a crown fire may be started by the flames running
up the trunk.

234 THE PRINCIPLES OF HANDLING WOODLANDS

Crown fires occur when the woods are very dry, and
when there is a high wind. Without a strong wind a
crown fire is seldom started, and even if the crown of an
individual tree is ignited, a fire does not usually spread
and run through the crowns on a still day. Before a
high wind, a crown fire spreads with great velocity, tak-
ing at once a V-shaped form with a distinct front or
head. This head may be only from 50 to 100 feet wide,
but in the case of the largest fires its width may be very
great. In the case of the larger fires the front is gener-
ally carried forward by a series of heads. The head of
the fire burns very rapidly through the crowns, and there
follows closely a surface fire burning with the same rapid-
ity. There are well-developed wings, where the fire
runs through the crowns on each side of the head.
These, in turn, are accompanied by surface fires, while
spreading out on the skirts are wider surface fires, eating
out diagonally with the wind and covering a broader area
than the crown fire.

The strong draft of heated air arising from the fire
carries up with it an immense quantity of burning cin-
ders and pieces of bark. The wind, in turn, carries this
material far in advance of the main fire-head, and thus
innumerable new surface fires are started. This gives
rise to the popular idea of a spontaneous starting of fires
in advance of a crown fire.

An ordinary crown fire does not run more than 2 or
3 miles an hour, although undoubtedly the great con-
flagrations of the north woods, such as the famous Hinck-

PROTECTION OF FORESTS FROM FIRE 235

ley fire in Minnesota in 1894, are swept along at a much
greater rate, particularly if the starting of new fires by
burning cinders is taken into consideration. Even in
extreme cases, however, it is questionable whether crown
fires burn at a rate of more than from 6 to 10 miles an
hour.

The behavior of a crown fire depends on the character
of the crowns. Crown fires are mainly confined to coni-
ferous forests, for the leaves of hardwoods are not easily
ignited.

They may, however, run through forests of mixed
hardwoods and conifers, and in such cases the heat gen-
erated is so great that the hardwood leaves are scorched
or killed. The velocity of the fire depends, further, on
the density of the stand, the thickness of the crow^ns, and
the force and steadiness of the wind. Other influences
affect the severity of crown fires in much the same way as
they affect that of surface fires.

Damage by Fires

The damage done by forest fires may be discussed
under the following heads:

1. Death of standing trees.

2. Injury to trees that are not killed.

3. Injury to the soil.

4. Reduction of the rate of growth of the stand.

5. Effect on reproduction.

Death of Standing Trees. — Crown fires usually kill
outright all trees in their path. In a severe crown fire

236 THE PRINCIPLES OF HANDLING WOODLANDS

the foliage of coniferous trees is completely consumed.
Hardwood trees in mixture are generally so badly scorched
that the buds, leaves, and living tissues in other finer
parts of the tree are killed, if not consumed, by the heat.
Sometimes, however, where the fire burns somewhat
irregularly — as, for example, where there are a good
many hardwoods in mixture or the fire is broken by
irregularities in topography — many single trees or groups
of trees escape injury.

Ground fires, also, usually kill all trees in their way,
for although they burn very slowly, they generate a great
volume of heat and kill the living tissues of the roots.
Sometimes the injury is not apparent above ground at
all, but the trees die and, after a time, are blown over,
because the roots have been killed and weakened.

Surface fires kill seedlings and young trees with ten-
der bark, but in a great many cases do not kill outright
the larger trees. Nevertheless, a very severe surface fire
may kill everything in its path, and, not uncommonly,
hardwood forests are entirely destroyed by fires which do
not at any time assume the character and proportions of
crown fires.

Some species have much greater power of resisting
surface fire than have others. This is usually due to the
character and thickness of the bark. Trees with delicate,
thin bark are killed much more readily than those with
thick, corky bark. Young trees are killed more readily
than old ones, because the bark is thin, and there has not
been developed the layer of cork, which increases in

PROTFCTION OF FORESTS FROM FIRE 237

amount with age. Accordingly, some trees which are
very resistant to fire when mature are exceedingly sensi-
tive when young. Good examples are the Eastern and
Western white pines, the red pine, the Western larch,
and Douglas fir. The cork in the bark acts as a non-
conductor, and protects the living tissues from overheat-
ing.

Some species exude from the bark a great deal of
resin, which catches fire and increases the intensity of the
heat. A good example is lodgepole pine, which often
exudes resin over a considerable portion of the trunk,
and increases the damage by fire. Other trees have soft,
flaky bark, which catches fire readily. Like the resinous
trees, these are killed at the point burned by the heat
generated in this way. Shallow-rooted trees may be
killed by surface fires w^hen the heat of the burning
humus is great enough to injure the insufficiently cov-
ered roots.

The living parts of a tree are more sensitive to intense
heat at some periods of the year than at others. The
most sensitive period is during the earlv part of the
growing season, when active cell division is taking place
and new cells are being formed, which are tender and
naturally sensitive to abnormal conditions. This is very
well shown by the damage of late spring fires. Thus, a
surface fire in May or June may entirely kill hardwood
trees which in the early fall would successfully resist a fire
of equal sev^eritv.

Living tissue is killed when it is heated to S4° C.

238 THE PRINCIPLES OF HANDLING WOODLANDS

( 129.2° F.)/ Very often the forester wishes to deter-
mine, after a fire, the extent of the injury. If the inner
bark is brown or black, in contrast to the normal green
color, this is an indication that the cambium is dead.

Injury to Trees. — Many surface fires do not kill trees
outright, but seriously injure them by killing a portion
of the roots or trunks. It is very common to find, after
a fire, that nearly all the' trees in the forest have been
killed on one side. This is usually the leeward side,
because here the flames have an opportunity to run in
immediate contact with the tree long enough to injure it.
If a fire is burning up a slope, even when there is no
wind, the upper side of a tree is usually more damaged
than the lower side, both because of the accumulation
of leaves and other litter above the tree, and because fires
are carried upward by the currents of hot air, just as a
fire on level ground is swept along by the wind.

In the case of a well-established tree, the killing of
one side may not result in its death for a long period;
and if the wound is not large it may heal over. Very
commonly, however, the killing of one side of the tree
induces the attack of some fungous disease, which ulti-
mately results in the tree's death. Trees injured and
weakened by fire are subject to the attack of insects.
In many cases the death of trees after a burn is the result
of insects' work and not of the killing of the tissues by
the fire. Damage by fire often follows damage by in-

1 " Der Waldbau," by Heinrich Mayr, p. 12.

PKOTKCilON OF l-ORKSIS !• KOM M RE 2M)

sects. Thus, in certain conifers insects injure the trunks,
causing a local accumulation of pitch. A surface fire
later burns the tree at this point and kills one side.
The defect called ''cat-face" is often caused in this way.
Insect attacks, moreover, by increasing the number of
dead trees in the forest, increase the fire danger.

In the case of large trees, which are very resistant to
fire, a first fire may kill the tissues on one side, and sub-
sequent fires may then burn into the dead wood until the
trunk is nearly hollow. This result is very commonly
seen in large white pines that have a large proportion o{
the butt gouged out by repeated fires and are still alive.
Many of the large trees on the Pacific Coast, like red fir,
yellow pine, sugar pine, and bigtree, stand for many
years after injury of this character.

The damage to a tree by killing a part of the trunk
or a part of the root depends on its resisting power and a
variety of other circumstances. In some cases the tree is
so weakened by the burning that it is afterward broken
off at the butt. This is very common in long-leaf pine
forests, where old turpentine ''boxes" burn out and
weaken the tree.

The injin-\' to the tree usuallv results in a reduced
rate of growth. It is obvious that if a portion of the tree
is killed, the whole tree cannot perform its functions
so efFectiveh' as before. The killing of a part of the
crown, stem, or root system necessarilv reduces the
amount of nourishment which the tree can take in and
furnish the growing parts.

240 THE PRINCIPLES OF HANDLING WOODLANDS

It is not only in shortening life and in reducing
growth that fires injure trees; the quality of the product
is also aliFected. Even where there is no injury by in-
sects or fungous disease, a fire that has killed one side of
a tree usually leaves its scar. In time the wound may
entirely heal over, hut there is nearly always a point of
weakness which may ultimately cause a seam or wind
shake, and unfit the butt log for lumber. If rot sets in,
it may spread throughout the trunk and make the tree
worthless, even if it does not kill it.

Injury to the Soil. — A surface fire burns the dry.
leaves, and usually the humus which lies on the surface
of the ground. If the trees are all killed by the fire, the
crown cover, as well as the layer of litter and humus, is
destroyed, and injury to the soil follows this exposure to
the wind and sun. If the canopy is not seriously inter-
rupted by the fire, and only the surface litter and humus
are burned, the extent of the soil injury from one burn-
ing is not serious. A very light surface fire, that merely
burns off the dry litter formed by one or two years' fall
of leaves has little influence on the soil; and probably no
single fire, even if it burned the entire humus and layer
of litter would so injure the soil as seriously to affect
the growth of well-established trees. Normally in every
forest a certain amount of humus is mixed with the min-
eral soil. This is of value, both physically and chemi-
cally. If a forest is burned over repeatedly, however,
the humus in mixture gradually disappears, and since
the leaves which fall are destroyed, and no new humus is

PROTECTION OF lORKSTS FROM FIRE 241

formed, the soil is injured. While the soil loses its sup-
ply of nitrogen and the physical benefits of hunuis, the
mineral ashes are not lost, except as they are subse-
quently leached away. Nevertheless, repeated fires are
very injurious to the forest.

Besides the direct injury to the soil through changes
in its chemical content and physical quality, fires do fur-
ther damage through opening the way to soil erosion.
A leaf litter reinforces the forest canopy in protecting the
soil against the impact of falling rain, and the network
of roots w^hich fills the ground holds the soil in place.
The greater the humus content of the soil, the more
absorptive the soil is. Fires leave the soil in condition
to be easily borne away by running w-ater, and increase
the amount of water which runs over the surface instead
of sinking in. If the slopes are steep and the soil easily
borne away, erosion is sure to follow fires. In mountain
country, if the rainfall is heavy, thin soils may be so
badly washed as to be no longer capable of supporting
forest growth.

Reduction of Density. — Most fires kill a certain num-
ber of trees, or injure them so that thev either die or
deteriorate in value before the forest can be cut. This is
particularly the case with immature forests. 7^he result
is a reduction in the number of trees which will come to
maturity, and hence a reduction of the total increment
and the final yield.

If a stand is mature and a part of the trees are injured
or killed, it is sometimes possible to prevent loss by cut-

242 THE PRINCIPLES OF HANDLING WOODLANDS

ting directly after the fire. Often, however, it is not
practicable to make a cutting in a given part of a forest
just when desired.

When some of the trees in an immature stand are
killed or injured, there is always a loss. If the stand is
cut, there is a loss through cutting trees which are in full
productive growth. If the stand is allowed to grow, the
final yield is reduced nearly in proportion to the reduction
in the number of trees killed in the dominant or leading
class.

An owner is often confronted with the problem of
dealing with an immature stand in which a part of the
trees — say 30 to 60 per cent. — are killed or injured by
fire. If the remaining trees are sound and thrifty, the
best plan is usually to cut out the dead and damaged
individuals, utilizing such as are marketable, and permit
the remainder to mature, provided enough can be real-
ized to cover substantially the cost of the work.

Influence on Reproduction. — Reproduction in the
forests of this country has been more influenced by fire
than by any other one factor. The present composition,
form, density, and yield of a great many stands are due
to the influence of fires on reproduction.

Repeated fires prevent reproduction by destroying the
seed and killing the seedlings. This is well illustrated
in certain areas of the South, where longleaf pine is not
reproducing itself — not because there is a lack of seed or
because the conditions for germination are unfavorable,
but because the annual fires kill the }'oung trees.

PROTECTION OF FORES'IS FROM FIRE 243

Fires may influence reproduction through their effect
on the soil and the soil cover. Frequently after fires the
ground is occupied by heavy brush or by grass, which
impedes or in some cases prevents the reproduction of
valuable trees. Many of the grass parks in the Western
mountains are the result of fire. A grass vegetation has
replaced the forest. The running wild of burned areas
to a heavy growth of brush is a common occurrence after
fires in many of our Eastern forests, as, for example, in
Pennsylvania.

Forest fires modify the composition of stands. The
opening up of a forest may so change the conditions of
germination that some species cannot develop even when
seed is abundantly supplied. This is in some cases due
to the drying of the soil. A species which requires pro-
tection against drought in early youth might be excluded
from openings made by fire. In the same way the repro-
duction of a species sensitive to frost in early youth is
often confined to areas protected by old trees.

Where the fire makes a large clearing, the succeeding
forest usually differs in composition from the burned
stand, except where there are only one or two species
native to the region. The first species to spring up on
the burn are those whose seed is readily and abundantlv
distributed to a distance from the seed-trees. Thus, in
the north woods of the Fast, birch and aspen are among
the first species, because their seed is verv light and is
blown by the winds to great distances. Bird cherrv
comes up in abundance, because its seed is spread widely

244 THE PRINCIPLES OF HANDLING WOODLANDS

by the birds, and probably much of it is already in the
ground before the fire. The trees with heavier seed
creep in gradually after a few years.

Fires may kill certain non-resistant species, and thus
stop their supply of seed. The tendency of repeated
fires is to reduce the number of species in a stand.

The Prevention of Fires

In some sections of the country forest fires have
always been of such common occurrence that there is a
popular notion that they cannot be prevented. The risk
from fires can never be entirely eliminated, for in the for-
est there is always inflammable material which is very
easily ignited. They may, however, be largely pre-
vented, and under efficient organization their damage
may be kept down to a very small amount. The prob-
lem is like that in cities, where fires can never be entirely
eliminated, but where the risk of loss to property may be
reduced almost to insignificance.

For the successful protection of a forest from fire
there are necessary:

1. The elimination, so far as possible, of the causes
of fires.

2. A proper organization of the forest, including
the disposal of slash, the opening of roads, the construc-
tion of trails, etc.

3. An adequate supervision.

4. Facilities for fighting fires, including an ade-
quate force of men, proper implements, etc.

I'ROTKCTION OK FORKS'I'S I ROM I I RK 245

Elimination of the Causes of Fires. — The causes of
fires may be grouped under the following heads:

(a) Sparks from locomotives; (b) sparks from saw-
mills, donkey engines, etc.; (c) camp-fires; (^) clearing
land and burning brush; (e) burning to improve pastur-
age; {/) careless smokers; (g) incendiarism; (h) light-
ning.

Back of any practical plan of fire protection there
must be State fire laws and a competent organization to
enforce them. In many States to-day there are laws,
some of them fully adequate, requiring the use of spark-
arresters on engines, and punishing incendiarism, care-
lessness in clearing land, and in leaving camp-fires, etc.
In most States, on the other hand, organizations to carry
out the laws and an enlightened sentiment to support
them are lacking. Education of the people to the value
of forests and the need for their protection is necessary to
overcome the carelessness and ignorance that cause fires
to originate from camp-fires and clearing land. Vigor-
ous application of the laws will accomplish this result, but
the laws will not be vigorously enforced until there is a
public opinion back of them.

For the most part, though probably not entirelv, the
starting of fires by sparks from locomotives may be pre-
vented by the use of spark-arresters. If the right of wax-
is properly cleared and patroled, such occasional fires
as start may readily be extinguished. Railroad fires are
therefore unnecessary. Railroads should be held respon-
sible for damage from fires which they cause.

246 THE PRINCIPLES OF HANDLING WOODLANDS

In the same way there are excellent devices for arrest-
ing the throw of sparks from the stacks of donkey en-
gines and sawmills. When fires start from these sources
it is usually because such devices are not used at all or
not properly used.

There will, of course, always be some accidental fires
and an occasional incendiary fire, just as in a city. In
certain districts also lightning will continue to be an
unavoidable cause of fire. The management of the for-
est must, therefore, be so organized that such fires as do
start may be extinguished as quickly as possible.

Organization of the Forest. — By organization of a
forest for protection is meant the establishment of such
conditions that the chances of a fire are reduced to a
minimum, and that such fires as are started may be extin-
guished with the minimum of damage. Among meas-
ures variously used to accomplish this are:

1. The disposal of slash from logging operations.

2. The development of roads, trails, and fire-
lines.

3. The establishment of lookout stations and tele-
phone lines.

4. The organization of a protective supervisory
and fire-fighting force.

5. The control of insects which kill trees and cause
an accumulation of dead, infiammable timber.

No one measure is sufficient for adequate fire protec-
tion. The disposal of dry tops and brush reduces the
danger from fire, but there always remains enough in-

PROTKCTION OF FORKSTS FROM FJRE 247

flammable material in a forest to make possible a damag-
ing fire. There must also be roads, trails, or fire-lines
giving ready access to the forest, so that fires may be
located and reached. Nor are these together sufficient,
for there must be a constant watching for fires in order
that they may be discovered and attacked when they are
small and easily controlled, and before they have done
much injury. All the measures of fire protection are
used together, and supplement each other.

Disposal of Slash. — The presence of dry tops and
piles of brush in the forest constitutes the greatest menace
from fires. The severity of a fire, and hence the damage
done, is in direct proportion to the amount of dry debris
on the ground. Still more serious is the fact that the
presence of this material makes it exceedingly difficult to
control and extinguish a fire. If there is no material on
the ground other than the ordinary leaf litter, a surface
fire may be easily extinguished. Old logs, dead and
down trees, and snags lying about on the ground are also
a great hindrance to fighting fires, for when once ignited
they are apt to smolder for long periods, and so continue
to threaten a further spread of the flames. In many of
our forests the dead, standing snags constitute a very
dangerous feature. If these are surrounded by a dense
stand of conifers, they often carry the flames up into the
canopy and make a crown fire; if isolated, they may burn
for ciays, and finally fall, throwing sparks in all direc-
tions. The forester aims to reduce the amount of this
inflammable debris in a forest as rapidly as possible, since

248 'I'Hi: PRINCIPLES OF

HANDLING WOODLANDS

PROTKCnoN ()!• lORKSrS 1 ROM IIRL 249

the **clean" stand is easy to protect in comparison with
a stand that is littered with dry debris.

Disposal of Brush and Debris. — A first practical step
is to prevent a further accuinulation of debris in a forest
by disposing of the slash from new cuttings. The ap*
plication in all forests of a uniform method for disposing
of this material would, however, be unwise. It should
be clearly understood that no fixed rule of procedure and
no single method could possibly lit all the different for-
est conditions in a country so large as the United States.
The method used in any given case must be chosen after
a careful study, and must rest upon a complete knowl-
edge of the local conditions. Many methods have been
tried in the disposal of brush, but those producing the
best results are the following:

1. Piling and burning as logging proceeds.

2. Piling and burning in separate operations.

3. Lopping the tops.

4. Lopping the tops and scattering the brush.

5. Broadcast burning.

Piling and Burning Brush as Logging Proceeds. —
The most economical method of destroying brush and
debris produced in lumbering is to burn it as the logging
proceeds. This is possible when the ground is covered
with snow or is so damp that fire will not spread. The
work is done by the logging crew. As the trees are
felled, convenient locations for burning the brush are
selected, where no damage will be done to the trees and
to young growth left standing, and where the fires will

250 THE PRINCIPLES OF HANDLING WOODLANDS

least interfere with skidding the logs. Small fires are
started, and as the branches are cut off the trimmers
throw them on the nearest fire. One reason why this
method is cheaper than the others is because the branches
need not be cut up so small, for the fire is already burn-
ing when they are thrown on. In coniferous forests
the tops burn readily, even on the snow or in stormy
weather. Sometimes when it is not practicable to start a
fire near a given top, the trimming of the limbs is de-
ferred until the skidders can haul it bodily near a fire.
The branches are then lopped and the last cut made,
enabling the skidders to go on with the top log, while
the choppers throw the brush on the fire.

If the work is systematized, the brush is practically
all disposed of as the logs are skidded, and the woods are
cleaned up as the logging proceeds. There is a distinct
advantage to the skidders through having open ground
to work over. This method should be used only when
there is no danger of a spread of fire. Its use on a large
scale is confined to logging during the season of snow or
rain.

The best method of calculating the cost of brush dis-
posal is on the basis of the amount of timber cut, meas-
ured in board feet, log measure. A determination of
cost per acre would be misleading, because of the great
variation of yield in different forests.

I'he cost varies widely under different conditions.
If trees have heavy crowns and large, heavy limbs, the
cost is much greater than where the crowns are smaller.

PROTECTION OF FORESTS FROM FIRK 2Sl

Thus, for example, the cost of destroying the brush
produced in lo^^in^ a stand of lar^e hemlock would be
greater per thousand feet of merchantable timber secured
than in lo<^<^in<jj an equal amount in a small-crowned spe-
cies like red pine. If the trees have a large volume, and
the stand is heavy, the cost of disposing of their tops is
less than it would be on an equal area for a sparse stand
of trees that yielded only a small amount of merchantable
timber per tree.

The cost and ef^ciency of labor must, of course, enter
into the cost of piling or burning brush, as it does in any
other logging operation. If the men know just how to
perform the work to the best advantage, and are indus-
trious and energetic, the cost of piling the brush is much
less than otherwise. In many cases the high cost of brush
disposal has been simply due to the fact that the men
who were doing the work were inef^cient, unwilling, or
unskilled. Still another factor influencing cost is the
ease of the work as influenced by the density and amount
of small growth and the irregularities of the ground.

The Forest Service, working in forests in the Lake
States composed of mixed red and white pine, has dis-
posed of brush in the manner described at a cost of 12
cents per thousand board feet.

Piling and Burning Brush in Separate Opera-
tions.— Where the logging is done during the dr\- season,
the brush is piled wherever convenient, but the burning
of the piles is deferred until a favorable time, such as
during damp \veather or after the first snow-fall.

252 THE PRINCIPLES OF HANDLING WOODLANDS

The best time for piling brush is during the cutting
and skidding of the timber. As the branches are lopped
from the stem they are immediately cut up and thrown
on a pile. The work is done by the regular trimming
crew, and, ordinarily, the extra work requires the ad-
dition of only one man to the regular number. The
advantages of organizing the brush-piling work in this
way are:

1. The brush is cleared at once for the skidding
of the logs.

2. The work is done more cheaply than if the brush
is piled by a separate crew after the logging is com-
pleted; besides, the trimmers have to throw aside the
brush in any case to clear the way for skidding. Piling
after the logging means a second handling of the brush,
and is an expensive operation on account of the inevitable
difficulties of picking up the branches from tangled piles.

3. The men work more efficiently and cheerfully
when part of a trimming crew than when they do noth-
ing but pile brush.

4. Supervision is more effective and less costlv
when the brush is piled with the logging than when it is
a separate later operation.

Sometimes, when the logging is done in the winter, it
is impracticable to burn brush at the time of logging, in
the way described in the previous pages, or on account
of the deep snow, to pile the brush for later burning.
In this event the piling is done in the spring, as soon
as the snow permits.

PROTECTION OF FORESTS FROM FIRE 253

In locating the piles it is necessary to take into con-
sideration the convenience and cheapness in handling the
brush, the clearance of way for skidding the logs, and
the safety to standing trees and young growth when the
piles are burned. Ordinarily they are placed at least 1 5
feet away from any trees or groups of young trees that
may be injured. In forests like spruce, which have a
great amount of branches, and where the trees stand so
close that the piles cannot be placed at this safe distance,
the brush is either piled and not burned, or is thorough-
ly lopped and left scattered evenly over the ground.
When the brush is piled after the logging, the piles are
located in the logging roads and skidding trails, and on
spots where skidways were located.

The brush piles should be small and compact.
(Fig. 51.) As a general rule, they should not be over
10 feet across or over 6 feet high. The very small
branches are put in the bottom of the pile, with suc-
cessively larger material laid on afterward. The ends of
the branches are placed toward the center of the pile.
Trimmed sticks may be leaned against the pile to hold
it in shape, keep it from blowing over, and render it
more compact for burning. Windrows and large piles
make control of burning difficult, and are likely to make
such a large fire that the crowns of trees are scorched and
injured.

When the piles are loosely thrown together complete
burning is very difficult and often impossible. To secure
**clean burning" (so called), it is necessary to rebuild

2S4 THE PRINCIPLES OF HANDLING WOODLANDS

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PROTECTION OF FORESTS FROM FIRE 255

open and loose piles. This is called '^chunking up" the
piles. It is very expensive, for it costs as much as the
first piling.

Brush should not be thrown on a top, at least until
all branches are trimmed off. Ordinarily, thev sh(juld
be piled away from the top piece of the stem.

In some instances in the National Forests the practise
has been to stake the piles. Sticks are driven into the
ground 6 or 8 feet apart, and the limbs are ranked length-
wise between them, as shown in Fig. 52. The adv^antage
of this method is that it insures thoroughness of work
and a compact pile. It has been proved that it costs
much less to burn a staked pile than the ordinary irreg
ular pile, and the area of ground burned ov^er is consid-
erably less. This method has been found of especial
value when the brush piling has followed the logging.
The foreman of the piling crew selects the locations for
the piles, drives the stakes, and supervises the work.
Organized in this way, the work is done rapidly, and
the expense is but little if any more than if the piles
are irregular. Any extra expense of the staking is more
than offset by saving in the cost of burning.

The cost of piling brush necessarily v^aries under
different conditions. The first work undertaken in this
country cost as high as $1 per thousand feet, log run, of
timber cut. This high cost was largely due to lack of
knowledge of methods and to the inexperience of labor.
With better organization and with trained workmen the
cost of piling brush in coniferous forests has been reduced

256 THE PRINCIPLES OF HANDLING WOODLANDS

to from 10 to SO cents per thousand. There is no reason
why the piling alone in coniferous forests should cost
more than 25 cents per thousand, except where the tops
are unusually large and the physical difficulties unusual.

Burning the Piles. — An excellent time for burning
brush piles is immediately after the first snow of winter.
This is usually a light fall, and the snow does not pene-
trate the compact piles of brush sufficiently to prevent
burning. There is no danger of the fire running on the
ground, and the branches of the standing trees are so
damp as to prevent injury by the rising fiames. If the
brush is burned before winter, it should be only during
damp weather, when the ground is so wet that fire will
not riin easily.

When large areas of piled brush are to be burned the
work should be organized with care. It should never be
undertaken when there is a strong wind, and the best
time is in calm weather. If there is any wand, the burn-
ing should begin with the piles on the lee side. Several
piles may be fired at one time, but they should be some
distance apart, with one or more unburnt piles between
them. When the first fires have burned down to coals,
the intermediate piles may be ignited. This alternating
method of burning the piles prevents the injury to trees
and young growth between the piles that might result
from the collective volume of heat of adjacent fires.
Just as the brush on level ground is burned against the
wind, so, on a hillside, the piles near the top are burned
first, and the work progresses down the slope*

PROTECriOX OF lORKSTS FROM FIRE 257

\\ hciicv'cr hirgc areas of })ilc'cl brush arc to he hiirned,
a sufficient force of men, equipped with fire-fighting im-
plements, should al\\a\s he present to insure that the fire
will not get beyond control. In some instances, when
brush is piled in the winter during logging and left for
later burning, the piles become very wet from the snow
and rain and do not dry out till late spring or summer, a
time when burning on a large scale is dangerous. If the
brush of winter lumbering cannot be burned as the log-
ging proceeds, the piles must ordinarily remain unburned
till the first snow^ of the following winter, or till especially
wet \veather comes in late summer or fall.

The devices used in different localities for starting
fires in piled brush are many. Some loggers use a torch
of burning wood, as resinous pine; others carr}' live coals
from one pile to another; others use a long-handled
torch; others, again, pour a little oil on the brush and
fire it with a match. The most satisfactory seems to be
an ordinary tubular torch with w icking and a ferrule into
which a rake-handle can be inserted. A good substitute,
though a crude one, for the last is a piece of bagging or
burlap wound around an iron rod or stick of wood and
occasionally saturated with oil.

The cost of burning piled brush in the coniferous
forests may vary from 1 to 30 cents per thousand, accord-
ing to the manner in which the brush is piled, the condi-
tion of the brush, the size of the crew needed to prevent
the running of fire, etc. Commonly, it ranges from ? to
15 cents per thousand feet. Where the cost has been

258 THE PRINCIPLES OF HANDLING WOODLANDS

higher than this, it has been attributable either to poor
work in piling or to inefficient management in the work
of burning. The average cost of both piling and burn-
ing should range in coniferous forests between 10 and 50
cents, and as the lumbermen become more experienced
in performing the work, the cost will be correspondingly
reduced.

In a Montana logging operation shown in Fig. 52,
where the brush was burned just after a slight snowfall
under particularly favorable conditions, the actual cost of
burning was only a fraction of 1 cent per thousand feet.
No watching of the piles to see that fire did not run
was necessary; it was simply a case of walking from one
pile to another and starting the fire.

In some coniferous forests careful records were kept
at the area actually burned over. Where the stands per
acre ran from 10,000 to 50,000 feet per acre, the aggre-
gate area burned over by the brush fires was found to be
approximately 7 per cent, of the tOtal area cut over in the
logging operations. Where the brush is burned as the
logging proceeds, the percentage of the area burned over
is less.

Disposal of Hardwood Brush. — Most of the work
of piling and burning brush has been in coniferous for-
ests. Of late, however, there has been considerable dis-
cussion of burning the slash after logging in hardwood
forests. So far as the author is informed, systematic
brush burning after hardwood logging has not been con-
ducted anywhere on a large scale or in a manner to justify

PROTECTION OF lORKSTS FROM FIRE

259

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260 THE PRINCIPLES OF HANDLING WOODLANDS

a judgment as to its practicability. Hardwood tops are
necessarily large, heavy, and awkward to handle. The
cost would be much greater than in coniferous forests.
It is probable that lopping and scattering will be used
rather than piling and burning.

The author has conducted some experiments in the
burning of hardwood brush in the second-growth forests
of New England, where the wood was utilized to about
3 or 4 inches, so that the amount of brush to be disposed
of was much less than would have remained from logging
old timber in the ordinary manner. The results of these
experiments showed the average cost of piling and burn-
ing to be between 10 and 25 cents per cord. In this
class of material with good organization the cost would
probably not exceed 10 to 15 cents per cord, though
these figures furnish but scant basis upon which to make
calculation of the cost of piling and burning the brush
and debris from an ordinary hardwood logging opera-
tion, where the size and number of the limbs would be
very much greater.

Lopping the Tops. — In some forests the burning of
the brush may be unnecessary or actually undesirable.
A method of brush disposal applicalTte in many forests is
to lop off the branches from the tops and leave the mate-
rial on the ground. The purpose is to bring all the
brush m close contact with the ground, so that it will
absorb moisture more readily, dry out less in summer,
and decay more rapidly than when propped high above
the ground.

PROTKCriON OF lOKKS'lS I ROM I I RE 261

So far as the author is informed this method was first
used on an extensive scale in the Adirondack Mountains
in kniibering spruce and pine. At first the plan was to
cut off only the upper branches of the top as it lay on
the grounci. This left the stem still propped above the
ground, as shown in Kig. S3. The next step was to cut
off the under branches and lower the whole mass to the
ground. The heavy snows during the first winter after
cutting flattened down the top and the branches. (Fig.
54.) In this condition the brush absorbs moisture so
rapidly that after three years there is little risk of fire.

This method was first used in private shooting pre-
serves, mainly to prevent the tops from obstructing the
hunter's view. It also enables a freer movement over
the ground and facilitates the fighting of fires.

A later development of the method is to cut up and
scatter the branches about ov^er the ground. This has
been used in the cuttings on second-growth woodlands
when the amount of material left after cutting the cord-
wood in the tops was small. It has also been extensivelv
used in certain National Forests in the dry districts of
the West, where the scattered branches serve as protection
to the soil and aid reproduction.

The cost of lopping the tops of spruce in the Adiron-
dacks was 12 cents per thousanci feet of lumber cut.

Lopping is the most advisable method of brush dis-
posal under the following conditions:

1. Where there is very little danger of fires start-
ing.

262 THE PRINCIPLES OF HANDLING WOODLANDS

2. Where the region is moist and the branches will
absorb moisture quickly.

3. Where the forest is so dense that piling and
burning is impracticable.

4. Where the conditions of logging and of the
market are such that the greater part of the tree is util-
ized and but little crown is left, while what is left will
not be especially dangerous if thoroughly lopped and
scattered.

5. Where the scattering of the branches is necessary
or desirable to protect the soil and small seedlings from
drought or frost.

Broadcast Burning. — For a number of years it has
been the custom of certain lumbermen to burn their
slashings, in order to protect valuable standing timber
on neighboring areas. There is usually no attempt to
regulate the fire within the area burned, and all living
trees and young growth upon it are destroyed along with
the brush and debris. From the standpoint of forest
production such fires are very destructive.

The principle of broadcast burning may, however, be
used to advantage in making clear-cuttings, provided
the fire can be confined to small areas and fully controlled.
Thus, in making clearings in patches and strips in cer-
tain of the National Forests, the slashings are burned on
the ground without piling. This method is now under
trial in some of the clear-cuttings in the northwestern
National Forests, where, in addition to the slash from
the cuttings, there is a great accumulation of debris and

PROTECTION Ol- lORLS'lS 1 ROM II RE

263

Fig. 53. — A Spruce Top Improperly Lopped.

Fic. 54.-^The Same Spruce Top Properly Fopped.

264 THE PRINCIPLES OF HANDLING WOODLANDS

the litter and humus is very heavy. In some instances
this debris and litter is a hindrance to reproduction, as
well as an invitation to fire, and its destruction is bene-
ficial. The heavy loss of humus which must accompany
so hot a fire may be more than counterbalanced by the
improved conditions for reproduction of the species
desired. The expense of piling all the slash and debris
in the ordinary manner would, under these conditions,
be very large, probably not less than from $1 to $2 per
thousand feet of timber cut.

In order to control the fire in burning over the
ground broadcast, ample fire-lines should be constructed
around the outside of the areas to be burned. These
should usually be not less than 1 rod wide, and should
be entirely cleared of inflammable material. The mate-
rial in the lines may often be thrown on the side of the
cut-over area and burned with the other debris, but if
this would make a dangerously large pile near the line,
it is better to burn it in piles on the cleared space.

The burning should be done with great caution. A
time should be selected when the slash is dry enough to
burn well, but not so dry that it will be impossible to
confine the fire within the fire-lines. The best time is
usually when the slash in the open, cut-over area has just
dried out sufficiently to burn, and while the contiguous
forest is still too damp to burn freely. In the case of
wide, cleared strips it may be advisable to construct a fire-
line through the middle, as well as along the edges.
Very often the logging trails can be used for intermediate

PROTECTION OF FORESTS FROM FIRE 265

fire-llnes for the control of the burning, and in this
way the expense of making special lines may be partly
saved.

In the work of burning it is usually advisable to have
a crew of at least 10 men, properly equipped with fire-
fighting implements, in order to control the fire. So far
as possible only small portions of the area should be
under fire at one time, especially when there is any possi-
ble danger of the fire spreading to the adjoining woods.

There is no question that this method is much more
dangerous than burning brush in piles, and for this
reason the latter method should be used whenever pos-
sible. A great objection to broadcast burning is that
any remaining trees, reproduction, or young growth, al-
ready started on the cut-over area, are almost inevitably
destroyed.

Annual or Periodic Burning of Litter. — In many
places, notably in the pine districts of the South, it has
been the custom to let surface fires run through the woods
every year, usually in order to improve the range. This
is defended on the theory that if the litter is allowed to
accumulate for a number of years, a fire would be so
severe as to kill all the timber, w^hereas an annual fire
burns only the year's fall of leaves or needles, and docs
little damage to the standing trees. Where the trees are
tapped for turpentine the litter is raked away from the
boxed trees, so that the fire will not reach them.

There is no question that in the unprotected yellow-
pine forests this custom has resulted in saving a large

266 THE PRINCIPLES OF HANDLING WOODLANDS

amount of old timber, but It has also retarded the repro-
duction of the forest by killing off ^^oung growth and
seedlings in their tender stage. Deliberate burning of
the litter as a protective measure is justified only under
special conditions and only on selected areas. The con-
siderations bearing on the use of fire in this way are:

1. It should never be used except where absolute
fire prevention cannot be assured, and there is real danger
resulting from heavy leaf litter.

2. It should be used only in stands in which there
is no reproduction that it is desired to conserve.

3. It should be used only where the benefit in fire
protection more than offsets the injury to the soil, result-
ing from repeated burning.

4. It should be used only with very fire-resistant
species.

5. It should be used only when the trees are old
and large enough to have developed the corky bark
necessary for resistance to the heat of the fires.

6. It should be used only when the fire can be con-
trolled.

The burning is done best in early spring, when the
loose litter is dry but the ground below is damp, the
purpose being to burn only the upper litter.

In many places it is very difficult to control the burn-
ing without the use of fire-lines. A tract divided by
roads and paths into small blocks presents a simple prob-
lem, for each block may be burned separately, and there
is no danger of the development of a fire too large to

PROTECTION OF FORESTS FROM FIRE 267

control. On large tracts without roads, ground-cleared
fire-lines may be used to protect areas of young growth,
or these may be developed at certain points to aid in the
control of broadcast burning.

Annual burning for fire protection is never justified
where it cannot be systematically controlled. The prac-
tise in many parts of the South and West, of setting out
fires to burn off the litter and brush — usually for the sake
of a better range — cannot be justified, for the fires are
uncontrolled, and they destroy an Immense amount of
young growth and otherwise damage the forest. Merely
setting fire to the woods without control Is nothing less
than forest destruction.

Fire-Lines. — Broadly speaking, a fire-line is a cleared
strip in the forest used as an aid In the protection from
fire. It may be a road, a trail, a river or stream, a line
cleared especially for a fire-break, or a plowed furrow.
The purpose of fire-lines Is to check or stop fires, and to
facilitate fighting them. A small surface fire may be
stopped entirely by a road or even a path. Some surface
fires are easily checked In their progress by narrow fire-
lines; others can be stopped only by very wide lines.
Crown fires and surface fires of unusual severity will
readily leap across even very wide fire-lines. Fire-lines,
therefore, should not be built with the Idea that they will
always stop fires. They are intended to serve primarily
as an aid, and often are an indispensable aid, In control-
ling fires and preventing their spread. Even when they
do not actually stop or check a fire they serve as vantage

268 THE PRINCIPLES OF HANDLING WOODLANDS

points from which the fighting crew may work. Their
establishment usually makes the woods accessible, so that
a crew can get to a fire or near it quickly with appliances
for fighting it. If back firing is necessary, it can often
be done best from the fire-line.

Fire-lines differ very greatly in construction and
width, according to local conditions of fire danger and
of special forest organization. They will be discussed
under the following heads: (1) Roads; (2) trails; (3)
special fire-lines.

Roads. — An ordinary dirt road ranks as one of the
best of all fire-lines. The wider the road the more
effective it is. A forest well cut up with roads is, there-
fore, much more easily protected than one with few or no
roads. In Europe, every well-organized forest has a
thoroughly planned network of roads. These are located
primarily with reference to the problem of logging, but
they serve also as a network of fire-lines, and special lines
are cleared to supplement them where necessary. Every
part of the forest is readily accessible, not only for patrol-
ing for fire during the danger season, but for the quick
transportation of fire-fighting appliances. In case a fire
should start in such a forest and be discovered within a
reasonable time, it would be easy to confine it to a small
area.

We cannot expect to have such a well-organized sys-
tem of roads and fire-lines in our forests for a long time,
but much can be done in the way of utilizing the more
or less temporary roads that are used in logging and

PROTECTION OF FORESTS FROM FIRE

269

270 THE PRINCIPLES OF HANDLING WOODLANDS

afterward abandoned. This is particularly true in the
second-growth woodlots.

In most woodlots there are a great number of old
wood roads, often badly overgrown with weeds, brush,
or trees. If these are kept clear they are of great value
in fire protection. They make the different parts of the
woods accessible and offer points from which the fighting
crews may work. The author has in mind a tract in
Pennsylvania which was burned over in 1909 with great
loss, but which might easily have been saved had the old
roads been clear.

It is usually impracticable, on account of the expense
entailed, to keep all the roads free of leaves, grass, etc.,
but they may be kept brushed out with very little cost.
The author recently had some work of this sort done on
a Pennsylvania tract, eight years after abandonment of
the road, for less than |3 per mile. It may not always
pay to repair bridges and restore badly washed roads, but
in almost every second-growth woodlot most of the over-
grown roads may be reestablished sufficiently for fire-lines
w4th very little cost.

Trails. — The first object of trails is to open up a for-
est and make it accessible for patrol and for fighting
fires. In the National Forests, this \\ork of trail con-
struction constitutes the first step in organizing for fire
protection. In undeveloped mountain regions it is im-
possible without good trails to get to a fire in a reasonable
time and with means for fighting it. The trails in the
National Forests are permanently constructed, and are

PROTECTION OF FORESTS FROM FIRE 271

designed for saddle and pack-horse travel, (t'ig. 59.)
While their first purpose is to facilitate patrol and access
to a fire, they may be used as starting-points for back-
firing, and will often check or actually stop a small
surface fire.

Special Fire-Lines. — When there are no roads or
trails which will answer the purpose, it ma\' be advisa-
ble to construct special hre-lines. Special fire-lines are
necessarily expensive, and are used where the property
to be protected is very valuable. They are most used
in woodlands in the better settled portions of the countrv,
where land values are relatively high. In many cases it
is advisable in a valuable woodlot to construct here and
there a special fire-line at points where it is not worth
while or practicable to build a road or trail. Thus,
special lines are frequently run along the boundaries or at
strategic points connecting roads. It is a sound princi-
ple, however, that special fire-lines should never be built
where a road or trail can be useci for the same purpose.

In the less intensive forest conditions, such as occur
in the lumber woods, special fire-lines have so far been
constructed only under exceptional conditions. In a
large forest, the first \\ork is to open up the area for com-
munication by the construction of trails, and, \\here
possible, of roads. Like all other \\()rk in forestrv in-
volving an investment, the use of fire-lines nuist be based
on sound business principles. They should be used
only where necessary, and where their expense is justified
by the returns.

272 THE PRINCIPLES OF HANDLING WOODLANDS

Special fire-lines may be classed under the following
heads: (a) Fully cleared lines; (I?) tree-cleared lines; (c)
ground-cleared lines.

Fully Cleared Lines, — The ideal fire-line is a com-
pletely cleared strip, from which are removed not only
the trees and brush, but also all ground debris down to
the mineral soil.

Fully cleared lines are advisable when the risk of fire
is very great and adequate protection can be secured only
by having a clear break, which will either stop or check
possible fires. Such lines are necessarily expensive to
construct and maintain. They are, therefore, used only
when the property is valuable and the damage from a fire
would be very great, as, for example, to protect nurseries,
plantations, or valuable blocks of timber.

They are especially necessary wherever fire will run
swiftly and it may not be possible to reach the fire
promptly with fighting appliances. A conspicuous
example of the necessity of such fire-lines and of the
service rendered by them is found in the chaparral
forests of the mountains in southern California. (Fig.
58.) The preservation of the chaparral cover is of
great importance in protecting the local watersheds.
The area is large, the mountains are rough and difficult
to travel, and fire runs with great rapidity. Fire-lines
are very necessary in such localities to control any fires
that may start, and they must be of a character to stop
fires, or to check them to such an extent that they can be
controlled. The Government is, therefore, building

PROTECTION OF FORESTS FROM FIRE 11 S

extensive trails for patrol to prevent fires, and supple-
menting them by wide, cleared fire-lines to stop any fires
that may start.

Cleared fire-lines are also used in extensive pine for-
ests on dry, sandy land. Fires start easily and run
swiftly under such conditions, and fire-lines are easy to
construct and comparatively cheap to maintain. Thus,
in the pine forests of northern Germany and southern
France, wide cleared lines are used to supplement the
road systems.

The danger from fire is always very great in the re-
gions of the Tropics that have a pronounced dry season.
In India, for example, fire protection constitutes one of
the greatest problems of management. The forest be-
comes very dry in the hot season, and there is a great
abundance of grass, which ignites readily and carries fire
swiftly. Under these conditions cleared fire-lines are
absolutely necessary for efficient protection.

The width of fire-lines varies greatly under different
conditions. In general, the following classes from the
standpoint of width may be recognized: Normal, from 6
to 15 feet; wide, from 15 to 30 feet; very wide, from 30
to 60 feet. In Europe lire-lines are usually about 10 to
15 feet wide, but in the pine plains they are often as
wide as 50 feet.

In this country such fire-lines as have been con-
structed are usually less than 1 rod in width. In the
chaparral of California, however, broad lines, from 40 to
60 feet wide, have given the best results in stopping fires.

274 THE PRINCIPLES OF HANDLING WOODLANDS

Fig, 56. — A Plowed Furrow that Stopped a Surface Fire.

Fig. 57. — A Fullv Cleared Fire-Line in the San Gabriel
Mountains, California.

I'ROTECTION OK lORKSTS FROM I I RE 275

It is seldom necessary or practicable to make fire-lines
over 60 feet wide. Usually it is more economical to
make a number of narrow lines rather than a fev/ very
broad ones.

In constructing a fully cleared fire-line the timber and
brush should all be removed or disposed of to the de-
sired width. Where it is impossible to utilize the tim-
ber, the logs may be left along the side of the lines.
The brush and other debris should be burned. Piling
the brush along the edge of the line is a dangerous prac-
tise. As a rule, the best plan is to burn the brush in
piles in the cleared area, and then burn the ground litter
by a broadcast fire.

In the best permanent lines the stumps are all grubbed
out and the soil is occasionally stirred by grubbing or
harrowing. Sometimes only a part of the line is cleared
to the soil. Thus, for example, the timber and brush
may be cleared from a strip from 10 to 15 feet wide, and
a narrow vStrip or trace about 4 feet wide ground-cleared.
This cleared trace may be located In the middle of the
line, or on one side. A good plan is to make two traces,
one on each sicie of the fire-line. The advantage of the
last plan is that it affords a very good protection when
burning the debris on the line.

The method of constructing a narrow, ground-cleared
trace, covering only a part of the fire-line, is very com-
monly used where there is a deep duff on the ground.
It is then a question of protection against ground fires.
Under such circumstances the trace amounts to a trench.

276 THE PRINCIPLES OF HANDLING WOODLANDS

In the north woods the duff is frequently 2 feet deep.
A narrow trench, from 1 to 3 feet wide to the mineral
soil, suffices to stop or check a ground fire. The trees
and brush are cleared for a width of 6 to 15 feet, to facili-
tate work in fighting fire and in constructing and main-
taining the trench.

Fully cleared fire-lines should be cleaned off every
year or two. The leaves and other debris accumulating
upon them should be removed by burning or otherwise,
and in the case of grubbed lines the soil should be stirred
over by raking or harrowing.

The work of burning over the fire-line can best be
done in early spring. The leaves and other debris will
become dry on the open fire-line sooner than in the
adjoining forest or chaparral. The aim should be to do
the burning at exactly the time when there will be the
least danger of the fire spreading to the woods. It is,
however, not always possible to organize the crew so as
to have the work done at the most favorable period. In
the case of an extensive tract the work may be begun
exactly on time, but the whole woods may become dan-
gerously dry before it can be finished. It is especially
difficult to carry out this work of burning over the fire-
line in open pine woods on dry, sandy soil.

When the burning has to be deferred until the woods
as well as the fire-line are dry, great care should be exer>.
cised in the work. If the ground cover consists of leaves
or needles, the procedure is as follows:

Narrow, cleared traces are made on each side of the

PROTKCTION OF FORKSTS 1 ROM 1 I RK 277

fire-line proper, by raking or brushing aside the leaves, or
needles, and debris. Sometimes, in fiat, levx-I areas it is
possible to make the trace by plowing one or two fur-
rows. Usually these traces need be no more than a foot
wide. A fire is set along the side of the fire-line. One
or more men follow this up, constantly brushing the
burning or smoldering embers toward the center of the
fire-line, the idea being to keep the fires confined between
the traces. Other men follow behind and watch the
burning area to prevent a possible spread of fire. If there
is a strong wind, no burning should be done. If there is
a slight wind across the line, one trace may suffice on the
lee side, and the burning should proceed against the
wind. Under ordinary circumstances a crew of from
four to six men suffices for burning over fire-lines, but
if the weather is very dry a much larger crew may be
required.

In very dry weather the burning is best done early in
the morning or in the late afternoon and evening. The
air is moister, and there is usually less wind at those
times.

In California, several interesting experiments in keep-
ing down the brush on the broad lines are being tried.
One is to pasture on the line a flock of goats which eat
down the new weeds and sprouts, and trample the ground.
Another experiment is to establish on the line a dense
growth of succulent, herbaceous plants which would keep
out ordinary weeds and obviate annual or periodic grub-
bing.

278 THE PRINCIPLES OF HANDLING WOODLANDS

The cost of constructing fully cleared fire-lines varies
enormously, just as does the construction of a road or
trail. The cost of clearing the line depends on the width,
character, and quantity of timber and brush to be cut, the
quantity of tops to be disposed of, and the character and
quantity of ground debris, as well as on the labor, the
difficulties of work, the efficiency of organization, etc.
If the ground is grubbed, the cost is affected by the char-
acter of the work done, the difficulties of working the
ground, and the topography. In general, the first con-
struction of an 8-foot fully cleared line costs anywhere
from J 10 to J 100 per mile. An average for a second-
growth woodlot would be from J30 to $50. If there is
a good market for cordwood and other material, the tim-
ber might return 50 or 60 per cent, of the whole cost.
The wide fire-lines in southern California cost from $100
to $200 per mile. They are now cleared every two years
at a cost of from $30 to $75 per mile. The cost of
maintenance will be progressively smaller from year to
year.

Tree-Cleared Lines. — By a tree-cleared line is meant
one from which the trees and brush are removed, but
from which no effort is made to clear the leaves or
other small litter. The object of such lines is not to
stop a fire, but to furnish a vantage ground for patrol
and for fighting fires. The brushing out of all wood
roads, already mentioned on page 270, makes the best
kind of tree-cleared lines.

Very frequently special tree-cleared lines are made

PROTECTION OF lORESTS I ROM llRb

279

4Br . l^

<, — ^nv;

Fig. 58.— a Fire-Line in the Chaparral. Angeles National
Forest, California.

280 THE PRINCIPLES OF HANDLING WOODLANDS

where there are no roads or trails, as, for example,
along the boundary of a tract, about a recent clearing,
around a body of young timber, etc. In Europe,
such lines are often made between two compartments
where there is no road or other permanent boundary.

The width of tree-cleared lines is usually from 6 to
IS feet. The European tree-cleared lines between com-
partments are usually about 6 or 8 feet. Often a line
from 10 to 15 feet is cut, especially where a road may
later be located. In a number of instances in this coun-
try very wide lines have been cut, 75 or 100 feet in
width. Such great width is ordinarily unnecessary.
Strips a rod wide are usually of fully as great value as
the very wide lines, except in conifers, where there is
danger of crown fires. The maintenance of these lines
consists in brushing them out every year or two.

Ground-Cleared Lines. — By ground-cleared lines are
meant strips on which the small brush and ground
debris are destroyed, and the larger trees are left stand-
ing. Ground-cleared lines may be made in open woods,
where there is little or no undergrowth to be injured or
to interfere with the work of clearing the ground. The
usual procedure is to burn a strip through the woods
from 10 to 20 feet wide. This can be done only where
the conditions are such that a surface fire may be con-
trolled and restricted to the desired strip.

The open pine woods of the South present an ideal
condition for the use of ground-cleared lines. In burn-
ing the lines, practically the same methods as those

PROTECTION OF lORKS'I'S I ROM MRE 281

described on page 276 for burning over regular fire-lines
should be used.

Location of Fire-Lines. — The existing roads usu-
ally constitute the base or framework of a system of fire-
lines. Ordinary roads, old wood roads, skidding trails,
and other open strips are used first, and special lines are
constructed only when necessary. Special lines should
always be located at the strategic points.

In any given forest the boundaries should first be pro-
tected. There must be protection from fires that may
start on a neighboring tract. Often roads running along
or near the boundary will give adequate protection. If
not, and there is danger of fire entering from the outside,
a fire-line is desirable, even if it is only a tree-cleared
strip.

Fire-lines are often constructed around recent cut-
tings, where there is young growth established or on
areas where there is still considerable slash.

One of the places where fire-lines are most needed is
along railroads. It is the custom of certain railroads to
keep their rights of way clear, usually by annual burn-
ing. In some States this is required by law. In spite
of this precaution, innumerable fires are set on the right
of way, and very commonly by sparks thrown into the
woods beyond.

Many special fire-lines have been tried. In general,
these are based on the principle that the right of way
should be cleared, then a strip of woods left standing,
and then a second cleared fire-line constructed back of

282 THE PRINCIPLES OF HANDLING WOODLANDS

this Strip of timber. The theory is that the trees on the
timbered strip will catch the sparks thrown beyond the
right of way. Any fire set by these sparks on the tim-
bered strip will be stopped by the second fire-line.

This principle has been used in a number of instances
in this country. One good example is found in a hard-
wood forest in southern New York. A railroad runs
through the tract, along a stream valley. The stream
acts as a fire-line on the low side of the railroad, but the
opposite side is exposed to frequent fires resulting from
the sparks escaping from the locomotives. A stretch of
several miles is on a steep grade, and the locomotives,
under forced draft, throw out great showers of burning
cinders, and no spark-arresters whatever are used. As a
protection, a fire-line, varying in width from 8 to 15 feet,
has been constructed on a bench at a distance of from 50
to 150 feet from the railroad. The strip between the
line and the railroad is left untouched. A patrolman
rides over the strip about the time the trains going up
grade pass by. Ordinarily the small fires are extin-
guished by beating. In case, however, a number of
fires are started by a train, as often happens, one or two
of them burn over the strip to the fire-line before the
patrolman can reach them. The strip is so narrow, how-
ever, that they gain little headway, and are absolutely
stopped by the fire-line.

In mountainous, country, fire-lines arc located with
reference to the topography. Where roads are used, or
fire-lines are made that are intended to be used later as

PROTECTION OF FORESTS FROM FIRE

283

Fig. 59.— a Mountain Trail Built for Fire Patrol.
Angeles National Forest, California.

Fig. 60. — Location of Fire-Lines in the Angeles
National Forest, California

284 THE PRINCIPLES OF HANDLING WOODLANDS

roads, the location is governed largely by the principles
of road construction. Special fire-lines, however, con-
structed for protection alone, are built mainly on the
crest of ridges. (Fig. 60.) For example, the wide lines
in southern California, already mentioned, are on the va-
rious ridges. A fire runs up a slope very rapidly and
works over a ridge slowly. If there is a wide, cleared
fire-line on the ridge the fire may be stopped entirely by
it alone. In the southern Appalachians and other moun-
tains, the old mountain trails on the ridges may be devel-
oped into admirable fire-lines.

The question of when and where to construct special
fire-lines must depend on local conditions, the danger
from fire, the value of the forest, the organization of
patrol and force available for fighting fire, the object
of the owner in protecting the forest, and many other
factors. As with other operations of management, the
expense must be justified by the results which their con-
struction is intended to accomplish.

Artificial Fire Obstructions. — It is well known that
a small, creeping surface fire is stopped or checked by a
stone wall or other similar obstruction. This principle
may be used in fire protection, and other types of fire-
lines may often be dispensed with where there are such
obstructions. A well-known railroad has been experi-
menting with a specially constructed fire-wall.

Supervision and Patrol. — A careful supervision or
patrol during the dry season is one of the most important
measures in organized forest protection. Its purposes

I'ROTF'CnON OF lOKKSTS 1 ROM M KK 285

are: (1) To prevent fires from starting; (2) to detect
fires as soon as possible after they start; (3) to fight fires.

The mere fact that a tract is carefully watched makes
it safer, because campers, hunters, and others crossing it
are less careless on that account. By an efficient over-
sight most of the unnecessary fires can be prevent-
ed, such as those arising from carelessness in clearing
land, leaving camp-fires, and smoking; from improperly
equipped sawmills, locomotives, donkey engines, etc.

One of the fundamental principles in fire protection
is to detect and attack fires in their incipiency. In an
unwatched forest a fire may burn for a long time and
gain great headway before being discovered. In a forest
under proper protection there is some one man or corps
of men responsible for detecting fires and for attacking
them before they have time to do much damage or to
develop beyond control.

Aids to Supervision and Patrol. — Under the head
of aids to supervision and patrol are included: (1) The
posting of fire warnings; (2) lookout stations; (3) tele-
phone systems; (4) signal systems.

The Posting of Fire Notices. — One of the first steps in
organizing protection in a forest is to post it with fire
warnings. These notices emphatically warn against care-
lessness in the use of fire, and often give instructions how
to construct camp-fires and how to extinguish them
when breaking camp. They usually contain also the
prescribed penalties for infringement of the fire-laws.
Notices are posted at frequent intervals along roads and

286 THE PRINCIPLES OF HANDLING WOODLANDS

trails, at camping grounds, near permanent camps and
settlements, and in many cases along the boundaries of
tracts. On private tracts the fire warning is combined
with the trespass notice.

In the National Forests fire-warning notices are print-
ed in English, Italian, French, and Spanish. Notices
printed in Italian are posted where Italians are employed
in railroad construction or section work. Spanish notices
are used in New Mexico, southern Arizona, or other
localities where there are many Spanish-speaking people.
Near the northern boundary French notices are some-
times used. Beyond question many forest fires have
been prevented by these warnings.

In the case of a forest owned by a non-resident it is a
good plan to have on the notice the name of the respon-
sible local agent, as well as the owner's name. This
lends emphasis to the fact that there is a local man who
is looking after the property.

Lookout illations. — Lookout stations include watch
towers, mountain lookouts, and other elevated stations
used for overlooking tracts and watching for fires. On
small tracts they consist usually of some simple structure
which enables the person responsible for the property to
overlook the forest to see if there are any fires, and, in
case he sees smoke, to locate the fire. Sometimes an
arrangement on the roof of the house or barn serves as a
watch-tower, or a lookout may be built in a tall tree, or
it may be necessary to build a rough tower to see over the
tree-tops. In a rugged country it is usually possible to

I'ROTECnON Ol' lORESl'S 1- ROM i I RE

287

a
X

288 THE PRINCIPLES OF HANDLING WOODLANDS

find some convenient peak from which a large area can be
overlooked.

In the organization of large tracts in mountain regions
special lookout stations are sometimes provided. These
are located at high points from which a large area of the
forest can be seen. A man is kept constantly at each
station during the dry season. The various stations
should be in communication by telephone or telegraph,
or by some system of signals. Each is provided with
range-finders or other equipment, by means of which any
fires that may occur can be precisely located. They are
also in communication with the forest ranger or superin-
tendent at headquarters, so that a force of men may be
called at once to the fire and put it out. In extensive
mountain regions these lookout stations constitute an im-
portant part of organized fire supervision. They have
been successfully operated in the National Forests.

Telephone System. — One of the great difficulties in ex-
tensive forest districts is to secure the necessary help in
fighting fires. The telephone is the greatest aid in fire
patrol. It enables the man who discovers a fire to call
for help and to give directions as to the number of men
and the equipment needed. By the use of the telephone
on the National Forests millions of dollars have doubtless
already been saved. The Forest Service has since 1905
built over 9,000 miles of telephone line, and it is ex-
tending the lines as rapidly as Congress furnishes the
funds for the work.

Signal Systems. — When there is no telephone system

PROTECTION OF FORESTS FROM FIRE 289

and a regular lookout station is not feasible, a special sys-
tem is used for signaling for help in fighting a fire.
Some prominent peak is selected, from which, in case of
fire, the location and size of the fire and the required help
are signaled by a prearranged code. There are various
systems of signals in use. The fire signal is one of the
oldest methods. At a time when the signals are not
needed small piles of wood, brush, or other inflammable
material are gathered and placed in position at about
equal distances, usually about 50 to 100 feet apart, ready
for firing on short notice. The number of fires burning
at the same time conveys the information required.
Thus, one fire might mean that a forest fire is burning
in a certain locality on one side of the mountain; two, in
another locality; three, in another; and so on.

Another system that is sometimes employed is the
smoke signal. This was once very commonly used by
the Indians in communicating with each other from one
distant peak to another. A small fire is built, and after
it gets under good headway, damp moss or earth is used
to deaden it and develop a heavy smoke. A blanket or
other covering is thrown over the top of it to smother
the smoke down for a few moments. The blanket is
then raised, and a dense puff of smoke is released.
The blanket is again thrown over the fire to check the
smoke for a moment, then it is again removed, and
another puff of smoke ascends. This system also re-
quires a prearranged code. The smoke signal may be
used in the same manner as the fire signal, by causing

290 THE PRINCIPLES OF HANDLING WOODLANDS

two or three separated columns of smoke from dampened
fires to be steadily rising at the same time. This system
of signaling may be used to good advantage on a still day
for communicating long distances. The separated fire
signal on top of prominent peaks can be used in the
night as well as in the day.

The heliograph is an instrument which may be used
for flashing signals from the lookout stations. The For-
est Service has recently conducted successful experiments
with this instrument.

In some cases it might be possible to use flags and
the code of the Army Signal Corps. Near settlements
the fire bell, gong, or whistle is commonly used to bring
together the men for fighting fires.

The organization of an efficient patrol varies under
the following conditions: (1) Size of tract; (2) character
of the forest; (3) condition of the forest with reference
to the amount of inflammable material; (4) difficulties of
communication; (5) difficulties of securing help in fight-
ing fires; (6) the topography with reference to the
amount of territory which can be overlooked; (7) special
sources of fire, such as the presence of a railroad; (8)
local sentiment.

Supervision of Small Tracts. — The supervision of
a woodlot attached to a farm is exceedingly simple. If
a farmer himself uses proper care in starting fires, in
clearing out his roads, in disposing of brush, and in
keeping a careful watch for fires, his woodlot is com-
paratively safe. Many woodlot fires are caused by the

PROTKCTION OF lORtSTS 1 ROM FIRE 291

owner's own carelessness in clearing land, destroying
brush, burning meadows, etc. The fact that the owner
is careful in the matter of fires becomes knc^wn very
quickly in the neighborhood, and that fact in itself is
a great protection. It is not necessary for a farmer to
patrol his woodlot at regular intervals, as would be
necessary in the case of a large tract.

Many fires start on the property of non-resident
owners, who themselves are unable to supervise it on the
ground. Non-residents may secure protection by an
arrangement with some farmer living near the forest.
The usual course is to pay a small retaining fee for gen-
eral supervision, with the understanding that the farmer
goes over the tract every few days, thus giving the im-
pression of constant patrol. In case fire starts, the agent
has the responsibility of repairing to the fire and putting
it out, and employing such help as is necessary. There
is no reason why this plan should not provide adequate
protection for tracts of from 100 to 500 acres at an annual
cost of from 3 to 5 cents an acre.

One of the most essential measures in the protection
of small tracts is to secure the cooperation of the owners
of all the neighboring tracts in watching for fires and in
mutual assistance in extinguishing fires, no matter on
whose land they start.

Supervision of Large Tracts. — In the protection of
large tracts from fire a special organization for patrol is
necessary. This organization can best be combined w ith
that required for the management of the tract. In every

292 THE PRINCIPLES OF HANDLING WOODLANDS

forest that is being developed there is necessary a certain
force to supervise any work such as logging, the con-
struction of roads, the protection of game, the prevention
of trespass, etc. This organization is best illustrated
in the National Forests. There is a permanent corps of
trained rangers who live on the Forest, each in charge of
a specified area. These men have executive charge of all
the work in the woods. During the dry season this
force may be supplemented by temporary forest guards
for special fire patrol. Each guard is assigned to a speci-
fied part of the Forest, which he is required to patrol
regularly; he prevents the start of fires as far as possible
and watches for any fires which may start within his
range. It has already been explained that one of the
purposes of the construction of trails through the Forests
is to enable the constant patrol and access to fires which
may be started. The guards ride or walk over these
trails under a systematic plan. There is usually a regu-
lar beat over which the guard travels at regular intervals.
In some tracts it is possible to go over the beat once a
day; in others it requires a much longer period. When
not on patrol the guards are engaged in other general
work on the Forest.

In the plan of patrol the guards keep in close touch
with each other and with the ranger in charge of the
whole work, in order that they may communicate in case
of fire by signal from lookout stations, by telephone, or
any other method of communication that may be estab-
lished in the Forest.

PROTECTION OF FORESTS FROM FIRE 293

Most of the National Forests of the West are in
rugged mountain regions, with comparatively few roads
and trails. The guards usually travel on horseback over
certain roads or trails, keeping track of the people who
enter the Forest, and giving them special warning regard-
ing carelessness with fire. In this way each person enter-
ing the Forest is impressed with the fact that his move-
ments are watched, and the result is that he is more
careful with camp-fires, smoking, etc.

On large tracts patrol is concentrated at critical points.
The guards spend the most time where there is the great-
est travel, frequently inspecting camp-grounds, sawmills,
and other points where fires are most likely to start.

In some instances the actual patrol over trails is more
or less dispensed with, and men are kept continuously at
lookout stations, from which a large area can be over-
looked. In case of fire, signals are sent to other lookout
stations and to headquarters, with the necessary instruc-
tions regarding the location of the fire, the number of
men needed to fight it, etc.

It is impossible to give a specific rule regarding the
number of men required to protect tracts of different
sizes. There is no question that the National Forests
are very much undermanned. In some cases a single
man has the responsibility of protecting more than 100,-
000 acres. This area is much too large even under the
most favorable conditions. Even with proper facilities
for communication, the fire protection force on the
National Forests should be quadrupled. Very good

294 THE PRINCIPLES OF HANDLING WOODLANDS

results would be obtained if there were, during the dry
season, one guard for each 1 S,()0() or 20,000 acres. This
will follow naturally as the increased receipts from the
Forests justify a more intensive management.

In flat regions more men are required for patrol than
in a rugged country, where large areas may be overlooked
from prominent elevations. It has been the general view
that in fiat regions like the Lake States and the plateau
portions of Maine and the Adirondacks there should be
at least one guard for each 10,000 acres.

The required force of guards is governed by the risk
of fire and the value of the property to be protected. In
the case of a forest of very great value there is necessarily
a correspondingly greater justification for expenditure in
fire protection, just as one takes out fire insurance in pro-
portion to the value of his property. As the value of
our forests increases, there will be a correspondingly
greater amount of money spent on protection. This
principle is illustrated in Europe, where the forests are
very valuable and where frequently there is one forest
guard for each 1,000 acres. (Prussia, one for 1,700
acres; Baden, one for 750 acres.)

Patrol Along Railroads. — Railroads in many cases
are the most prolific source of fires. In some sections
over 50 per cent, of the fires are from the sparks from
locomotives. While most of these fires could be pre-
vented if the railroads used proper appliances on the
locomotives for arresting the sparks, nevertheless, in
many cases, it is probably impossible to prevent sparks

PROTECTION OF FORESTS FROM FIRE

295

Fig. 62. — ^A Watch Tower in the Tusayan National
Forest, Arizona.

296 THE PRINCIPLES OF HANDLING WOODLANDS

which will start fires in very dry weather. It is, there-
fore, necessary to supplement the use of spark-arresters
by patrolling the right of way.

7'he most effective method of patrol is to follow
every train with a speeder equipped with mattocks,
shovels, pails, and other necessary equipment for fight-
ing fires. A fire started by a spark from a locomotive
may then be put out before it has an opportunity to gain
any considerable headway or to do much damage.

It is not always practicable to follow every train over
a long distance, and it may happen that there is danger
from the sparks only at steep grades. In that event the
patrol is concentrated at the dangerous points.

The plan of following every train by patrolmen may
be practicable where the distance traversed by the road is
not great, but it would not be feasible for a great mileage.
Thus, for example, the problem of patrol is being con-
sidered by certain large railroads with the view of apply-
ing it over the entire system, wherever there is danger
from fires. The purpose is to save the annual expense
of fire damages. One system in the Northeast, cov-
ering not over 2,000 miles, is said to have an annual
expense of over J 5 0,000 for forest-fire claims. It is
probable that the most practical method of supervision of
the right of way would be through the organization of
the section men, with a special patrol at certain grades
where the danger from fires is particularly great. There
is no reason why the section men, if provided with proper
speeders and other equipment, should not be trained to

PROTECTION OK FORESTS FROM I IKE 297

repair at once to fires which inay start alon^ the ri^ht of
way and put them out, with a comparatively small loss of
time.

In Minnesota the law requires that railroad companies
must put on patrolmen to patrol their tracks. The forest
commissioner may compel the companies to put on as
many as one man to each mile of track.

The Methods of Fighting Fires
The principles of fighting forest fires are essentially
the same as those recognized in fighting fires in cities.
The following are of first importance: (1) Quick arrival
at the fire; (2) an adequate force; (3) proper equipment;
(4) a thorough organization of the fighting crew, and (5)
skill in attacking and fighting fires.

Quick Access to Fires. — Quick access to fires is ac-
complished through the work of supervision and patrol
in discovering fires before they hav^e gained much head-
way, and by a well-developed system of communication
through the forest by roads and trails.

An Adequate Force of Fighters. — A small lire may
be put out by one man, but in extensive forests several
hours may pass before the fire can be reached. It is im-
portant to secure an adequate force of men and to get
them to the fire quickly. In a well-organized sNstem of
patrol the guard w^ho discovers a fire communicates
quickly to other guards and to headquarters bv telephone,
signal, or other means, and indicates the number of men
he needs. It is essential that there be definite arraniie-

298 THE PRINCIPLES OF HANDLING WOODLANDS

rnents for securing a force of men in case of fire. This
may be accomplished by cooperation with lumber or saw-
mill operators who employ forces of men, and through
cooperation with local residents, or, in case of small
tracts, through the cooperation of neighboring owners,
each of whom agrees to assist his neighbor in case of
fires. In some States there is a system of fire wardens.
In case of fire, the fire warden may call upon residents to
assist in extinguishing it. They are required by law to
repair to the fire in case of call, and there is a small statu-
tory compensation for services. In case of extensive
forests cooperative arrangements should be made with
every resident within the forest and with every user of the
forest to assist in fighting fires. In most cases where
lumbering is going on the men who are employed in the
logging operations, at sawmills, in road construction,
etc., will furnish a large force on occasion. Through
an efficient system of cooperation it is possible to secure
quickly a large force of fighters, and through this same
system all the residents soon take an active interest in
preventing fires from starting.

The cooperative fire protective associations in the
Northwest, following the example of the Forest Service,
have organized systems of patrol and are doing highly
important work in suppressing forest fires in the white
pine regions of Idaho and Montana, and the fir forests of
Washington. These associations now include practically
all of the large timber owners in the Northwest, and
many small owners as well. The expense of maintaining

PROTECTION OF FORESTS FROM FIRE 299

a patrol during the dry season, of fighting fires, and of
building trails and telephone lines to assist in fire fight-
ing, is apportioned among the members of the association
on an acreage basis.

Proper Equipment for Fighting Fires. — Just as In a
city the efficiency of a fire service depends In large part
on the equipment, so also In forest work It Is essential
that fire fighters be furnished with the proper tools and
other equipment. The Implements needed for fighting
fires differ under different conditions. Wherever dirt
can be used the men should be provided with long-han-
dled shovels. If water Is available, buckets should be
provided, and, where possible, bucket pumps. Under
most conditions It Is desirable to have mattocks and iron
rakes, and there should always be axes to aid in clearing
brush or cutting through down timber and old tops.

These implements should be kept In a convenient
place for use in fighting fires. Proper organization for
fire protection includes an adequate equipment for the
fire-fighting force. No matter how numerous or skilled
the crew, the men are helpless without proper Imple-
ments. In the protection of woodlots in settled regions
every farmer who repairs to a fire usually takes his own
shovel, rake, ax, or other Implement. In the more re-
mote forests under organized protection, the implements
are usually provided by the ranger. A very good plan
is to have caches at convenient points on the trails or at
the lookout stations, containing fire-fighting tools. In
some cases in the mountain regions tools are kept in a

300 THE PRINCIPLES OF HANDLING WOODLANDS

special pack outfit ready to be thrown upon horses and
taken at once to the fire. Such special outfits usually
include shovels, collapsible pails, axes, mattocks, ropes,
and in some cases fire-extinguishers, and a small quantity
of provisions to enable fire fighters to camp out over-
night if necessary. Where there are good roads, as in the
woodlot regions, special fire wagons have been used to
advantage. These consist of an ordinary wagon of the
Concord type, furnished with a complete equipment of
tools, bucket-pumps, fire-extinguishers, water-tanks, or
barrels, etc. The author has used on his own tract in
Pennsylvania a crude fire wagon consisting of a two-
seated buckboard provided with a special galvanized-iron
water-tank with a capacity of about 1 >^ barrels. The
wagon is also equipped with two fire-extinguishers, two
bucket-pumps, one-half dozen buckets, shovels, rakes,
axes, and such other tools as are needed in fighting fires.

Organization of the Fighting Crew. — It is important
that there be in charge of the fighting crew some one
in authority to thoroughly organize the work. A small
crew, well organized, can do much more effective work
than a loosely organized large crew. One of the advan-
tages of the fire-warden system adopted in a number of
States is that the warden has authority not only to impress
men to fight fire but to direct their work.

The efficiency of the fire-fighting crew depends very
largely on their skill and experience, and particularly on
the skill and experience of the man directing the work.
It is not only a question of knowledge of how to assign

PROTFXTION OF FORESTS FROM FIRF 301

each man where his work will be most effective, hut
judgment must be exercised in determining the general
method of attack. The character of the fire, the charac-
ter of the forest, the condition of the atmosphere, the
strength and direction of the wind, the rapidity with
which the fire is running, and many other points have to
be taken into consideration.

Methods of Fighting Surface Fires. — Small surface
fires may often be beaten out. This is possible when the
fire is burning chiefly in a dry leaf litter or short grass.
Where there are tops or piles of dry brush, or the fire is
burning through thick brush or undergrowth, beating is
very difficult.

There are various devices for beating. A blanket,
coat, or riding slicker is often used. A gunny-sack or
piece of canvas is a good implement for beating, particu-
larly if it can be wet from time to time. A handful of
green brush serves also very well for a beating device. In
beating out a fire, one strikes the fire with a sideways
sweep, driving the flames and burning material back
upon the burned ground. A direct stroke scatters the fire.

The best way to extinguish running surface fires is to
throw sand upon the flames. This method is, of course,
practicable only when the soil is fairly clear of rocks and
loose enough for ready digging. In the plains of the
Atlantic Coast, for example, the sand is so loose that it
can be dug up and thrown on a fire almost anywhere.
The fighting crews are equipped with long-handled
shovels, and the sand is thrown along the litie of fire.

302 THE PRINCIPLES OF HANDLING WOODLANDS

When the fire is running in the open woods, in pine
needles, a single shovelful of sand, properly thrown, will
extinguish over 10 feet of fire.

Loose loam is also very good, but not so effective as
sand. Heavy soil which clods is difficult to manipu-
late. Frequently sand or loose loam can be dug up in
spots, but it is too stony to secure it all along the line of
fire. The fighters must then supplement the use of sand
or earth with beating or other methods.

Where, on account of the accumulated debris, the
flames are intermittently too severe for beating, water is
used if available. Water usually has to be brought from
some distance; it must therefore be used very economi-
cally. The best way is to deaden the flames by a little
w^ater, and then beat them out with a gunny-sack or other
device. Experience has shown that water may be most
effectively applied by a hand-spray pump. This pump
throws a stream 20 or 30 feet and makes it possible to
apply the water exactly where it is most needed. The
pump can be purchased at prices varying from |3 to
$4.50. They are extensively used by farmers in the
Northeast. Collapsible pails are excellent for carrying
water, because of their lightness and compactness. Or-
dinary metal water pails are commcjnly used by farmers,
and are much cheaper than collapsible pails.

When water must be brought over mountain trails
special water sacks are used, which can be slung on a
pack saddle. Water kegs, adapted to pack horses, have
been tried in Pennsylvania. Where there are passable

PROTECTION OF FORESTS FROM FIRE 30.^

roads water is liuulcd in barrels or in specially constructed
tanks.

Patent fire-extinguishers have also been used in fight-
ing fires. These throw a stream of water from 1 S to 20
feet. The stream is chemically charged, so that it is
very effective in putting out flames which would be little
affected by ordinary water. In practise a crew is pro-
vided with several extinguishers, a supply of water, and
extra chemical charges. As soon as an extinguisher is
emptied it is reloaded, so that there may be a continuous
play along the line of fire. In case of an ordinary fire
running through grass or leaf litter, one extinguisher will
put out 200 feet of flame.

A very good method in fighting running surface
fires, where there is not much slash, is to make a narrow
trace in front of the fire by raking to one side the leaves
and other litter. As soon as the fire reaches the trace it
is checked and readily beaten out. Sometimes, on level
land and in open woods, a furrow is plowed as an emer-
gency fire-line. (Fig. 56.) This same principle mav be
used to check fires burning through young growth and
brush, where it is difficult to get at the flames. A
narrow lane is cut through the brush ahead of the fire.
This gives a space where the crew can work without hin-
drance. As soon as the fire approaches, it is attacked by
all the crew with the v^arious fighting devices v>ith which
they may be provided.

Sometimes the front of the fire is so fierce that it is
impossible to meet it directly. One method under such

304

THE PRINCIPLES OF HANDLING WOODLANDS

circumstances is to direct the course of the fire. The
attack is made on the sides near the front, separating the
forward portion of the fire from the main wings. A part
of the crew attacks the forward part and others run down

Fig. 63. — Fip^hting- a Ground Fire by Trenching^.

and extinguish the wings. The front of the fire, attacked
from the sides, is forced gradually and constantly into a
narrower path. Usually the front can be directed toward
some cleared space, road, pond, stream, swamp, or fire-
line, when it will l»e checked enough to admit of a direct

PROTECTION OF FORESTS FROM FIRE 303

front attack. Sometimes, by this plan, the front may he
rapidly narrowed by working from the sides, until it is at
last entirely extinguished. The plan of giving direction
to the course of the fire has often been successfully carried
out when the fighting crew is too small for a direct attack.

Methods of Fighting Ground Fires. — Ground fires,
burning in the deep layer of organic matter, are exceed-
ingly difficult to extinguish. If the layer of vegetable
matter is not very deep, it is sometimes possible to put
out the flames by water or sand. If the layer is deep,
trenching is the only practical method of stopping the
progress of the fire. In using this method of fighting
ground fires, one judges the rapidity with which the fire
is burning and then, at a proper distance away, digs a
trench through the vegetable layer down to the mineral
soil, using axes, mattocks, and shovels, as the particular
case may require. Such a trench, which has a width at
the bottom of 1 foot, will enable the fighters to stop an
ordinary ground fire, especially if the work can be sup-
plemented by the use of water or sand at the trench.

Methods of Fighting Crown Fires. — Crown fires are
always accompanied by surface fires. Crown fires stop
when there are no longer inflammable crowns through
which the fire will rLin, or when there is no longer any
material on the ground to carry the surface fire. An
orciinary crown fire will jump a wide fire-line, and many
fires have been known to cross wide rivers, almost w ith-
out check. In the mountains, a crown fire running up a
slope is almost impossible to check.

306 THE PRINCIPLES OF HANDLING WOODLANDS

Back-Firing. — On level ground it is possible to
stop crown fires by back-firing, when the conditions are
such as to make back-firing possible at all. Thus in the
pine forests of the Atlantic Coast crown fires are frequently
checked by back-firing. The back-fire burns of? the sur-
face material, and thus in itself acts as a check to the
crown fire, and, if the area burned by the back-fire is
large enough, will stop it in this way. At other times,
when the back-fire has been successfully started and is
well under way, eating back against the wind, it is caught
by the hot volume of air generated by the heat of the
crown fire. The flames are then turned quickly toward
the crown fire, and the meeting of the two lines of flame
stops the advance of the fire.

When fires gain such headway that it is impossible to
stop them by direct attack, no matter how numerous and
efficient the crew or complete the equipment for fighting,
back-firing becomes the only means of stopping the fire.
It should, however, be used only when it is absolutely
necessary. One of the commonest mistakes in fighting
fires is to overestimate the rapidity of the fire and the
difficulty of putting it out. A forest fire is always a
frightening spectacle, particularly if it is sweeping in the
direction of one's own property. Men often become
excited and start back-fires when it is entirely unneces-
sary. Back-firing necessarily involves deliberately burn-
ing over property. When this belongs to another person
and one's own forest seems to be in danger, there is. a
great temptation to sacrifice it.

PROTECTION OF FORESTS FROM FIRE 307

A second {principle in hack-firing is to burn over as
small an area as possible. The counter-fires are, there-
fore, set only as far ahead of the fire as is necessary to
make them effective. Very often, however, there is onlv
one point from which a back-fire can safely be started, so
that the fighters have no choice.

If it is found that a back-fire is necessary, a favorable
point is selected directly in front of the fire, from which
to set the new fire. This must be a point where it is
safe to start a back-fire, such as a road, fire-line, stream,
or swamp. The leaves are ignited at points 5 feet to a
rod apart for a distance not greater than the estimated
width of the head of the fire. These small fires gradually
meet and form a continuous line, eating back against
the wind.

A part of the crew is stationed across the road, or
other break from which the back-fire is started, and put
out at once the small fires which may result from the
sparks blown over from the back-fire.

The meeting of the two fires stops at once the head
of the main fire. It is usually possible then to attack
the wings with the ordinary methods of fighting. It is
necessary to attack the wings at once, particularly if there
is a strong wind, for otherwise each wing of the old fire
would soon form an independent fire with a well-de\'el-
oped head. It is necessary, also, that a number of men
be stationed where the original fire and the back-fire meet
in order to extinguish smouldering fires in tops, logs,
and other debris.

308 THE PRINCIPLES OF HANDLING WOODLANDS

Patrol After a Fire is Extinguished. — A fire is never
out until the last spark is extinguished. Often a log or
snag will smolder unnoticed after the flames have appar-
ently been conquered, only to break out afresh with a
rising wind. After the fire-fighting crew has left the
ground it is always well to assign at least one man to
patrol the edges of the burned area until it is certain that
the fire is entirely out. This may not be for several
days.

CHAPTER VIII

PROTECTION FROM OTHER INJURIOUS AGENCIES

Protection from Insects

Next to fire the greatest damage to forests is done by
insects. Sometimes the depredation by insects manifests
itself in a wide-spread invasion in which a large percent-
age of the most valuable trees are killed over hundreds of
square miles. Such outbreaks have unquestionably oc-
curred from time immemorial. It is probable that in
some cases insects are responsible for the practical destruc-
tion of whole forests. In recent years there have been
numerous great invasions in different forest regions of
the country, causing damage to the extent of millions of
dollars. More often the work of insects is less conspicu-
ous, and for this reason the importance of protecting
forests from this source of damage has not been fuUv ap-
preciated bv the public, nor even bv practising forestt.^.
There are at all times throughout everv forest hordes of
insects at work on the trees. Some of these are relativelv
harmless, but there are nearlv alwavs some injurious
species at work. It is verv common to find trees dving
here and there, individually or in groups, as a result of
the work of insects. The aggregate loss from these scat-
tered injuries is enormous.

309

310 THE PRINCIPLES OF HANDLING WOODLANDS

The subject of forest entomology is, therefore, of
great importance in the practical handling of woodlands.
It is just as essential to protect the forests from in-
sect invasions as from fire. The protective measures
which must be used depend entirely upon the nature
of the attack, and hence upon the species of insect doing
the work. It is necessary to understand the life history
of the different insects and the manner in which they
work under different conditions, in order to be able to
prescribe measures for their control. The list of in-
jurious insects is very large, and it would be entirely
beyond the scope of this book to include an adequate de-
scription even of the more important genera. This in-
formation must be obtained from special works on forest
insects. The purpose here is to call attention to the im-
portance of the subject and to explain some of the general
principles of the problem. Information regarding insects
attacking the forests of the United States may be obtained
from the publications of the Bureau of Entomology of
the U. S. Department of Agriculture, especially the
works of Dr. A. D. Hopkins, who has taken the lead in
developing Forest Entomology in this country.

Death of Trees. — The most extensive damage is done
by bark-beetles, which burrow in the inner bark of the
trunk and girdle the trees. Coniferous forests in partic-
ular suffer from the attacks of various bark-beetles. It
is very common in the coniferous forests to see here and
there trees or groups of trees turning red and dying. A
close examination usually reveals small perforations in

PROTECTION FROM OTHER AGENCIES .U 1

the hark, numerous pitch tuhes, and fine hc^rin^-dust at
the hase of the tree, all of them indications of the work
of bark-beetles.

It was a species of bark-beetle that caused the so-
called spruce blight which has appeared in the red spruce
forests of the Northeast from time to time during the last
century, and which in certain sections caused the death
of most of the mature spruce. It was another species of
bark-beetle which has been devastating the forests of the
Black Hills in South Dakota.

Still another species of bark-beetle destroys annually
an untold number of trees in the pine forests of the
Southeast. To-day this insect constitutes one of the
greatest menaces of the pine timber of the South, unless
provision is made to prevent the development of an in-
vasion.

One of the most serious present outbreaks is located
in eastern Oregon in the Wallowa and Whitman National
Forests. Previous to 1903 only a few isolated areas of
less than a section each were infested. There was no
check to the spread of the insects, and in 1910 the inva-
sion has spread over about one million acres, having
already killed 35 per cent of the lodge-pole pine in
addition to a large amount of yellow pine. Unless the
invasion is checked the damage will amount to hundreds
of thousands of dollars.

Extensive injury is also done by defoliating insects.
When a tree is defoliated only once, it is not necessarily
killed. If it is thriftv, it mav produce leaves again the

312 , THE PRINCIPLES OF HANDLING WOODLANDS

following year. It is, however, weakened, and continued
defoliations will ultimately kill it. The most conspic-
uous example of an invasion of defoliating insects is the
present outbreak of the gipsy and brown tail moths in
New England. Extensive wood-lots have been entirely
killed. The States, the Government, and the various
communities are spending hundreds of thousands of dol-
lars to check the depredations.

Another illustration of the damage by defoliating
insects is seen in the outbreak of the larch-worm, which
has occurred in the Northeastern States within recent years.
In many sections 50 to 100 per cent, of the mature larch
has been killed by repeated defoliations of the trees.

Injury to Trees. — Certain classes of insects attack the
wood of living trees, but do not kill them. These in-
sects bore into the interior of the trees and seriously
afiFect the value of the lumber cut from them, often ren-
dering it useless.

The damage done by the chestnut timber worm is well
known. In some sections practically every mature chest-
nut is more or less affected. Dr. Hopkins estimates that
the reduction in value of the lumber of chestnut amounts
to about 30 per cent on account of the attacks of this in-
sect.

The locust suffers so constantly from the attacks of
the locust borer that foresters hesitate to propagate the
tree at all. Another example of damage by borers is
seen in the defects of white and rock oak, beech, yellow
poplar, and other hardwoods, resulting from the work of

PROTECTION FROM OTHER AGENCIES 31.'^

one of the ainhrosiii beetles. The injur)' in reducing the
value of the lumber may amount in many localities to
from 25 to 75 per cent.

Another class of injury is seen in the xyork of the
\yhite pine \yeevil. This insect repeatedly attacks the
leading shoots of young white pine, causing a distorted
growth. The trees develop a crooked stem, and their
value is consequently very much reduced.

Dying and dead trees are especially subject to attacks
by insects. The loss caused by them is principally in
the reduction in value of the product of the trees. In
some cases insects attack and kill trees weakened by fire
or some other cause, which otherwise might have recov-
ered and lived.

There is a very close relation between forest fires and
damage by insects. It is believed that in some cases
when the past destruction of forests has been attributed
to fire, it has been primarily the work of insects. The
timber was first killed by the insects. The dead trees
furnished fuel for the later fires, which also killed all
young growth and retarded reproduction. The presence
of the dead trees which had been killed by insects, always
increases the menace from fire, not only by the added
amount of inflammable material, but also because of the
chance of their being struck by lightning and starting a
forest fire.

When a forest has been burned, the final death of the
trees is often due to attacks by insects. The presence of
fire-scorched trees may cause a rapid multiplication of

314 THE PRINCIPLES OF HANDLING WOODLANDS

insects injurious to trees. Ordinarily the effect is to ex-
tend an invasion rather than to be the primary cause of
an outbreak.

There is also a close relation between insects and
fungous diseases affecting trees. The burrows in the
bark and wood often afford entrance for the fungi, and
hasten the decay of the tree. Then, too, trees weakened
by disease may be attacked the more readily by certain
insects.

Injury to Reproduction. — Insects affect the reproduc-
tion of the forest chiefiy by attacking seed. Undoubt-
edly natural reproduction is often retarded because a
large proportion of the seed is destroyed by insects.
Young seedlings are also subject to attack by certain in-
sects.

Control of Insects. — In the systematic control of for-
est insects, provision must be made, first, for prevention
of a possible outbreak, and, second, for attacking an in-
vasion.

The principles are comparable to those used in fight-
ing fires. In fire protection the first aim is to reduce the
causes of fires and to prevent them from being started.
In the same way in insect control, it is essential to pre-
vent the multiplication of insects to a point where an in-
vasion may be developed. If there is an invasion, then
very drastic measures must be used to stamp it out, just
as in the case of a dangerous forest fire.

The enemies of insects are very numerous. Birds,
parasitic insects, parasitic fungi, and unfavorable seasons

PROTECTION FROM OTHER AGENCIES 315

are constantly contributing to check the multiplication of
insects. Very frequently, however, there is a combina-
tion of favorable conditions resulting in the rapid devel-
opment of a given species of insect to a point where the
natural enemies can no longer keep them in check, and
an invasion is the result.

In preventive control work, it is necessary to watch
the forest constantly for any indications of the spread of an
injurious insect which may cause an invasion. Where
the markets for wood and timber permit intensive silvi-
culture, all trees found to be infested are promptly re-
moved. The forest is kept clear of logs, tops, and other
slashings, not only to reduce the danger from fire, but
also to remove breeding-places for insects. In this way
the loss bv desultory attacks of insects is reduced to a
minimum, and the chance for an outbreak is eliminated.

Unfortunately the conditions in most of our forests
do not permit intensive forest management. In the ex-
tensive forests where forestry has not advanced much be-
yond the stage of mere protection, the first aim is not to
attempt to prevent the entire loss caused by death of an
occasional tree or group of trees, but to prevent a damag-
ing invasion. Even under our present conditions it is
entirely practicable to prevent large outbreaks of insects.
It is necessary to keep careful watch of the forest for any
general large development of insect work. As soon as it
is apparent that there is danger of an invasion, it is
necessary to apply immediately remedial measures, even
if it is necessary to incur considerable expense.

316 THE PRINCIPLES OF HANDLING WOODLANDS

In attacking an insect invasion the attempt is not
made to destroy all the insects. That would be im-
practicable, and fortunately it is not necessary. A destruc-
tion of a part of the insects checks their further multi-
plication, scatters the energy of the invasion, and subjects
the remainder to check by their natural enemies. Often-
times it is necessary to destroy only 50 to 75 per cent of
the broods.

The most serious problem of insect control is in the
great coniferous forests of the South and the West, where
there is almost constantly a certain amount of damage by
some species of bark beetle. As soon as there is danger
of an invasion immediate steps should be taken to de-
stroy enough of the insects to check their further multi-
plication. If there is a market for the timber, the trees
containing the broods may be cut and removed with lit-
tle or no extra expense. Frequently, however, the dep-
redations occur in the remote forests, where there is no
market for the timber, or only the largest and best trees
can be sold. Under such circumstances the work of
control must be largely an investment representing in-
surance, just as in the case of expending money to fight
dangerous forest fires.

One method of destroying insects is to cut the trees
down and destroy the bark on the main trunk. Another
method is to peel the bark from the body of standing
trees to a height of about 20 to 30 feet. If the work is
done at the right season of the year it is necessary only
to remove the bark^ without burning it. This method

PROTECTION FROM OTHER AGENCIES 317

was used in the attempt to control the invasion of the
bark-beetle in the Hlack Hills. Special tools were de-
veloped for removing the bark of standing trees. Where
the trees cannot be utilized, the design is to cut or peel
only such trees as are absolutely necessary to check the
spread of the insects. Ordinarily it is necessary under such
conditions to employ an expert, who is thoroughly
familiar with the habits of the beetle, to select the trees,
in order to secure the greatest possible economy in the
work.

In the case of some insects, control work is conducted
by the use of so-called trap-trees. Thus, in the case of
insects which breed in fallen logs, tops, stumps, etc.,
trees may be felled here and there as traps. The insects
are attracted to them as breeding-places. At the right
season of the year the bark is removed and the broods
destroyed.

Other measures are used in the case of certain defo-
liating insects. At the present time drastic measures are
being used to suppress the outbreak of gipsy and brown-
tail moths in the Northeast. Various measures are used,
including the destruction of egg masses where these can
be reached, the wrapping of trees with burlap or tangle-
foot, and wholesale spra\ ing with high-power spraying
machines. This work is expensive, but it is necessary
to protect propert\ which will inevitably be destroyed
unless the insects are checked.

The above iUustrations show the general character of
the work required in controlling an insect invasion. They

318 THE PRINCIPLES OF HANDLING WOODLANDS

serve to emphasize the necessity of preventing an inva-
sion from starting. Careful preventive measures save
not only the loss of timber resulting from the work of in-
sects, but also the expense of fighting an invasion.

Protection from Fungous Diseases

The protection of trees from attacks of parasitic
fungi is of great importance in forestry. The most seri-
ous defects in timber are caused by fungi. Every woods-
man is familiar with certain external indications of such
defects, and is often able to distinguish trees which con-
tain so large a proportion of unsound lumber as to render
them unprofitable to cut. There is, however, an im-
mense amount of hidden defect, resulting directly from
fungous attacks. Fungous diseases enormously reduce
the value of timber and the profits of lumbering. They
contribute directly to the death of trees, sometimes work-
ing slowlv, as in the case of those which attack the interior
of the tree, and sometimes rapidly, as is illustrated by the
chestnut-bark disease which may kill the trees within a
few years after the first infection.

Fungous diseases are spread by minute spores which
are carried by the wind, and which gain access to trees
through wounds. 'Hie wood is readily reached through
fire scars, broken branches and tops, bruises, borings
made by insects, etc. 'I'he rapid spread of injurious
fungi is illustrated in man\' mature forests. Southern
lumbermen appreciate the damage done by the so-callied
red rot, which in some localities affects the majority of

PROTECTION FROM OTHER AGENCIES 319

the mature trees. There are many Instances in the W est-
ern forests where nearly all trees of a given species are
affected by disease, including not only the old but the
middle-sized trees as well. An illustration is the hem-
lock in certain localities in northern Idaho.

It is one of the aims of forestry to maintain a forest
in healthy condition, in order that the trees may be sound
when ready for the market. In a forest under intensive
management diseased trees are promptly removed as soon
as their condition is discovered. In this way the spread
of disease is checked. In operating virgin forests it is
essential to make the first cuttings in those portions on
which the trees are past maturitv and are rapidly suc-
cumbing to disease.

The study of the diseases affecting American trees is
in its infancy. It is of increasing importance to deter-
mine the facts regarding the habits of different fungi, in
order to develop practical measures to protect our forests
from their injurious effects.

Protection Against Other Agencies

Trees suffer damage from various other agencies.
Mention has already been made, in the discussion of the
silvicultural systems, of damage by windfall. While this
cannot be altogether prevented, it can be ver\' largelv
reduced through the proper location of cuttings and the
application of careful siUiculture.

In addition to the soinxes of injurv alreadv men-
tioned, trees are injured by certain animals, bv ice, snow.

320 THE PRINCIPLES OF HANDLING WOODLANDS

and hail-storms, by inundation by water, by exposure to
acid fumes from smelters, etc. For a full discussion of
these various injuries and the methods of protection from
them, the reader is referred to special works on forest
protection, of which Dr. Schlich's '^Manual of Forestry,"
Volume IV, is recommended.

INDEX

Accretion cutting, 202, 209, 216
Adirondacks, 12, 17, 44, 75, 76,

94, 233, 261, 294
Advance growth, 112, 135, 161,

165, 182, 190
Age class, 28
Alder, European, 188
Alternate cleared strips, 123
Ambrosia beetles, 313
Angeles National Forest, 283
Annual burning of litter, 265
Arapahoe National Forest, 51,

66, 73
Area of original forests, 1
Arizona, 254, 295
Artificial reproduction, 88, 89,

98, 103, 126, 135, 158, 175
Ash, 170

Ash, European, 188, 218
Aspen, 243
Associations, fire protective, 27,

225, 298
Atmosphere, influence of, on

fires, 230
Austria, 33, 160

Back-firing, 268, 305
Bark-beetles, 310, 316
Basswood, 170
Beating out fires, 282, 301
Beech, 80, 312

European, 33, 98, 136, 159,
188, 191, 218
Big Horn National Forest, 139
Bigtree, 239
Birch, 80, 170, 227, 243

European, 168
Black Hills, 122, 147, 160, 222,

311, 317
Blocks of trees, reserved, 36,

103, 127
Broad-cast burning, 202, 275
Brown-tail moth, 312, 317

Brush, disposal of, 246

piling, 248, 249, 251, 254, 275
Brush fire, 231
Bucket-pumps, 300
Burning brush, 249, 251, 255, 259,
275

Cabinet National Forest, 287

California, 4, 272, 274, 279, 283

Cedar, western red, 23, 86, 92,
102, 106
white, 134

Chaparral, 232, 272, 273, 279

Cherry, 243

Chestnut, 170, 177, 183, 312

Choice of species, 40

Classification of trees, 27

Cleanings, 190, 220

Clear-cutting, conditions requir-
ing, 83
disadvantages of, 86
in strips, 36, 37, 97, 130
in patches, 36, 37, 97, 135
systems, 36, 83, 101
the whole stand, 36, 95, 101
use in this country, 90
with artificial reproduction,

36
with natural reproduction,
36, 89, 98

Coconino National Forest, 254

Co-dominant trees, defined, 29,
30

Colorado, 51, 66, 73

Composite forest, 30, 32

Composition of stand, 9

Connecticut, 10

Coppice, forms, 30, 32
simple, 38, 170
with standards, 32, 38, 184,
185

Cornell tract, forestry on, 94

Cost of silviculture, 18, 24

321

INDEX

Crown class, 28, 29, 201
Crown fires, 226, 233
Crown-ratio, 207
Cutting cycle, 47
Cutting series, 133, 164

Damage cuttings, 190, 220, 222
Deer Lodge National Forest, 117,

130
Defoliating insects, 311
Density, of stand, 10
maintenance of, 174
reduced by fire, 240
Diameter limit, 53
application of, 56
determination of, 53, 77
example of, 80
Diseases of trees, 112, 220, 240,

314, 318
Disposal of slash, 246
Distribution of seed, 101, 103,
106, 110, 120, 123, 129, 138,
157, 163
Dominant trees, defined, 29, 30
Drought, protection from, 87,

120, 125, 137, 139, 158, 163,
199, 262

Elm, European, 188

Erosion, 87, 125, 241

Europe, 35, 39, 70, 97, 98, 109,

121, 130, 136, 151, 158, 166,
172, 175, 176, 185, 191, 208,
217, 273, 280

Even -aged form, 31
Exhaustion of supplies, 3, 22

Final cutting, 141, 145, 150, 153,

165
Financial returns, 19
Fir, balsam, 66

Douglas, 23, 86, 92, 103, 106,
116, 121, 125, 237, 239, 298
European, 136, 165, 168
white, 103, 106
Fires, causes of, 245

classification of, 226
damage by, 3, 171, 220, 235,

238, 243
equipment for fighting, 299,

300, 303
life history of, 227, 229, 230,
235

Fires, methods of fighting, 297,
301, 305

prevention of, 244

protection from, 225

rapidity of, 230, 231, 233, 234
Fire-head, 234
Fire-lines, 246

fully-cleared, 272, 274

ground-cleared, 280

location of, 281, 282

maintenance of, 277

special, 271

tree-cleared, 278

width of, 277
Fire, notices, 285

obstructions, 284

patrol, 244, 246, 284, 290, 291,
294

protective associations, 27,
225, 298

trace, 275
First cutting, 144, 149
Flury, Dr., 210
Forestry, defined, 6
Form of stand, 30
France, 210, 273
French method of thinning, 210
Front of a fire, 226, 234
Frost, 87, 113, 120, 137, 139, 158,

262
Fungi, 314, 318

Germany, 26, 33, 130, 141, 201,

208, 273
Germination of seed, 108, 113,

124, 159
Gipsy moth, 312, 317
Girdling hardwoods, 67
Grass fires, 231
Ground fires, 275
Groups, of seed-trees, reserved,

36, 116
shelterwood cuttings in, 37,

164
Growth, 12

Hardwoods, 95, 96, 114, 116, 170,
178, 183, 191, 213, 312
brush disposal, 528
thinnings in, 213
Hemlock, Eastern, 80, 103, 106,
251
Western, 23, 86, 92, 102, 106,
319

INDEX

323

Hickory, 170, 177, 181, 183
High forest, 30, 31
Holding-over reserves, 177
Hornbeam, European, 168, 188,
218

Idaho, 27, 52, 105, 106, 298, 319
Improvement cuttings, 27, 64, 189
India, 273
Injuries to trees, by fire, 238

insects, 310
Insects, damage by, 3, 87, 125,

199, 220, 238, 239, 240, 246,

309
control of, 314
enemies of, 314
invasions of, 309
Intensive forestry, 15, 69, 87, 166
Intermediate trees defined, 29,

30
Intolerant species, 63
Investments in forestry, 22, 24,

104, 108
Irregular cleared strips, 128
Irregular form of stand, 31
Irregular stands, improvement

of, 219

Kaniksu National Forest, 105

Larch, Eastern, 312
European, 168, 212
Western, 103, 106, 237

Liberation cuttings, 190, 194

Lightning, 245, 313

Limitation of cut, 48

Linden, 218

Location of seed-trees. 63

Locust, 170, 312

Logging conditions, influence of,
129, 140

Lookout stations, 246, 286

Lopping brush, 260, 263

Maine, 5, 54, 294

Maple, 80, 116, 170, 177, 227

European, 188, 218
March of forest destruction, 2
Market conditions, influence of,

40, 41, 65, 78, 100, 140
Marking, 57

axe, 58

cost of, 59
Maryland, 197

Massachusetts, 115, 213
Maximum of production, 12
Mayr, Heinrich, 208
Measure of production, 12
Minimum of production, 13
Minnesota, effect of fire in, 11
Minnesota National Forest, 39,

109, 114
Missoula National Forest, 55,

248, 259
Mixed stands, advantages of, 43

defined, 42
Montana, 55, 103, 117, 130, 248,

259, 287, 298

National Forests, 15, 54, 90, 225,
255, 261, 270, 286, 288, 292

Natural pruning, 198

Natural reproduction, 88, 89, 98,
100, 103, 126, 129, 181

New Hampshire, 115, 205

New Jersey, 134, 170

New York, 17, 74, 85, 170, 282

North Carolina, 222

Oak, 116, 170, 177, 181, 183, 227,
312
European, 98, 168, 172, 175,
188
Oregon, 23
Original forests, 1
Overwood, 187, 218
Owner, purpose of, 15

Patches, clear-cutting in, 36, 37,

97, 135
Patrol, fire, 244, 246, 284, 290,

294, 308
Pennsylvania, 8, 20, 193, 270, 302
Period of reproduction, 140, 146,

150, 164, 166, 184
Piling brush, 249, 251, 254, 275
Pine, loblolly, 116, 121, 197

lodgepole, 85, 117, 139, 229,

237, 311
longleaf, 116, 121, 142, 228,

239, 242, 265, 280, 311
pitch, 227

Scotch, 168, 206, 218
shortleaf, 222
sugar, 239

western yellow, 92, 93. 116,
121, 147, 160, 167, 311

324

INDEX

Pine, white, 26, 81, 94, 114, 121.

191, 205, 207, 223, 227, 237,

251, 261
western white, 103, 106, 237,

239 298
Planting, ' 87, 89, 93, 95, 97, 98,

103, 135, 159, 175
Polewood coppice, 38, 178, 180
Preparation of soil, 112, 128, 159
Preparatory cuttings, 153, 163,

181
Primary cuttings, 165
Private forestry, 18, 20, 25
Progressive cleared strips, 133
Protection, from fire, 225
from insects, 309
of young growth, 68, 112,

146, 150, 161, 174, 183
Pruning, 223
Public forestry, 15, 20
Pure stands, defined, 42

Railroad fires, 245, 281, 294

Red pine, 237, 251

Reduction of supplies, 3

Redwood, 4

Regular form of forest, 31

Removal cuttings, 151, 153, 161,

163, 165, 184
Reproduction, cuttings, 27, 181

by sprouts, 179

effect of fire on, 242

effect of insects on, 314

method of, 87
Reserves in coppice, 177
Reserving, blocks of seed -trees,
36, 103, 105

groups of seed -trees, 36, 116,
117

scattered seed -trees, 36, 107

thrifty standards, 36, 118
Returns from public forests, 20
Rigid diameter limit, defects of,

60
Roads, use of, in fire protection,

244, 246, 268, 269
Rotation, defined, 18

Scattered seed -trees, reserved,

36, 107, 109
results from, 113
second cutting, 126, 132, 145,

150, 152, 184
system applied, 114

Second growth, 116, 179, 206,
261, 270

secondary cutting, 165
Seed, destruction of, 63, 314

distribution of, 103, 104, 110,
120, 123, 124, 125, 129

germination of 113, 124
Seed-cutting, 141, 144, 147, 153,

156, 163, 165, 181
Seeding, 87, 89
Seed -trees, 63, 108

character of, 111

cost of, 114

location of, 108

left in groups, 116

number of, 120

selection of, 81
Selection, form, 31

stands, improvement of, 219
Selection system, 35

choice of, 72

cost of, 67

illustrated, 51, 55

intensive development of, 69

limitation of cut in, 48

origin of, 44

practical application of, 74

results of, 71

theory of, 45
Shelterwood system, 37, 137, 139,
148, 160, 167, 181, 195, 217

advantages of, 139

disadvantages of, 140

cuttings in groups, 37, 164

cuttings in strips, 37, 162

cuttings, uniform, 37, 153

intensive application of, 152

primitive application of, 139,
141

progressive development of,
150

results of, 146
Signal systems, 288
Silvicultural systems, application
of, 39

classification of, 34

combination of, 38

defined, 32
Silviculture, cost of, 18, 24

defined, 7

investments in, 18, 24

objects of, 8
Simple coppice, 38, 170, 171
Site, 204

INDEX

325

Size class, 28

Slash disposal, 246, 247, 249
Soil, drying of, 87, 113, 120, 125,
138

injury by fire, 240

preparation of, 112, 128

protection of, 138, 218, 262
South Dakota, 3, 122, 148, 160,

222, 311
Spark arresters, 245, 246
Sprout forest, 30
Spruce, Engelmann, 51, 66

European, 33, 136, 153, 159,
165. 168, 191, 210

red, 74, 85, 95, 103, 261, 263,
311
Stand, defined, 30

form of, 30

origin of, 30
Standards, coppice with, 184, 185

number of, 120

reserving thrifty, 118

selection of, 119
State forestry, 15, 20, 27, 93, 245,

298
Stream flow, disturbance of, 5
Strips, alternate cleared, 123

clear cutting in, 36, 37, 97

irregular cleared, 128

location of, 123, 129

progressive, 132

shelterwood cuttings in, 37,
162

width of, 124, 164
Suppressed trees, defined, 29, 30
Surface fire, 226, 236

Telephone lines, use of, in fire

protection, 246, 288
Thinnings, 190, 196

grade of, 202

need of, 198

practical application of, 212

Thinnings, repetition of, 208

results of, 200

theory of, 201

time to begin, 204
Tolerant species, 63
Towers, watch, 286, 295
Trace, fire, 275
Trails, use of, in fire protection,

244, 246, 269
Trap-trees, 317
Trench, 275
Tulip-tree, 170, 312
Tusayan National Forest, 295
Two-storied form, 31
Two-storied system, 166, 217

Underplanting, 168, 218
Under-story, 168
Underwood, 188, 218
Uniform shelterwood cuttings,

37, 153
Unregulated cutting, results of, 5
Upper-story, 168

Value of stand, 10
Virgin forest, 50

Wallowa National Forest, 311
Washington, 16, 27, 84, 86, 91,

298
Watch towers, 286, 295
Weevil, white pine, 313
Whitman National Forest, 311
Willow, 171, 172
Windfall, 56, 64, 81, 85, 104, 118,

126, 128, 132, 140, 155, 163,

204, 216, 319
Wings of a fire, 226, 232, 304,

307
Woodlot, 96, 206, 270
Wyoming, 3, 139

Date Due

Aprir36

A, r 18 '36

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1978

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