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Problems of thinning and small log handling in second growth western hemlock stands with special reference… Adamovich, Lazlo Leslie 1962

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PROBLEMS OF THINNING AND SMALL LOG HANDLING IN SECOND GROWTH WESTERN HEMLOCK STANDS with SPECIAL REFERENCE TO THE RESEARCH , FOREST ON EAST THURLOW ISLAND by LASZLO ADAMOVICH Di p l . Forestengineer, Technical University of Hungary, Sopron, 1946. A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF FORESTRY in the Faculty of FORESTRY We accept t h i s t hesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA March, 1962. : In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of Hhe requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis f o r scholarly purposes may be ""granted by the Head of my Department or by his representatives. It i s understood that copying or publication of this thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of ^ V T ^ C A J ^ . I O . s^.,cii.Oa^ , - ^ r ^ V r ^ - ^ . c ^ s u t M The University of B r i t i s h Columbia, Vancouver 8, Canada. Date Q - V ^ ' - L J - < L IQ„ , tS fa 2. i ABSTRACT Diminishing v i r g i n timber on the Coast of B r i t i s h Columbia leads to consideration as to how management of the second-growth forests w i l l supply the timber industry with a s u f f i c i e n t quantity of good quality raw material in the future. One of the p o s s i b i l i t i e s would be intensive forest management supported by thinnings. The stands of western hemlock (Tsuga heterophylla (Rafn.) Sarg.), which comprise the largest area on the Coast, may be suited to t h i s t r e a t -ment because of t h e i r advantageous s i l v i c u l t u r a l character-i s t i c s . L i t t l e information exists on proper methods of thinning these hemlock stands. In addition, experience i n logging methods and means of economically handling small logs are lacking. Among the few experiments which have been established to study thinning of hemlock, one i s located on East Thurlow Island where nearly pure stands of hemlock occur. The Research Forest on the Island was scheduled to become an experimental and demonstration area f o r the study of thinning techniques. Studies under way on that area have shown that the methods used, had limited economic success. Commercial thinning operations turned out to be unprofitable p a r t l y because there was no adequate road system avai l a b l e f o r logging. i i Thinning problems i n general, as well as the p a r t i c u l a r aspect of thinning western hemlock and the methods of hand-l i n g small logs are discussed i n t h i s thesis to i l l u s t r a t e the basic problems involved i n a development plan f o r the Research Forest. F i n a l l y , this thesis presents a general road development plan for the Research Forest area and proposes a preliminary management and logging plan. Through cost analysis i t i s shown that the basic access road system can be constructed economically during a preparatory period by c l e a r c u t t i n g scattered overmature stands. Subsequent thinning experiments can be based on that road network. The approach to these problems i s general rather than s p e c i f i c because there are few detailed data available from past experiments. i i i Table of Contents. Page Introduction 1 Description and History of the Research Forest on East Thurlow Island 7 General Description 7 History of past experiments 12 Hemlock growth and-yield studies 12 Thinning experiments 12 • Commercial thinning experiment 1953-54 15 Description of the-Operation 16 Commercial thinning experiment 1959-60 19 Description of the operation 21 Time and production data 22 Thinnings ' . 24 The purpose of thinning 25 Thinning methods 26 Intensity 27 The effects of thinning 26* S i l v i c u l t u r a l e f f e c t s 23 E f f e c t on y i e l d 29 E f f e c t on wood qual i t y .* 31 F i n a n c i a l effects - 32 Other effects of thinning 33 Harmful ef f e c t s 34 i v Thinning problems i n the P a c i f i c Coast region 34 Thinning of Douglas f i r stands i n B.C 36 Thinning western hemlock stands 38 S i l v i c a l c h a r a c t e r i s t i c s of hemlock 38 Thinning experiments i n w. hemlock stands 40 Damage problem of thinning 42 Economical aspects of thinning western hemlock 46 Logging and transportation problems of thinning 52 The importance of road network i n intensive f o r e s t r y practices 53 Special logging problems of thinning operation 61 F e l l i n g and bucking 62 Skidding problems of thinning 64 Mobile high-lead 65 Tractors 67 Pre-yarding 72 Cable yarding systems 76 Reviving old skidding methods 82 Loading 83 Hauling . 86 Bundling and r a f t i n g 88 .Scaling 89 Logging of thinning as compared to clearcut operations... 90 Design of thinning experiments 91 Mechanization of thinning operations 93 V Preliminary road location plan f o r the Research Forest on East Thurlow Island 104 General consideration on the road network 10$ Estimated funds available for road construction 113 Design elements , 115 Cross section 115 Grades 116* Curves 119 Drainage •• 121 Surfacing 124 Road construction costs 126 Preliminary management plan for the Research Forest on East Thurlow Island 12# Objectives 123 Summary of basic f a c t s 129 Allowable annual cut and cutting methods 130 Proposed logging methods 134 Clearcut 134 Thinning operations 139 Tractor and truck logging 140 Necessary minimum d a i l y output 141 Alternative plan f o r thinning operations 144 Estimated production and cost of Lasso Cable i f i n s t a l l e d on East Thurlow Island 147 Summary and conclusion 151 Bibliography 152 v i Figure LIST OF FIGURES Page 1 Relation between standing volume and volume increment 30 2 Graphical determination of the zero margin diameter 49 3 The Garrett Tree Farmer tr a c t o r i n operation 69 4 Theoretical lay-out f o r combined t r a c t o r skidding operation 75 5 Comparison of slow and f a s t crawler type t r a c t o r on the basis of output as.a function of distance 75 6 Special pulley for Lasso Cable 78 7 The Lasso Cable.hook with load 78 8 The Lasso Cable yarder 78 9 T y p i c a l lay-out for Lasso Cable 79 10 Support of loaded.and return cables on.the.new system 80 11 I n s t a l l a t i o n of Lasso Cable support on a standing tree.... 81 12 Lasso Cable i n operation with heavy load i n a beech f o r e s t . 8 l 13 Temporary lowering of . cable on landing 82 14 Tractor with b u i l t on loader 85 15 Truck with hydraulic self-loader 85 16 Theoretical scheme f o r s t r i p thinning 96 17 S t r i p cutting near Port Arthur, Ontario 101 18 Theoretical scheme f o r triangle-patch thinning 100 19 Checker board logging i n New Zealand 101 20 Road and skid t r a i l lay-out f o r thinning i n New Zealand...101 21 Checker board arrangement of patch thinning .100 22 Graphical solution f o r absolute minimum radius for . truck and t r a i l e r 120 23 Cross section of nailed " I " beams with plywood webs 124 24 Thinning operation lay-out for the Research Forest 145 25 Lay-out and operation of'the "Sepson" radio controlled winch 150 v i i Table LIST OF TABLES Page 1 Time to l i q u i d a t e exploitable mature forests on basis of present cut 2 2 Stand c h a r a c t e r i s t i c s of the Research Forest on East Thurlow Island 10 3 Average monthly and annual mean and absolute temper-atures for periods shown for inactive weather station i n Thurlow 10 4 Time data of extraction process based on 46 observations.. . 2 3 5 Production and cost data of four types of loading equip-ment used i n thinning operations 86 6 Relative importance of various phases of logging i n thinning and clear cut operations 91 7 January, 1962 log prices i n the Vancouver Forest District.113 8 Road construction charges available per cunit i n dollars..114 9 Total income availabfe for road construction 114 10 Relationship between curve data and widening f o r a logging truck and t r a i l e r on a single-lane road 118 11 Cost estimate f o r main roads A,B,C,D (3 .25 miles) .127 12 Main stand c h a r a c t e r i s t i c s of the Research Forest on East Thurlow Island 129 13 Cutting plan f o r old stands 132 14 Logging methods and sequence of clearcut with the expected output 137 15 Cost of clearcut operation 138 16 Cost of thinning operation 141 V l l l LIST OF APPENDICES Appendix 1 Preliminary ro ad lo c a t i o n plan f o r the Research Forest 2 Road lo c a t i o n plan f o r thinning operations. i x ACKNOWLEDGEMENTS Acknowledgement i s made to the members of the University of B r i t i s h Columbia Faculty of Forestry and Research Forest Sta f f , f o r the advice and assistance they have given during the d i f f e r e n t stages of my work. In p a r t i c u l a r , the writer should l i k e to express his sincere appreciation to Professor F.M. Knapp, and Mr. J.P. Tessier(Resident Forester,for t h e i r h e l p f u l suggestions throughout the preparation of t h i s work, and to Dr. J.H.G. Smith,Associate Professor, for h i s c a r e f u l review of t h i s t h e s i s . The writer wishes also to acknowledge Mr. G.C. Warrack, Research O f f i c e r , Research Division,Forest Service of B r i t i s h Columbia, who supplied a l l available information about the Research Forest on East Thurlow Island. - 1 -INTRODUCTION The Continuous Forest Inventory of the B.C.F.S. (1958) and supplementary reports (1959) (I960) show that there w i l l be a dra s t i c decrease i n the amount of mature stands available for logging. According to the inventory, the present exploit-able volume of mature hemlock on the Coast i s roughly 7 .6 C v l l " b i l l i o n cubic f e e t . The average f o r the period from 1952 to 1956 i s 0.25 b i l l i o n cubic f e e t . This means that i f the present annual cut continues at the same rate, i n t h i r t y years, around 1990, a l l mature hemlock fore s t s w i l l be li q u i d a t e d . On the same basis the si t u a t i o n i s even worse i n the case of Douglas f i r (Pseudotsuga menziesii (Mirb.) Franco.), and western red cedar (Thu.ja p l i c a t a Donn.) (Table 1 ) . Accord-ing to these data aft e r eight and t h i r t e e n years,respectively^ there w i l l be a heavy pressure on v i r g i n hemlock forests, and the presently expected l i q u i d a t i o n period f o r hemlock w i l l be shortened to an average of 23 years. At that time, an area of 4 .34 m i l l i o n acres w i l l be covered by second growth hemlock stands ranging from 0 to about 80 years of age and representing a volume of 21.6 b i l l i o n of cubic feet, as usable, sound wood volumes. The data given i n Table 1. are based on currently exploit-able volume. As the presently inaccessible stands and timber on lower s i t e s represent an important r e s e r v o i r of wood, with improved logging methods, t h e i r timber might extend the above mentioned time l i m i t considerably. - 2 -Table 1. Time to Liquidate Exploitable Mature Forests on Basis of Present Cut. C O A S T Species Exploitable Mature Average Annual Years Volume - cu. f t . 1 Cut - cu. f t . to - Liquidate F i r > 2 ,437,653,000 295,536,608 8 Red Cedar 3 , 0 0 7 , 8 0 3 , 0 0 0 218,136,861 13 Hemlock 7 ,590,903,000 254,916,889 29 1 Currently exploitable volume. 12 inches plus, i n accessible operable mature forests on productive s i t e s of average or better growth capacity. (Continuous Forest Inventory of B. C. pjn 127.) -3-The immense areas of young growth f o r e s t s on the P a c i f i c Coast Region of B r i t i s h Columbia w i l l soon provide foresters in general, and loggers i n p a r t i c u l a r , with many problems in connection with t h e i r most economical use. As the practice of f o r e s t r y i s getting more and more intensive, when the idea of multiple use forestry i s widely discussed and generally accepted, the problem of thinning i s possibly the next step i n improving present f o r e s t management practices. When thinning "becomes necessary there must be enough l o c a l knowledge about the best methods to 'use. The only way to get s c i e n t i f i c information i s by experiments. There has been a great amount of research work done already on thinnings, mostly i n Europe, where intensive f o r e s t r y has been practiced for a long time. In B r i t i s h Columbia most studies have dealt with Douglas f i r because t h i s i s the most valuable species on the Coast. However, the area of young hemlock exceeds that of Douglas f i r and the proportion of hemlock i s increasing and, therefore, more studies should be made i n hemlock stands. Although a great amount of p r a c t i c a l knowledge i s already accumulated on thinnings and some research programs are under way, in general, very l i t t l e i s known about the s p e c i a l problems of thinning hemlock. Sloan (1957) was correct in his state-ment that among the lessons taught by experience through the centuries one i s , that every forest type has i t s own i n d i v i d u -a l i t y . There i s a need, therefore, for s p e c i a l thinning -4-experiments i n hemlock stands, and that these experiments should be carried out on areas which are the most repre-sentative. Through these experiments quite accurate r u l e s could be developed f o r maintaining an adequate, healthy, growing stock. Thinning studies could answer i n t h i s period the questions of: (1) necessary stocking to provide a continuous stream of the product desired, (2) what would be the best and most economical method of thinning, (3) the optimum logging method to give the highest possible p r o f i t , (4) methods of logging to prevent excessive damage. The B r i t i s h Columbia Forest Service has an area of 2,000 acres on East Thurlow Island which could be used as a research and demonstration forest where various studies i n connection with pure hemlock stands could be carried out. The Island i s representative of good s i t e s f o r hemlock f o r e s t s . Preliminary studies- have been made on the area but the d i f f i c u l t y of access made i t p r a c t i c a l l y impossible to organize large scale systematic research work. Under present market conditions, even with adequate access roads, the economic j u s t i f i c a t i o n of commercdial thinnings on East Thurlow Island i s questionable. The d e s i r a b i l i t y of experiments, on the other hand, i s unquest-ionable. Experimentation i n thinning may be s t r i c t l y s i l v i c a l , or include the aspects of economics as would be the case on the Island. Although the pre-commercial thinnings may be very worthwhile, the p r a c t i c a l sequence of the experiments -5-on the Coast must s t a r t with thinnings that produce merchantable products with a value at least equal to the cost of the extraction. As previous experiments showed, 9 this i s impossible on East Thurlow Island without a perma-nent road system. Thinning, with i t s low production per acre and low volume per unit logged, cannot i n most cases support the costs of constructing such a road system. With a management plan which keeps clear cutting and thinning i n tine r i g h t proportion, the necessary road system can be established on the research area. This combination would make commercial thinning studies economically j u s t i f i -able . The f e a s i b i l i t y of thinning w i l l depend on many other factors as w e l l . I t w i l l be influenced by logging and transportation methods used, the minimum s i z e of the logs removed and the market conditions. One of the primary purposes [of t h i s thesis i s to evaluate the economic"I p o s s i b i l i t y of erecting a permanent road system necessary to the research forest to f u l f i l l i t s purpose, which i s to serve to best advantage the needs of research and demonstration of sound f o r e s t r y practices i n the hemlock zone. In a preliminary management and logging plan the p o s s i b i l i t y of commercial thinning w i l l be proposed. - 6 -I t i s anticipated that these experiments w i l l bring p o s i t i v e r e s u l t s and w i l l be of great value i n producing f a c t u a l data f o r the f o r e s t manager i n the future to f i n d the best ways to manage the immense areas of second growth hemlock stands on the Coast. I f damage to the r e s i d u a l stand i s great and i f the value of products removed i s low, the research w i l l demonstrate the i m p r a c t i b i l i t y of t h i n -nings under s i m i l a r circumstances. This possible negative r e s u l t w i l l give s c i e n t i f i c confirmation to present clear cut operations. Because of e x i s t i n g d i f f i c u l t i e s , t h e B r i t i s h Columbia Forest Service Research D i v i s i o n does not plan to esta b l i s h new thinning studies i n the next decade. There i s a need-, however, to maintain at least those experiments which were previously established on East Thurlow Island. - 7 -DESCRIPTION AND HISTORY OF THE RESEARCH FOREST ON EAST THURLOW ISLAND General Description East Thurlow Island i s one of the several islands i n the S t r a i t of Georgia between Vancouver Island and the Main-land. I t is 40 miles North-East of Campbell River and i s along the East side of the Inner Passage to Alaska, which i s among the most b e a u t i f u l shorelines i n the world. There are some small logging camps on the Island, one of which i s near a store and gasoline s t a t i o n at Shoal Bay, formerly c a l l e d Thurlow. This supply center i s very close to the Research Forest and accomodates logging crews. The i s l a n d has rocky ridges, with maximum elevation of 1500 feet, wide U-shaped v a l l e y s between the ridges and lakes and swamps i n great number. Hemming Lake, c e n t r a l l y located, i s the largest. There are several good booming grounds along the shore and the best i s located i n Bickley Bay adjoining the Research Forest. The northern part of East Thurlow Island was allocated to the Research D i v i s i o n of the Forest Service of B. C. with the o r i g i n a l objective of studying the empirical growth and y i e l d of hemlock. The Research Forest i s within the boundaries of the experimental reserve between Bickley Bay and Hemming Lake. It i s three miles long with an average width of one - 8 -mile, as shown on the attached map (Appendix 1.) The t o t a l area of the forest i s close to 2,000 acres. The stand data and age d i s t r i b u t i o n are given i n Table 2. The s i t e index varies from 70 to 150 f o r hemlock, and on the average i s 134. The present d i s t r i b u t i o n of species i s as follows: By t o t a l volume: H 80% F 15% Misc. 5% By number of tree s : H 87% F 7% Misc. 6% The reason for the r e l a t i v e l y higher percentage volume of Douglas f i r is t h a t , i n the scattered old growth stands, Douglas f i r is predominant. The climate i s t y p i c a l of the Coast. Its outstanding feature i s the mildness and humidity of the winters f o r the lat i t u d e , and the heavy p r e c i p i t a t i o n on the mountains. The average yearly r a i n f a l l i s 60 inches,based on 34 years observations as reported by the B. C. Department of Agri -culture i n I960. The same report gives 48?F° as the annual mean temperature. The monthly averages and the absolute maximum and minimum temperatures are given i n Table 3. As logging i s affected by rainy days, and the thinned stands by winds, the observed values f o r a six-month period during a commercial thinning operation i n 1954 are shown: Days with sunshine 21% Cbudy - without r a i n 36% Continuous r a i n 18% - 9 -- Showers 25% Mild winds Severe winds Days with calm 100$ 100$ Topography of the Research Forest i s described as r o l l i n g , with a wide U-shaped valley between Hemming Lake and Bickley Bay. The area toward Shoal Bay, on the east side of the Forest, forms a plateau on an elevation of 200 f e e t . The logging i s handicapped because there are no roads except a very eroded logging t r a i l on the west side and two old paths leading from Bickley Bay toward Hemming Lake and Shoal Bay. Several small creeks and swampy places,together with heavy debris i n many places ]create d i f f i c u l t i e s i n yard-ing and hauling.' The f l a t t e r r a i n around Bickley Bay i s ' suited f o r a logging camp; the Research D i v i s i o n has a modern cabin there at present. The s o i l over most of the area i s a deep g l a c i a l deposit, s i l t y , clayey, and subject to erosion. There are few gravel deposits but several rock outcrops of granite. The moderate t e r r a i n and deep s o i l combined with the moist climate provide good s i t e s for Hemlock stands. Merchantable products are sawlogs and pulpwood. The closest market for them i s about 40 miles away at Duncan Bay, however, booms are also towed to more distant points such as Nanaimo and Powell River. Table 2. Stand Characteristics of the Research Forest on East Thurlow Island Forest Type Area Acres % of To t a l Scattered Old Growth With Undergrowth ' Second Growth Second Growth Shrubs or areas of S.I. 70 or under TOTAL 116 1130 241 410 1897 Species Average Average Annual Merch.Volume Total Age of Merchantable* per Stand Increment acre Years 6 . 0 59.7 12.7 21.6 100 % F(H.C.Sp) 350-500 H H(F.C.) H(C.F.) HFC 65 65 50 no data cu.ft. 110 110 no data no data cu.ft. 12,320 7,100 5,450 Volume cu.ft. 1,432,996 8,023,000 1,313,450 10,769,446 * Based on trees 9" d.b.h. and over, close u t i l i z a t i o n . Months •Table 3. Average Monthly and Annual Mean and Absolute Temperatures for Periods Shown fo r Inactive Weather Station i n Thurlow. Max. and Min.Temp. Period Annual Absolute of Jan. Feb. March Apr. May June July Aug. Sep. Oct. Nov. Dec. Mean Max.Min. Records Average 28 34 39 45 53 60 62 61 56' 46 41 36 47 93 -1 1947-50 Temperatures F. -11-Th e Research Forest was logged using b u l l teams p r i o r to 1894. In 1896 a very hot f i r e burned over the entire area cleaning out a l l the residual stand except a very few scattered Douglas f i r . The trees forming the dominant canopy were established the next year. A smaller area near Hemming Lake was reburned about 1912. The area was declared a Research Forest i n the late twenties. History of Past Experiments Hemlock Growth and Y i e l d Studies To lay a foundation for future studies on the research forest, s i x t y - s i x subplots were l a i d out, and measured i n 1930 by G. H. Barnes and J. C. H. Robertson. F i f t y - e i g h t plots were i n 33-year-old stands and eight i n 18-year-old stands. Each subplot was c a r e f u l l y located and marked on a de t a i l e d map, drawn to f a c i l i t a t e r e l o c a t i o n . It was intended that these plots be remeasured at 10-year i n t e r -v a l s . The data obtained from the sample plots were used to elaborate the widely used y i e l d tables of G. H. Barnes (1953). His s i t e index curves based on average t o t a l height of domi-nant and codominant trees are based p a r t l y on Joergensen's (1949) study of s i t e index curves f o r western hemlock who col l e c t e d the. necessary data on East Thurlow Island. -12-Thinning experiments In the early f i f t i e s the o r i g i n a l purpose of the research forest was extended to commercial thinning experiments i n second growth hemlock stands. The Research Divi s i o n of the B. C. Forest Service ca r r i e d out thinning experiments on young Douglas f i r stands on the Cowichan Lake Experiment Station.. Joergensen (1951) who was involved i n setting up these experiments, soon recognized the d e s i r a b i l i t y of extending thinning experiments to hemlock stands. Our r e s p o n s i b i l i t y i n connection with these experi-ments i s challeneged by his words: -13-i •t " I f i t i s a l l possible to v i s u a l i z e the pattern of forest management just a few decades from now, i t can hardly be questioned that any lack of production data from thinned stands w i l l be a very serious drawback. Further i t can hardly be questioned that those suffering t h i s disadvantage can r i g h t f u l l y blame us t h e i r predecessors, i f we neglect to make preparations to meet a si t u a t i o n which i s more than l i k e l y to occur." With th i s intention a new series of experimental plots has been established. The basic conception of the method used was as Joergensen expressed "experiments should be done on a scale small enough to avoid any excessive r i s k by mistakes but large enough to make the experimental r e s u l t s s i g n i f i c a n t for p r a c t i c a l a p p l i c a t i o n " . The p r o j e c t , c a l l e d Experiment 3#8, was established i n 1953-The object of the experiment was: 1. To study the ef f e c t s of repeated thinnings of d i f f e r e n t i n t e n s i t i e s on the major stand and tree factors and to draw up p r a c t i c a l thinning regimes with correspond-ing yield tables. 2 . To determine the net value on the stump of the thinning material, with production costs s p e c i f i e d . This might be extended to include calculations of f i n a n c i a l y i e l d and determination of r o t a t i o n . 3. To demonstrate s i l v i c u l t u r a l techniques and logging methods most suited to pure hemlock stands. -14-Twenty sample plots were established }each 2 x 2 chains in s i z e . With four r e p l i c a t i o n s , four d i f f e r e n t thinning i n t e n s i t i e s plus one unthinned control p l o t were allocated randomly. The proposed experiment as a randomized block design. was done according to the following schedule. Control: basal area at i t s natural l e v e l . Very l i g h t thinning (t ): leaving 225 sq. f t . b a s a l 1 area per acre. Light thinning ( t 2 ) : leaving 200 sq. f t . b a s a l area per acre. Medium thinning ( t o ) : leaving 175 sq. f t . b a s a l area per acre. Heavy thinning ( t , ) : leaving 150 sq. f t . b a s a l ^ area per acre. I t was anticipated that thinning and plot examinations would be c a r r i e d on as long as useful information related to p r a c t i c a l thinning regimes w i l l continue to accumulate. It was expected that periodic; .'. analyses would indicate when conclusive r e s u l t s could be f i n a l i z e d . The proposed technique was to cut only trees of poor stem form and crown development. The aim faas at even spacing. For commercial evaluation i t was intended to keep s p e c i f i c accounts of a l l expenses applicable to the complete operation from forest to m i l l , as well as man hours where possible. The study was c a r r i e d out under two timber sale contracts, one i n 1953-54, the other i n 1959-60. -15-Commercial thinning experiment 1953-54 In 1953-54 the Comox Logging and Railway Co. did the experiment under supervision of the s t a f f of the Research Di v i s i o n of the Forest Service of B r i t i s h Columbia. To make the timber sale more a t t r a c t i v e , clearcut and thinning were combined i n the operation. The clearcut area was close to the booming ground, with an average yarding distance of 900 f e e t . The thinning was on the area of Experiment No. 388 with average hauling distance of 0 .6 mile. Total area f o r sale was close to 100 acres. The f i n a l r e s u l t of the experiment showed that at that time with conventional cat-logging method neither a big crew (12 men i n 1953) nor a small crew (3 men in 1954) could pro-duce p r o f i t from thinnings. The experiment showed however many i n t e r e s t i n g d e t a i l s which were of importance in planning future studies. These w i l l be i l l u s t r a t e d in some d e t a i l . In 1953 the logging crew consisted of twelve men and a camp was established on the shore at Bickley Bay. i The main equipment which was used during the operation included one C a t e r p i l l a r t r a c t o r , model D6 with arch, one C a t e r p i l l a r t ractor, model D4 with arch, two welding machines, two power saws, one boat and a variety of hand tools, blocks, spare parts, etc. -16-Description of the operation The D6 t r a c t o r was used f o r road construction chunking out t r a c t o r t r a i l s , and yarding. D4 was used i n yarding only. Logs were bunched before being hooked to the tractor main l i n e . The t r a c t o r then skidded the load to the bundling platform, where after four or f i v e turns the logs were strapped together and pushed into the booming ground. In the second year, after the i n e f f i c i e n c y of the large crew was obvious, the number of men was reduced to three, and the two t r a c t o r s operated together only f o r a short period. The trees were ninety feet high and had an average diameter of nine inches. There were 85 cords per acre and the average cut in thinnings was 21 cords per acre. The average log was 26 feet long and contained 9 cubic feet of wood. One i n t e r e s t i n g item from the f i r s t year's operation i s a comparison between production i n clearcut and thinning operations. Average d a i l y production from clearcut areas was 562 cubic feet per day, whereas i n thinnings production was 473 cubic feet per day or 47 and 39 man-days respectively. Although the crew was not experienced i n thinning, the pro-duction was higher than one would expect. But even the clear cut production was not high enough to make the operation f e a s i b l e . •The cost of logging during the 1954 season ($30.68 per cord) was $10.08 per cord less than in 1953, nevertheless even t h i s lower cost was s t i l l twice as much as the l o c a l -17-market price f o r hemlock pulpwood. The high cost of the f i r s t year's operation originated from the large crew, the i n i t i a l high cost of camp e s t a b l i s h -ment, the heavy machinery used, the lack of access roads, the small log size and the lack of experience i n thinning operation. The cost reduction i n the second year was mainly due to the small crew and the reduced size of camp, but other high cost elements were s t i l l in e f f e c t . Because of the small size of logs the d a i l y production f e l l to 387 cubic feet. Borzuchowski (1955) of the Research D i v i s i o n collected data during the second operation and published a paper on i t . He formed the opinion based on his time study, that a some-what larger crew (5 men) using two tractors would be more economical. In his view a D6 tractor should not have been used i n both bunching and yarding, but these phases should have been executed by two separate units . Analyzing the f a i l u r e of the operation, Borzuchowski found that there was a psychological reason. One logger was a new man on the job but he showed f a i r interest i n some for e s t r y a c t i v i t i e s . The other two men were experienced, worked hard but they showed no i n t e r e s t i n thinning practices. It was very obvious, wrote Borzuchowski, that they did not l i k e the job or the place, were constantly complaining about t h e i r work and were very reluctant to accept suggestions or instructions from the research for e s t e r i n charge. -18-A further reason for the unsuccesful experiment was the unusually bad weather, which made logging conditions d i f f i c u l t . The rainy weather made the yarding spurs extremely muddy. A minimum of time was spent by the loggers on cutting extraction lanes. The experimental area was almost without roads and those which were present were very poor, resembling muddy erosion l i n e s rather than roads. The logging methods were not altered to the s p e c i a l need of a thinning operation. The men f e l l e d too many trees in advance of extraction, locking themselves up i n a jungle of logs and slowing down the whole operation. Another reason was that the operation was controlled by random a l l o c a t i o n of blocks (plots) which could not be, connected e a s i l y with roads. Damage to the r e s i d u a l stand varied from 10% to 58% by number of t r e e s . Injuries in many cases could have been avoided or at l e a s t much reduced i f loggers had exercised more interest i n t h e i r job and more patience i n adapting themselves to the more exact conditions of a thinning oper-ation. Wind damage was l i g h t i n the more exposed and already thinned stands. The operation was cancelled by the company, at a time ' when 17,8$0 cu. f t . reamined to be cut. A l l trees which had been marked for thinning were f e l l e d and l e f t on the ground. This jeopardized the commercial thinning study but made i t possible to continue some s i l v i c u l t u r a l studies. -19-To improve operations i n the future Borzuchowski made the following suggestions: "Extraction roads should be prepared or l a i d out p r i o r to cutting. The properly located skidding t r a i l s should be drained i n the dangerous places that w i l l ease the yarding d i f f i c u l t i e s and speed up the operation. A l l main roads should be constructed i n advance and kept well drained and in all-weather condition so there w i l l be no danger of d i s -rupting the transportation of logs during wet periods." G. C. Warrack, then assistant f o r e s t e r i n the Research Division,at that time examined the operation ,and f e l t that a small crew, with experience i n small-log logging, using the best organization methods could be economical. He had problems as how to solve the high damage i n hemlock and how to be able to prepare roads f o r the next operation. His one main point was that roads should be b u i l t before f e l l i n g and yarding rather than during the operation. Commercial thinning experiment 1959 - 60 In 1959 G. C. Warrack prepared another timber sale extending for a three-year period, using past experience to overcome the d i f f i c u l t i e s of commercial thinning. The timber sale was given t o a small operator with experience i n a previous thinning operation on Cowichan Lake Forest. He was interested i n i t and knew the s i l v i c u l t u r a l aspects of the operation w e l l . He owned up-to-date equipment -20-H 1 constructed for thinnings tincluding a Garrett Tree Farmer rubber-tired-tractor. The operator hoped to make a p r o f i t by s e l l i n g pulp-wood at the m i l l at Duncan Bay for $14.50 a cord or at Harmac for 19 cents a cubic foot. There were problems however which could not be overcome. • The operator had l i t t l e c a p i t a l and t h i s put pressure on him to get as high a d a i l y production as possible. The operator t r i e d to eliminate time consuming preparatory work which,if done,could have resulted i n much better production on the average. J The sale area was of 130 acres adjacent to the areas thinned in the previous study but not r e s t r i c t e d to experi-mental p l o t s , g i v i n g more independence to the operator, and permitting large scale s i l v i c u l t u r a l t e s t s . The closest point of the sale proposed for thinning was about 2,000 feet from the booming ground, the farthest about one mile. The con-t r a c t was prepared for a three-year period, and contained among other things the following points: (1) The thinning r a t i o as given by Langsaeter (1941) should be d/D = .85 * 10%. (2) Trees logged should be selected from those of poorest stem form and crown development. (3) Approximately 150 sq. f t . basal area per acre should be l e f t after thinning, which was equivalent to the heaviest thinning i n the previous experiment. (4) Spacing should be around 18 feet 'between trees l e f t standing. (5) Stump height of 12 inches was - 2 1 -prescribed. (6) Merchantable trees should be any l i v i n g , dead or down Douglas f i r , hemlock or cedar trees which, i n the judge-ment of the f o r e s t o f f i c e r , contained a log of 8 feet i n length and 5 inches or over i n diameter at the small end. (7) A l l trees f e l l e d should be topped and a l l slash scattered in such a manner as to l i e close to the ground, and away from l i v e trees. A two man crew from the Research Division of B. C. Forest Service were stationed on the Island at the time of the oper-ation, including the writer. Their duty was to scale the logs, to measure the trees on plots and to c o l l e c t production and time-study data. Description of the operation The operator moved onto the Island, b u i l t a small cabin and employed two experienced loggers, i n the summer of 1959. He operated the Garrett Tree Farmer tr a c t o r i n pre-yarding, (bunching) yarding, t r a i l preparing and bundling, while the loggers did the f e l l i n g , limbing:; and bucking. They also co-operated i n preparing the loads i n pre-yarding. The f e l l i n g , bucking and limbing were done by powersaw and axe. The product was mainly 24-foot pulpwood up to 19 inches maximum butt diameter. The smallest top diameter was 5 inches. The larger logs (usually Douglas f i r ) were cut as sawlogs,or boomsticks up to 66 feet i n length. The logs were winched to the t r a c t o r 5 to 15 at a time and then yarded to the booming ground. The road was i n poor condition, and not maintained properly. The spurs were not - 2 2 -prepared i n advance at the s t a r t , but l a t e r the necessity-was so obvious that a l l yarding t r a i l s were constructed according to a provisional plan. The Tree Farmer was not powerful enough to remove stumps larger than 30 inches but smaller obstacles were e a s i l y overcome. The bundling was done by a bundling device on the shore, using the t r a c t o r ' s blade. Two, one inch wide s t e e l bands were used to each bundle. Later, aluminum wires proved to be more p r a c t i c a l and economical. Two or three t r a c t o r loads made up one bundle. The bundle was pushed into the water by the tractor and stored in the water u n t i l enough bundles accumulated to form a boom, which was towed to the pulpmill i n Duncan Bay. In a l a t e r phase the bundling platform was put i n the water to get higher production. Every bundle was scaled by piece t a l l y and a record kept of the d a i l y production. As the f a l l e r s cut more trees than the tractor could yard, the crew was reduced to two men. The d a i l y production soon equalled that of the three-man crew. The damage to the standing trees was very low due to the use of three simple iron-plate-aprons. Time and production data The writer made 46 observations on the time needed for a complete turn; 25 turns of the t r a c t o r during the period when three men were working and 21 when the two-man crew was in operation. - 2 3 -The analysis showed that the size of the crew did not af f e c t s i g n i f i c a n t l y the yarding time as shown i n Table 4 . The following production was scaled for 46 days. Total production was 27,252 cu. f t . of which 21,292 cu. f t . was pulpwood, (118 bundles = 2,300 pieces), 3,010 cu. f t . sawlogs (90 pieces), 2,950 cu. f t . boomstieks (26 pieces). The average d a i l y production was 593 cu. f t . Average number of pieces per turn was 9 . 6 3 . Average number of logs i n bundles was 19.52 Average volume per bundle was 192.42 cu. f t . Average log volume (pulpwood only) was 9.95 cu. f t . Average tree diameter was 10" DBH. According to these figures the anticipated 80,000 cu. f t . production f o r the f i r s t year could have been reached i n 135 working days. Lost production was mainly the r e s u l t of excessive breakdown. Because of f i n a n c i a l d i f f i c u l t i e s the contractor gave up his operation during the next summer. Table 4 . Time Data of Yarding and Bundling Based on 46 Observations Average yarding distance: 2 , 0 0 0-feet Size of Average Standard Average time Standard Average time Standard crew time f o r f o r of one turn unhooking bundling Men Minutes Deviation minutes Deviation Minutes Deviation 3 61 14.25 9.23 3 13.44 6 .9 2 59 10.00 9.23 3 13.44 6 .9 Average 60.65 9.23 - 13.44 - 2 4 -As bunching was a •time-consuming part of the operation, a method using pre-yarding devices to prepare loads f o r the tr a c t o r would have improved productivity, but i t was impossible under the circumstances, because the operator had no c a p i t a l f o r further investment. The main problem was the lack of adequate roads, although there was no way to solve t h i s problem. The operator was not aware of the importance of roads and did not r e a l i z e that the skid t r a i l s should be prepared i n advance. The lack of a l l -weather roads renders impossible further studies on the research forest, e s p e c i a l l y i n stands which are farther from the shore. The Research Divi s i o n therefore stopped a l l t h i n -ning studies u n t i l the prerequisite road system can be established. The writer spent the summer of I960 on the Island to find out whether there was any p o s s i b i l i t y of establishing an economic road-network on the area. Before reporting further on the road system, the writer w i l l discuss the complex problems of thinning and experi-mentation done on the P a c i f i c Coast, with p a r t i c u l a r emphasis on hemlock stands. THINNINGS Thinning i s defined by many authors as a systematic removal of some stems i n an immature stand i n order to give the remaining trees better conditions f o r growing and pro-ducing better quality wood. - 2 5 -Th innings have been carried out i n many European countries f o r more than two hundred years. Research on the e f f e c t of thinnings has been conducted for at l e a s t ninety years. As reported by Braathe (1957) the European l i t e r -ature on the subject i s very voluminous. The h i s t o r y of thinnings i n America i s quite recent and on the P a c i f i c Coast i t i s not more than t h i r t y years old. The purpose of thinning In European fo r e s t r y c a r e f u l planning for future needs i s a very pronounced feature. The main purpose of thinning, as described,is to u t i l i z e the growing p o t e n t i a l to the f u l l extent and put the increment on stems of high q u a l i t y . As Moller (1954) explained, in Europe the wood removed by t h i n -nings w i l l usually have some value, but placing too much emphasis on harvesting values w i l l confuse the task of t h i n -ning. That i s why the f o r e s t e r r a r e l y looks f o r the trees to be removed, but rather f o r the most desirable stems to r e t a i n f o r future growth. This s i l v i c u l t u r a l aspect might be acceptable i n countries where manpower i s cheap, where the f o r e s t s are e a s i l y accessible and where f o r e s t r y personnel i s abundant. At the beginning of the t r a n s i t i o n age, from extensive forest management toward intensive f o r e s t r y , the American - 2 6 -d e f i n i t i o n of thinning i s d i f f e r e n t . According to Hawley (19A-6) the fundamental objectives of thinning are: (1) to r e d i s t r i b u t e the growth pote n t i a l of the stand to optimum advantage and (2) to u t i l i z e a l l the merchantable material produced by the stand during the r o t a t i o n . Worthington (1961) gave the opinion that i n the coastal region only thinnings of commercial type would be considered. A thinning i s defined as commercial i f the value of the material removed equals or exceeds the cost of logging. A commercial thinning i s i d e a l i f i t can be done at a p r o f i t and i s s i l v i c u l t u r a l l y desi-rable or at least not undesirable. The l a t e s t European l i t e r a t u r e shows, that p r a c t i c a l foresters are planning along t h i s same l i n e . Thinning methods Thinning methods vary considerably but may be grouped according to the type of the trees to be cut. The trees in a stand are c l a s s i f i e d by different authors in many ways. To simplify t h i s problem the w r i t e r w i l l use only four classes: suppressed, intermediate, co-dominant and dominant trees. Low thinnings demand removal of suppressed or i n t e r -mediate trees which would die before the next cut. Crown thinning removes trees mainly from the upper and middle crown classes, e s p e c i a l l y among the co-dominants. 1 - 2 7 -Selection thinning removes mainly the largest trees and i s usually carried out i n r e l a t i v e l y young stands. Free thinning removes trees from a l l classes with the objective that the residual stand be as evenly spaced as possible, and that the best trees s h a l l be l e f t , depending upon the f i n a l product desired. The methods used vary with the nature of the stand, and even i n a given stand, according to i t s age. The usual practice in North America, in even-aged stands, i s that the f i r s t thinning i n a young stand w i l l resemble a selection thinning; l a t e r i t w i l l appear to be a crown thinning, and in older stands a low thinning. Intensity The i n t e n s i t y of thinning can be l i g h t , moderate, or heavy, 'in general the Central European slogan regarding thinning was: early, often, l i g h t l y , whereas i n America there i s a d i s t i n c t borderline between s i l v i c u l t u r a l thinning and commercial thinning. The l a t t e r w i l l characterize the degree of inte n s i t y , consequently the emphasis i s on the. material removed. There are many ways to measure the int e n s i t y of t h i n -ning, e.g. by number of stems removed, by basal area and by volume. Another common measure of thinning i n t e n s i t y used by Langsaeter (1941) i s the mean diameter of the trees removed (d) i n r e l a t i o n to the mean diameter of the trees l e f t (D). -28-When d/D i s 0.7 or lower, the thinning i s l i g h t ; when between 0.7 and 1.00 i t i s moderate; when over 1.00 i t i s heavy. The degree of thinning i n t e n s i t y has increased i n Central Europe during recent decades, and i n Scandinavia the trend i s toward heavy thinnings, as reported by Moller et a l (1954), and affirmed by Samset (1961). The E f f e c t s of Thinning S i l v i c u l t u r a l e f f e c t s The s i l v i c u l t u r a l effects of thinning were described c l e a r l y by Hawley and Smith (1954). The temporary gaps which are p e r i o d i c a l l y created in the crown canopy by most thinnings allow more p r e c i p i t a t i o n to reach the forest f l o o r and the r e s u l t i n g increase in s o i l moisture permits the roots of the trees to penetrate more deeply than before. Decompo-s i t i o n of l i t t e r i s sometimes accelerated, thus increasing the amount of inorganic nutrients available i n the s o i l . Temperature i s generally increased at a l l l e v e l s within the stand as well as i n the s o i l . Unless the temperature increase i s extreme, t h i s e f f e c t alone should accelerate photosynthesis. Furthermore, the solar r a d i a t i o n reaching the leaves at the lower l e v e l s i n the canopy i s increased. Nevertheless, the evidence indicates that these d i s t i n c t l y b e n e f i c i a l i n f l u -ences are counteracted sometimes by harmful e f f e c t s of thinning. - 2 9 -There i s a r e l a t i o n s h i p between thinning and length of l i v e crown.. Thinnings a f f e c t d i r e c t l y the s e l f pruning a b i l i t y of the stand, and in some cases increase the seed production. Removal of i n f e r i o r trees that otherwise would l i v e to the end of the rotation, leaves the better trees as seed bearers. This genetic improvement i s e s p e c i a l l y important in species which regenerate e a s i l y . E f f e c t on y i e l d Hawley and Smith (1954) came to the conclusion that thinning can be used to increase the economic y i e l d of a stand but not i t s gross production. The e f f e c t of thinning on stand development has been studied by many f o r e s t e r s . It was found that thinning methods applied under d i f f e r e n t circumstances a f f e c t height growth, diameter growth and tree form. Several experiments showed that the e f f e c t of thinnings on height growth i s very small, but diameter growth can be greatly stimulated, d i r e c t l y a f f e c t i n g y i e l d since diameter increment and number of trees per unit area are the main factors i n volume production of a stand. Figure 1. shows the relationship between density of stocking and growth i n cubic volume as given by Langsaeter (1941) . -30-i Y Volume per Acre Figure 1. Relation between standing volume and volume increment. In the broad range of stocking indicated by Density Type III , increment of cubic volume i s v i r t u a l l y independ-ent of v a r i a t i o n i n stocking. The usual objective of thinning i s to keep the growing stock somewhere within t h i s optimum range. By doing so, the number of trees can be reduced to an optimum number giving a higher average diameter to the stand which means better quality, the quantity remain-ing the same. Smith et a l (1961) saw the main importance of the thinnings i n the same way stating, "In some species the variations i n tree q u a l i t y can be so great that the advantages of concentrating growth on those trees of better q u a l i t y can be used to demonstrate a r e a l need f o r thinning." Staebler (1959) expressed the d i f f i c u l t i e s encountered with the Langsaeter curve: "In most forest types we are a long way from being able to draw our growth growing-stock - 3 1 -curves with s u f f i c i e n t p r ecision to define the optimum range for thinning". It remains to be determined to what extent t h i s theory-holds true f o r species i n d i f f e r e n t climates and continents other than where i t was tested, i n Europe (and with two -species, beech and Norway spruce. Braathe (1957) thought that i n untreated forests with unfavourable s o i l conditions,and retarded growth,a thinning w i l l most l i k e l y speed up the rate of decomposition of humus and an increased volume growth might be expected. Only a few thinning experiments have been made along t h i s l i n e i n Europe. Experiments i n overstocked,older second-growth hemlock stands in B r i t i s h Columbia to see the response to release could bring valuable r e s u l t s . E f f e c t on Wood Quality It i s doubtful that thinning can improve wood quality s u b s t a n t i a l l y . Wangaard (1954) stated that i n coniferous species the control of s p e c i f i c gravity by the influence of growing space must be dealt with somewhat d i f f e r e n t l y than i n the broad-le a f species. In order to produce timber with high strength properties i n the shortest possible time i t w i l l be necessary to t h i n the stands c a r e f u l l y to maintain as good s o i l con-d i t i o n s as possible. Thus quantity and quality production are apparently combined on the more f e r t i l e s i t e s . - 3 2 -Wellwood's (196L) data on f i b e r length and s p e c i f i c gravity of hemlock show that increase i n rate of r a d i c a l growth reduces f i b e r length. Thus ;increasing rate of growth suddenly by thinnings may decrease the f i b e r length. This may further influence the strength properties of wood,lower-ing i t ' s value. The studies also show that the s p e c i f i c gravity may decrease very s l i g h t l y with increased growth i n radius per decade, giving less pulp y i e l d to thinned stands. Benson (195^) found that s p e c i f i c gravity changed i n Southern Pines a f t e r release are very i r r e g u l a r . Unless weighing i s accepted generally as a pulpwood scaling technique, the volume increase of thinned stands w i l l be more important than s p e c i f i c gravity increase or decrease. F i n a n c i a l E f f e c t s An important influence of heavy thinning or i n i t i a l wide spacing on stand management i s that a shorter rotation 1 can be applied to the stands because products of a given size can be produced e a r l i e r . The e f f e c t of commercial thinning i s that cash returns are available p e r i o d i c a l l y throughout the rotation and are not postponed u n t i l the f i n a l harvest. Worthington and Staebler (1961) had the opinion that a thinned stand i s worth twice as much as an unthinned stand, for i t s f u l l r o t a t i o n age. - 3 3 -A forester wishing to earn a high rate of interest on his c a p i t a l must seek forms of management that require small amounts of growing stock i n r e l a t i o n to income y i e l d . This can be achieved by wide spacing i n the case of plantations, in natural stands, thinning affords a major avenue for a t t a i n -ing t h i s objective. With properly applied thinnings the amount of these intermediate returns increase cumulatively during the r o t a t i o n . As Joergensen (1951) explained: "Correctly applied thinnings remove the poorer trees and leave the better ones with the r e s u l t that each consecutive thinning places future volume production i n a higher-quality class than i t was before. Not only w i l l the f i n a l crop benefit from t h i s e f f e c t but also each succeeding thinning." Other E f f e c t s of Thinning The resistance of stands to damage of a l l kinds i s generally increased by thinning, except in some species with a shallow root system where windthrow can occur. It i s l o g i c a l to think that a well thinned stand with no snags and windfalls i s more r e s i s t a n t to f i r e . Experiments by (Langsaeter 1941) showed that thinned stands had more resistance to attack by insects and fungi and that the thinned stands i n general are healthier than unthinned stands. - 3 4 -One o f t h e i n d i r e c t b e n e f i c i a l e f f e c t s o f t h i n n i n g comes f r o m t h e f a c t t h a t t h i n n i n g s c a n be made e c o n o m i c a l o n l y i f t h e f o r e s t a r e a i s a c c e s s i b l e . Improved a c c e s s a l s o b e n e f i t s a l l a s p e c t s o f f o r e s t management. H a r m f u l E f f e c t s T h i n n i n g may have h a r m f u l e f f e c t s on t h e s t a n d . The i n t e n s i t y o f t h i n n i n g s c a n be s u c h t h a t vo lume r e d u c t i o n f o l l o w s , i n s t e a d o f g r o w t h i n c r e m e n t . A f t e r heavy t h i n n i n g s , w i n d t h r o w and snowbreak may o c c u r . W i t h c a r e l e s s e x t r a c t i o n t h e damage t o ? : r e s i d u a l t r e e s may c r e a t e i n f e c t i o n h a z a r d . THINNING PROBLEMS I N THE P A C I F I C COAST REGION To d e m o n s t r a t e how w e l l we a r e a b l e t o a n s w e r t h e p r o b l e m s o f t h i n n i n g s a s a p p l i e d t o o u r r e g i o n a s h o r t r e v i e w o f work done on t h i s f i e l d w i l l f o l l o w . The f i r s t s t u d i e s and e x p e r i m e n t s on a c t u a l t h i n n i n g s were done i n t h e U n i t e d S t a t e s i n D o u g l a s f i r s t a n d s . W o r t h -i n g t o n and S t a e b l e r (1961) enumerated 75 a r t i c l e s , b u l l e t i n . s . o r o t h e r s t u d i e s w r i t t e n on t h e s u b j e c t . The f i n d i n g s and c o n c l u s i o n s a r e i n t e r e s t i n g t o c o m p a r e . O p i n i o n s r a n g e f r o m c o m p l e t e d e n i a l o f t h e n e c e s s i t y o f t h i n n i n g t o i t ' s r e c o g n i t i o n as an i m p e r a t i v e n e e d . - 3 5 -The question arises why don't we use the accumulated re s u l t s of thinning practices i n Europe. Tinney and Malmberg (1948) expressed the sound b e l i e f that i t i s impractical to adopt other countries' findings in connection with thinnings because the growth habits and u t i l i z a t i o n standards of the Douglas f i r are e n t i r e l y d i f f e r e n t . The importance of such studies was expressed by Kirkland and Brandstrom as early as 1936. It i s in t e r e s t i n g to note that the importance of a permanent road system was c l e a r l y explained: "The steps toward e f f e c t i v e management are: to open up the property quickly ... to provide permanent roads so that the growing stock can be kept under continuous se l e c t i v e control ... maintaining t r a c t o r - t r a i l s through l i g h t and frequent use, as needed not only f o r orderly l i q u i d a t i o n but also for e f f i c i e n c y i n logging and for market selection and salvage". In that early study no attempt was made to evaluate the f u l l economic advantages of the proposed thinning methods but the s i l v i c u l t u r a l aspects were discussed i n d e t a i l . Although many authors thereafter followed the same l i n e , specifying the s i l v i c u l t u r a l problems of thinning of Douglas f i r stands, the commercial aspect of the problem came into the picture very early. The l a t e s t comment concerning the problem was given by Worthington and Staebler (1961): "Commercial thinning - t h i n -ning that pays i t s way - has tremendous p o t e n t i a l i t i e s i n the Douglas f i r region possibly adding as much as 1 3/4 b i l l i o n board feet to the region's sustained-yield capacity. - 3 6 -Although not widely practiced, extensive t r i a l s have shown that i n accessible stands, near favorable markets, thinning w i l l not only s u b s t a n t i a l l y increase usable production of the f o r e s t but w i l l also return an immediate p r o f i t " . To emphasize the s t i l l open nature of the problem in many respects Worthington and Staebler (1961) ended t h e i r study with these words: "In the absence of t r i a l s over long periods, long-term f i n a n c i a l , e f f e c t s of thinning are v i r t u a l l y unknown". Thinning of Douglas F i r Stands i n B r i t i s h Columbia The problem of thinning came up in B r i t i s h Columbia for the same reason as in United States but much l a t e r . The f i r s t studies were also i n connection with Douglas f i r . Although early thinnings were done at Cowichan Lake (1929); in 1951 Joergensen s t i l l complained about i n s u f f i c i e n t experi-ments . In 1957, the same author reported on 35 thinning experi-ments underway i n the province. The experiments were mainly on Douglas f i r , mostly of s i l v i c u l t u r a l or pathological naturey although many have been stated as commercial studies also. The most important findings i n connection with these experiments on Douglas f i r are those of Joergensen (1952) and Warrack (1959). Joergensen (1952) reported on the r e s u l t s of the f i r s t commercial thinning operation practiced i n B r i t i s h Columbia on the Research Forest of the B. C. Forest Service at Cowichan Lake. After presenting the data the author f e l t that " a l l - 3 7 -th i s was only one drop i n the ocean. The s h e l l of uncertainty that encompasses the complexity of problems related to y i e l d and revenue from intermediate cuttings has been opened i n just one place, i n one type of stand, under one set of log-ging conditions and one type of thinning. Ahead l i e s a wide open f i e l d of (further) i n v e s t i g a t i o n " . Warrack (1959) explained the p o s s i b i l i t y of forecasting y i e l d s i n r e l a t i o n to thinning regimes. He analyzed i n his study the prediction of basal area increment related to thinning methods. Eighteen formulae have been created to provide sa t i s f a c t o r y predicting mechanisms f o r periodic annual basal-area increment per cent i n f i r stands of 25 years or older. I t was believed that the method can be applied to second growth stands of Douglas f i r i n the 20 to 60 age-class. In the absence of l o c a l thinning y i e l d tables the demonstration of cubic-volume predictions provide the forester with means to program p r a c t i c a l thinning regimes. In h i s estimation he supported the theory of Moller (1954) and extended i t to Douglas f i r stands by saying that "Volume increment over long periods i s not affected by the degree of thinning within wide l i m i t s " . In an evaluation of f i n a n c i a l considerations Warrack came to the conclusion that i n the Southern Coastal regions of B r i t i s h Columbia, " i t i s possible to forsee an intensive management of immature Douglas f i r stands, developing thinnings as a sound economic method of r e a l i z i n g maximum forest wealth." -38-As thinning experiments are long-range experiments we are f a r from b eing able to propose the best possible management fo r the immense second growth areas. Thinning Western Hemlock Stands The thinning experiments on East Thurlow Island are concerned with almost pure hemlock stands. Therefore i t seems appropriate to elaborate on the thinning problems of hemlock. Thinnings have three aspects which are inseparable i n practice but for discussion purposes can be d i f f e r e n t i a t e d , namely, the economical ( f i n a n c i a l ) , b i o l o g i c a l ( s i l v i c u l t u r a l ) and t e c h n i c a l (logging) aspects. In further discussion these three aspects w i l l be examined, keeping in mind that complete separation i s impossible. It w i l l be shown that research on thinning hemlock i s very limited at present, and the multitude of unanswered , questions need further investigations. The possible methods of experiments w i l l be r e f e r r e d to, without proposing d e f i n i t e procedures to follow on East Thurlow Island. S i l v i c a l C h a r a c t e r i s t i c s of Hemlock The s i l v i c a l c h a r a c t e r i s t i c s of Western hemlock (Tsuga  heterophylla (Raf n.) Sarg.) are s u f f i c i e n t l y well known to give a firm basis for further studies on stand improvement, t h i n -ning and so f o r t h . Bernstein (1958) summarized the f a c t s about western hemlock. - 3 9 -It thrives best i n the humid and mild climate along the P a c i f i c Coast, where frequent fogs and r a i n provide moisture during the growing season. I t prefers deep, i n -t e r n a l l y well drained s o i l but can t h r i v e well under unfavourable s o i l conditions. Best development of hemlock is at elevations between sea l e v e l and 2,000 feet along the coast from Alaska to Oregon. Western hemlock i s usually subordinate in association with other coniferous species, but sometimes dominates and occasionally occurs i n pure stands, as in the case of stands on East Thurlow Island. In some dense stands scarcely any herbaceous or shrubby vegetation i s present. In the Coast Range hemlock consistently outproduces its'- associates in both frequency of cone crops and quantity of seeds. Seed may be carried long distances by wind.^ Because Western hemlock i s highly tolerant and germinates and survives ea s i l y , natural regeneration can be obtained with harvesting methods varying a l l the way from i n d i v i d u a l tree selection to clear cutting. In dense stands a large number of trees die from suppression during stand development. Hemlock usually responds well to release even after a long period of suppression and in dense even-aged stands, natural pruning takes place early. A number of damaging agents are reported by Bernstein (1958) among them fungi, dwarf-mistletoe, insects, the weather, -40-windthrow, sunscald, f i r e and logging. Thin hark and frequent occurrence of exposed roots are reasons for a high suscepti-b i l i t y to damage. Thinning Experiments in Western Hemlock Stands Western hemlock i s a good subject for s i l v i c a l and commercial thinning experiments because i t responds well when released and because i t grows mostly i n r e l a t i v e l y even-aged stands of rapid growth and high volume per acre. Haddock (1958) in a l e t t e r to Hopkins wrote: "The s t r i k i n g a b i l i t y of hemlock to respond to release makes i t almost imperative that we learn, somehow, to make use of thinnings". Kirkland (1936) was one of the f i r s t who examined the p o s s i b i l i t y of thinning hemlock. For a long period there-after there was not much intere s t i n hemlock, because the commercial nature of thinnings seemed impossible. Preus (1956),in his essay,could enumerate only 21 references on Western hemlock including very general descrip-t i v e textbooks. Joergensen (1957) gave an index of a l l thinning experi-ments i n B r i t i s h Columbia and reported that there were only three experiments under way in pure hemlock stands and another two i n mixed stands containing hemlock. One of those was on the University Research Forest at Haney. G r i f f i t h (1959) reported that the thinned stands grew i n basal area more than twice as fa s t as the trees on control p l o t . - 4 1 -Another experiment was on Turnour Island by Buckland and Marples (1953) gave data concerning the e f f e c t of t h i n -ning on dwarf-mistletoe damage. The t h i r d experiment i s the one on East Thurlow Island. Smith et a l (1961) emphasized the importance of early control of spacing i n Douglas f i r and hemlock stands. According to th e i r calculations, mean annual net increment per acre of normal and open-to-normal hemlock stands d i f f e r s by 67$ i n favour of the l a t t e r , at the stand-age at which growth culminates. Control of spacing may be gained by planting, or by pre-commercial thinning or cleaning in very young natural stands. An experiment to determine the influence of spacing and thinning was established i n mixed stands of hemlock, cedar and Douglas f i r on the University Research Forest at Haney in 1959. The influence of spacing on growth of the natural stand is being studied by a c a r e f u l l y designed experiment. A t o t a l of 24 half-acre plots was established and s i x spacing distances used from approximately six feet to twenty-one feet, created by g i r d l i n g the trees, which should have been thinned. It i s planned that, when data on growth becomes ava i l a b l e , plots w i l l be analyzed on an i n d i v i d u a l -tree basis, with appropriate adjustments using multiple regression or covariance techniques. There are experiments on thinning hemlock under way on the P a c i f i c Coast outside of B r i t i s h Columbia. - 4 2 -In Alaska there have been experiments on the commercial f e a s i b i l i t y of thinnings, but the r e s u l t s have been negative. In Washington Staebler (1957) reported on commercial thinning tests and the s i l v i c u l t u r a l consequences. Gross increment was s i g n i f i c a n t l y higher i n the crown thinned stands a f t e r treatment. Realized increment, which i s the sum of mortality salvaged i n the second thinning and increment, re-tained i n the growing stock, showed a pronounced advantage for thinning. During 1959, a study was i n i t i a t e d at the Forest Research Centre, C o r v a l l i s , Oregon, on the ef f e c t of s i l v i c u l t u r a l treatment of precommercial stands of hemlock. I t was hoped that by taking advantage of the vigorous growth of young trees through intermediate cuttings, a stand of improved quality with increased wind firmness would be formed, also wood normally l o s t through suppression would be salvaged. E f f e c t s of various treatments, both on the stand i/tself and on i n d i v i d u a l trees i n the stand, and costs and returns of management would be assessed. The experiment would be r e p l i -cated four times, each i n a d i f f e r e n t l o c a l i t y . There i s no further data available yet on t h i s p a r t i c u l a r study. Damage Problem of Thinning The s u s c e p t i b i l i t y of hemlock to damage and decease made the s i l v i c u l t u r i s t interested i n the problem of how thinning w i l l influence the health of hemlock stands. - 4 3 -Because of i t s ' t h i n bark Western hemlock i s very-susceptible to f i r e i n j u r y . Thinned and pruned stands are much more f i r e r e s i s t a n t than natural stands. In frequently thinned stands, the amount of f u e l on the ground i s minimized because of salvage and prevention of mortality. Ease of a c c e s s i b i l i t y to a l l parts of the frequently thinned forest i s important from a f i r e control standpoint. Skidroads and t r a i l s , i f kept open through frequent use, provide ready-made f i r e l i n e s . In stands with shallow root systems, the windthrow a f t e r thinning can be of major importance. On the thinning operation on East Thurlow Island (1953-54) however, the research f o r e s t e r reported no w i n d f a l l at a l l , although heavy wind storms were experienced during the operation. Bernstein (1958) however reported a heavy loss after thinning because of windthrow. The danger of windthrow i s d i r e c t l y related to the occurrence of heavy storms a f t e r thinnings, to the length of l i v e crown- and to the location of i t s ' center of gravity, to the depth of the roots and t h e i r c h a r a c t e r i s t i c s , to the physical nature of the s o i l , to the s o i l moisture during storms and so f o r t h . Western hemlock has a moderately deep, well spread root system but i t s ' dense crown creates a r e a l windthrow hazard. An e a r l y , pre'commercial thinning for spacing regulation i s of great benefit f o r the stand i n the respect that the root system develops better and the center of gravity of the crown remains lower. In belated - 4 4 -thinnings, great care must be taken as to trimming i n t e n s i t y i f the factors influencing windthrow are i n an unfavourable combination. Bernstein (195#) found that losses from snow-breaks are most severe i n the inland range of Western hemlock, es p e c i a l l y in thinned stands. The danger of snow-break i s d i r e c t l y connected with the wetness of the snow, the area of snow holding surface of the crown and the slenderness r a t i o of the tree. T h e o r e t i c a l l y Western hemlock should be r e s i s t a n t to snow-break because i t has f l e x i b l e branches which e a s i l y d e f l e c t under the weight of the snow and i t s ' wood has the highest strength i n compression of any conifers on the Coast, although the slenderness r a t i o might be high as a r e s u l t of low taper. Sunscald occurs only when the i n t e n s i t y of thinning creates an open stand, which i s not the general practice yet in thinning hemlock stands. Dwarf-mistletoe has many harmful e f f e c t s on hemlock, as reported by Wellwood (1956). Buckland and Marples (1952) found i n t h e i r investigation that the dwarf-mistletoe reduced the vigour of the trees and lowered the y i e l d of stands below t h e i r actual p o t e n t i a l . The best method to manage such hem-lock stands, i n t h e i r opinion,is to thin the trees infected with mistletoe during a selection cutting near the end of the rotation which should remove the infected trees. - 4 5 -According to them, thinning operations should not be carr i e d out in the late summer or f a l l , at which time mistletoe i s f r u i t i n g . The f i n a l clear-cut area should be large, and i f seed trees are to be l e f t to reproduce an area they should be selected for t h e i r good form and apparent freedom from mistletoe. Wounds on trunk and roots are important avenues for the entrance of decay-causing fungi as reported by Shea (I960), because of the absence of a copious supply of r e s i n . Evidence of decay was found i n 91% of the trunk scars of hemlock examined in the corse of his investigation. However, losses due to decay averaged only 0.9% of the t o t a l merchantable cubic volume. Equipment and skidded logs were indicated as important sources of in j u r y . Detailed planning of the location of skid t r a i l s should reduce i n j u r i e s from t h i s cause. In the commercial thinning experiment on East Thurlow Island, 27% of trees were damaged,according to Borzuchowski (1954). The factors contributing towards the incidence of tree i n j u r i e s were steep topography, soft ground, heavy accumulation of debris, dense stands, lack of t r a i l s , careless yarding, lack of experience in thinning, and long logs. It is obvious that during the thinning operation, the damage to residual trees cannot be eliminated, but i t s ' severity can be kept at a low l e v e l . A l a t e r thinning operation i n the same area (1959) showed a great improvement due to prepared yarding l i n e s , skidding with a suitable type -46-of tractor, using iron-plate aprons on the trees but mainly because of the loggers' understanding of need to prevent injury to the r e s i d u al stand. Wright and Isaac (1956) provided useful guides for estimating decay associated with logging i n j u r i e s to western hemlock. -The available tables can give forest managers a basis f o r estimating present losses i n stands logged pre-viously or to forecast future losses to be expected i n currently logged stands. There i s some evidence that root injury i s not as serious for some species, but t h i s i s not proven yet for hemlock. There are several insects that attack hemlock. The major outbreaks cannot be influenced s i g n i f i c a n t l y by management methods, at l e a s t not i n the short run. But good thinning practice favours the development of healthy, vigorous trees with well-established root systems. Such trees can r e s i s t attacks by insects and other diseases more e a s i l y . Economic Aspects of Thinning Western Hemlock The hemlock region supports the best s i t e s i n B r i t i s h Columbia fo r sustained production of pulp and sawlogs. In area the hemlock f o r e s t s exceed the Douglas f i r forest by 400 thousand acres. Hemlock as a raw material o r i g i n a l l y was considered to be i n f e r i o r as compared to other species on the Coast. As -47-Dimock (1958) said, "Not so long ago western hemlock was l i t t l e more than a nuisance to the logger, merely something to be brushed aside i n the head-long race f o r Douglas f i r sawtimber." With today's heavy demand for paper and chemical c e l l u l o s e products, western hemlock plays a v i t a l r o l e i n our economy as a leading source of high-quality pulpwood. Harlow and Harrar (1950), quoting an eminent Swedish chemist's report s;aid that western hemlock sulphite pulps exhibit physical and chemical properties second to none. Smith et a l . (1961), i n t h e i r very thorough examination of the economic problems of r e f o r e s t a t i o n i n the Vancouver Forest D i s t r i c t , came to the conclusion that Douglas f i r w i l l remain a preferable species to hemlock i n o v e r a l l value and where i t i s possible the area covered by f i r should be increased. The f i r s t question which i s often brought up by econo-mists i s whether to thin hemlock stands at a l l , or whether to follow the present practice of extensive clear-cut management without previous thinnings. There are many experts who advise the l a t t e r . Taylor (1934), experimenting i n Alaska, came to the conclusion: "The r e s u l t s indicate that nature can take care of dense stands and as the small sized material removed i n thinning has no commercial value, i t may be best to l e t nature take i t s course." Hemlock stands of natural regeneration are usually overstocked, and consequently the mortality in the stand i s high. The potential volume available from mortality alone i s -48-very s u b s t a n t i a l . I t must be pointed out, however, that a great part of the loss i s of no commercial value and import-ance, because of i t s small s i z e . There are others who are more optimistic about the p o s s i b i l i t y of commercial thinning of hemlock. Davies ,(1960) thought that i n spite of a l l the present obstacles (bad market conditions, lack of access, i n e f f i c i e n t logging methods) the Coast i s i n a revolutionary t r a n s i t i o n from wild forests to managed f o r e s t s . As t h i s change progresses there w i l l be more and more dependence on small logs, and many of them w i l l come from thinnings. Heavy thinnings could become an economically f e a s i b l e enterprise now but t h i s would depend on the s i z e of logs available f o r such operations. A curve showing re l a t i o n s h i p between d.b.h. and logging costs (Figure 2 . ) indicates that there i s a diameter l i m i t below which i t i s not economical to cut. The l e v e l of the curve depends on the logging method used and the e f f i c i e n c y of the operation, whereas the marginal diameter i s determined by the type of product (pulpwood, sawlog) and by the market conditions, but the general r e l a t i o n s h i p w i l l be always s i m i l a r to that shown i n Figure 2 . - 4 9 -M O o o o o c •Diameter of zero margin log Log Size in DB 'H Figure 2. Graphical determination of the zero ' margin diameter. Within cert a i n l i m i t s , the u t i l i z a t i o n value per unit volume of wood is proportional to i t s diameter, while the production costs are inversely proportional to i t s diameter. Expressed g r a p h i c a l l y , the crossing point of the two curves w i l l show the economic margin diameter at which wood can be produced and sold without incurring a l o s s . In an actual thinning experiment this i n t e r s e c t i o n point can be e a s i l y determined. There have been several cost studies in connection with minimum log size for commercial u t i l i z a t i o n of many species, but none i n connection with hemlock. Doyle and Calvert (1961) showed that with Jack pine . (Pinus bansiana Lamb.) in Northern Ontario there was no p r o f i t on logs smaller than 7.5 inches i n diameter. The study of commercial thinning in Douglas f i r con-ducted by Worthington and Staebler (1961) was based on d i f f e r e n t operations where the average d.b.h. of the trees -50-removed was from 8.8 inches to 19.4 inches with a mode of 13 inches. The minimum d.b.h. logged ranged from 5 inches to 12 inches. Tessier and Smith (1961) reported, in a cost study-carried out on the U.B.C. Research Forest at Haney, that alder trees smaller than 11 inches i n d.b.h. and logs smaller than 8 inches i n top diameter cannot be logged and mille d to y i e l d a p o s i t i v e conversion return. According to Barnes (1953) commercial thinning i n hemlock stands cannot s t a r t e a r l i e r than at 55 years of age i f saw logs are the main product. Because pulpwood i s merchantable from a 5-inch top diameter, thinnings could s t a r t at a mu'ch e a r l i e r age than that for saw-logs provided a suitable market e x i s t s . There i s i n s u f f i c i e n t data to evaluate the minimum merchantable tree size in thinning hemlock. The question remains whether the smallest p r o f i t a b l e diameter should be the lowest l i m i t , below which a tree should not be cut. In thinning hemlock, the s i l v i c u l t u r a l requirements might demand the elimination of some trees from lower diameter classes a l s o . The emphasis then should be on thinnings o r i g i n a t i n g at an age where marginal returns can be expected, cutting only enough higher diameter trees to compensate f o r trees of smaller diameter than the deter-mined marginal minimum for that operation. With t h i s approach the successive thinnings might create benefits and we can expect quality improvement from the f i n a l harvest. -51-This type of la t e thinning i s not selective cutting or pre-logging because the aim i s to leave the re s i d u a l stand with higher or at least the same average diameter that i t was before (d/D = 1 or over). The damage to the residual trees w i l l be less i n t h i s case than i n the opposite method of selective cuttings. The impulse for growth w i l l a f f e c t remaining good quality trees, r e s u l t i n g with favor-able phenotypes for the f i n a l cut. Whether the delayed thinnings are acceptable s i l v i -c u l t u r a l l y i s a d i f f i c u l t question to answer with so l i t t l e knowledge of the behaviour of hemlock under such circum-stances. It i s obvious that to thi n on a marginal basis w i l l mean a loss of maximum p r o f i t s at the time of thinning. The removal of smaller than marginal trees w i l l decrease or eliminate the p r o f i t and t h i s can be j u s t i f i e d only i f the remaining stand produces extra quantity or quality of wood at a rate such that the p r o f i t l o s t compounded to the next thinning, or to the f i n a l cut, w i l l be repaid. There are very few f a c t u a l data available to j u s t i f y the v a l i d i t y of t h i s s i l v i c u l t u r a l p ractice. It i s hoped that s i l v i c a l c h a r a c t e r i s t i c s of hemlock, responding with enough vigor to such thinnings, w i l l f u l f i l l the expected r e s u l t s . Quality improvement i s more l i k e l y to occur because with heavier thinnings removal of pulpwood w i l l allow f o r a greater percentage of sawlogs of higher grade i n the f i n a l - 5 2 -c u t . I n a d d i t i o n t o t h e d e l a y e d t h i n n i n g s a p r e - c o m m e r c i a l t h i n n i n g w o u l d be n e c e s s a r y , o f c o u r s e , i n an e a r l y age o f the s t a n d , f o r s p a c i n g r e g u l a t i o n and s e l e c t i o n . The z e r o m a r g i n d i a m e t e r i s d e p e n d e n t n o t o n l y on l o g g i n g c o s t s b u t a l s o on u t i l i z a t i o n v a l u e . I n t h e c a s e o f h e m l o c k p u l p w o o d t h e p r e s e n t m a r k e t p r i c e ($15.00 p e r c o r d t o $19.00 p e r c u n i t ) seems t o be u n r e a s o n a b l y l o w . P u l p m i l l s e l s e w h e r e on t h e C o n t i n e n t pay h i g h e r p r i c e s f o r l o w e r q u a l i t y p u l p w o o d m a t e r i a l . The o b v i o u s r e a s o n f o r t h e l o c a l l o w p r i c e i s t h e p r e s e n t abundance of m i l l w a s t e a v a i l a b l e f o r c h i p s . W i t h a l t e r i n g m a r k e t c o n d i t i o n s and r e a s o n a b l e p r i c e s t h e z e r o m a r g i n d i a m e t e r c o u l d be r e d u c e d and l a r g e r a r e a s o f h e m l o c k s t a n d s w o u l d be a v a i l a b l e f o r c o m m e r c i a l t h i n n i n g . LOGGING AND TRANSPORTATION PROBLEMS, OF- THINNING The s m a l l l o g s w h i c h come f r o m t h i n n i n g s c r e a t e a d i f f i c u l t economic p r o b l e m f o r l o g g e r s . The method r e q u i r e d must be one w h i c h i s s i l v i c u l t u r a l l y a c c e p t a b l e , t e c h n i c a l l y p o s s i b l e , a n d e c o n o m i c a l l y f e a s i b l e . To c o n n e c t t h e p r o b l e m d i r e c t l y w i t h h e m l o c k s t a n d s , t h e p r o b l e m o f l o g g i n g on t h i n n i n g s i n g e n e r a l w i l l be d i s -c u s s e d . I n t h e case o f t h i n n i n g a c c e s s i b i l i t y i s t h e most i m p o r t a n t p r e r e q u i s i t e t o l o g g i n g , t h e r e f o r e t h e a c c e s s p r o b l e m w i l l be p r e s e n t e d f i r s t . - 5 3 -The Importance of Road Network in Intensive Forestry Practices The road network i n a forest, l i k e the blood vessels in the human body, gives l i f e to the area, serving not only for transportation of the products removed but with the same importance for movement of workers and equipment. The road system i s c l o s e l y related to the type of management of the f o r e s t . Each type of management has an optimal economic road or transport system for f u l f i l l i n g i t s purpose. A road was defined by S i l v e r s i d e s (1951) as economical i f i t costs less per mile than the c a p i t a l i z e d savings effected because of i t s existence. On that basis the roads in an extensively managed f o r e s t are only constructed to f a c i l i t a t e logging. In t h i s case the roads are temporary, timber types and market conditions w i l l a l t e r road plans f o r any one year. Taking the other extreme i n a forest which is intensively managed for multiple use^ a permanent road system should be planned with mainly permanent l i n e s to allow the f u l f i l l m e n t of a l l necessary forestry a c t i v i t i e s to be carried on,including s i l v i c u l t u r e and protection as well as logging. Forests used f o r rec r e a t i o n a l and the research purposes are closest to th i s i d e a l . In the l a t t e r case i t is d i f f i c u l t to show the savings i n do l l a r s because of the existence of the road system, but the noted advantages are: (1) An adequate road system permits the - 5 4 -salvage of insect-infested groups of trees as well a s r the cutting of high hazard trees to reduce the p o s s i b i l i t y of insect outbreaks. (2) Execution of f i r e control plans is a v a i l a b l e . (3) Inaccessible timber in remote areas may be brought under management. (4) Forestry personnel and workers may reach e a s i l y any part of the forest, giving higher production i n logging, planting, pruning, (5) It f a c i l i t a t e s thinnings, pre^Logging, s e l e c t i v e cutting'. In short, the harmonious work of an intensively managed forest on a sustained y i e l d basis can be economical only i f a permanent road system a s s i s t s to i t . The research f o r e s t on East Thurlow Island f a l l s close to the type of forest,, previously described. As shown in commercial thinning experiments there no p r o f i t can be expected without permanent road network. The importance of a well-established permanent road system i n managing i n t e n s i v e l y a forest area i s accepted as a sine qua non i n Europe. There are several books or texts written on the subject in almost every country of Europe, e.g. Hafner (1956), Glaser (1951). In America, Matthews (1942) was the f i r s t to underline the importance of f o r e s t roads, mainly i n connection with the economics of logging. In his book, "Cost Control i n the Logging Industry", there i s basic information about the economic location of roads, the determination of the economic service standard f o r roads and the sel e c t i o n of road spacing. - 5 5 -Th e t r a n s i t i o n to more intensive management practices on the Coast w i l l emphasize the importance of roads. More roads w i l l be needed i n the future. The 'more' does not mean necessarily more expensive investments, rather better planned, more economical road patterns, with emphasis also on roads of lower standard. Bruce (1953) found i n his study of access roads, that i n a c c e s s i b i l i t y i s the primary obstacle to reaching sustained y i e l d capacity in the U.S.A. Some s i l v i c u l t u r i s t s are worried about the increased loss in productive area. The loss i n productive area, however, i s not d i r e c t l y proportional to loss i n volume produced because the encroachment of roots and crown produces more growth on trees standing on roadsides. European reports point out that a s t r i p eight feet wide does not reduce volume production. An experiment made by Kramer (1958) showed that when the roads are prepared at an early stage of the stand, e.g. at the time of the f i r s t thinning, one may clear skidding t r a i l s of 9 to 15 feet width without any y i e l d decrease, because the bordering trees w i l l u t i l i z e enhanced increment conditions of the t r a i l . I f the skidding t r a i l s are l a i d out in a nearly mature stand, one w i l l experience a certain decrease i n y i e l d but i t i s small (2 to 3 per cent for 9 feet t r a i l width and t r a i l - s p a c i n g of 100 f e e t ) . I f the skidding t r a i l can be maintained at a width of 8 feet wood production would hardly be jeopardized. - 5 6 -Silen and Gratkowski (1953) discussed the problem of a c c e s s i b i l i t y i n the P a c i f i c Douglas f i r region. In an e s t i -mate of the amount of road necessary i n the staggered-setting system of clearcutting, they found, on an experimental area i n Oregon, that 9.8% of the area was disturbed by roads and landings. Due to reforesting of much of the f i l l s and part of the cuts the estimated t o t a l loss i n productive forest land could be kept to a minimum of 4«1%« Intensive management does not allow a type of practice <s in road network design that plans Roc only one year ahead. This usually r e s u l t s i n an uneconomical pattern f o r a management unit. In designing a forest road, the future road network of an area should be v i s u a l i z e d i n i t s entirety and the detailed plans f o r a si n g l e road should be harmonized with the whole system. The correct process i s then a long-range general road plan and the yearly road construction w i l l be applied to this basic plan. This method i s also more economical. S i l e n (1955) presented h i s opinion about more e f f i c i e n t road patterns for a Douglas f i r stand and found that with a well established pattern, the length of roads on an area usually can be reduced without reducing i t s e f f i c i e n c y . He proposed also, that the number of roads that climb between levels can be reduced and the length of roads on d i f f e r e n t l e v e l s spaced on the economic i n t e r v a l can be increased with the same r e s u l t . In a p a r t i c u l a r comparison S i l e n (1955) showed that the new pattern, though 0.62 miles - 5 7 -shorter, had the same e f f i c i e n c y as the old layout. The economic./, spacing of roads, according to Matthews formula: S = mile, V is cu. f t . volume per acre, C i s yarding cost per 100 feet and S i s road-spacing i n units of 100 feet, i s i n r e c i p -r o c a l square root r e l a t i o n s h i p with volume per acre. This would mean that the road network f o r f a c i l i t a t i n g thinnings is economical only i f the spacing i s wide. On the other hand, the r e l a t i v e l y small size of logs does not allow long yarding distances. The c o n t r o l l i n g f a c t o r f of road spacing )in the case of thinning , w i l l be therefore the optimum yarding distance of the yarding method used, not taking the volume per acre available into consideration. The road network in a forest area consists of roads of d i f f e r e n t standards which are usually c a l l e d ,in order of importance }main access roads, secondary roads, branch roads and spurs. In a road development program f o r areas under intensive management, the standards of some roads w i l l change during the rotation. As Berg (1961) said, roads may be developed step-wise by pushing in a pioneer road f o r the f i r s t thinning and then improving the road by ditching, i n s t a l l i n g culverts, and grading as successive intermediate cuts are made. It apparently has not occured to loggers on the Coast that secondary roads and branch roads could be of a permanent [0.33Ri where R i s road construction costs per VC -58-or semi-permanent nature. In case of intensive thinnings however, secondary and branch roads must be of semi-permanent nature i n some cases,to reduce road maintenance costs and to make year Lround operations possible. The semi-permanent standard can be achieved by using inexpensive, l i g h t l y paved roads of s t a b i l i z e d earth and gravel. These are usually s u f f i c i e n t for the loads and amount of t r a f f i c expected. There are several methods of constructing roads types of s t a b i l i z e d earth and gravel. S t a b i l i z a t i o n i s usually begun with the strengthening enforcement of base and sub-base. The structu ral strength of any road i s dependent upon the a b i l i t y of the subgrade to carry loads under a l l climatic conditions. This can be achieved by mechanical s t a b i l i z a t i o n , or by adding s t a b i l i z i n g agents such as sulphite liquor, bituminous materials, lime, portland cement, calcium chloride or sodium chloride. Surface s t a b i l i z a t i o n i s p a r t l y f o r increasing load-carrying capacity, but i t s main purpose i s to reduce road deterioration from weather effects such as f r o s t , absorbed water and to act as a dust-layer. The same methods as for subgrade s t a b i l i z a t i o n are usually used f o r i t with only minor t e c h n i c a l changes in applic a t i o n . Edwards and Towns end (1961) gave a good evaluation of the importance • of f o r e s t road s t a b i l i z a t i o n i n Canada. The- l a t e s t figures on earth road s t a b i l i z a t i o n show that the costs are not high. "Zee" Chemical Company, for instance, claim that they can s t a b i l i z e e x i s t i n g earth roads f o r $1,000.00 - 5 9 -p e r m i l e . ( A d v e r t i s e m e n t , W e s t e r n T imber I n d u s t r y , F e b r u a r y 1962). They m a i n t a i n t h a t a f t e r t h e i n i t i a l t r e a t m e n t w i t h " r o a d p a c k e r " , t h e s u r f a c e i s a l o n g l a s t i n g , a l l w e a t h e r , s u r f a c e . The o n l y equipment needed t o a p p l y t h e c h e m i c a l i s a g r a v i t y f e e d s p r i n k l e r - t r u c k f o l l o w e d b y a n o r d i n a r y g r a d e r . L a t e s t f i g u r e s a b o u t o t h e r s t a b i l i z a t i o n methods show t h e same l o w c o s t s . S t a b i l i z a t i o n w i t h s a l t i n t h e f o r e s t s o f A r i z o n a runs up t o $2,000.00 p e r m i l e ; Day (1962). The most p r o m i s i n g method w o u l d be cement s t a b i l i z a t i o n w i t h some l i g h t o i l i m p r e g n a t i o n , as u s e d on many f o r e s t r o a d s i n U . S . A . and i n E u r o p e . T a b l e s i n the L o g g i n g R o a d Handbook (I960) a r e a v a i l a b l e t o e s t i m a t e h a u l i n g c o s t s on r o a d s due t o d e s i g n e l e m e n t s , equipment u s e d and r o a d s u r f a c e s . These t a b l e s a r e a p p l i c -a b l e m a i n l y to a c c e s s r o a d s d e s i g n e d f o r h i g h s p e e d . N e v e r -t h e l e s s t h e d e s i g n and c o n s t r u c t i o n w i l l i n f l u e n c e h a u l i n g c o s t s on t h e s e c o n d a r y r o a d s y s t e m a l s O j b u t i n a d i f f e r e n t manner. S i l v e r s i d e s (1951) p o i n t e d out t h a t t h e d e s i g n c o s t s a r e v e r y l o w i n Canada compared t o c o n s t r u c t i o n c o s t s and t h e y n e v e r e x c e e d 5% o f the t o t a l c o s t . C a r e f u l d e s i g n , m a i n l y an a p p r o p r i a t e r e c o n n a i r i c e on t h e g r o u n d , s o i l t e s t i n g i f n e c e s s a r y , e c o n o m i c c o m p a r i s o n o f p o s s i b l e a l t e r n a t i v e s ^ and so f o r t h ^ s h o u l d i n c r e a s e d e s i g n c o s t p e r c e n t a g e b u t t h i s c e r t a i n l y w i l l be o u t w e i g h e d by t h e d e c r e a s e i n c o n s t r u c t i o n and m a i n t e n a n c e c o s t s . -60-Th i s type of road network design needs t e c h n i c a l l y trained men who are familiar; with the special requirements of d i f f e r e n t forests }not simply engineers who are able to design a good but usually unnecessarily expensive road between two given points. Forest roads b a s i c a l l y d i f f e r from public roads and highways i n t h e i r purpose. Even the technical design elements must d i f f e r , because the nature of t r a f f i c i s d i f f e r e n t . The load-transport i s always directed in one d i r e c t i o n and not alternating as on highways. The t r a f f i c flow i s not continuous,'^usually r e s t r i c t e d to a part of the year and even then the t r a f f i c i n t e n s i t y i s very low compared to public road t r a f f i c . The main d i f f e r -ence l i e s i n the f a c t , t h a t , i n designing a f o r e s t road, the future road network of an area should be v i s u a l i z e d i n i t s en t i r e t y and the detailed plans f o r a sing l e road should be harmonized with the whole system. The suggested type of road pattern w i l l not replace the present pattern i n a short time and.only in places where intensive management can be practiced economically. The t r a n s i t i o n w i l l originate in places where logging roads already exist. The long range road development plans f o r areas of this kind should be such that not only the present require-ments of logging,but also the expected future forest work necessities;should be considered. These preliminary plans should not be of a r i g i d pattern but rather f l e x i b l e to be altered i n d e t a i l , i f changing logging methods i n the future w i l l necessitate i t . -61-The road network i n a given management unit w i l l l a r g e l y depend on the proposed logging methods to be used. The logging methods used f o r thinning d i f f e r greatly from those of clear cutting. It i s l o g i c a l then, that the road system must d i f f e r also. To pursue this problem farther, the s p e c i a l problems of logging in a thinning operation w i l l be discussed. Special logging problems i n a Thinning Operation Small-log logging on the Coast i s in a r e l a t i v e l y recent experimental stage. As small logs are becoming more and more important as a source of raw material, the search for new ways of logging is being i n t e n s i f i e d accordingly. Davies (I960) commented that c e r t a i n methods have become standard on the Coast and i t is d i f f i c u l t to change them. He complained about the conservativeness of loggers and of t h e i r slowness to adapt the new methods already developed and proved i n other countries or other regions. Worthington and Staebler (I960) had the opinion that engineering p r i n c i p l e s and practices of conventional logging must be modified considerably to adapt them to the p a r t i c u l a r requirements of commercial thinning. The contrast between logging old growth,and thinning,is probably greater on the Coast than in any other forest region of the country. Equipment requirements in p a r t i c u l a r are d i f f e r e n t . -62-The Timberman in i t s May issue (1961) gave a twenty-f i v e page p i c t o r i a l report on small-log handling equipment and|methods used at present. "There i s no more universal problem fa c i n g the logger today than that of f a l l i n g , bucking, skidding and loading small logs" - said the i n t r o -duction of the report. I t i s interesting to see, however, that over onehundred different devices discussed are b a s i c a l l y not new equipment, only modifications of presently-used machines. The way to f i n d new methods and equipment i s s t i l l open to those with imagination. As the logging process i s usually broken down into the working phases of f e l l i n g and bucking, yarding, loading and hauling, farther discussion of the problem w i l l be grouped s i m i l a r l y . F e l l i n g and Bucking The development of l i g h t power saws has made them i d e a l f o r f e l l i n g and bucking^especially in thinning. Mobile c i r c u -l a r saws are not used on the Coast because the heavy debris make them useless, although i n Europe they are used e f f e c t i v e l y . For tree-length yarding,however, they would be useful for bucking at landings due to t h e i r f a s t cutting. In thinning operations the f a l l i n g d i r e c t i o n i s very important. Trees should be f e l l e d toward skid t r a i l s i n a herring-bone pattern to favour l a t e r skidding. In young or dense stands, f e l l i n g i s a time consuming operation because of frequent hangups. For that reason, the trees are usually -63-f e l l e d toward the most favourable openings i n the crown canopy, regardless of skidroads. Limbing i s done by axe or power saw. A l i g h t portable c i r c u l a r saw with a long handle i s used i n Russia and Japan with good e f f i c i e n c y but not t r i e d yet i n B r i t i s h Columbia. Bucking i s done almost u n i v e r s a l l y by power saws, either at the place of f e l l i n g or i n case of tree-length yarding at the landings. Tree-length yarding versus log-length yarding i s a question open to debate. Some of the advantages of t r e e -length yarding a r e : ( l ) that bucking can be done under favour-able conditions with^less well educated bucker at landings-, (2) bunching costs are lower as time f o r choker setting i s reduced; (3) yarding costs are reduced by allowing for heavier loads per turn. In case of thinning thowever, yarding i n tree length has 2. i also disadvantages. The damage to standing trees increases with increasing log length and pre-yarding is more d i f f i c u l t . In second growth hemlock stands the product of thinning i s usually f a i r l y uniform (mostly pulpwood) which does not need s k i l l e d bucking, therefore the advantage of bucking at landings i s not s i g n i f i c a n t . Worthington and Staebler (1961) reported that f e l l i n g , bucking and limbing required about 1.3 man hours per hundred cubic feet i n thinning operations on the Coast under average conditions i n second growth Douglas f i r stands. ! - 6 4 -In f e l l i n g and bucking operations the problem of contract versus a day rate can be assessed. The contract payment has the advantage of high productivity which i s a d i r e c t r e s u l t of the incentive pay basis; but the d i f f i c u l t supervisory problem, which i s not associated with day labor,'and the effect of cutting the largest trees to increase output, w i l l c o n f l i c t with some s i l v i c u l t u r a l considerations i n thinnings. Therefore day labor with possible bonuses (for low damage, no hangups and so forth) seems to be the best procedure i n thinnings. Skidding Problems of Thinning Pre-yarding and yarding or skidding account for most of the time spent i n thinning. The r e l a t i v e l y small size of the material from thinnings creates the largest economic problem i n skidding. Heavy-duty machinery, such as i s used on the Coast, i s uneconomical f o r handling small logs. (Sky-lines,' the e l e c t r i c arch and so forth) On the other hand the logs i n a thinning operation on the Coast are usually not small enough to allow the use of l i g h t equipments which are used i n the East or i n Europe with good e f f e c t . Different ways may be used to solve the problem of skidding small logs economically, such as: 1. By modifying heavy-duty machines, now used to log large timber to enable them to handle small logs more e f f e c t i v e l y , (e.g. mobile highlead, smaller tractors with arches.). - 6 5 -2. By introducing small-log logging methods which are already used in other regions or countries but with possible modifications to adapt them to the s p e c i a l circumstances of the Coast, (e.g. Lasso Cable conveyor, etc.). 3. By reviving old logging methods now outmoded (e.g. horselogging, chutes, e t c . ) . 4. By experimenting with completely new ideas such as the use of helicopters. As there i s no information about t h e i r p r a c t i c a b i l i t y i n thinnings the writer w i l l omit discussion of these new ideas. Mobile High-lead In the case of modified high-lead, there are already examples showing good r e s u l t s i n salvage logging, prelogging and selective cutting, which are similar to thinnings i n t h e i r extracting methods. These systems d i f f e r from the conventional form by being e a s i l y transported from one setting to another, having portable spars. The r i g up time and moving time i s reduced and does not require expert riggers. The most common types are the M a d i l l s t e e l spar, the Berger Porta-Tower, the Windrow and the Skagit mobile yarder-loader. The l a s t type was used with great success for salvaging old-growth Douglas f i r as reported by Carow (1959). -66-A 90 - f o o t p o r t a b l e s t e e l s p a r was u s e d i n a s t u d y o f p r e - l o g g i n g by M c i n t o s h and Gunn ( I 9 6 0 ) who compared y a r d i n g u p h i l l v e r s u s d o w n h i l l . The t i m e a n a l y s i s showed t h e a v e r -age y a r d i n g t i m e p e r c u n i t was 1 4 . 1 2 m i n u t e s u p h i l l and 1 7 . 3 0 m i n u t e s d o w n h i l l . A v e r a g e y a r d i n g d i s t a n c e s were 3 6 5 f e e t and 5 0 5 f e e t r e s p e c t i v e l y . T e s s i e r and Knapp ( 1 9 6 1 ) r e p o r t e d t h a t d i r e c t l o g g i n g c o s t s o f m o b i l e h i g h - l e a d i n c l e a r - c u t o p e r a t i o n s were w e l l i n l i n e w i t h r e g i o n a l a v e r a g e s : $ 4 . 7 6 p e r M f . b . m . B a s e d on r e s u l t s o f t e n p o r t a b l e s p a r s i n use on V a n c o u v e r I s l a n d i n c l e a r - c u t o p e r a t i o n s i t was f o u n d t h a t t h e m o b i l e u n i t s had y a r d i n g c o s t s a v i n g s o f $ 1 . 4 8 / M f . b . m . o v e r t h e c o n v e n t i o n a l h i g h - l e a d s y s t e m ( M u n n i s 1 9 6 1 ) . The S k a g i t M o d e l RCC - 1 0 Sky C a r , an e q u i p m e n t s i m i l a r t o m o b i l e h i g h - l e a d , was u s e d w i t h s u c c e s s i n t h i n n i n g o p e r -a t i o n s on t h e Clemons T r e e Farm o f t h e W e y e r h a u s e r Company. The amount o f t i m b e r removed a v e r a g e d 1 5 M f . b . m . p e r a c r e . I t was r e p o r t e d t h a t p r a c t i c a l l y no damage was done t o t h e r e s i d u a l s t a n d (The T imberman, A u g u s t , 1 9 6 1 ) . These s y s t e m s m i g h t be a p p l i c a b l e t o t h i n n i n g b u t o n l y on c e r t a i n t o p o g r a p h y s u c h as on s t e e p s l o p e s where t r a c t o r l o g g i n g w o u l d be h i n d e r e d , o r a l o n g a l r e a d y e x i s t i n g a c c e s s r o a d s . To keep t h e l o g g i n g c o s t s o f t h e s e s y s t e m s l o w , t h e m a t e r i a l removed on any one s e t t i n g must be s u b s t a n t i a l . - 6 7 -Tractors Tractors are the most promising machines for thinning but to recommend the best type f o r our coastal forests i s rather d i f f i c u l t . I t i s safe to say, however, that tractors under 30 hp. are too l i g h t for our thinnings, and tractors over 70 hp. cannot be used to f u l l capacity, de Megille (1956), i n a lengthy study on tractors i n which he compared cost and production values f o r d i f f e r e n t types of t r a c t o r s , came to the same conclusion, s t a t i n g that for thinning under d i f f i c u l t conditions medium powered tractors of 40 to 50 hp. are the best. There are many tractors available in t h i s category, both crawler types and rubber t i r e d . Crawler tractors have the advantage of low pressure contact with the ground. They can bulldoze skidding t r a i l s with less d i f f i c u l t y than the rubber-tired types and can p u l l heavier loads f o r the same machine weight. However, as they are not e a s i l y maneuverable, damage to standing trees i s usually severe. Their slow speed does not allow f o r long yarding distances, usually not more than 2 ,500 feet. Tractors s i m i l a r to C a t e r p i l l a r Model D6 are the maximum size which should be used, but D4 would be the most economical model and in some places the D2. In many instances the crawler t r a c t o r s would be p r o f i t a b l e additions to rubber-tired types where skid-ding distances are greater than one-half mile. Rubber-tired t r a c t o r s can t r a v e l at a higher speed, but t h e i r load capacity i s lower -68-than that of crawlers with the same horse power. I f r a i n f a l l often soaks the ground th i s may render d i f f i c u l t , i f not im-possible, the use of wheeled tractors and crawler tractors w i l l be preferable. Damage to standing trees i s less with rubber-tired t r a c t o r s due to t h e i r maneuverability. Operator fatigue i s also reduced. They are not suitable, however, for bulldozing t r a i l s under d i f f i c u l t conditions. The load carrying capacity of rubber-wheeled skidders i s comparable to that of crawlers as follows: Rubber-wheeled type Equivalent Crawler class 10- ton C a t e r p i l l a r Model D-6 7-ton C a t e r p i l l a r Model D-4 32^ton John Deere 440 There are tractors which can be used either as crawlers or as rubber t i r e d as necessary. The track shoes can be removed or i n s t a l l e d i n ten minutes. Multiple use tr a c t o r s have been developed in Europe and used economically, e.g. the Unimog i n Germany and the Motormule i n Austria. They have many sp e c i a l accessories which make them able to do d i f f e r e n t jobs i n the forest, such as planting, spraying, road maintenance, yarding and hauling. The rubber t i r e d Unimog was t r i e d under B r i t i s h Columbia conditions but i t s T performance was not s a t i s f a c t o r y . A si m i l a r unit to the Motormule,which i s a fast,crawler-type tr a c t o r with t r a i l e r ( might be better suited to thinning operations on the Coast. Figure 3. The Garrett Tree Farmer t r a c t o r i n operation. One of the most promising r u b b e r - t i r e d type of t r a c t o r on the Coast i s the G a r r e t t Tree Farmer t r a c t o r . (Figure 3.) I t was used r e c e n t l y i n the t h i n n i n g operation on East Thurlow I s l a n d , where the author could gain a d i r e c t impression of i t s performance. The Garrett Tree Farmer i s a s m a l l (3.|-ton), narrow gauge, compact u n i t w i t h an a r t i c u l a t e d frame. S l i p s h a f t s and u n i v e r s a l j o i n t s on the main d r i v e s h a f t and four-wheel d r i v e , give the machine a short t u r n i n g r a d i u s , enabling i t to weave around stumps and other o b s t a c l e s , as w e l l as to climb steep slopes. A b u l l d o z e r blade mounted on the f r o n t assembly i s s u i t a b l e f o r c l e a r i n g w i n d f a l l s and other obstacles from the s k i d t r a i l s and keeping skidway s i t e s f r e e . I t i s not power-f u l enough, however, to b u l l d o z e s k i d t r a i l s i n dense stands -70-where large stumps and heavy debris are present. The front wheel assembly, lacking springs, i s pivoted to give '18-inch o s c i l l a t i o n to the f r o n t wheels for clearance. A slow speed logging winch operates from a power take-off and holds 75 feet of cable l/2 inch in diameter. Travel speeds are the following: Rated horsepower i s 48 hp. Drawbar horsepower i s 35 hp. Highest single load i s 1,140 f.b.m. or two cunits of pulpwood. Wilson (I960) reported on an operation where a tree Farmer was used successfully. In his opinion, some of the • a t t r a c t i v e features of t h i s machine are i t s low operating and maintenance costs due mainly to s i m p l i c i t y of design, and i t s good performance i n rough t e r r a i n , and i t s high volume production in the better stands. As he pointed out, inexpensive t i r e s , absence of springs, a simple chain-drive system ,and maneuverability,make the Garrett Tree Farmer an a t t r a c t i v e machine for thinnings. According to his report 5based on an operation which was carried out under winter conditions^, the t r a c t o r i s capable of operating in snow to a depth of 10 inches without t r a i l s . During the three-month operational period, d a i l y records were kept and the following r e s u l t s were obtained: Average production per day was 10.7 cords. Average production per man-day was 2.7 cords under poor skidding conditions. The 1st gear 2nd gear 3rd gear 4th gear Reverse 2.2 mph 4.9 mph 7.2 mph 14.7 mph 1.9 mph -71-production went up under good skidding conditions to 15.2 cords per day or 3 . 8 cords per man-day. The topography-was broken,flat to r o l l i n g . The maximum length of yarding was 900 feet. The Timberman reported i n 1959 on an operation, where the Tree Farmer was used and i n which logging costs of $16.05 per M f.b.m. with a two-man crew,and $12.63 with a three-man creWjWere obtained. Logs averaged 9 .5 inches upper diameter inside bark. Average yarding distance was 1,340 f e e t . Production was 750 f.b.m. per t r a c t o r hour. The Tree Farmer was used by the Research Division of B r i t i s h Columbia Forest Service i n a thinning operation at Cowichan Lake in 1959. Production was 1.8 cords per man per day, including t r a i l construction-; which took 30$ of the time on the operation. At the end of the operation, the production rose to 3 . 0 cords per man-day with about 1,200 feet average yarding distance and a crew of three. The Timber jack, a rubber-tired unit, worked e f f e c t i v e l y in Eastern Canada even i n three feet of snow, as reported by Caplan (1962). Its average production was 16 cords during an eight-hour day, with an average skidding distance of 550 feet. The t o t a l cost per cord was $ 8 . 0 3 . In the same operation a heavier unit, the Timberskidder, with two drums, had a d a i l y output of 21 cords,with 2,000 feet yarding distance and with a yarding cost of $9.51 per cord. The crews were large, 6 and 7 men respectively. -72-Many factors should be considered i n the choice of t r a c t o r . Topography and climate, s o i l and ground conditions (debris), density of stand and size of logs, existence or absence of t r a i l s and t h e i r standard, a l l are important factors which have an influence on the choice of t r a c t o r s , as f a r as weight, horsepower and type i s concerned.. As the plan on East Thurlow Island i s to create an a l l -weather s k i d - t r a i l system i n the experimental f o r e s t , rubber wheeled tractors are preferable. Further experimentation i s needed to f i n d the best method of working with the tractor i n thinnings, the optimum size of crew and the best load-speed r e l a t i o n s h i p . •Pre-yarding Tractors used i n skidding are handicapped when there i s a lack of skid t r a i l s and by the time consuming bunching, which precedes yarding. S i l v i c u l t u r a l l y the best solution i s for the skid t r a i l network to be dense enough so that the tr a c t o r need not enter the stand. Bunching with the trac t o r ' s winch i n many cases i s not economical, i f the same tractor does the yarding. Pre-yarding or bunching should be done separately beforehand i f possible. It i s most advisable to prepare loads for tractors not only because of increased production but also for reasons of damage reduction. - 7 3 -Pre-yarding or bunching can be done i n d i f f e r e n t ways, by horses, by winches, by crawler type motor cycles, or by bunching t r a c t o r s . Horses would be the most i d e a l means to keep damage low. They have so many drawbacks, however, that t h e i r use in the Coastal forest i s r e s t r i c t e d . The usually heavy debris and heavy logs (especially hemlock) w i l l not allow longer pre-yarding distances fhora 200 to 300 feet. The necessity of the continual presence of personnel for t h e i r maintenance, even on non-working days, increases the cost. Accidents and danger of loss by i l l n e s s make the operation hazardous. F i n a l l y , t h e main problem i s that there are few good horses and experienced teamsters available on the Coast. Crawler type, motorcycles are used in Eastern Canada and in Europe and may be adaptable under certain conditions, to coastal B r i t i s h Columbia. Winches are useful equipment i n pre-yarding. Many sled-mounted, semi-mobile and mobile units are available as single or double drum winches. With application of blocks they can be used under almost any circumstances. An i n t e r e s t i n g new winch on the market i s the Swedish "Sepson" radio controlled mobile yarding winch. Its operation i s i l l u s t r a t e d i n Figure25. As the sketch shows, i t can be operated by one man. Production data are not yet available but the techn i c a l data allow an estimate of about 2 cunit per hour with a distance of 300 feet^assuming a single load of 20 cubic feet. Technically the system allows thinnings with - 7 4 -the smallest possible crew, even with a single man. F e l l i n g , bucking and bunching can be done p r i o r to yarding, the l a t t e r being done when i t i s convenient to use a t r a c t o r or truck on a r e n t a l basis. Present price i s $ 1 , 2 0 0 . 0 0 f o r a single drum unit and $1 ,600.00 for a double drum. Operating speed i s 200 feet per minute; p u l l i n g power i s 2,000 l b s . ; motor perform-ance i s 13.5 hp. The writer had the impression regarding the Tree Farmer operation on East Thurlow Island (1959) that the most delay was caused by bunching. I f the logs could have been prepared beforehand, the t r a c t o r , with i t s higher speed could have had a much higher production. A solution might be to use a small crawler t r a c t o r for bunching, and to prepare t r a i l s and loads fo r the Tree Farmer. This solution however, would only be p r a c t i c a l with long yarding distances. With shorter skidding distances the r e l a t i v e l y slow crawler t r a c t o r with heavy loads can outproduce the Tree Farmer with i t s higher speed but smaller loads. The Tree Farmer can be economical with short yarding distances, i f loads are increased to maximum, using the lowest gear r a t i o . This approach approximates that explained i n Spiers' thesis (1956) as shown by his t h e o r e t i c a l layout for a combined skidding operation (Figure 4 ) . In both cases, however, the pre-yarding must be done in advance to increase output of yarding. - 7 5 -o o c o c Area of direct skid to rood o o 0) 3 IT 400" 800 Rood t _ Figure 4. Theoretical layout for continued tr a c t o r skidding operation . If the carrying capacity for each gear r a t i o i s known, i t i s possible to determine the break even point of economical yarding distance,' o shown for C a t e r p i l l a r Model D4 and Motor-mule on the graph"as given by Leloup (1956)/ui Figure 5« 0-5 I |-5 Yarding Distance in Miles Figure 5. Comparison of slow and fa s t crawler type tractors on the basis of output as a function of distance. -76-Th e c o m p a r i s o n o f a C a t e r p i l l a r M o d e l D4 w i t h a T r e e F a r m e r g i v e s a s h o r t e r d i s t a n c e o f 0 . 4 m i l e f o r e q u a l o u t -p u t , c a l c u l a t e d w i t h t h e f o l l o w i n g l o a d s and s p e e d s : C a t e r p i l l a r T r a c t o r Type D4 speed w i t h l o a d 2.5 mph f u l l s p e e d 5.3 mph 2.4 c u n i t l o a d G a r r e t t T r e e F a r m e r Speed w i t h l o a d 4 . 9 mph f u l l speed 14.7 mph 1.0 c u n i t l o a d C a b l e Y a r d i n g Systems M o d i f i c a t i o n s o f some o f t h e E u r o p e a n l i g h t y a r d i n g d e v i c e s have been t r i e d on t h e C o a s t i n r e c e n t y e a r s . One o f t h e s e , t h e Wyssen s k y l i n e c r a n e , i s a c o m b i n a t i o n o f h i g h -l e a d s k i d d i n g and a e r i a l t r a n s p o r t a t i o n . I t has been u s e d so f a r on t h e C o a s t e x c l u s i v e l y f o r c l e a r c u t o p e r a t i o n s . I t i s a g r a v i t y s y s t e m w h i c h has p r o v e d t o be e c o n o m i c a l u n d e r s p e c i a l c i r c u m s t a n c e s s u c h a s on s t e e p , i n a c c e s s i b l e m o u n t a i n s i d e s . The main a d v a n t a g e s o f i t s u s e a r e t h e s m a l l d i s t u r b -a n c e s o f t h e s o i l , r e d u c e d l o g b r e a k a g e and t h e g r e a t s a v i n g i n r o a d c o n s t r u c t i o n . G i o r d a n o (1959), i n h i s book a b o u t l o g g i n g c a b l e w a y s e n u m e r a t e d a number o f s i m i l a r c a b l e w a y s y s t e m s . Some o f them were u s e d i n E u r o p e , m a i n l y i n S w i t z e r l a n d , i n t h i n n i n g -77-operations. Under present conditions i t would seem improbable that any of these types could be used on the Coast i n thinning operations. I f only s i l v i c u l t u r a l aspects regulated thinnings, these systems c e r t a i n l y would be used in thinning steep mount-ain sides. Only the helicopter could exceed them in the respect of l i f t i n g the material above the stand and reducing to a minimum damage to the r e s i d u a l stand. There i s another Swiss cable system which i s not widely known and not yet used on the American Continent. In the writer's opinion, with some modification, i t would be an excellent logging device for thinnings on certain places. As i t c a r r i e s the load e n t i r e l y i n the a i r , the d i f f i c u l t ground conditions of the coastal forests would cause no problem i n i t s operation. As the hauling process creates a continuous flow of the logs, the production r a t e i s high despite the slow speed of i n d i v i d u a l logs. This equipment i s c a l l e d a Lasso Cable Conveyor. The Lasso Pulley (Figure 6) and the Lasso hook (Figure 7 ) , together with the endless hauling rope, are the basis of the Lasso Conveying System. The star-shaped pulleys allow for passing the hooks without d i f f i c u l t y . The hook i s ca r r i e d by the cable through f r i c t i o n . . A s p e c i a l l i g h t v e r t i c a l - a x i s single drum is mounted on the 2$ hp. yarder machine (Figure 8). The lay-out of the system i s i l l u s t r a t e d i n Figure 9 . i Figure 8. The Lasso Cable Yarder. - 7 9 -Figure 9 . Typical layout of Lasso Cable The f i r s t i n s t a l l a t i o n needs about ten to twenty days, but change of yarding road can be done in a few days, i f properly prepared. Cost of the unit i s $30,000.00 including i n s t a l l a t i o n cost which i s done by the company. The Lasso Cable can be as long as two miles and the service can be continuous under a l l climatic conditions. Five to s i x men are necessary to operate the system. - 80-Th e o r i g i n a l Lasso Cable would not be p r a c t i c a l on the Coast, because i t was designed to carry l i g h t logs,usually fuelwood ,but the Lasso Cable Company, l a t e l y designed a new, heavier cable, which can carry a load of 680 lbs. per hook. The loaded cable i s more firml y supported i n t h i s case. (Figure 10). Figure 10. Support of loaded and return cables on the new system. -81-The e n d l e s s m o n o c a b l e s e r v i n g as c a r r i e r a n d t r a c t i o n c a b l e , a n d d r i v e n b y a s k i d - m o u n t e d d i e s e l e n g i n e , i s i n s t a l -l e d i n t h e woods on a t e m p o r a r y b a s i s , a t a c o n v e n i e n t l o a d i n g h e i g h t and more o r l e s s p a r a l l e l t o t h e g r o u n d . The l i n e may f o r m any k i n d o f c l o s e d p o l y g o n , d e p e n d i n g on t h e l o c a t i o n o f t e m p o r a r y l a n d i n g s . A t i n t e r v a l s o f a p p r o x i m a t e l y 100 t o 300 f e e t t h e c a b l e i s a t t a c h e d t o s t a n d i n g t r e e s by means of p r e f a b r i c a t e d , e a s i l y m o u n t a b l e , s p i k e d w h e e l s . The i n s t a l l a t i o n i s s i m p l e and d o e s n o t need s k i l l e d w o r k e r s . ( F i g u r e 11). The l o a d s a r e a t t a c h e d one by one a t any p o i n t o f t h e l i n e by means o f c h o k e r s p r o v i d e d w i t h a s p e c i a l h o o k . H e a v i e r l o a d s a r e s u p p o r t e d a t b o t h e n d s . ( F i g u r e 12). F i g u r e 11. I n s t a l l a t i o n o f L a s s o F i g u r e 12. L a s s o G a b l e i n C a b l e S u p p o r t on S t a n d i n g o p e r a t i o n w i t h t r e e s . h e a v y l o a d . -32-I f a convenient landing i s available i n the stand the l i n e i s brought down for the time of loading- with specially-mounted supports. (Figure 1 3 ) . temporary loading Figure 13. Temporary lowering of cable on landing. The weight of the load keeps the hook ti g h t on the l i n e , and the logs t r a v e l at an average speed of s i x feet per second," spaced at intervals of t h i r t y to f i f t y f eet, to the landing. There the logs h i t a simple i n c l i n e d wooden platform thus causing the hook to f a l l off the l i n e and dump the logs. The empty s l i n g s and hooks are returned to the woods along the l i n e i n bundles. Al t e r n a t i v e l y , i f the loads are heavy, the cable may stop from time to time to make the loading and unloading easier. Reviving old skidding methods In Oregon and Washington horse logging has made new gains in thinnings. As Worthington and Staebler (1961)stated; "For thinning products with a volume less than ten cubic feet, (e.g. 9" top diameter by 2A'' log) horses are more s a t i s f a c t o r y -83-for skidding provided that the t e r r a i n i s favourable and skidding distances are l e s s than 600 feet. Well-trained, l i g h t horses, handled by a s k i l l e d teamster, give an excel-lent account of themselves under such conditions". The cost of horse skidding was $2.40 per hour i n Washington. As the writer has stated in connection with pre-yarding, there i s l i t t l e p r o b a b i l i t y that horse logging w i l l be used in our coastal hemlock stands. Koroleff (1951) stated that yarding small logs on o steep slopes can be done economically by g r a v i t y using a suspended wire rope.' Light, e a s i l y transportable, metal chutes b u i l t i n sections are s t i l l i n use i n Europe and Eastern Canada, mostly for yarding small wood. Aluminum i s a durable l i g h t metal and might be a good material from which to manufacture an e a s i l y transportable chute, constructed f o r steep slopes. Loading E f f i c i e n t loading i n a thinning operation requires f a s t , mobile, l i g h t equipment such as the following: (1) Tractors with built-on loaders, enabling them to put t h e i r load d i r e c t l y onto t r a i l e r s (Figure 14). (2) For larger products the fork l i f t loader i s the best available equipment. (3) Load-ing winches are used e f f e c t i v e l y i n many cases. One of i t s application i s the Easy Way Logger. This truck with special frame and loading winch i s a very p r a c t i c a l s e l f - l o a d e r . -84-(4) Hydraulic self-loaders can be mounted behind the cab for loading trucks (Figure 1$). Worthington and Staebler (1961) had the opinion that fi x e d landings are unnecessary and that f i x e d loading devices, such as gin poles, A-frames or rollways are not s a t i s f a c t o r y for thinning operations. Fixed landings, however, need not necessarily be equipped with fixed loading devices. A fixed landing with mobile loader would be more economical than loading along the road. Topography sometimes o f f e r s good central loading places, which a s s i s t s the co-ordination of the logging operation, e s p e c i a l l y i f more than one f e l l i n g , bucking and,yarding crew operates i n one area. As the loading cost per unit f o r small diameter mater-i a l i s high, any device which i s able to load several pieces together i s desirable. This can be done e a s i l y on semi-permanent landings. I f the topography allows the construction of rollways t h i s may be another solution for loading. Production and cost data of four types of loading equip-ment used i n thinning operation are presented i n Table 5. F i g u r e 15. Truck w i t h h y d r a u l i c s e l f l o a d e r - 8 6 -Table 5» Production and cost data of four types of loading equipment used i n thinning operations Equipment Production Cost per Source per hour hour of cunits | information Tractor f o r k l i f t 3.2 1.20 Worthington and Staebler Truck loader 3 . 0 4 Worthington and Staebler Shovel Loader (4,."'C O-yard) 2 .39 Worthington and Staebler Easy Way Logger 4.5 Tessier The three f i r s t phases of logging are i n the following r e l a t i o n s h i p to each other,based on thinning experiments as reported by Worthington and Staebler (1961). F e l l i n g and bucking 34$ of t o t a l time Skidding 50$ of t o t a l time Loading 16$ of t o t a l time Crews should be assigned on the basis of experience data such as t h i s . On a•well—organized average thinning job, 3.80 man hours are required t o f e l l , buck, skid and load 100 cubic feet of wood. Hauling . For hauling short logs and pulpwood, a dual-axle, fl a t b e d truck i s best; f o r longer products normal trucks of about 150 to 200 hp. are the most economical. For long products, a truck or t r a c t o r and t r a i l e r unit i s more conventional. Hauling longer distances using the -86 Table 5 . Production and cost data of four types of loading equipment used in thinning operations Equipment Production Cost per Source per hour hour of cunit? $ information Tractor f o r k l i f t 3.2 1.20 Worthington and Staebler Truck loader 3.04 Worthington and . Staebler Shovel Loader (4*160-yard 2.39 Worthington and Staebler Easy Way Logger 4.5 — — Tessier The three f i r s t phases of logging are in the following relationship to each other based on thinning experiments as reported by Worthington and Staebler (1961). Felling and bucking * .34$ of total time Skidding. <.. 50$ of total time Loading......° 16% of total time Crews should be assigned on the basis of experience data such as thi s . On a well-organized,average thinning $cib, 3..#0 man hours are required to f e l l , buck, skid and load 100 cubic feet of wood. Hauling For hauling short logs and pulpwood, a dual-axle, flatbed truck is best, for longer products normal trucks of about 150 to 200 hp. are the most economical. For long products, a truck or tractor and t r a i l e r unit i s more conventional. Hauling longtr distances using the -&7-continuous transportation method, a truck or t r a c t o r with three t r a i l e r s would be the most economical. Semi-permanent landings are best i f the economical three t r a i l e r - one truck (or,tractor) system i s used f o r transportation. This method cuts the i d l e time of the vehicle to a minimum so that with good organization i t i s possible to make the hauling continuous. One loaded t r a i l e r w i l l be under way to the unloading (dumping) place. When the loaded truck (or tractor) arrives at the dumping place i t w i l l be unhooked and the empty t r a i l e r w i l l be hooked to the vehicle. During the round t r i p , the t h i r d t r a i l e r i s being loaded on the permanent landing. This t r a i l e r w i l l be hooked to the vehicle as i t ar r i v e s , leaving the empty t r a i l e r behind f o r reloading. This type of organized haul-ing was used i n Hungary and i n Russia with good economy, and l a t e l y i n B r i t i s h Columbia (Alaska Pine and Crown Zellerbach Companies on Vancouver Island). Worthington and Staebler (1961) emphasized the importance of well-organized hauling, s t a t i n g : "The truck i s an expensive piece of equipment fo r a thinning job, and the savings to be made by keeping i t f u l l y occupied must not be overlooked". The economy of hauling i s dependent on: (1) use of the best type of.equipment for small log transportation on a well organized hauling process, and ( 2 ) the q u a l i t y of the hauling road. A road system of r e l a t i v e l y low standard, but well designed and maintained, i s best f o r thinnings. With present -88-market conditions i t i s almost c e r t a i n that thinnings can not pay even f o r such hauling roads. Thinning operations, when f i r s t commenced, must s t a r t along existing roads. In Worthington and Staebler's (1961) opinion, the loading and hauling can be contracted separately from f e l l i n g , bucking and skidding. Several smaller crews can provide enough logs for a well organized hauling crew to keep i t busy. This proposal has the advantage that a separate hauling crew takes more care i n maintaining the road than the woods-worker who i s concerned more with the thinning operation i t s e l f . The production,and cost of hauling,depend on many factors. Because one f a c t o r , the hauling distance, i s a variable, d i f f e r i n g greatly from one operation to another i t i s d i f f i c u l t to present average hauling-cost figures f o r thinnings. To make comparisons easy the ton-mile or cunit-mile cost data should be calculated f o r an operation. The Logging Road Hand-book, (I960)) i s an excellent source from which to calculate and predict hauling-costs i n a given s i t u a t i o n . Bundling and r a f t i n g . The s p e c i a l s i t u a t i o n on East Thurlow Island required that the logs skidded or hauled to Bickley Bay be bundled and rafted for further transportation. Bundling was performed on the shore, using a simple, bundling device. One-inch-wide s t e e l bands, l a t e r aluminum wires^were used f o r bundling, two f o r each bundle, placed -29-close to the end of logs. At the end of the l a s t operation, the bundling was done i n the water, which slowed down the scaling, but eliminated the problem of pushing the bundles into the water. The change of the tides was used to simp l i f y the operation. Bundling was done with high t i d e , scaling with low tide., Where t r a i l e r s are used f o r transportation, the bundling might be performed on semi permanent landings which could reduce hauling time. About 150 bundles should make up a boom. The booms held together by boomsticks should be towed on a r e l a t i v e l y calm water, because on rough sea the bundling bands or wires can break e a s i l y i f h i t by other bundles. Bundling and r a f t i n g can be eliminated i n some thinning operations i n the future i f portable barkers and oh'ippers w i l l -work economically. It was reported (The Timberman, January, 1962) that one such unit i n s t a l l e d i n a Crown Zellerbach 7 ,~ operation was successful. They f e e l that t h i s i s the most important t e c h n i c a l breakthrough i n wood recovery since the pulp industry began using chips from lumber residues. A somewhat smaller unit could be used on East Thurlow Island on the sea shore, as i n Bickley Bay, barges could harbor with-out costly wharf i n s t a l l a t i o n . Scaling Scaling of materials coming from thinnings i s expensive because s c a l i n g costs are higher than f o r big logs f o r the same volume. To overcome t h i s d i f f i c u l t y present scaling methods -90-should be changed in actual operations. Scaling i s required for three purposes: (1) as a basis for royalty payments to the B r i t i s h Columbia Forest Service, (2) as a basis for payments to contractors, i f employed on that basis, and (3) as a basis for cost control related to accounting and production c a l c u l a t i o n s . In thinning experiments the nature of the study might demand that s c a l i n g should be done on a 100 per cent basis, as i t was done on Thurlow Island. There are good possi-b i l i t i e s , however, of replacing t h i s system with others of adequate accuracy. These include a weight system using immersion tanks, and sample sca l i n g calculating the average bundle or load size, e.g. Tessier's (1958) system. The sample method promises the most economical r e s u l t s on East Thurlow Island. I f the bundles are scaled to 100 per cent for a period, u n t i l the error of estimate can be reduced to an acceptable l e v e l , the further scaling can be made to a desired accuracy by sampling bundles randomly. If the r e l a t i o n s h i p between bundle volume and number of pieces per bundle i s established, the scaling can be done on a pieces per bundle basis. - 9 1 -LOGGING OF THINNING AS COMPARED TO CLEARCUT OPERATIONS The r e l a t i v e importance of the logging phases can be seen by comparison of the working hours or unit costs of each cycle. Table 6 shows that the yarding phase i s the most expensive i n thinnings compared to cl e a r c u t t i n g . Table 6 . Relative importance of various phases of logging in thinning and clearcut operations. Operation Man-Hour requirements Clearcutting i n phase i n thinning Douglas f i r Vancouver Forest Worthington and Staebler Distr.Smith et a l (1961) (1961) per cunit per M. f.b.m. % % F e l l i n g , bucking 1.29 • 1.95 19 11 Skidding or yarding 1.90 2.90 34 17 Loading 0.60 1.03 10 6 Hauling 0.49 0.77 14 15 Miscellaneous 0.43 0.77 23 51 Total 4.71 7.42 100 100 DESIGN OF THINNING EXPERIMENTS In the previous chapters i t was shown that there are' many questions unanswered about economic, s i l v i c u l t u r a l and technical problems of hemlock thinning. Thinning experi-ments are therefore s p e c i a l procedures because of t h e i r complex nature. There are d i f f e r e n t opinions about the design of such experiments. - 9 2 -Staebler (1957) suggested that the p r a c t i c a l sequence of experimentation should s t a r t with t e s t s of commercial thinning often before adequate s i l v i c u l t u r a l information i s a v a i l a b l e . As a r e s u l t , research i s faced with the problem of s e t t i n g up an experiment to t e s t economic and s i l v i c u l t u r a l aspects simultaneously. As f a r as the design technique i s concerned, Smith (1959) was'Of the opinion that study of small sample plots with a fi x e d number of trees would be the most economical way of experimenting. Others l i k e Joergensen (1952) were i n favour of larger sample plots of equal area established before the thinning begins, i n a randomized block designed i n such a way that d i f f e r e n t s i t e s , d i f f e r e n t logging conditions and d i f f e r -ent degrees of treatments would be r e p l i c a t e d . This, i n time, w i l l form a pattern of case h i s t o r i e s . The f i r s t commercial thinning experiment on East Thurlow Island i n 1953-54 was arranged i n t h i s fashion. According to Staebler (1957) the best method would be to have the entire area,thinned by a given treatment, become the observation u n i t . Reliable cost and conversion returns can,be obtained only from a commercial operation. He reasoned that some i n e f f i c i e n c y i s inevitable while the operator gains experience. Certain fixed costs which are incurred i n establishing any logging operation, should be d i s t r i b u t e d over enough volume to keep them from being - 9 3 -u n r e a l i s t i c a l l y large per unit volume. In addition, commercial thinnings conducted p r i m a r i l y for research are usually expected to have substantial demonstrational value. For t h i s purpose, p i l o t plant size operations are most useful. This system was to be followed i n the operation i n 1959-60 on East Thurlow Island. I t might be possible that some other thinning schemes could also be experimented with at the commercial l e v e l . The v i s i o n of such new schemes i s implied i n reports from the Scandinavian countries dealing with new trends i n thinning. MECHANIZATION OF THINNING OPERATIONS t Samset (1961) i n his paper: "Influence of Mechani-zation on S i l v i c u l t u r e . " dealt with the problem of thinning i n an age of ever increasing labour costs, and came to the conclusion that both the logger and the s i l v i c u l t u r i s t must give up t h e i r conservative ideas i n the face of increasing mechanization i n f o r e s t r y work. He disagreed, however, with the ideas of both Braathe (1957) and Hagstrom (1961) who were respectively of the opinion that thinking too much about harvesting value w i l l confuse the task of thinning, and, on the other hand, that future machinery and equipment w i l l decide the methods of s i l v i c u l t u r e . -94-After presenting much argument and pointing out some re s u l t s of new thinning experiments i n Scandinavia, Samset (1961) came to the compromised conclusion that thinnings i n even aged conifer stands are necessary but f o r p r o f i t -able logging and without appreciable s i l v i c u l t u r a l danger, the number of thinnings must be reduced to a few, not more than four, but preferably to two or even one. These thinnings must s t a r t i n the l a s t stage of the forest, not much p r i o r to stand maturity. Precommercial thinning i n h i s opinion should be done at a very young age, mostly i n stands which are overstocked. Because this cannot be done p r o f i t a b l y the cheaper i t can be achieved the better. Mechanization could be used to replace the expensive manpower used for that purpose i n Europe. A solution might be to use bulldozers before sapling age to create p a r a l l e l roughly-cleared s t r i p s . Kramer (1958) showed that such s t r i p s of 9 to 15 feet width, some of which might be used l a t e r as skidding t r a i l s do not decrease y i e l d because the bordering trees w i l l u t i l i z e the improved growing conditions. The cost of t h i s operation w i l l be balanced by savings obtained from better access to thinning areas i n the future and may even allow a second selection thinning at a l a t e r date. -95-Commercial thinnings at a l a t e r age of the stand w i l l allow more economical use of machines. To do t h i s e f f e c t i v e l y a good road network i s an absolute necessity. This constitutes a very important s i l v i c u l t u r a l enter-pr i s e , and f a c i l i t a t e s the e f f e c t i v e management of the fo r e s t property. It is desirable however, that y i e l d studies should be conducted i n these types of thinnings, as the only data yet available are i n connection with Norway spruce stands. In the case of few, heavy, l a t e thinnings the t h i n -ning scheme must be such that the logging machinery used could work with the highest possible e f f i c i e n c y . Gayer's group system of natural regeneration was very popular i n Europe but could not be brought into practice simply because i t was not possible to serve the randomly" created groups around openings i n the canopy. The lack of geometrical order was eliminated by Wagner and Roth who proposed group arrangements i n d e f i n i t e l i n e s thus creating a basis f o r a road network to a s s i s t i n logging. Thinning schemes could aslo be arranged i n geomet-r i c a l l y organized manner. They could be done i n s t r i p s or i n patches or even with alternating clearcut and thinning s t r i p s or patches. The possible higher production of clearcuts w i l l help the operator to make a p r o f i t more e a s i l y . A f i r s t attempt of that kind was - 9 6 -i n i t i a t e d by G. Warrack in the 1959 thinning experiment on East Thurlow Island by arranging three twinplots, one of each being clearcut the other thinned. The plot size was 0 . 2 of an acre. The i d e a l microclimatic conditions created on the small patches were obvious and a good regeneration was observed i n the following year. I f Douglas f i r had been planted on them good r e s u l t s would have been c e r t a i n . Thinnings or alternate clearcut and thinning can be organized i n s t r i p s , according to the scheme shown on Figure 16. Figure 16. Theoretical scheme of s t r i p thinning. - 9 7 -Th e s t r i p s along the skid t r a i l s would be thinned f i r s t or w i l l be clearcut. The number of s t r i p s and thei r width w i l l depend on the number of thinnings planned. A similar pattern,practiced since 1952 on a 40,000 acre stand near Port Arthur, Ontario,can be seen on Figure 17. (Pulp and Paper Magazine of Canada, September, I960) This stand became a woodlands laboratory i n which foresters of the A b i t i b i Power and Paper Co. Ltd. carry on numerous cutting, planting, seeding and thinning experiments designed to maximize y i e l d and protect the forest, the same aim as that of the Research Forest of East Thurlow Island. I f Kramer's (1958) findings would hold also i n hemlock stands, namely, that 8 to 10 feet wide t r a i l s reduce y i e l d of older stands only by 2% to 3% thinnings could be replaced by clearcutting narrow s t r i p s of 10 feet wide alternating with 20 to 30 feet wide s t r i p s of the r e s i d u a l stand. The present practice of uniform thinning with a predetermined int e n s i t y , might be changed into thinnings with uniformly changing i n t e n s i t y , e.g. the i n t e n s i t y of thinning would be the heaviest along skid t r a i l s , with gradual t r a n s i t i o n into l i g h t e r thinnings i n r e l a t i o n to increasing distance from the skid t r a i l s . These systems c e r t a i n l y need a much denser road and skid t r a i l network than i t i s now customary i n clearcut operations. Skid t r a i l system w i l l be a great asset to -98-s i l v i c u l t u r e even i f t h e i r standard i s low with no further maintenance u n t i l the next thinning. These skid t r a i l s i n cases of emergency such as f i r e , insect out-break can be reconstructed e a s i l y . Old skid t r a i l s on East Thurlow Island which were used more than f i f t y years ago, could be traced e a s i l y i n I960. There was a delayed regeneration on the skid t r a i l s but the trees were suppressed and soon died. These th i n snags and the debris from other mortality which are now covering these t r a i l s could be e a s i l y removed with a small bulldozer. I t was apparent that the trees along the skid t r a i l s were of larger diameters than the average stand diameter. This.fact would enable to determine whether these skid .A t r a i l s reduced y i e l d in stands alongside or not. The skid t r a i l spacing always w i l l depend on the type of yarding and bunching system used as well as upon the available volume per acre and the s i l v i c u l t u r a l requirements. The d i r e c t i o n of the s t r i p s must take into consider-ation the p r e v a i l i n g wind d i r e c t i o n and topographical requirements to minimize wind damage and help i n yarding. I f the skid t r a i l s are l a i d out i n a more less p a r a l l e l manner, depending on topography, the yarding process w i l l usually be f a c i l i t a t e d . On f l a t and r o l l i n g topography, tra c t o r s would be the best equipment, on steep slopes a l i g h t Wyssen skyline crane, i n rough places the - 9 9 -Q but wifWci Lasso Cable system. A system si m i l a r to hi-lead Amobile 1 t a i l - s p a r could o f f e r good r e s u l t s shown on sketch, Figure 18,and proposed by Tessier (1962). In t h i s case the thinning and clearcut areas w i l l show as adjoining t r i a n g l e s . This pattern and the l a t e r proposed chess-board l i k e pattern w i l l have many s i l v i c u l t u r a l advantages, e.g. better microclimatic conditions, better resistance to erosion, and so f o r t h . P a r a l l e l roads would enable the operation to use a type of equipment which can be v i s u a l i z e d as a cross between the Lasso Cable type of conveyor and mobile spars with intermediate supports on standing trees or on temporary spars i f necessary. The yarding method would be s i m i l a r to the action of the steam plows used i n the early years of mechanized a g r i c u l t u r e . This method would resemble somewhat patch logging, except that the patches would be separated by the '.: size of l e f t over stands i n which the thinning w i l l be practice and the size of patches would be smaller and of t r i a n g u l a r or rectangular shape. Walker (1961) reported on s i m i l a r type of thinning i n New Zealand. (Figure 19)• Tractor logging i s being practiced there with truck hauling. The absolutely f l a t t e r r a i n allowed the laying out of road and skidroad net-work i n an i d e a l i s t i c way. (Figure 2 0 ) . It can be seen that the proper layout of permanent landings i s an important feature i n the network design. This pattern can not be used on the Coast, but the idea behind i t can -100-be adapted, and the layout modified to the mountainous topography. Figure 21. Chess-board l i k e arrangement of patch thinning. Figure 20. Road and skid t r a i l layout for thinning i n New Zealand. -102-The size of the squares would depend on the yarding method used and on the topography, as these w i l l influence the skid t r a i l or road spacing. For example i f horse logging were used the patches could be about one acre or l e s s . The same size could be used with winches. In the case of t r a c t o r yarding the size.of one square should be between 1.6 and 5 acres giving, a maximum pre-yarding distance of 264 to 462 f e e t . Road spacing would then be 528 to 924 feet r e s p e c t i v e l y . The s i l v i c u l t u r a l advantage of t h i s pattern would l i e i n the establishment of improved microclimatic conditions, good protection from the wind of any dir e c -t i o n and more i d e a l f i r e control. The cutting order w i l l depend on the number of thinnings planned. The clearcut acres w i l l most probably regenerate i n hemlock e a s i l y . This new stand w i l l be about ten years old when the No. 2 patches w i l l be c l e a r -cut. These patches then can be planted with Douglas f i r , under the protection of the previously regenerated hemlock patches. There w i l l c e r t a i n l y be some hemlock regeneration among the Douglas f i r but i t can not be such as to suppress the f i r . In t h i s way the value of the stand can be increased. Whether the aforementioned schemes could be applied to older, second growth stands on the Coast i s . clgbatable. -103-I t might be worthwhile to t r y i t on experimental basis and the Research Forest on East Thurlow Island would c e r t a i n l y be a good place where the necessary comparisons might be made e a s i l y with the conventional thinning experi-ments. It could be argued that i t would be better to use hemlock stands which are already accessible, closer to markets and e a s i l y manageable fo r experiments. I t would c e r t a i n l y be necessary to see new experiments established because the problems needing answers are many. Thinning experiments are long range experiments and since there are very few existing i t would be the wrong p o l i c y to abolish an already existing experiment, with almost ten years of accumulated data. The information required from these experiments to develop adequate thinning schedules may include such items as: Influence of spacing on tree growth by d.b.h., age and s i t e classes; influence of change i n spacing on the same factors. Influence of spacing, d.b.h., age and s i t e on mortality; influence oh d.b.h. on cost of logging; influence of d.b.h. on value of production; influence of logging on i n j u r i e s and so f o r t h . -104-PRELLMINARY ROAD LOCATION PLAN FOR THE, RESEARCH  FOREST ON EAST THURLOW ISLAND As e a r l i e r investigations on the Island c l e a r l y showed there i s no possible way to thin commercially a h -without "adequate road system. -There i s no assurance, however, that the thinnings ipso facto w i l l be fe a s i b l e after the road network exi s t , because there are other requirements such as above marginal log size, appropriate logging methods, and favourable market conditions. But even so the road network i s of primary importance. In planning an optimum road network some preliminary determinations should be made. I t should be calculated whether or not there i s enough timber to cover the con-str u c t i o n costs of the road system. In order to give useful information to the man who w i l l kesign)the f i n a l l ocation i n d e t a i l , some advice should be given beforehand, regarding design elements and other s p e c i a l engineering a . aspects of the road. Before„road system can be developed i t is necessary to decide on the logging methods which w i l l be used, as d i f f e r e n t logging methods require d i f f e r e n t network scheme. After that a preliminary layout of the road system can be done on maps or a e r i a l photos. This layout should be then checked on the ground to reveal every problem that could a f f e c t the f i n a l layout of the network. -105-The preliminary nature of t h i s plan implies that i t does not replace the necessary considerations to be made i n connection with the f i n a l location plan. I t i s only a h e l p f u l t o o l to make the correct f i n a l decision from t e c h n i c a l and economical points of view. General Considerations On The Road Network I t was anticipated that tractor logging and truck hauling would be the most economical i n thinning on the Research Forest and the road network should be designed to make t h i s possible. A e r i a l phots taken i n May of I960 were of great assistance i n arranging the preliminary layout of the roads. The topography made i t possible to locate more alternatives i n the road network on the photos. When the area was logged around the turn of the century, a network of skidroads were l e f t behind, but these are now impassable because of log debris or young trees growing on them. Some of the skid t r a i l s , however, can be reconstructed e a s i l y and they have been used as parts; of the planned system of new roads. Two of the old t r a i l s are being used now: the Hemming JLake t r a i l and the Shoal Bay t r a i l (Appendix 1), but they are not suitable f o r vehicles due to narrowness and lack of bridges. -106-Scattered old growth stands were l e f t from e a r l i e r clearcut operations and could be spotted e a s i l y on the photos. Since these stands were covered with 100% coverage i n I960 important data i s available to evaluate the economical p o s s i b i l i t y of building the main roads. The position of the old stands, the f i e l d survey on possible re-use of the existing old t r a i l s , examination of the l o c a t i o n and various s o i l s and gravel deposits, creeks and swampy places made i t possible to choose from the various alte r n a t i v e s for i the best road network. (Appendix 1). As the d i r e c t i o n and loc a t i o n of the creeks and swamps together with rock outcrops are the main influence on the construction and maintenance costs of the roads, much time was spent on f i n d i n g the best possible l o c a t i o n f o r the roads to eliminate expensive bridges and avoid swamps and rocks. As the map shows (Appendix 1) there are several small creeks and some swampy places i n the area. The s o i l i s clayey or s i l t y and erodes very e a s i l y . That i s why the creek beds are deep, making d i f f i c u l t to cross them other-wise than with bridges. Smaller temporary creeks could be crossed, however, by c u l v e r t s . The shape of the Research Forest i s such t h a t the main access road has to consist of two branches. -107-The positions of the old stands make i t necessary that the main two branches of the roads should run i n about the same d i r e c t i o n as the old Hemming Lake t r a i l and Shoal*Bay t r a i l . The Hemming Lake t r a i l has a central location and easy grades, except the l a s t mile to Hemming Lake with a 10 per cent adverse grade. Running on the west side of the main creek, however, i t has to cross a number of side creeks. These have wide deep beds, i n some places of "swampy nature. In the f i r s t mile, s i x to eight bridges and two to four large culverts should be b u i l t . The best young stands cover t h i s side of the main creek. The f e r t i l e s o i l with i t s high clay and s i l t content i s , on the other hand, of the|lowest quality f o r a subgrade. From the engineering point of view, and also due to the presence of merchantable old growth timber on the other, side of the creek, the location of the main road seemed to be more economic on the east side of the main creek. It could then cross over to the west side and j o i n the old Hemming Lake t r a i l where there are no side creeks on the r i g h t side of the creek. (Road A and B on the map.) This approach w i l l also help to give a better l o c a t i o n for the old Shoal Bay t r a i l which at i t s s t a r t from Bickley Bay has a very steep slope. With a well situated switch-back from the planned road nA n, i t w i l l j o i n the old t r a i l -108-at a point very convenient f o r joining other branch roads or creating a semi permanent loading place (road C on the map). This would enable i t to serve almost the entire plateau l y i n g east of Bickley Bay. The two main access roads can be connected with the main log dump i n Bickley Bay where the f l a t shoreline creates an i d e a l place f o r dumping or storing the logs. The f l a t area i s large enough f o r a logging camp as i t has already been previously used f o r that purpose. A permanent, well-designed cabin f o r o f f i c e and accommodation for tiie research crew, was b u i l t here i n 1954. The two main roads have been marked on the ground with red p l a s t i c ribbons attached to the trees. The location of "A" and n B n main roads on the east side of the main creek leaves the west side without access. Secondary road nD" was therefore planned to serve t h i s area. I t p a r t i a l l y follows the recent yarding road which was used i n the previous thinning operation. This road is washed out so badly that nD n road should be put beside i t , leaving the o r i g i n a l t r a i l as a drainage d i t c h . The f i r s t 2,100 feet of the old Hemming Lake t r a i l i s very much handicapped as a road because of many small creek crossing. For t h i s reason, road nD" swings westerly and then easterly to avoid these creeks. I t ends at the next b i g side creek bed, thus eliminating the need f o r any c o s t l y bridges. -109-Th e planned t o t a l length of the main roads i s 3 .25 miles. The main roads are evenly d i s t r i b u t e d on the area. The secondary branch road system i s based on them. In most cases old t r a i l s which have not been maintained but are r e a d i l y v i s i b l e have been used as branch roads. These roads are shown on the map with red l i n e s and are marked on the ground with red p l a s t i c ribbon on trees. The red roads with dotted l i n e s on the map are not taped on trees e but have been reconnoiter&l i n the f i e l d . The branch roads are numbered onv the map from one to nineteen. The secondary road system was planned to tr a c t o r logging. The economical spacing between these roads was found to be approximately twenty chains, according to the follow-ing c a l c u l a t i o n . The average road construction costs f o r such roads as given by Worthington and Staebler (1961) is $6,600.00 per mile. This amount i s r e a l i s t i c under the circumstances, because the topography i s gentle, there are almost no rock outcrops along the planned roads, and the layout was planned i n such a way as to avoid culverts and bridges, running mostly p a r a l l e l with the creeks, on the f l a t , r e l a t i v e l y dry land between the creeks. Available volume for thinning per acre according to the l a s t experi-ments on the Island i s two thousand cubic feet, removing -110-one-third of the t o t a l merchantable volume. The cost of skidding by t r a c t o r s per cunit i s #5.25 f o r 800 feet average yarding distance or $0.66 for 100 feet as given by Worthington and Staebler (1961). The spacing using Matthew's formula: The secondary road system w i l l serve the logging and other f o r e s t r y work i n the following way: No. 1 road serves the east area close to the cabin and joins with a switch-back to road "A". No. 2 road would play an important r o l e between roads n B n and "Dn serving the good stands closed i n between the two main creeks where E.P. 27 and 28 are marked. The v a l l e y of the creek leading to Hemming Lake (through E.P. 97) i s barely accessible from No. 9 road. I t i s planned therefore to open i t up by the roads No. 4 and No. 5 "joining d i r e c t l y to road "Btt. No. 7 road, together with No. 6 would be the main hauling road for Stand No. 5. Old Stand No. 1+ could be served by an old t r a i l , now No. 8 road. No. 9 , as a secondary road i s the continuation of road "B" and would be the axis of a road system serving the south part of the area. This branch road has not been elaborated at t h i s time. o 1,300 feet - 20 chain - I l l -1 a . No. 10 road, through E.P. 91 i s ^ w e l l l a i d out old t r a i l . I t would need only minimal maintenance work to reb u i l d i t . Roads Nos. 11 and 12 reach a scattered old stand but the general topography suggests that i f the stand were logged i t should be brought to Shoal Bay on good existing logging road.which runs outside the boundary of the Research Forest. No. 14 i s the continuation of road "C", with accept-able adverse grades running through good second growth stands. Nos. 15, 16 and 17 are also old t r a i l s and would not need much construction work to bring them into usable condition. The branch roads Nos. 1 to 19 with some l a t e r exten-sions are able to serve the whole area. They could be b u i l t successively whenever the a c t u a l forest work makes them necessary. The t o t a l length of the secondary road system, when completed would be approximately 35,310 feet s 6 .7 miles. The road system as i t i s now on the map i s only one of the many possible solutions. The present plan implies some other possible v a r i a t i o n s . 1-(1) I f emphasis were put on the problem of the stands to the west of the main creek then road MD n should be -112-b u i l t as one of the main roads. Two bridges should be then constructed beyond i t s end on the old Hemming Lake t r a i l - . In that case road "A" and "C" would s t i l l e x i s t as main roads to open up the Shoal Bay plateau, but road "B" would be constructed only as a branch road whenever i t would be necessary. (2) No. 1 road could be b u i l t as a main road i n -stead of "A" and W C W and j o i n with a bridge with the Shoal Bay t r a i l . In that case nA", "B n and nC" would be branch roads. (3) The o r i g i n a l system would go i n ef f e c t but road n B n would" continue with branch road No. 2 as a main road, leaving the other parts of i t as a secondary road. The f i n a l d e cision as to which of these systems would best serve the area could be the r e s u l t of a meet-ing on the subject between the engineering crew and o f f i c e r s of the Research D i v i s i o n , a f t e r the crew f i n i s h e d i t s preliminary survey or location of the l i n e s mentioned befor e i To see i f there i s any p o s s i b i l i t y of covering the expenses of the road system, we must examine the available funds by the clearcut operation of the old stands. -113-Estimated funds available f o r road construction In the f i r s t f i v e years of operation there should be a clearcut of scattered old growth patches. With allow-ances i n stumpage price the following c a l c u l a t i o n show, that the planned all-weather road network can b e constructed to the necessary standard i n the f i r s t f i v e year period. Theold growth stands were cruised by the w r i t e r by grade on 100 per cent basis i n I960 and No. 1 logs were t a l l i e d separately. Mature volumes were compiled using log-position volume tables. (Fligg and Breadon (I960) ) . In the cruising notes, remarks;- were entered f o r every tree concerning i t s health, lowest branch, etc. The compiled data has been used in the following c a l c u l a t i o n . Table 7 . January, 1962 log prices i n the Vancouver Forest D i s t r i c t . Price per M f.b.m. Price per cunit Pulpwood price per Species Grade(sawlogs) Grade(sawlogs) cunit 3 2 1 3 2 1 < A s N o - 3 ) Douglas f i r 57.00 67.00 77.00 31.30 36 .90 43.20 31.30 Cedar 57.50 47 .50 57.50 20.60 26.10 31.60 20.60 Hemlock 43.75 50.00 55.00 24.00 27.50 30.20 24.00 Note: Prices are as given i n the B. C. Lumberman, January, 1962. -114-Table 8. Road construction charges available per cunit i n d o l l a r s . Species S e l l i n g Stumpage P r o f i t C 0 s t of Total Remaining pri c e 15% of logging deductable fund s e l l i n g excluding ' f o r roads pr i c e r.const fn. per cunit per cunit at m i l l Grade per cunit Ccf Df 1 42 .30 4 6.35 12.45 1 22.80 19.50 2 36.90 4 5.53 12.45 0 21.98 14^92 3 31.30 1 4 .69 16.06 2 21.75 9 .55 H 1 30.20 4 4.53 12.45 20.98 9.22 2 27.50 4 4.12 12.45 20.57 6.93 3 24.00 1 3 . 6 0 16.06 20.66 3 .34 C 1 31.60 4. 4 .74 12.45 21.19 10.41 2 26.10 4 3.92 12.45 20.37 5.73 3 20.60 1 3 . 0 9 16.06 20.15 .45 1. Tessier and Knapp (1961) 2. Worthington and Staebler (196l) Table 9^ Total income av a i l a b l e f o r road construction. Species Grade Df 1 2 3 H 1 2 3 C 1 2 3 H right of way Merchantable Volume Available i n 5 years cut cunit 1329 1116 1117 105 2451 7577 79 200 461 1845 T o t a l Amount Available f o r roads 25,915.50 16,650.72 10,667:35 968.10 16,985'.43 25,307.18 822:39 1,146.00 207.45 6 , 0 5 2 . 3 0 Grand"total* $ 104,722.45 -115-The construction of 6.7 miles of secondary roads w i l l cost |44,220.00 with an average cost of $6,600.00 per mile. -The remaining $60,500.00 w i l l allow construction of main roads with an average cost of $18,600.00 per mile.. This seems unreasonably high for t h i s area but gives the opportunity to r a i s e the stumpage price to a more r e a l i s t i c l e v e l . The cost of road construction must be covered by the operator governed by the timber sale contract. The writer i s of the opinion, however, that as much money should be spent on i n i t i a l all-weather road construc-t i o n as i s r e a l i s t i c a l l y possible i n order to create a s i t u a t i o n where even pre-commercial thinning might be practiced with the hope that the low hauling costs, on the then r . c e x i s t i n g good roads w i l l bring these operations above the marginal l i m i t . Design elements The proposed road system i s planned as a permanent net-work because t h i s i s the best way to serve the experimental forest i n i t s aim to create an intensivelyr.managed research area with continuous yearly operation. The nature of t h i s C ' a b o u t • network demands some s p e c i a l considerations v^> the design c-elements concerned. Cross section The design of cross section i s usually f a c i l i t a t e d by using standard cross-section types. The B r i t i s h Columbia -116-Forest Service Engineering Services D i v i s i o n has i t s own Forest road s p e c i f i c a t i o n describing seven road classes. -According to Worthington and Staebler (1961) i t was found that on the coast for thinnings, a 16 foot road bed with a three-foot allowance for ditches i s most s a t i s f a c t o r y . For the right-of-way, f i v e feet was cleared on both sides of such roads. This type of road would be closest to that of No. 5 class roads i n the f o r e s t service standards. Specifications for i t are: surface width - 12 feet; subgrade width - 16 f e e t ; d i t c h depth - 1 foot; R W width - 50 f e e t . It i s seen that the right-of-way i s approximately 20 feet wider than Worthington's (1961) s p e c i f i c a t i o n . Taking into consideration the wet climate and the clayey s o i l of the island, the proposed 50 feet of right-of-way i s most advisable i n order to permit adequate drying. The clear cut on the right-of-way area w i l l enable the contractor to increase his productivity and w i l l help to pay o f f the construction costs of the road. The surface width i s only wide enough for a single lane, which w i l l necessitate the construction of turnouts at convenient distances, i f the amount of t r a f f i c requires i t . The main road system, however, should be of a higher class than the branch roads because i t w i l l serve the whole area's transportation. The Forest Service of B r i t i s h Columbia t h i r d c lass road i s the most appropriate, with one chain r i g h t -of-way width. -117-S p e c i f i c a t i o n w i l l be: surface width - 18 feet; subgrade width - 24 feet; ditch depth - l\ feet; R W width -66 feet. Slopes of cut and f i l l w i l l be 6:4 and 2:1 respectively, or as the subgrade material requires. The cross section on curves changes, being widened and superelevated.-The wider road i n curves and the superelevation make i t possible to maintain the speed of the v e h i c l e s . Long vehicles l i k e logging trucks with t r a i l e r s must have enough width to keep the wheels on the road surface. In the design of forest access roads i n B r i t i s h Columbia there i s not enough emphasis on widening of the road on curves. Reference books to the engineering surveys of B r i t i s h Columbia Forest Service (1957) do not even mention t h i s . The widening (W) depends on the radius of curve (R) and the length of the log transported, or better, on the distance between the t r a i l e r axle and the truck rear axle (L). An equation giving good approximation, based on the geometry of the vehicle on the curve i s : (Figure 22) W = L 2 2R ¥ i s the widening, L i s the distance between f i r s t and rear axles and R i s the radius, a l l measurements are i n feet. - 118-Th e necessary widening f o r some standard r a d i i and degrees of curvature have been calculated f o r the standard logging .truck i n B r i t i s h Columbia and the data are given i n Table 10. This table shows c l e a r l y that i n curves above 300 feet radius or under 20 degree of curvature the widening can be neglected. Table 10. Relationship between curve data and widening for logging truck with t r a i l e r on a single lane road. 1 - 5 1 feet, l 2 = 2,601 f e e t 2 R feet Degree of D° R Widening radius i n feet D widening Curvajture feet i n feet 75 (Rmin) 76°30» 17.3 76°30'Dmax 7 5 . - 17.3 150 38°10» 8.7 20G00' 286.48 4 . 5 300 19° 6 ' 4.3 10O00' 572.96 2.3 1000 5°42» 1.3 6O00' 954-93 1.4 As the design speed for- logging roads i s low the super-elevation can be a standard 1.25 inch per one foot based on i c y road conditions. Grades Hauling costs are greatly affected by the grades. The e f f e c t of grade on travel time, as stated in Logging Road Hand Book (I960) i s of a quadratic nature. Despite the afore-mentioned f a c t , i t . i s conservative to l i m i t the grade on f o r e s t roads to less than 8$ f o r favourable and les s than 3$ f o r adverse grades. The less the grade i s , the -119-longer the road has to be to overcome a given height d i f f e r -ence. It means that the gain i n hauling costs w i l l be overcome by higher construction costs. The t r a c t i o n force and braking-power of the vehicles used on the Coast i s so powerful that the l i m i t a t i o n of grade? fon ; t h i s reason does not enter the picture. The main l i m i t i n g factor on Thurlow Island w i l l be s o i l condition. The clayey s i l t y s o i l would not allow a higher grade than 8 per cent without the danger of erosion. The r o l l i n g topography makes i t possible to design the alignment with grades-around 6 per cent and adverse grades below 3 per cent. Curves Radius of curve a f f e c t s the t r a v e l speed in.a quadratic manner according to the Logging Road Handbook (I960). Minimum radius should be determined which would allow to maintain the design speed on the road. Assuming 30 m.p.h. design speed the minimum radius, should be 229' or equivalent a 25°30 t degree of curve. I f the topography i s rough, the use of curves with t h i s minimum radius would cause high construction costs. Bearing this i n mind, i t i s u s e f u l to determine the absolute minimum possible radius for curves where the vehicle i s able to proceed with lowered speed. This depends only on the s t r u c t u r a l feature of the vehicle, and can be done graph-i c a l l y (Figure 2 2 ) . -120-As the figure shows the absolute minimum radius would be 75 feet. This radius w i l l apply to the main roads only, where logging trucks w i l l haul the logs from the old stands. On secondary roads sharper curves could be used i f necessary. Figure 22. Graphical determination of absolute minimum radius for truck and t r a i l e r . The importance of the main roads makes i t advisable that the curves should be designed with t r a n s i t i o n curves. On highways t h i s i s la r g e l y for safety reasons. On fore s t roads, however, t h e i r use i s mainly f o r economical reasons, as a good alignment with appropriate t r a n s i t i o n curves f i t s the road much better to the t e r r a i n than using c i r c u l a r curves. The construction costs w i l l consequently be lower. The ali:jement of the main roads (A, B, C and D) should show the l e a s t possible curves and as long tangents as possible. -121-Drainage To solve the problem of the drainage i s the most important i n the preliminary design of the alignment. y Construction costs are greatly affected by the i n s t a l l a t i o n s necessary to avoid erosion or washouts, (culverts, bridges, reta i n i n g w a l l s ) . On the Coast $2.00 to $4.00 per l i n e a r foot may be spent f o r forest roads whereas the cost of f o r e s t bridges i s around $50.00 per foot. The reduction in the number of such i n s t a l l a t i o n s i s then very important. The t o t a l cost of the roads, however, i s affected not only by construction costs but also by yearly maintenance cost. An inadequate drainage system w i l l r e s u l t i n high mainten-ance and high hauling costs. The alignment therefore should ' be such that with the possible l e a s t number of i n s t a l l a t i o n s the best possible drainage w i l l be achieved. The necessary drainage i n s t a l l a t i o n should be f o r both surface and subsurface drainage. To make the drainage e f f e c t i v e , well-maintained, normal-sized ditches, culverts with adequate cross sections and with well-constructed i n l e t s and outlets, should be established. The surface drainage provides f o r the removal of the r a i n water from the- surface of the road, and w i l l be necessary on a l l roads i n that area. I f the surface water i s allowed to soften the subgrade, the road w i l l lose i t s e f f i c i e n c y -122-under t r a f f i c . Surface drainage can be provided by main-taining the side grade of the cross section and by simple surface-drainage i n s t a l l a t i o n s . The subsurface drainage i s even more important i n that type of s o i l . A wet substratum cannot give either a good road or a f i r m subfoundation for the surface. Because of the wet climate on the islan d and the nature of the s o i l , there should be no hesitancy i n spending s u f f i c i e n t money to make the subsurface drainage system e f f i c i e n t , as t h i s w i l l e f f e c t a considerable saving i n the subsequent cost of maintenance. The subsurface drainage can be constructed using rocks f o r f i l l , with or without drainage pipes. The cross drainage structures which provide for the passing under the road of a creek or stream, crossed by the l i n e of road, can be a culvert of a bridge depending on the size of waterflow. The r e l a t i v e l y small watershed area allows the use of culverts for the most part because the side creeks are not heavily flooded even a f t e r heavy rains , as noted by the author during the f i e l d operation. Culverts should be i n s t a l l e d where the waterflow necessitates i t and at l e a s t i n every ten-chain distance along the road. * Single wooden culverts might be used with cedar stringers as the material i s a v a i l a b l e for i t on the l o c a t i o n . In the i n s t a l l a t i o n j c a r e should be taken to provide a correct foundation, and i n the construction of the i n l e t s and o u t l e t s . -123-The i n l e t should be b u i l t with a catch basin to hold the s i l t and s o l i d matter. This should be cleaned from time to time to prevent early clogging of the culvert . The outlet should be constructed with a stone apron to prevent washouts. The erection of one bridge with a t h i r t y - f o o t span and several smaller bridges, which can be of a simple lot)-stringer type using the available logs nearby, w i l l be necessary. An easily-constructed type of bridge might be an alternative for the large bridge, i f caleulationsowould) show;W*at-. it,more economical. Bridges with glued, laminated beams or with nailed w I n and box beams are such types. Nailed beams have been very common f o r bridges during World War I I . Their advantages are that '(ifr do£s)) not need s k i l l e d workers f o r construction, any small si z e material can be used such as two by fours ?and their carrying capacity can be increased very e a s i l y i f necessary by the use of addi t i o n a l flanges. Plywood sheets can be used as webs. I f there is no further use f o r the bridge i t can be e a s i l y taken apart and transferred to another place, which i s not the case i n this s i t u a t i o n , however. The main construction elements of such a bridge as described are shown on Figure 23. -124-i Figure 23i Cross section of nailed " I " beams with plywood webs. Surfacing The all-weather nature required of the roads makes i t necessary to cover them with a resistant surface. The simplest, cheapest and temporarily-adequate surface would be gravel. There i s a problem, however, to get good gravel material, because there are only a few gravel deposits in the area. The best source f o r graveling the f i r s t part of the road would be the seashore. The next -125-closest good gravel deposit i s about 2.5 miles from the shore. The location crew for f i n a l layout should take extra time to search the v i c i n i t y of the main road l i n e s to look f o r gravel deposits. S u f f i c i e n t t e s t p i t s should be dug at suitable locations. The f i n a l cost of road surfacing to the desired standard w i l l depend on hauling distances and the quality of the gravel. I t i s anticipated a n £ ~' „ that gravel deposits w i l l be ava i l a b l e to allow ".overhaul of less than one mile. There are many rock outcrops near the planned road system, but the rock i s too s o l i d to crumble by b l a s t i n g . To i n s t a l l a rock crushing machine might be economical in the long run, because i t could provide crushed gravel for l a t e r maintenance, i t i s d i f f i c u l t , how-ever, to j u s t i f y i t f o r less than ten miles of road work. The material for the subgrade w i l l be mostly sand, s i l t , clay mixture which covers the largest part of the area. At the time of the f i n a l road location a thorough s o i l analysis w i l l be necessary. I f the re s u l t s of the s o i l t e s t s neces-s i t a t e i t , s t a b i l i z a t i o n of the s o i l should be done, because the funds available for construction are adequate. The f i x a t i o n of the subgrade and surface can be done either mechanically by mixing s o i l s with gravel or sand i n a given r a t i o , or by the addition of other substances such as cement, sodium chloride, bitumen, etc. as described before. S t a b i l i z e d -126-earth roads are increasing i n importance as forest roads throughout the world, because of t h e i r cheapness and, i f well constructed, of t h e i r a b i l i t y to r e s i s t the action of t r a f f i c and weather. ( The area w i l l have continuous program, as the nature of sustained-yield management and thinnings require. Accord-ing to Worthington and Staebler (1961) temporary roads are not compatible with such a program and w i l l prove uneconomic. The main roads (A, B, C, and D) and numbered branch roads should be designed and constructed to a higher standard that w i l l permit all-weather use with a minimum of maintenance f o r the balance of the rot a t i o n . Skid t r a i l s are not designed i n advance and w i l l be . constructed to a lower standard as semi-permanent extraction line s. Road construction costs Road construction cost per mile f o r main and branch roads are d i f f i c u l t to predict p r e c i s e l y because of the preliminary nature of t h i s road network design. Due to observations on the scene i t can be stated however, with good pr o b a b i l i t y ^ t h a t the easy topography w i l l create no r e a l d i f f i c u l t i e s i n construction, but the s o i l w i l l necessitate some kind of s t a b i l i z a t i o n and a thorough drain-age which w i l l increase costs. -127-In any case the road construction costs would not run much above the sum which is,, available and calculated previously. To support t h i s opinion an abbreviated road-cost estimation f o r the main roads follows i n tabular form. (Table 11) . Table 11. -Cost estimate f o r main roads A, B, C, D(3.25 miles) Description Clearing and Grubbing a) Right of way b) Gravel p i t Roadway and Drainage  Excavation a) S o l i d rock b) Other material Overhaul on Excavation Compacting Watering Gravel base and Gravel  Surfacing Gravel Haul I n s t a l l a t i o n s a) Culverts b) Bridges Additional Allowances (mobilization and demobilization,overhead, contingency,&eight and haulage) Quantity Unit Basic Price Total Cost 26 1 100 48,000 32 12 26,800 13,400 13,400 acre acre cu.yds. cu.yds. day 1,000 g a l . 26,800 cu.yds. 26 30 cu.yds. cu.yds. cu.yds. piece l i n e a r f t . 350.00 350.00 2.76 0.35 120.00 3.50 0.35 0.04 0.10 70.00 50.00 T o t a l basic costs 35 fo 9 , 1 0 0 . 0 0 350.00 276.00 16,750.00 3 , 8 4 0 . 0 0 42.00 9 , 3 7 0 . 0 0 536.00 1 ,340.00 1,820.00 1,500.00 44,924.00 15,700.00 GRAND TOTAL $ 6 0 , 6 2 4 . 0 0 -128-The c a l c u l a t i o n followed c l o s e l y the method used by the B r i t i s h Columbia Forest Service Engineering D i v i s i o n . Road-way and drainage excavation was estimated according to ground conditions along main roads with an average 10 per cent side slope. Compacting costs were based on an anticipated 1,500 cu. yard per day basis. One gallon for each four cubic yards was estimated for watering. Gravel- base and gravel surfacing costs include a one foot s t a b i l i z a t i o n ' on the t o t a l width of the subgrade and an additional one foot f o r the width of surface. A maximum of one mile overhaul for gravel was estimated. Only i n s t a l l a t i o n .cojsts were included for culverts and bridges, because l o c a l material can be used f o r t h e i r construction. The main road construction costs w i l l be $60,624.00 f o r 3.25 miles, or $18,650.00 per mile. This amount coincides very c l o s e l y to available funds calculated previously as $18,600.00 per mile. -129-PRELIMINARY MANAGEMENT PLAN FOR THE RESEARCH FOREST  ON EAST THURLOW ISLAND Objectives This management plan has the objectives of obtaining a sustained y i e l d on 1,487 acres, building up a research forest with a permanent program mostly on thinnings and creating a demonstrational forest of the coastal hemlock region. The objectives i n d i r e c t l y suppose that through an adequate road system, the protection of the forest from f i r e , insects and diseases w i l l be possible and that the quality and the quantity of the crop w i l l be successively improved. Summary of basic f a c t s The basic data in connection with the area, such as forest types, l o c a l conditions, growth and volume available, have previously been presented. To make orientation easier the areas and volumes available are repeated i n the following table. (Table 1 2 ) . The 410 acres of shrubs or inaccessible areas with stands of s i t e index 70 or under were excluded from the calc u l a t i o n because t h e i r production does not con-t r i b u t e s i g n i f i c a n t l y to the t o t a l y i e l d of the Research Forest. I t i s usual to s t a r t the organization of a sustained y i e l d unit by d i v i d i n g the area into compartments. This was already done when the area was mapped and i s shown on the attached map. (Appendix 1.) Table 12. Main stand c h a r a c t e r i s t i c s of the Research Forest on East Thurlow Island. Forest types Scattered old growth 65-year old HFC second growth 50-year old HFC second growth Shrubs or inaccessible areas Area Merchantable volume per acre intermediate u t i l i z a t i o n Acres cubic feet 116 12,320 1,130 7,100 241 5,450 Total volume cubic feet 1,432,996 8 , 0 2 3 , 0 0 0 1,313,450 S.I. 70 or under 410 TOTAL 1,897 10,769,446 -130-Th e old stands were cruised i n I 9 6 0 , the second growth stands i n 1 9 5 2 . The present annual average growth for the even-aged second-growth stands was based on l a t e s t experimental-plot measurements showing 1 1 0 cubic feet per acre. A l l the volumes represent merchantable volumes for trees above 8 inches d.b.h. Allowable annual cut and cutting methods Because only a rough approximation of the allowable cut i s desired in the preliminary plan the determination of indicated cut i s done by using the uniform-area regul-ation method. The almost uniform even-aged second-growth cover representing 7 3 $ of the area would suggest the same. The s i t e index i s also f a i r l y uniform. The rotation to be chosen i s based upon the average d.b.h. at which mean annual increment culminates. According to Smith et a l ( 1 9 6 1 ) i n normal hemlock stands t h i s average d.b.h. i s 1 2 inches on S.I. 1 5 0 . This would mean, according to t h e i r tables, a rotation of about 6 5 years. Based on the above-mentioned suppositions the average annual cut w i l l be 1 0 , 7 6 9 , 4 4 6 + 6 5 = 1 6 5 , 0 0 0 cu. f t . This i s well i n l i n e with the gross merchantable timber on 2 3 acres of 6 5 - y e a r old HFC stands, ( 7 , 1 0 0 x 2 3 = 1 6 3 , 3 0 0 cu. f t j , and even better when compared to the average current annual growth on the whole area. ( 1 , 5 0 0 x 1 1 0 = 1 6 5 , 0 0 0 cu. f t . ) The sustained y i e l d can e a s i l y -131-be maintained under that plan with the necessary checks at about ten-year intervals. It i s hoped that the thinnings , and the establishment of open to normal stands by thinning,, w i l l increase the y i e l d progressively. To s t a r t with thinning experiments as early as possible, the old stands must be clearcut f i r s t to cover the cost of building the necessary road network. The object of regulation i s to d i r e c t the management unit in such a way that i t w i l l reach the desired balanced p o s i t i o n with the l e a s t s a c r i f i c e , i n the shortest time. In the f i r s t f i v e years there should be an overcut by volume to eliminate the stagnating o ld stands and to get funds f o r the road network. The yearly road construction was calculated on a two-mile per year basis. The yearly clearcut w i l l be according to the plan shown in Table 13. Table 13. Cutting plan f o r old stands. Year Stand- No. , Area of Cut Volume available No. acres mature immature 1 No. 1 24.3 147,670 73,080 2 No. 2 Part of No. 3 14.4 10.0 119,629 42,300 99,960 84,000 3 Part of No. 3 23.0 97,400 193,200 4 Part of No. 3 19.2 81,400 161,600 5 No. 4 and No. 5 24.6 186,236 189,840 115.5 674,635 801,680 Road to Construct Name on Map A, B (0.8 mile), C. B (0.5 mile), D, No. 1,2,3. No. 10 to 17. No. 4, 5, 6, 18, 19. No. 7, 8, 9. TOTAL 1,476,315 -133-The next s i x t y years of the rotation w i l l be on a clearcut and thinning basis with an average yearly clearcut of 23 acres and thinnings on about 30 acreSj.or as the f u t u r e -experiments require. Thinnings w i l l be kept under experi-mental status as long as required. The yearly 53 acres under logging are very close i n size-to.f the areas cut i n the 1953 and 1954 operation. The yearly volume to be clear cut w i l l be around 150,000 cubic feet, somewhat les s than that calculated, because of the overcut in the f i r s t f i v e years; plus the volume of thinnings which w i l l depend on the nature of experiments. The cutting order i s not determined in t h i s plan, because i t w i l l depend mainly upon the research forester i n charge, who can determine and prepare the timber-sale con-t r a c t s according to the research program i n progress. The cutting order w i l l be affected also by the type of the experimentation used. If the sequence of the cuts follows the direction's from Bickley Bay toward Hemming Lake and from Bickley Bay toward Shoal Bay, the proposed road network makes i t possible to work toward both d i r e c t i o n s separately with two or three small':1!." crews at the same time. This would allow comparative studies with d i f f e r e n t crews and methods. This, preliminary management plan i s a tentative one and/that'approach i s j u s t i f i e d by G. S. Allen (1944) who -134-s t a t e d : " R a t i o n a l f o r e s t p r a c t i c e r e q u i r e s a s o l i d f o u n d a t i o n o f e x p e r i e n c e , r e s e a r c h and d e t a i l e d k n o w l e d g e o f t h e r e g i o n and f o r e s t t y p e s t o be m a n a g e d . S i n c e a l l t h r e e p r e r e q u i -s i t e s a r e l a c k i n g t o a g r e a t e x t e n t i n h e m l o c k f o r e s t t y p e s , management r e c o m m e n d a t i o n s c a n be r e g a r d e d o n l y as s t r i c t l y t e n t a t i v e and o f a v e r y g e n e r a l n a t u r e . T h e y may f o r m a b a s i s f o r i n i t i a l management t o b e r e p l a c e d o r i m p r o v e d i n t h e l i g h t o f i n c r e a s e d k n o w l e d g e " . The management p l a n s h o u l d be r e v i s e d t h e r e f o r e a f t e r t h e f i r s t d e c a d e , and m o d i f i e d i f n e c e s s a r y a c c o r d i n g t o t h e a c c u m u l a t e d d a t a d u r i n g t h a t p e r i o d . PROPOSED LOGGING METHODS The p r o p o s e d m e t h o d s f o r l o g g i n g a r e d i s c u s s e d s e p a r a t e l y f o r t h e i n i t i a l f i v e y e a r s o f t h e management , when t h e o l d s t a n d s w i l l be c l e a r c u t and f o r t h e t h i n n i n g s a f t e r w a r d . A s ' l o g g i n g me thods f o r t h i n n i n g a r e i n a more o r l e s s e x p e r i -m e n t a l s t a g e on t h e C o a s t , t h e p r o p o s e d m e t h o d s s h o u l d be r e v i s e d i f more e x p e r i e n c e w i l l a d v i s e i t . C l e a r c u t T h e r e w i l l be no s p e c i a l p r o b l e m i n v o l v e d i n l o g g i n g t h e s c a t t e r e d o l d s t a n d s w h i c h w i l l be c l e a r c u t i n t h e f i r s t f i v e y e a r s , a c c o r d i n g t o t h e p r o p o s e d management p l a n . - 1 3 5 -Th e scattered mature trees in the old stands are in t e r -spersed with second growth stands. This s i t u a t i o n w i l l require the use of prelogging practices, removing the small trees f i r s t . The main roads are planned i n order to get the shortest possible yarding distances. Because of the oblong shape of the old growth areas i t w i l l be possible to keep the external yarding distances to about 800 feet. This w i l l make p r a c t i c a l any high-lead or tractor yarding system. I f high-lead i s used, any of the mobile spar tree systems might be applicable but using a l o c a l tree f o r a spar would be preferable. There are conventional high-lead operations on the Island at present using raised spars. As f i r trees are available for spars i n the old stands, the conventional high-lead should be used. The other p o s s i b i l i t y i s to use tractors with arches f o r d i r e c t yarding to the shore. The topography makes i t possible, but the ground conditions in wet weather could create d i f f i c u l t i e s . With crawler-type tractors the pro-blem could be e a s i l y overcome f o r the f i r s t two or three years as the short hauling distances would allow d i r e c t yarding to Bickley Bay. Old stands farther away, however, w i l l need truck transportation to make the logging econo-mical. This could be served better by high-lead logging. The ground allows to locate landings(places)^ along the road at almost any convenient point. Slash disposal and burning should be done on clearcut t o : " areas to reduce ,fire hazard and f a c i l i t a t e r e f o r e s t a t i o n . The areas should be replanted with Douglas f i r , or Sitka spruce or perhaps with some exotic species for spacing-experiments. Hemlock w i l l come i n by natural regeneration, , As there are no deer on the Island ^satisfactory s u r v i v a l can be expected provided other f a c t o r s are favourable. Table 14 shows the proposed yearly order of the cle a r -cut operation. Table 14. Logging methods and sequence of cut with the expected output. Years to Area Logging method Av.yard Hauling Volume to cut Daily output Working clearcut Acres proposed distance distance days feet feet cunit cunit necessary 1 24.3 Crawler tractor 2,000 2,200 31 70 2 14.4 10.0 Crawler tractor High-lead 3,000 400 5,000 2,200 . 1,260 25 45 89 28 3 2 3 . 0 High-lead 600 6,000 2,900 33 85 4 19 .2 High-lead 600 8,000 2,400 33 73 5 11.0 13 .6 High-lead 400 500 12, 000 . 12,000 1,750 1,950 45 4 0 . 39 49 TOTAL: 14,660 -138-As the clearcut operation w i l l be close to the average on the Coast the data f o r each phase can be borrowed from Tessier and Knapp (1961) showing the following cost f i g u r e s : Table 15. Item Cost per M f.b.m. F a l l i n g and bucking $ 4 .52 Yarding and loading 7 .05 Hauling 7.91 Road maintenance .63 Supervision .69 Miscellaneous 1.87 Road construction 5.11 TOTAL: $ 27.78 Daily output was estimated according Brandstrom Ts (1933) data. Settings and landings are shown on the map. (Appendix 1) As the calculation, shows,the r e l a t i v e l y small size of the scattered old stands would allow a shorter period f o r t h e i r l i q u i d a t i o n . This could be done i n a two or three year period by bigger companies. This would solve the road-construction problem for the area i n a shorter time, giving better opportunity f o r thorough preparation for thinning experiments. -139-Thinning Operations After the overmature stands have been cut and the necessary road system constructed, commercial thinning experiments could s t a r t . Thinnings conducted i n any manner designed by the research personnel should be combined with clearcuts. This w i l l a t t r a c t loggers who are not enthusiastic about thinning i f there i s not a good p o s s i b i l i t y r a i s i n g the p r o f i t above tne-marginal l i m i t . As the preliminary management plan proposed, each year 23 acres should be clearcut and t h i r t y acres would be thinned. There are many ways to arrange the logging operations. -Two proposals w i l l be made as now considered as the best p o s s i b i l i t i e s . Tractor and truck logging The f i r s t a l t e r n a t i v e is based on the use of uniform logging methods upon the entire area. The road l o c a t i o n plan was prepared with t h i s system i n mind. The i n d i v i d u a l logging s i t e s w i l l be using a medium-light tractor for yarding ( l i k e the Tree Farmer) and tractor "swing" or truck and t r a i l e r hauling. A small logging crew of three or four men should be used. When the operation is farther out i n the .forest, ' r: bunching should be done. -140-Using the average data from s i x experimental thinning operationsas given by Worthington and Staebler (1961), the d a i l y production would be approximately seven cunits or eight coiris. The proposed yearly cut of 150,000 cubic feet could be achieved i n that case i n 214 days. With three d i f f e r e n t thinning and logging crews, a 50,000 cubic feet per year contract would be more a t t r a c t i v e . The road net-work would allow t h i s without c o n f l i c t . In t h i s case the operation could be ca r r i e d out under optimal weather con-d i t i o n s , interesting comparisons could be made and r e p l i c a t i o n s could be arranged with good organization. The cut should s t a r t with thinnings, leaving the clearcut areas u n t i l the l a s t . This w i l l prevent the spread of dwarf mistletoe as suggested by Marples et al.(1955) The temporary yarding route should be prepared i n advance of the f e l l i n g and bucking, to create the best opportunity f o r bunching and yarding. The tractor must not use the permanent roads f o r arch skidding but only for hauling with t r a i l e r s . •The semi permanent landings should be prepared p r i o r to the loading and hauling operations; Approximate cost of thinnings w i l l run close to that reported by Worthington and Staebler (1961) based on six thinning operations on the Coast and shown in Table 16. -141-Table 16. Cost of thinning operations F a l l i n g and bucking Item Yarding 5.25 Loading 2.17 Hauling 2.81 Miscellaneous 2.57 TOTAL: .$16.06 Necessary minimum d a i l y production In the chapter with regard to economic problems of thinning i t was pointed out that for every thinning operation there i s a minimum diameter l i m i t s p e c i f i e d . This diameter value can be described graphically as the in t e r s e c t i o n point of two curves, the curve showing the relationship between u t i l i z a t i o n price and diameter and the curve of logging costs vs. diameter of trees to cut. For the operator, however, i t i s more p r a c t i c a l to draw the l e v e l of necessary minimum d a i l y output. This can be done with a simple cal c u l a t i o n i f some basic cost figures are known. As these data are usually given as hourly costs -142-or costs per u n i t volume, the cost equation f o r normal p r o f i t operation can be expressed as follows: Average t o t a l cost of operation per one hour Addit'onal f"x d .Minimum hourly output v T ^ j ^ o u t p u t unit s = S e l l i n g price per u n i t . Using symbols for the values i n the equation: C hourly * p „ p °Min. and the o from i t : 0 . = C min mm p_p and the d a i l y output: 0 . 7 l ., mm/daily = H x 0 . min/hour Where H i s working hours per day. The average cost per hour must be calculated i n a way,that the values involved must represent the actual e f f i c i e n c y of the operation. I f t h e o r e t i c a l maximum values only would be available a reduction factor f o r actual e f f i c i e n c y must be introduced. To i l l u s t r a t e the c a l c u l a t i o n , l e t us determine the necessary d a i l y output of the thinning on East Thurlow Island on the same basis as i t was done i n 1959 by a three-man crew, and the Garrett Tree Farmer tractor at the begin-ning of the operation. -143-1 . Calculation of C. value. Total cost of operation per one hour: f> a) F e l l i n g , bucking and bunching 2 x $ 18.88"*"= 4.70 b) Cost of owning and operating powersaw O.46 c) Yarding and Bundling $ 2 0 . 4 8 1 - 2.58 8 ~ d) Cost of owning and operating 2 Garrett Tree Farmer per hour (operators wage not included) 1.23 TOTAL $ 8.97..C 1 From wage scale f o r independent logging operations 1960-61 Cat driver I 2 0 . 4 8 F a l l e r and bucker day rate.... | 18.88 2 Worthington and Staebler (1961) 2 . Calculation of F value Additional f i x e d cost per 1 0 0 cubic f e e t . $ a) p r o f i t 15$ of s e l l i n g price 2 . 8 5 b) miscellaneous (p a y r o l l taxes, supervision, scaling, bookkeeping and o f f i c e expenses) Worthington and Staebler (1961) 2 .57 c) towing one cunit to Marmac (Towing Co.) O.58 d) stumpage 1 . 0 0 $ 7 . 0 0 . . F 3 . S e l l i n g p r i c e at Harmac ( 1 9 V c u . f t . 1 9 5 9 ) #19 .00..P -144-The necessary hourly output then: o 0 = 3.97 = 0.747 cunit 1 9 . 0 0 - 7 . 0 0 and the necessary d a i l y output » 8 x 0.747 - 5.98 cunit As the actual average production was 593 cu. f t . per day the operation with a three-man crew was not p r o f i t a b l e . The operator changed his crew to two. I f we calculate the necessary minimum d a i l y production f o r t h i s crew we w i l l get 441 cu. f t . Because of l a t e r breakdown of the tra c t o r and unusually wet weather, which made the yarding t r a i l s almost impassable the d a i l y production f e l l down consider-ably, which forced the operator to give up the contract. This type of calc u l a t i o n can be done i n any given operation. The minimum necessary d a i l y production, i f com-pared to actual production, w i l l show the p r o f i t r a t i o . The actual d a i l y production should be further compared to the ' optimum production t h e o r e t i c a l l y possible i n a given work organization i n order to estimate the e f f i c i e n c y of the operation. Alternative plan f o r thinning operations The alternative solution of thinning operations would divide the area into three separate units as shown on the sketch (Figure 2 4 ) . EAST THURLOW ISLAND Research Forest Scale : I inch =40 chains Fig- 24 Thinning operation lay-out for the Research Forest-- 146-Th e areas along the main access road A and B would be logged i n the same way as proposed i n the f i r s t a l t e r n a t i v e . The areas east of Bickley Bay on the plateau would be logged with t r a c t o r s , yarding d i r e c t l y to the shore, i n the same manner as proposed by Spiers (1956) and pre-viou s l y described. Up to a one-half mile one tr a c t o r would and be used f o r greater distances a bunching tractor should help to prepare t r a i l s and loads. In the areas west of the main creek, which are covered with the best young stands, the Lasso Cable should be used. The broken t e r r a i n , heavy debris together with the presence of good sized trees along the t r a i l s f o r supports, would a l l be fa c t o r s for success. The motor would operate on the shore and a supple-mentary counterweight of simple construction could be established a t the end of the l i n e i n one of the deep side creek canyons. In between the side creeks, good temporary landings could be placed. The material could be yarded to the land-ings by using winches or l i g h t t r a c t o r s . The operational length of such a system i s about two miles, which would f a c i l i t a t e the transportation of logs from as f a r as the divide between Hemming Lake and Bickley Bay. This a l t e r n a t i v e w i l l , of course, a l t e r the o r i g i n a l road location plan according to the need of t h i s system as indicated on Appendix 2. -147-Estimated production and cost of Lasso Cable i f i n s t a l l e d on East Thurlow Island The basic data for' the c a l c u l a t i o n were obtained from logging operations on Thurlow Island in ' 1 9 5 9 , from the Lasso Cable Company i n Switzerland and from-the Wood Handbook ( I 9 6 0 ) . S p e c i f i c gravity of hemlock usually ranges from 0 .38 to 0 .42 and averages 0 . 4 0 , At 74$ moisture content one cubic foot-of green hemlock weights 4 3 . 4 l b s . In the 1959 oper-ation the average logsize was ten cubic feet., or 434 l b s . plus bark, which would be about 7 per cent more by volume, giving an approximate value of 450 lbs. This means that the f u l l load capacity of 680 pounds per hook i s not r e a l i z e d and i t would a c t u a l l y be possible to carry logs of 28 cubic feet volume, e.g. l 8 n x 16 ' or 14" x 24 ' size logs. For an eight hour day the d a i l y production would be, assuming 2 minutes for loading and 5 feet per second t r a v e l ~ speed: 8 x 60 = 240 pieces = 2 ,400 cubic feet per day 2 It would take 70 days to bring out one year's cut according to the management c a l c u l a t i o n . To reduce logging costs at least two years cut would be necessary to log i n one season. -148-Cost analysis: Ownership costs: Depreciation based on ten years 3 , 0 0 0 . 0 0 Interest on investment 30»000 x 1 1 X Q.,06. 990.00 Insurance and other uninsured r i s k s 5 % of average investment of $ 1 6 , 5 0 0 . 0 0 . . . 8 2 5 . 0 0 Operation costs: Labour $20.00 including Workmen's Compen-sation, holiday pay, etc. (12$ of t o t a l payroll) (5 men for 140 days) 1 4 , 0 0 0 . 0 0 Supplies and repairs (10 gallons gasoline per day @ 22 cents) 392.00 Spare parts (Manufacturer's estimate) 600.00 Maintenance(lubrication service) (Manufacturer's estimate) 300.00 With a yearly production of 3,360 cunits the yarding, cost per cunit w i l l be: $5.98 (24 cunit per day x 140 = 3,360 cunit) Assuming that other cost items of the extraction process w i l l be s i m i l a r to thosepublished by Worthington and Staebler (1961) for the Hemlock Forest Experiment Station, the t o t a l logging cost per cunit w i l l be: „ TOTAL: $ 20,-107.00 F e l l i n g - Bucking 2.86 Bunching 4.38 Yarding 5.98 Miscellaneous 2.15 Total $15.37 per cunit. or $12.72 per cord. -149-The cost would allow,according to the calculations, a commercial thinning showing a marginal p r o f i t . On East Thurlow Island the Lasso Cable operation would eliminate construction of a road system on the r i g h t side of the main creek, where the topography i s the most rugged and the debris i s heavy. This type of operation could be started anytime because the necessary pre-yarding equipment could reach the stands e a s i l y on the available old t r a i l s and would allow thinning experiments to s t a r t before' the scattered old stands w i l l be clearcut. The main advantages of the operation would be: the mobility of the i n s t a l l a t i o n , the continuous service under a l l c l i m a t i c conditions, the use of u n s k i l l e d labourers. The pre-yarding could be done by mobile winches, l i k e the radio operated "Sepson" double drum winch, type 40-05 which costs $ 7 ,950.00 or Swed Krone - $ 1 , 5 9 0 . 0 0 . This winch would reduce the bunching cost according to the following c a l c u l a t i o n : Ownership costs: $ Depreciation ( f i v e years) 340.00 Interest or investment 61 .00 Insurance and other uninsured r i s k s 26.00 Operation costs: Labour (two men for 140 days)@$20. 5,600.00 Supplies and f u e l (1 g a l . gas... per day @ 280) 4 0 . 0 0 Maintenance, spare parts, wire rope etc 80.00 To t a l $ 6,147.00 - 1 5 0 -E s t i m a t e d p r o d u c t i o n b a s e d on t e c h n i c a l d a t a o f t h e w i n c h , w i t h an a v e r a g e y a r d i n g d i s t a n c e o f 150 f e e t i s 24 c u n i t s p e r d a y . C o s t p e r c u n i t o T ^ v T n = $ 1 ' ^ 2  r 24 x 140 T a k i n g i n c o n s i d e r a t i o n t h a t t h e L a s s o C a b l e w i t h a maximum y a r d i n g d i s t a n c e o f 1 0 , 0 0 0 f e e t c a n s e r v e a n a r e a o f 138 a c r e s i t w o u l d mean t h a t on E a s t T h u r l o w I s l a n d w i t h an a p p r o p r i a t e l a y o u t one c o u l d s t a y i n one p l a c e f o r a t l e a s t two y e a r s . F i g u r e 25. L a y - o u t and o p e r a t i o n o f t h e " S e p s o n " r a d i o - c o n t r o l l e d w i n c h . -151-SUMMARY AND CONCLUSIONS Future management of second-growth Western hemlock stands on the Coast of B r i t i s h Columbia depends on experiments to provide foresters with facts about the s i l v i c a l , economic and t e c h n i c a l aspects of thinnings. Evaluation of the few past experiments shows that there are not enough data accum-ulated yet to prescribe management methods for young hemlock. Such problems as thinning methods, ef f e c t s of thinnings, economic and t e c h n i c a l ways of handling small logs and the mechanization of thinning operations have been inadequately investigated for hemlock stands. Experiments i n the Research Forest on East Thurlow Island might provide solutions f o r many questions about commercial thinning, i f a well developed road system were established there. Scattered old growth stands, i f clearcut, should provide s u f f i c i e n t funds f o r road development. All-weather main and branch roads are e s s e n t i a l . I t is highly probable, that with adequate roads as described herein commercial thinning experi-ments on the Research Forest can be established successfully. -152-BIBLIOGRAPHY Alaska Forest Research Center Technical Notes No. 3 and No. 7. 1949 and 1951. Thinning second-growth hemlock-spruce for pulpwood. 2pp. Allen, G.S. 1944. Management recommendations for the hemlock and associated f o r e s t types of the Juan de Fuca Region of southwestern Vancouver Island. Research Not No. 11, B.C. Forest Service. Berg, Alan B. 1961. Logging precommercial Douglas f i r . Forest Res.Lab. Oregon State Univ. -Res. Note 4 5 . 19pp. Bernstein, CM. 1958. S i l v i c a l c h a r a c t e r i s t i c s of western hemlock. 'P a c i f i c N.W. Forest & Range Expt. Station. 16pp. Barnes, G.H. 1949. S i t e c l a s s i f i c a t i o n for even-aged stands of western hemlock. P a c i f i c Northwest Forest and Range Expt. Sta., Res. Note No. 50, Portland, Oregon. 1953. Y i e l d of even-aged stands of western hemlock. Preliminary report, P.N.W. For. and Range Expt. Sta. 8 l p p . B. C. Forest Service. 1958,1959,1960a. Continuous Forest Inventory of B r i t i s h Columbia, I n i t i a l Phase and Supple-ments. 1957. B.C.F.S., Surveys and Inventory D i v i s i o n , V i c t o r i a . Borzuchowski, R. 1955. P a r t i a l time study of a second-growth hemlock thinning. B.C. Forest Service,Res.Notes No.30.: - , 14PP. Braathe, Peder. 1957. Thinning i n even-aged stands, a summary of European l i t e r a t u r e . Faculty of Forestry, Univ. . of N.3., 92pp. Brandstrom, Axel, J.F. 1933. Analysis of logging costs and operating methods in the Douglas-fir region. Charles Lathrop Pack Forestry Foundation. 117pp. Brown, N.C 1950. Logging. John Wiley and Sons, Inc., N.Y. 418 pp. Bruce, M.B. 1952. An access road program for National Forests. The Timber man. 53(12): 6pp. -153-Byrne, J.J. and R.J. Nelson and P.H. Googins. 1 9 6 1 . Logging road handbook. The e f f e c t of road design on hauling costs. -U.S.D.A. Forest Service. No.183. 6 5 p p . Canada Lumberman. 1 9 6 2 . Wheeled skidders tackle rough going i n Quebec. Feb. 3 p p . Carow, J. 1 9 5 9 . Yarding and loading costs f o r salvaging i n old-growth Douglas-fir with a mobile high-lead yarder. U.S.Dept. of Agric. Pac.N.W. For. and Range Expt. Sta. Res. Paper No.32. 2 6 p p . Davies, W.A. i 9 6 0 . Small log harvesting. For.Products Journal 1 0 ( 4 ) : 1 8 7 - 1 8 9 . Day, R. 1 9 6 2 . Low cost roads. Canadian P. &P.Industry.Feb. 1 9 6 2 . 4 p p . Dimock 1 1 , E.J. 1 9 5 8 . Don't s e l l western hemlock short.Pulp and Paper. 3 2 ( 5 0 ) 3 p p . Doyle,-J.A. & W.W. Calvert. 1 9 6 1 . E f f e c t of tree size of jack pine on harvesting and conversion to lumber i n northern Ontario. Canada Dept. of For.Tech.Note No. 1 9 . 2 6 p p . Faculty of Forestry, U.B.C. I 9 6 0 . Annual report on University of B.C. Research Forest, Haney,-B.C. 2 6 p p . FAO of the United Nations. 1 9 5 7 . Endless "Lasso" Logging Cable-ways. Forestry Equipment Notes. C . 2 1 . 5 7 . 3 p p . F l i g g , D.M. and R.E. Breadon, I 9 6 0 . Log position volume tables B. C. Forest Survey Note No. 4 . Fobes, E.W. I 9 6 0 . Improved harvesting methods. Equipment survey notes. Wyssen Cable System. U.S. Dept. of Agric. Forest Service. Rept. No. 1 6 3 7 - 2 7 . 2 p p . Giordano, G. 1 9 5 9 . Logging cableways. United Nations P u b l i -cation. .FAO/ECE/LOG/60. 14 5 p p . Glaser, H.D. 1 9 5 1 . Das Rucken des Holzes. Bayerischer Landwirt-schaftverlage Munch en. 2 4 0 p p . ' Gunn, D.C. and F.W. Guernsey. 1 9 5 8 . Skidding time studies i n the B.C. Southern Interior.B.C.Lumberman 4 2 ( 2 ) : 4 p p . G r i f f i t h , B.G. 1 9 5 9 . The e f f e c t of thinning on a young stand of western hemlock. Faculty of Forestry. U.B.C. Research Paper No.24. Forestry Chronicle 3 5 ( 2 ) : 1 1 4 - 1 3 3 . Hafner, F.D. 1 9 5 6 . F o r s t l i c h e r Strassen und Wegebau. Verlage Georg Fromme & Co. Wien und Munchen. 3 8 3 p p . -154-Harrison, ,J.L. 1951. Forest Engineering. Roads and Bridges. Oliver and Boyd Pub. Co. London. Hawley, R.C. and D.M. Smith. 1954. The practice of s i l v i -culture. John wiley & Sons, Inc. New York. Chapman and H a l l Ltd. London. Heiberg, S.O. and P.G. Haddock. 1955. A method of thinning and forecast of y i e l d i n Douglas f i r . Jour.For.53:10-18. Hewes, L.I. and C.H. Oglesby. 1954. Highway Engineering. John Wiley and Sons, Inc. New York. 658pp. Joergensen, Chr. 1957. Thinning experiments. B.C. Forest Service, V i c t o r i a , B.C. Tech.Publ. 4 5 . 22pp. 1951. Experimental thinning operations on a commercial scale. The For. Chronicle 2 7 ( 1 ) . Upp. 1952. A commercial thinning experiment i n Douglas f i r . B.C.Forest Service.Res.Notes No.22. 21pp. Kirkland, B.P. and A.J.F. Brandstrom. 1936. Selective timber management in the Douglas-fir region. U.S.Dept. of Agric. 121pp. Koroleff, A. 1954. F u l l - t r e e logging - a challenge to research. Pulp and Paper Res. I n s t i t . of Canada. Woodlands Research Index No. 9 3(B - 1 ) . 100pp. Lasso Ropeways Ltd. 1961. Lasso Cable conveyors. Pamphlet. 8pp. Leloup, Marcel. 1956. Tractors for logging. FAO Forestry Development Paper No. 1. 189pp. Moller, CM. and J. A b e l l , Th. Jagd, F. Juncker. 1954. Thin-ning problems and practices i n Denmark. College of Forestry at Syracuse. Tech. Publication No. 76. 92pp. Mcintosh, J.A. and D.C. Gunn. I960. Prelogging with a portable s t e e l spar. For. Prod. Lab. of Canada. 5pp. I960. How log loading a f f e c t s u t i l i z a t i o n . For. Prod. Lab. of Can. 4pp. Munnis, J.K. 1961. The s t e e l spar tree used i n high-lead log-ging. Undergraduate thesis, Faculty of Forestry, U.B.C. Nixon, G.R.W. and D.C. Gunn. 1957. F e l l i n g and bucking studies. The B. C. Lumberman. 4 1 ( 4 ) : 5pp. -155-Paul, Benson H. 1958. S p e c i f i c g r a v i t y changes i n southern pines a f t e r release. Southern Lumberman. Dec.15, 1958. Samset, Ivar. 1961. Influence of the development of mechaniz-ation on s i l v i c u l t u r e . XIII. IUFRO Congress, Vienna. Section 32 Paper No. 5 . 31pp. Shea, K.R. I960. Decay i n logging scars in Western hemlock, and Sitka spruce. Wyerhaeuser Co.For.Res.Note 25 . 13pp. 1961. Deterioration r e s u l t i n g from logging injury i n Douglas-fir and Western hemlock. Weyerhaeuser Forestry Res. Note 3 6 . S i l e n , R.R. 1955. More e f f i c i e n t road patterns for a Douglas-f i r drainage. The Timberman. Vol. 5 6 ( 6 ) . and H.J. Gratkowski. 1953. An estimate of the amount of road i n the staggered-setting system of clear-cutting. U.S. Dept. of A g r i c , P a c i f i c Northwest Forest and Range Expt. Sta. Res. Note 92 . 4pp. S i l v e r s i d e s , C.R. 1949. Construction and maintenance of forest truck roads. P. & P. Res. Inst, of Can.Woodlands Res. Index No. 60. 137pp. Sloan, G.McG. 1957. The forest resources of B r i t i s h Columbia, 1956. Queen Ts Printer, V i c t o r i a , B. C. Smith, J.H.G. 1959. Comprehensive and economical designs f o r studies of spacing and thinning. For. Science 5 ( 3 ) : 237-244. and J.W. Ker, J. Csizmazia. 196l. Economics of re f o r e s t a t i o n of Douglas f i r , Western hemlock and Western red cedar i n the Vancouver Forest D i s t r i c t . Faculty of Forestry, U.B.C. Forestry B u l l e t i n g No.3.144PP» Spiers, J.J.K. 1956. Some considerations i n planning a mobile logging operation. Master's t h e s i s . Faculty of Forestry, U.B.C. Staebler, G.R. 1957. Early effect of two successive thinnings i n Western hemlock. U.S.Dept. of A g r i c , Pac.N.W. For. and Range Expt. Sta. Res. Note 146. 8pp. 1957. Design f o r a te s t of commercial thinning on the Hemlock Experimental Forest i n western Washington. J.For. 55: 810-813. Stewart, M. 1956. Cost Study of p a r t i a l cutting treatments i n Int e r i o r wet b e l t of B r i t i s h Columbia. B.C.F.S. Res. Note No. 3 2 . 21pp. -156-Stoeckeler, E.G. and H.E. Young. 1957. Application of a i r -photq techniques i n planning logging road networks. Tech." Notes of Univ. of Maine. No.44. 3pp. Swan, D.A. 1959. Soil-cement - a p o s s i b i l i t y f o r permanent woods roads? American Pulpwood Assn. Tech. Release No. 59-R42. 3pp. Taylor, R.F. 1934. Yield of second-growth Western hemlock Sitka Spruce stands i n Southeastern Alaska, U.S.D.A. Tech. Bui. 412. Termas, M.E. and R.H. Ruth, CM. Berstein. 1955. An analysis of production and costs i n high-lead yarding. Pac. N.W. For. and Range Expt. Sta. Research Paper No.ll . 3 7 p p . Tessier, J.P. 1956. Report on Easy Way Logger. 5pp. Tessier; J.P. 1958. The salvage of pulpwood a f t e r sawlog operations i n Coastal B r i t i s h Columbia. Association of B. C. Foresters Thesis35pp " and F.M. Knapp. 1961. Cost analysis of a mobile logging operation on the U.B.C. Research Forest, Faculty of Forestry, U.B.CRes.Paper. No. 4 1 . 16pp. Tessier, J.P. and J.H.G. Smith. 1961. E f f e c t of tree size of red alder on harvesting and conversion to lumber. Fac. of Forestry, U.B.C. Res. Paper No. 4 5 . 8pp. Tinney, W. A. and D.B. Malmberg. 1948. Management and marking rules second growth Douglas-fir. University of Washington, College of Forestry. 33pp. The Timberman, 1962. Barker-chipper taps new wood supply. January. 3pp. The Timber.man.. 1961. Mobile spar and radio controlled sky-l i n e carriage t h i n timber. August. 3pp. The Timberman. 1961. How to handle small logs smarter with modern machines and equipment. Vol.62(6): 25-66. 1959. November. Tree farmer yards small logs at lower cost. p.111. 1955. November. 46th P a c i f i c Logging Congress considers how to get maximum u t i l i z a t i o n , p.57. Wackerman, A.E. 1949. Harvesting timber crops. McGraw-Hill Book Co. Inc. N.Y. 435pp. . . -157-Walker, Dean. 1 9 6 l . Forests replace farms as source of New Zealand's wealth. Pulp and Paper Magazine of Canada. 62(11) . 6pp. Wellwood, R.W. 1956. Some ef f e c t s of dwarf mistletoe on western hemlock. For.Chron. 32(3): 282-296. • I960. Speci-fic g r a v i t y and tracheid length v a r i a t i o n s i n second-growth Western Hemlock. Jour, of For. V o l . 5 8 ( 5 ) . Wilson, D i I 9 6 0 . The Garrett tree farmer. Can. Pulp and Paper Assn. Mech. Note No. 34 . 7pp. Worthington, N.P. and G.R. Staebler. 1961. Commercial thinning of Douglas-fir i n the P a c i f i c Northwest. U.S. Dept. of Agric. Forest Service. Tech. B u l l . No.1230. 124pp. 1961. Tree damage i n thinning Douglas f i r and Western hemlock. Pac.N.W. For. and Range Expt. Sta. Res. Note 202. - - 1961. Cost of thinning 50-year-old Douglas-fir f o r pulpwood at Voight Creek Expt. For. P.-N.W. For. and Range Expt. Sta. Res. Note 215. Wright, E. and L.A. Isaak. 1956. Decay following logging injury to western hemlock, Sitka spruce, and true f i r s . U.S. Dept. A g r i c , Tech.Bui. 1148, 34pp. PRELIMINARY ROAD LOCATION PLAN E.P 2 9 4 EXPER IMENTAL R E S E R V E E A S T T H U R L O W I S L A N D . Revised June /347. : ScaleI Incfj =IO chains. L E G E N D . m ^ ^ m Mdin roads Culvert B r i d g e O l d s W d Re.se.rve, Boundary. Lot Lines Run. Lot Lines Not Run. Ma intain ed Tra i/s. Type. Linens. Sub-typo, Lines. Key Reference, frosts. O l d s t ^ w i ' 1 = 1 2 2  0 / 0 A^ re> Subpiot Number 22 u»vt%iwt m e v c S a ^ ^ U Substitute type for date if not /m mature Areas w/ibin reserve boundaries oniy. Appendix 11 EAST THURLOW ISLAND Research Forest Scale: I inch = 40 chains Loaend Scattered ©3d growth Truck reads Main tractor skid-roods Lasso Cable Road lay-out for alternate thinning plan Hemming Lake //// fay //// T ft/, T I T fa //// T Q = clearcut X=thinnlng Road I ^ Diameter of zero margin log Log Size in D-B-H-temporary loading Road Road I st cut — thinning (I) I st cut — clearcut (I) thinning (2) 2nd cut — clearcut (I) thinning (2) O f 2nd cut — clearcut (2)thinning (3) 3rd cut — clearcut (2)thinning (3) 3rd cut - clearcut (3) 4 th cut - clearcut (3) EAST THURLOW ISLAND Research Forest Scale:I inch=40 chains Fig- 24 Thinning operation lay-out for the Research Forest-Appendix I i EAST THURLOW ISLAND Research Forest Scale-1 inch = 4 0 chains Legend H^H^  Scattered o^ld growth Truck roads — Main tractor skid-roads Lasso Cable Road lay-out for alternate thinning plan 

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