METHODS FOR DESCRIBING DISTRIBUTION OF SOUNDWOOD IN MATURE WESTERN HEMLOCK TREES by DONALD D. MONRO B.S.F„, University, of British Columbia, 1960 M.S., Oregon State University, 1964 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in the Department of FORESTRY We accept this thesis as conforming to the required standard . THE UNIVERSITY OF BRITISH COLUMBIA May, 1968 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and Study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by hiis representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of The University of British Columbia Vancouver^ 8, Canada . ABSTRACT Supervisor: Professor J. H. G. Smith Estimation of soundwood volume and value is particularly important in British Columbia because nearly half of the forests are overmature or decadent. The objective of this thesis was to develop -analytical techniques to define distribution of gross and net volumes within individual standing trees in order that appropriate reductions for decay could be made for estimates of volumes of logs of specified sizes and grades. Relationships of heartr-ot to stand and tree characteristics and to external abnormalities were analysed for 369 western hemlock (Tsuga heterophilla (Rafn.) Sarg.) trees from the Yale Public Sustained Yield Unit in British Columbia. Comprehensive sorting, correlation and regression analyses were carried out on an I. B. M. 7044 electronic computer. One multiple regression equation provided estimates of total decay volume within individual trees from DBH, total height and external indicators of decay. It had a standard error of estimated decay volume of 18.7 cubic feet (19.5 per cent). A second equation estimated decay volume within individual logs in standing trees from the above variables and from section height. It had standard errors of estimate ranging from 13.7 cubic feet (31.6 per cent) in butt logs to 0.1 cubic feet (2.9 per cent) in top logs. The best taper function which could be derived to estimate upper stem diameters inside bark had a standard error of estimate of 1.29 inches using measures of DBK and total height. Combination of the log and tree decay estimating functions and the taper function facilitated complete description of.the soundwood volumes in the sample of 369 trees. A graphical analysis was developed whereby percentages of trees in a stand with more or less than specified decay volumes could be estimated. Preliminary chemical studies of western hemlock wood infected with Echinodontium tinetorium E. and E. indicated that cellulose yields were slightly less than those from soundwood. Such partly decayed wood might be used for the manufacture of pulp without serious reductions in yield on a volume or weight basis. Further research is needed to substantiate the possible cyclic nature of decay losses and to determine the influence of bark thickness and natural pruning on the distrubution of decay within individual trees. Application of the analytical techniques developed for western hemlock to other species should result in more precise estimates of soundwood volumes and values, thereby contributing to improved management planning and utilization. Ill ACKNOWLEDGEMENTS The author wishes to express his thanks and appreciation to the following: The late Dr. J. E. Bier for helpful suggestions during the planning stages of the study. Dr. Bier was to have served as Co- chairman of my Supervising Committee. M.W. Bradshaw for assistance in providing data and for many hours of patient explanation and discussion. The British Columbia Forest Service, Inventory Division, for provision of the basic stem analysis data used herein. The Computing Centre, University of British Columbia, for provision of computing facilities. The Faculty of Forestry, University of British Columbia, especially Dean J. A. F. Gardner, for financial assistance and pro• vision of office and laboratory space. Dr. R.E. Foster for helpful analytical advice and review of the manuscript. Dr. R. W. Kennedy for advice in experimental design and chemical analyses of decayed wood and review of the manuscript. J. Kiss for cheerful assistance and guidance during field observations near Blue River, B.C.. Dr. A. Kozak who regularly acted as my statistical ''sounding board" and who, from time to time, extricated me from seemingly unresolvable computer programming difficulties. MV Lambden for draughting the figures. The National Research Council of Canada for financial assistance for a field trip. Dr. Vidar J: Nordin for provision of listings from the INTREDIS Register System for Literature Retrieval in forest pathology. Dr. J. H. G. Smith for inspiration, encouragement and constructive criticism throughout the study. Dr. R. W. Wellv/ood for suggestions during the preparation of the literature review and for review of the manuscript. E. L. Young for permission to use the data collected by the -Inventory Division of the British Columbia Forest Service. F. Adams, M. Jackson and G. Plester for assistance in data coding and laboratory analyses. T. Bapty, D. MacLelian and L. Polonich for typing the manuscript. Numerous North American forest pathologists who so kindly responded to my mail survey of the status of work in this field. Finally, I wish to express my special appreciation to my wife Nona, and to my sons Lance and Deane for their patience, understanding, encouragement and sacrifice throughout this study, particularly during the latter stages of manuscript preparation. TABLE OF CONTENTS ABSTRACT ACKNOWLEDGEMENTS... TABLE OF CONTENTS LIST OF TABLES. ................ LIST OF FIGURES ... LIST OF PHOTOGRAPHS . ..... ..... • . CHAPTER I INTRODUCTION .... CHAPTER II LITERATURE REVIEW. ....... Important Heartrot Fungi in British Columbia's Forests. ... Echinodontium tinctorium E. and E. Fomes pini (Thore) Lloyd Important Heartrot Fungi in Western Hemlock Environmental Conditions Required For Fungal Establishment and Growtb. Food Air . Temperature Moisture Decay Resistance Regional variation Sapwood-heartwood relationships . © vi Page Position in tree '.' 26 Effects of Decay on Wood Quality. 26 Chemical 26 Mechanical .... ............... 27 Specific Gravity ......... 29 Color. ................... 29 -Moisture-holding-capacity 30 Utilization of Decayed Wood ............... 31. Pulp . 31 Other manufactured products. 34 Relationships Among Tree and Stand Age, DBH, Site Quality and Decay. 35 External Indicators of Decay. 40 Distribution of Log Size and Gross , Volume Within Trees . 50 Conclusion 53 CHAPTER III DATA COLLECTION AND INITIAL;, SUMMARIZATION . 55 CHAPTER IV DEVELOPMENT OF TREE DECAY . FACTORS 93 Selection of Equation Form 93 Results and fiiscussion. 94 Conclusion 101 CHAPTER V DEVELOPMENT OF LOG POSITION DECAY FACTORS 108 Selection of Equation Form 108 Results and Discussion • Ill vii Page Conclusion. .............. 119 CHAPTER VI DEVELOPMENT OF TAPER.FUNCTION ......... 120 Derivation of Basic Function 120 Results and Discussion. ' 122 : Conclusion. 131 CHAPTER VII ESTIMATION OF VOLUME AND VALUE OF SOUND AND DECAYED WOOD. ............ 136 Estimation of Tree and Stand Volumes and Values. ... '." . 136 Estimation of Log Volumes and Values 142 Estimation of Cellulose Quantity and Quality in Decayed Wood. 146 Laboratory procedures 147 Results and discussion 148 Conclusion 153 CHAPTER VIII SUMMARY AND SUGGESTIONS FOR FURTHER RESEARCH 154 LITERATURE CITED . 158 APPENDIX I Log position decay factors for western hemlock 169 APPENDIX II Comparison of estimated per cent, of gross tree volume decayed 'from tree decay equation (A) and log ; ' position decay equation (B) for ' . several suspect classes'. ." ..• v '. 1178 APPENDIX III Taper table for'western hemlock• 180 APPENDIX IV Tabulation (Part I) and explanation (Part II) of values derived during calculation sequence for estimation oof gross and net cubic foot volumes by log position within a tree . APPENDIX V Tree stem and decay profiles for three western hemlock trees . ix LIST OF TABLES able . Page f 1 Area classification .of British Columbia. ...... 1 2 Volumes in British Columbia forests 3 3 Gross volumes of commercial species on commercial forest land in British Columbia. ........ 4 4 Total volume of accumulated decay in trees 10 in. DBH+ in forests in British Columbia 5 5 Soundwood, decay and gross volume in coast and interior forests 5 6 Average annual decay losses in forests in British C O XllTTlL) 13. • • • • • . • • • • • • . • • • • • 7 7 Comparison of annual decay loss and annual growth in the forests in British Columbia 7 8 Common butt rots and host species. ... ..... 10 9 Common trunk rots and host species . 11 10 Relative infections and decay volumes for important heartrots of western hemlock in several geographic locations 19 11 Pathological age classes defined by the British Columbia Forest Service 37 12 Influence of age and site on the proportion of trees with visible indications of defects • 41 13 Distribution of tree classes by DBH classes for western hemlock in five Public Sustained Yield Units (P. S. Y. U.) in British Columbia 42 14 Per cent decay in western hemlock trees having varying numbers of sporophores ........... 46 15 Distribution of decay