American forest regulation

Part II, Herman H. Chapman TO

JAMES W. TOUMEY

IN RECOGNITION OF HIS SERVICES

AS A TEACHER OF FORESTRY

IN THE YALE SCHOOL OF FORESTRY

Preface

"American Forest Regulation" is intended primarily as a textbook on the theory and application of regulating the cut. It may also serve as a guide to forest administrators who must solve broad regulation problems at a reasonable cost. Emphasis has been placed on the discrimination and choice of material, rather than the collection and elaboration of a multitude of methods — many totally unsuited to American conditions. Forest management in the United States cannot be successful until it is definitely recognized that the cutting on all forests held for permanent production must be controlled by working plans based on sound silviculture, local economic requirements and rate of yield.

Not the least perplexing of the problems encountered has been the question of terminology. The author, a member of the Committee of the Society of American Foresters, which recommended standard terms* and definitions, has followed the Committee's report, except where it departs from well established common usage. "Working circle" has accordingly been substituted for "working unit." The student who is assigned additional reading or study in the works of other authors, cannot help but be confused by a varying use of terms. For example, "working group" may be termed "working section" by one author, "working figure" by another, and "working circle" by a third. The "working unit" of the S. A. F. again may be described as "working circle" by Sir William Schlich**, thus further perplexing the student. The writer felt that no personal preference for terms should enter into this new book on American Forest Regulation but that "working circle," widely used in the United States, was preferable to "working unit." On the other hand, the new term "management plan," largely used by the Forest Service in place of the term "working plan" (adopted for generations by English speaking foresters), has not been adopted.

To simplify study, the regulation of cut methods in Part I have been treated systematically, as follows: (i) Definition, (2) Discussion, (3) Illustration, (4) Class room questions or quiz. This plan has not been rigidly adhered to, yet so far as the subject matter lends itself to this form of treatment, it is used throughout. Formulae have first been stated in English (instead of in "formulae equivalents") because the writer found they were more readily grasped by the student. A special feature is quite complete foot-note references to American Literature on each subject.

A rather theoretical discussion of soil-rent (after Endres) has been given, notwithstanding the fact that it is likely that a large proportion of the best American forests will eventually be owned or controlled by the public, and consequently need not necessarily be managed strictly on the basis of the

* Published 1917 in the Journal of Forestry, Vol. XV, No. i.

**Schlich, Sir William, Manual of Forestry (Forest Management, Vol. 3, p. 273).

vi American Forest Regulation

highest soil-rent. Yet this financial side may eventually be of weight in planning the management of many private American forests, where business reasons may usually be foremost. Because of this considerable space in the appendix has been given to a frankly Germanized explanation of soil-rent, and to Endres' discussion and illustration of its application.

The contrast between French and German text-book methods is evident even to the casual reader. The German is apt to treat the subject exhaustively; he will describe twenty different formulae, each varying from the other ever so little, while the French writer will perhaps narrow the formulae down to three fundamental and radically different methods, and omit the others. This book (with the exception of soil-rent) has been written from the French rather than from the German viewpoint, and, consequently, may err in its simplicity rather than in the complexity of subject matter. Commenting on this very feature of German thoroughness and complexity. Sir William Schlich states:*

"Of the seventeen methods described several have only an academic interest, if so much, and all of the others have for their object to secure a sustained yield by gradually producing such a proportion between the different age classes that each shall, as nearly as possible, occupy about the same area, w^hether they are found on different areas or scattered over the whole forest .... there is not nearly so much difference in the several methods as their inventors believe."

This viewpoint explains why the author of this volume has omitted the usual elaboration of textbook methods and formulae which differ from each other in some minor degree.

Rather than include data on American working plans which are untried and preliminary in character, the writer has omitted the usual treatment of this phase of organization. In Appendix A — E some "working plan" data have necessarily been included so as not to mar a complete translation of a portion of Martin's Forsteinrichtung.

Acknowledgment has been made in the foot-notes for material borrowed directly from other sources, but necessarily many of the ideas and much of the data included, have been absorbed and adapted from text-books on the same subject, especially from Volume III (Fourth edition) Manual of Forestry by Sir William Schlich ; from Lehrbuch Waldwertrechung and Forststatik by Max Endres; and from Volume III, Economic Forestiere by G. Fluffel. The description of regulation in the various German states and in Austria given in the appendix is translated from Martin's Forsteinrichtung. Acknowledgment is also due C. E. Carter (of Australia), Yale School of Forestry, 1922, T. S. Hansen, Yale School of Forestry, 1917, T. T. Munger, U. S. F. S., E. J. Hanzlik, U. S. F. S., E. Koch, U. S. F. S., and M. H. Wolff, U. S. F. S., for a review of and a critical comment on the manuscript of Part I.

When the original plan of February i, 1917 of publishing under joint authorship with Professor Chapman had to be abandoned, the following acknowledgment was agreed upon :

"This manuscript was (largely) written in 1917, with the consent and cooperation of H. H. Chapman. The technical order and arrangement followed the Yale lecture notes

Sir William Schlich (Quarterly Journal of Forestry. 1913, p. 201).

Preface vii

of Prof. Chapman, but the American and European details and references and scheme of treatment, are original with the writer. Tlie manuscript was revised and completed by the writer in 1920 (1921). While Prof. Chapman assumes no responsibility, whatsoever, as to technical details, the writer wishes to acknowledge his very great indebtedness to him for the use of his notes as a guide. Those who took his lectures at Yale will recognize just how great this indebtedness is."

In 1920 Prof. Chapman kindly agreed to contribute Part II on "Correlation of Regulation and Growth in Extensive American Forests," with the understanding that the book would be immediately published under my authorship. The slight duplication of Part I in Part TI is an advantage rather than a detriment and Chapman's comment on the correlation of growth and regulation is invaluable.

When chief of silviculture in the Forest Service, District No. 3, the need for regulating the cut of timber on National Forests was very apparent. After giving the courses in management at the Yale School of Forestry, 1916- 17 (when Professor Chapman took my place in the West) I was convinced that regulation had been misunderstood and neglected in the United States and that, therefore, there was an immediate need of a thoroughly Americanized edition on this essential and important phase of forest management. The opportunity of service with the A. E.' F. in France explains the four years delay in publication, but I am certain that the need for such a book to-day is all the more acute.

Theodore S. Woolsey, Jr.

New Haven, Conn.

December, 1921.

PART I POLICY AND THEORY OF REGULATION

Introduction To Forest Regulation

Page

1. Definition and Significance of Forest Regulation i

2. Conception of Regulation in Europe 3

3. Scope of Regulation 4

4. Land Classification, an Initial Step 4

5. Details Must be Systematized in Working Plans 5

6. Progress of American Regulation in Early Working Plans 5

Stock Taking by the Forest Service Preliminary to Regulation 6

Regulation on Privately Owned Property 7

Quiz 7

Chapter II Background Of A Regulation Policy And Sustained Yield

10. Basic Conditions that Show Need for the Conservation and Regulation of Forests 9

11. Basic Studies 10

12. Curtailment of Production ? 10

13. Continuous Forest Production 1 1

14. Early Western Land Policy and Its Results 11

15. Effect of Economic Lumbering on Forest Management 12

16. Possible Solutions ; Restricted Private Control or Public Ownership? 13

17. Policy and Definition of Sustained Yield 14

18. Comparison with Conditions in France 15

19. Financial Aspect of a Sustained Yield 15

20. Sustained Yield on Public Forests 16

21. Sustained Yield Objectives and Difficulties in Practice 17

22. Summary of Limitations on a Sustained Yield Policy 17

Chapter III Management And Administrative Subdivisions

24. Definition of and Size of Subdivisions 20

25. Definition of Management Subdivisions 20

26. Discussion of Management Subdivisions 21

27. Factors that Justify Formation of Working Groups 22

28. Working Circles 23

29. Policy of Small or Large Working Circles 24

30. Definitions of Block, Compartment and Lot 24

31. Discussion of Block, Compartment and Lot 25

32. Definition of Administrative Subdivisions 26

ZZ- Discussion of Administrative Subdivisions 26

Contents ix

CHAPTER IV ROTATIONS-TECHNICAL, SILVICULTURAL, AND ECONOMIC Page

Definitions of Rotation (and Felling Age) 28

Not to be Confused with Cutting Cycle 29

Conception of Length of Rotation 29

Basic Policy for Rotations 3°

Mean Rotations for an Entire Stand 30

Kinds of Rotations 30

Definition and Discussion of Technical Rotations 31

Illustrations of Technical Rotations 3i .

Definition and Discussion of Silvicultural Rotations , 32

Illustrations of Silvicultural Rotation Limits 33

Definition and Discussion of Economic or Quantitative Rotations 34

Choice of Economic Rotation with Illustrations 35

Quiz 38

Chapter V Financial Rotations

48. . Definition of Financial Rotations and Related Subjects 39

49. (A) Rotations for Maximum Forest Rent or Highest Mean Annual Net Money

Return 40

50. Illustrations of Alaximum Forest Rent 40

51. Distinction Between Forest Rent and Soil Rent with Illustrations 41

52. (B) Rotations for Maximmn Soil Rent or Highest Returns per Dollar Invested .. 43 53- (a) What Rate of Interest Should Be Used ? 44

54. (b) What is Influence of Final Yield? 45

55. Illustrations of American Attempts at Calculating Maximum Soil Rent Rotations . . 46

56. Final Choice of a Rotation 51

57. Summary of Principles Affecting Length of Rotations 52

Chapter VI The Normal Forest

59. Definitions of Normal Forest, Normal Increment 56

60. Discussion of the Normal Forest 56

61. Three Phases of Abnormality 56

62. A Normal Distribution of Age Classes 57

63. Artificial and Natural Factors Influencing Distribution of Age Classes 57

64. Normal Increment 58

65. Normal Growing Stock 58

66. Growing Stock Formulae 59

67. Illustration of Simplest Normal Growing Stock Calculation 61

68. Yield Table Method of Computing Growing Stock 62

69. Illustration of Calculating Normal Growing Stock from Yield Table 62

70. Comparison of Normal Growing Stock Formulae 64

71. Illustrations of Munger Formula 64

72. Flury's Normal Stock Formula with Illustration 65

73. A Normal Stock Calculation in Lodgepole Pine 65

74. Importance of Normal Growing Stock in the United States 66

X American Forest Regulation

Chapter VII Regulating The Cut

Page

76. Definition and Aims of Regulating the Cut 68

77. Basic Policy in Regulating the Cut 68

78. To Attain Regulation Compromises are Necessary 70

79. Relation between Increment and Growing Stock 70

80. Definitions and Classification of Methods of Regulating the Cut 71

Chapter VIII (a) Volume Methods Of Regulation

81. General Principles and Classification of Volume Methods 74

82. ( I ) Volume Regulation Based on Growing Stock 75

83. (2) Volume Regulation Based on Increment Alone 78

84. (3) Volume Regulation Based on Growing Stock and Increment 79

85. (a) The Modified Austrian Formula 80

86. (4) Volume Regulation Based (on Growing Stock) and Size Classes (and Periods) 82

87. Discussion of French Method of 1883 82

88. Illustration of French Metliod of 1883 85

89. (5) Volume Regulation Based on the Tree as a Unit; (a) Indian Single Tree

Method (Brandis) 86

90. (b) Diameter Limit (Pinchot-Graves) 88

Chapter IX (b) Area, And (c) Area-volume Methods Of Regulation

92. Value and Classification of (B) Area Methods ,90

93. (i) Fixed Area as a Basis for Regulation of Cut 90

94. Illustration of Fixed Area for Limiting the Cut 91

95. (2) Area Allotment by Periods as a Basis for Regulation 91

96. Use of Yield Tallies in Computing Volumes 92

97. (C) Area- Volume (and Age) Basis of Regulation — Value and Classification 93

98. (i) Volume and Area- Volume (and Age) Allotment as a Basis for Regulation ... 93

99. Modern Allotment Principles 94

100. Regulation by (Americanized) Stand Selection (after Judeich) 95

lOi. Illustrations of Stand Selection in Eastern and Western Forests 95

102. Differences between Area-Volume Allotment and Stand Method 100

103*. Use of Age Classes in Regulation loi

104. Regulation on Basis of Cutting Cycles and Felling Reserve loi

PART II

CORRELATION OF REGULATION AND GROWTFI IN EXTENSIVE AMERICAN FORESTS

Chapter X The Cutting Cycle As A Determining Influence In American Forest Regulation

Page

106. Attitude of Private Owners 105

107. Preliminary Requirements 10:5

108. Obstacles to Regulation of Yield 106

Contents xi

Page

Policy as Influenced by Character of Ownership 107

Goal of Public Management 108

Influences Determining Initial Cut per Acre 108

The Cutting Cycle ; Definition ; Length 109

Growth on Cut-Over Lands 109

Growth on Virgin Forests ; Intermittent Yields no

Relation between the Cut Per Acre and the Cutting Cycle no

Similarity of Even-Aged and Alany-Aged Forests m

Residual Growing Stock and Felling Reserve 112

Illustration of a Transition Cutting Cycle in a Normal Forest 112

Ultimate Form of the Forest 1 13

Principle of Allotment of Definite Stands for Cutting During Period 114

Principle of a Horizontal Cut to Fixed Limits of Age or Size 114

Application of These Two Principles in Contracts for the Purchase of Timber

Cutting Rights 115

Eflfect of a Surplus of Over-mature Timber upon the Minimum Exploitable Age . . 116

Desirability of Short Cutting Cycles when Possible 117

Necessity for Horizontal Cut and Long Cutting Cycles for Virgin Forests 117

Illustration of Application of Principles to Western Yellow Pine 118

Basis of Computing the Annual Cut by the Principle of a Horizontal Cut 119

Ouiz 122

Chapter XI The Application Of Regulation To American Forests

129. Resume of Principles 123

130. Application of These Principles to American Forests 125

131. Preliminary Cutting Cj'cle for Valuable Species in Mixed Forests 125

132. Transition Cutting Cycle; Examples of Intermittent Yields under Forest Man-

agement 126

133. Assumption that Growth Balances Decadence 127

134. Formula for Regulation of Cut Based on This Assimiption 127

135. Illustration, Coconino National Forest 128

136. Comparison with Von Mantel's Formula 128

137. Illustration, Munger, Western Yellov/ Pine in Oregon. First Cutting Cycle 129

138. Summary of Principles i33

139. Separation of the Forest into Age Classes 134

140. Siunmary of Possible Conditions I35

141. Illustration from Tusayan National Forest 136

142. For Many-Aged Stands i37

143. Illustration from Yellow Poplar in Tennessee 138

144. A System of Regulation of Yield for Alany-Aged or Selection Forests Based on

Diameters and Diameter Growth, Preliminary in Character and Dispensing with

the Yield Table I39

145. Illustration with Scattered Shortleaf and Loblolly Pine Growing with Mixed Hard-

woods ( Southern States) I39

146. Factor of Loss of Numbers 140

147. Determination of Normality 141

148. Overcutting 142

149. Method of Regulating Yield I43

150. Comparison with French System of 1883 I43

151. Summary of Distinctive Characteristics of American Regulation I45 xii Auicrica)i Forest Regulation

Chapter XII The Problem Of Sustained Yield

Page

153. The Ultimate Problem — Sustained Yield 147

154. Allowed Cut, Empirical Yield Table and Normal Stock 147

155. Comparison of Mean Annual Increment and Austrian Formula; Its Limitations ... 149

156. Necessity for Data on Age Classes 151

157. A Method of Separation of Age Classes 151

158. Application of Yield Table to tlie Forest 152

159. Separation of Stand Table into Age Classes 153

160. Average Age of Groups 1 54

161. Illustration from Coconino National Forest 157

162. Immature Age Classes 157

163. The Prediction of Actual or Empirical Yields for the Forest 159

164. Application to Group Selection Forests 160

165. Coordination of Cutting Cycle with Area and Volume of Existing Age Classes .... 161

166. Comparison of Annual Cut by Methods of Regulation Proposed 162

167. Summary of Basic Principles 163

168. Factors Indicating a Shortening of the Cutting Cycle ; Illustrations 164

Chapter XIII Regulation Of Forests Composed Of Even-aged Stands

170. Regulation of Forests Composed of Even-Aged Sfands i6t

171. Similarity of Problem with That of Many-Aged Forms 166

172. Application to Eastern Mixed Hardwoods 166

173. Prediction of Yields of Mixed Hardwoods 168

174. Correlation of Regulation with Methods Proposed 169

175. Coordination of Regulation with the Silvicultural Practice 170

176. Illustration, Lodgepole Pine 170

177. Summary of Principles for American Regulation 173

Appendix

A. (a) Forest Management in Nine European States (after Martin) 178

(b) Financial Rotations (after Endres) 200

B. Growing Stock and Yield, Harvard Forest 204

C. Example of a Preliminary Policy Statement for Inyo National Forest 205

D. Results of Forest Management in Savoie, France 208

E. Examples of Yield Calculations from National Forest "Management Plans," 1921 . . . 210

F. Comment on Wolff Formula 212

SYMBOLS USED

Symbol Equivalent

Gn Normal growing stock.

Ga Real or actual growing stock,

n Normal,

r Rotation,

r' The difference between the age when the tree reaches merchantable size and

the rotation age.

s Age when tree reaches merchantable size.

i Increment (c. a. i. and m. a. i. are symbols for current and mean annual increment).

N Number of years.

Yn Normal yield.

Ya Real or actual yield.

X Number of years within which to distribute the surplus or deficit.

M% Mortality per cent (M is the symbol for Gernxan marks in appendix A).

M ft. 1,000 feet board measure,

cc Cutting cycle.

Res. Timber reserved after cutting.

F$ Final yield (in dollars).

1$ Intermediate yield (in dollars).

E$ Expenditures (if annual, symbol is AE$) capitalized.

C$ Costs (initial).

a, b, etc. Yield table figure for yield at lo years, 20 years, etc.

A Area.

TABLES Table Page

1. Economic Rotation for Pine, Spruce, Fir and Beech in Europe 35

2. Synopsis of Gross Returns, Expenditures, and Mean Annual Net Returns in Dollars

Per Acre for a Fully Stocked Quality III Spruce Stand 40

3. Rate of Interest Earned in European Forestry 45

4. Value of Fully Stocked Stands of Loblolly Pine, etc 47

5. Cost of Growing Cordwood in Fully Stocked Stands of Loblolly Pine, etc 48

6. Interest Rates (Compound) to be Expected on Money Invested in Growing Ash, etc. 49

7. The Financial Rotation of White Pine 50

8a. Soil Expectation Value for Douglas Fir, Quality II Site, Western Cascades 50-51

8. Yield of White Pine in New Hampshire 63

9. Normal Growing Stock in Board Feet Per Acre for Rotations of 20 to 60 Years by

Different Formulae 64

ID. Real and Normal Growing Stock and Periodic Annual Increment, etc 65

11. Relative Classification of Methods for Regulating the Cut Used by Different Writers ^2

12. List of Formulae Omitted from Text 72

13. Distinctions between Formulae Based on Growing Stock and Increment 79

14. Number of Trees in Different Diameter Classes Per Acre Required to Obtain a

Continuous Yield from a Fully Stocked Group Selection Stand of Pure Poplar . . 138

15. Empirical Yield Table of Western Yellow Pine Reduced from Normal by Factor

66.2% 148

16. Yield Table for Bernice Division, Deerlodge National Forest. Lodgepole Pine,

Reduction to 33/6% 171

FIGURES

1. Relation of Regulation to Other Subjects 4

2. Diagrammatic Sketch Map Illustrating the Distinction between Working Group and

Working Circle ( Syn., Working Unit) 21

3. Diagrammatic Representation of Normal Growing Stock, etc 59

3a. Proof of Wolff Formula 61

4. Diagrammatic Scheme of the Yield Table Yields 62

5. Illustration of the Result of Using a Correction Factor for Von Mantel's Formula . . 76

6. Illustration of Residual Growing Stock, Felling Reserve, and Surplus 120

7. Volume of Western Yellow Pine, Distributed by Diameter Classes, Coconino National

INTRODUCTORY

By B. E. Fernow

The question is sometimes raised — even in professional circles — whether silviculture or forest regulation (organization) is the more important subject. To raise this question is like inquiring whether the shelves in the library are more important than the books, the implements used in raising a crop more important than the crop itself. Nevertheless as suggested by ^sop's noted fable on the quarrel of the members, forest regulation (organization) is absolutely essential for a well conducted forestry business, just as the systematic management of a factory is all important to the success of that business.

In applying the various methods of regulation, the needs of silvicultural operations must necessarily produce modifications of the mathematics involved in regulating the felling budget. How far these silvicultural considerations are to influence the economic considerations will depend upon the character and the interests of the owner. For instance for forests under State ownership the interests of the future could and should dominate and more economic or financial sacrifices may be justified in attaining the normal forest than is the case in private ownership. The conditions for an economic sustained yield may be more rapidly attempted by the former, while the latter may be satisfied with a mere silvicultural sustained yield, i.e., keeping the land in forest. Conditions vary so greatly that it is impossible to lay down principles. Compromises will be necessary which depend upon the financial ability and other modifying circumstances of the owner.

The forestry business has an advantage over most other businesses in that it has its ideal formulated, namely in the normal forest (with its normal growing stock, age class gradation, and distribution, and normal increment), consciously and expressed or unconsciously and unexpressed. As with all ideals, practical considerations and conditions keep us from attaining them fully, and the problem for the forester is always how far he will sacrifice present advantages to this ideal of the sustained yield forest.

It should be borne in mind that the European methods of regulation represent a historic evolutionary series, each one having acceptable features which are borrowed by the next. With modern means of transportation, the need of making any small forest completely normal has become less imperative and has permitted the freedom of handling it a la Judeich. Moreover the extensive application of the division and allotment methods had brought about the existence of suitable age classes when the stand method became practicable.

Although only one state (Baden) has adopted the Karl Heyer (see paragraph 85) method of regulating the forest, I am inchned to consider this method the most practical in attaining a normal forest condition without too much sacrifice if carried out in Heyer's spirit. It will also be applicable in the United States in many cases.

The effort of investigating the applicability of European methods and of developing American methods, as attempted in this volume, is one which is worthv of all praise. -d t- t-

^ B. E. i^ERNOW.

December, 1921.

PART I

POLICY AND THEORY OF REGULATION

Chapter I Introduction To Forest Regulation

I. Definition and Significance of Forest Regulation. Forest Regulation* (syn. organization) is that branch of forestry zvhich concerns itself with the organization of a forest property for management and maintenance, ordering in time and place the most advantageous use of the property, with the aim of securing a sustained yield. The broader term forest management includes all subjects dealing with the inventory, condition, and proper and systematic development of forest resources, and the organization and administration which will secure their continuous productiveness. Regulation aims chiefly at continuity of productiveness but also at utilizing to the fullest extent the resources under forest management; the normal timber capital is property held in trust, while the cut constitutes the ozvner's returns. It is the most important ultimate goal of the forester to bring his forest property to a sustained yield so as to produce a nearly equal annual or periodic return. It is only by systematic regulation that permanent economic production can be secured. This principle of sustained yield is of importance to the individual and to the nation. It is customary for the private owner to require equalized returns on his investments and the wood industry of the nation also requires fairly sustained annual production in order to keep wood-using industries in full operation. Serious depression, when industrial production is curtailed, may warrant a corresponding diminution of output from public and private forests. On the

* It is important to differentiate clearly between forest economics, forest economy, forest finance, forest management, forest mensuration and forest regulation.

Forest Economics {syn. Forest Policy). A comprehensive term including all matter referring to the position of forests in public affairs.

Forest Economy. A comprehensive term including all matter dealing with the business aspects of forest management. (See also Fernow, B. F., Economics of Forestry, p. 103, 5th edition, New York.)

Forest Finance. That branch of the science of forestry which relates to the forest as an investment. It includes two distinct subjects. Forest Valuation and Forest Statics; the first concerning valuations of soil and growing stock, increment, and damage; the second with a comparison of the financial results of different methods of treatment and other questions of profitableness and financial effects.

Forest Management. The practice of the application of forestry in the conduct of the forest business.

Forest Mensuration. That branch of forestry which deals with the determination of the volume of stands, trees, logs and other timber products, and v/ith the study of growth and yield of trees and stands.

other hand, in times of stress, as was evidenced in France during the War, a nation is fully justified in over-cutting its public and private forests for the good of the state.

Of the technical factors which lead to an assured annual yield, the most important is the age of the different stands. For it is evident that if all the timber in a forest is immature, there can be no production of sawtimber until these individual stands ripen. If, however, all the timber is mature, the problem of securing a continuous yield of sawtimber may be assured, provided the owner is willing to make certain sacrifices, often obligatory when part of the decadent and overmature timber is held without cutting for long periods.

Russell and Roth (see § 12) have pointed out the hiatus in national timber production which is sure to follow our present era of destructive lumbering. Our national timber resources are largely composed of virgin stands* of mature and decadent timber and of idle cut-over land, much of it barren or only partially stocked, with valuable species; aside from woodlots there is but little forest land today in the United States stocked with middle-aged timber; therefore it is easy to visualize what will happen when our virgin stands are destroyed ; the nation surely will be confronted with a shortage of timber land stocked with merchantable timber. Our publicly owned forests will be insufficient in area to supply national demands. Even if we wake up to the need for permanent forest production before all our virgin timber is gone, we cannot now repair the damage in time to avert a serious shortage, because it takes from 60 to 120 years or more (see chapter IV-V) to produce sazvtimber as contrasted with conkvood. Even if every acre of potential forest land were fully stocked with valuable immature timber, when the last of the virgin stands disappears, many sawmills must shut down until these areas of immature trees ripen. A¥e would be in much the same situation that England was when the demand for ammunition overran the supply. Factories capable of enormous production were being built but had not yet reached the production stage. Fortunately, in the industrial world such a shortage can soon be relieved, but in forest management we must face squarely the hiatus in production sure to occur if there are no middle-aged stands ready to grow into merchantable timber that is certain to be required by our rapidly increasing population.

The owner of merchantable timber when deciding upon the proper cutting policy to adopt has three alternatives :

• (i) In anticipation of higher prices due to the predicted timber shortage he may carry his timber as a speculation ;

(2) He may rapidly convert his stumpage into money and realize on his forest investment. High taxes and heavy carrying costs on forest and plant investments have induced practically all American lumbermen to follow this course ; or,

(3) He can make a compromise between (i) or (2) ; but after the owner

* Of course virgin stands contain young and middle aged timber but this is usually all destroyed by "destructive lumbering."

Introduction to Forest Regulation 3

has decided not to hold his timber as an investment against higher prices or to realize on his forest, there is still the important decision, hozv much to cut and when. This question must be answered by applied regulation, which should always aim at a sustained yield of timber and permanent production. It goes without saying, as Dr. Fernow has emphasized in his Introductory Note, that regulation cannot be successful without sound silviculture, nor are the two incompatible. Rc-grozvth, ordinarily by natural regeneration, will always remain the sine qua non of successful forest management in the United States.

2. Conception of Regulation in Europe. It is instructive to see what the European idea of regulation is in the exact words of great foresters. Huffel,* the foremost French authority says : "The management (or regulation) of a forest includes all operations which aim at systematizing the cut." He argues that public forest owners have only the right to income from properties and must pass the principal on to the future generations unimpaired ; that this is the fundamental idea of forest regulation. He admits, however, that the private owner should be given more freedom in the use of his property according to his individual needs. All owners are, however, benefited by systematic forest working plans, "which indicate for a definite period, (i) the date, (2) the method, (3) the location, (4) the extent (degree) of all fellings which will be made in the forest."