Springer Series in Wood Science Editor: T. E. Timell M. H. Zimmermann Xylem Structure and the Ascent of Sap (1983) J.E Siau Transport Processes in Wood (1984) R.R. Archer Growth Stresses and Strains in Trees (1986) W.E. Hillis Heartwood and 'free Exudates (1987) S. Cariquist Comparative Wood Anatomy (1988) L. W. Roberts(P.B. Gahan/R. Aloni Vascular Differentiation and Plant Growth Regulators (1988) C. Skaar Wood-Water Relations (1988) J.M. Harris Spiral Grain and Wave Phenomena in Wood Formation (1989) B. J. Zobel! J. P. van Buijtenen Wood Variation (1989) Bruce J. Zobel· Johannes P. van Buijtenen Wood Variation Its Causes and Control With 98 Figures Springer-Verlag Berlin Heidelberg New York London Paris Tokyo Prof. Dr. BRUCE J. ZOBEL Zobel Forestry Associates, Inc. P. O. Box 37398 Raleigh, NC 27627, USA Dr. JOHANNES P. VAN BUlJTENEN Head, Reforestation Department Texas Forest Service and Professor Forest Science Department, Texas Agricultural Experiment Station Texas A&M University, College Station Texas 77843, USA Series Editor: T.E. TIMELL State University of New York College of Environmental Science and Forestry Syracuse, NY 13210, USA Cover: Transverse section of Pinus lambertiana wood. Courtesy of Dr. Carl de Zeeuw, SUNY College of Environmental Science and Forestry, Syracuse, New York ISBN-13: 978-3-642-74071-8 e-ISBN-13: 978-3-642-74069-5 001: 10.1007/978-3-642-74069-5 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustrations, recitation, broadcasting, reproduction on microfilms or in other ways, and storage in data banks. Duplication of this publication o'r parts thereof is only permitted under the provisions of the German Copyright Law of September 9, 1965, in its version of June 24, 1985, and a copyright fee must always be paid. Violations fall under the prosecution act of the German Copyright Law. © Springer-Verlag Berlin Heidelberg 1989 Softcover reprint of the hardcover 1s t edition 1989 The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regula tions and therefore free for general use. Typesetting: K+ V Fotosatz GmbH, Beerfelden 213113145-543210 - Printed on acid-free paper This book is dedicated to Dr. H. E. Dadswell Much of the best early work on wood variation was done in Australia by Dr. H. E. Dadswell, who was a leader in stimulating research on a world basis and who had a very strong influence on the concepts and ideas expressed in this book. Although not formally a teacher, he taught many persons about the importance and recognition of wood variability and the necessity to use this knowledge. Dr. Dadswell had a major influence on the philosophies, ideas, and knowledge of the authors about wood variation, as well as on the whole field of wood utilization. Preface Wood is the usual end product of a forestry operation. Because of its importance, numerous studies have been made relative to wood prop erties, the causes of wood variation, and how best to develop wood for desired products. There is voluminous literature related to these subjects, but it is neither well known nor appreciated by foresters because the publications are often not available or are not well understood by the forester or by those who use the wood. Frequently, the literature is confusing and contradictory, making it difficult for the nonspecialist to use what information is available. In order to produce and use wood efficiently, the variation pat terns within trees, among trees within species, and among species must be understood. This also requires some knowledge of the causes of variation and the effects of different wood properties upon utiliza tion. The information about variation patterns, their causes, and con trol and effect upon the product must be known by the tree grower, the tree breeder, and the tree harvester as well as by those who ultimately convert wood into a final, salable product. It is the objective of this book to take the vast amount of informa tion available on wood variation, its causes, and control and sort it out, categorize it, and summarize the main concepts and trends for the reader. We will attempt to separate the important from the unim portant and to emphasize those concepts that are based upon the best and most reliable information available to us. Unfortunately, many studies relating to variation in wood are of limited value, and sometimes even leave the wrong impression, because the studies were too limited, were incomplete, violated biological principles, or were poorly designed or analyzed. The book is much more than a literature review in that it contains frequent summaries of the literature plus the stated attitudes and ex periences of both of us whose entire professional careers have dealt with wood quality, wood variation, the genetic control of wood, and utilization of wood. Special emphasis will be placed on the wood of tree species that are grown as exotics; this is done because exotic forestry is rapidly increasing in importance and wood of the exotic species sometimes has marginal utility when the trees are grown in the new environments. Additionally, some especially troublesome prob lems relative to wood have arisen when forest trees are grown in exotic environments that differ from those of the indigenous range of the species. These shortcomings must be recognized and corrected as much as possible through silvicultural manipulation, through the ap- VIII Preface plication of genetics, and through improved and innovative manufac turing technology. Wood is a very variable substance, with differences occurring among species and genera, among geographic sources within a species, among trees within a geographic source as well as within each individual tree. 1tee to tree variability is especially large, with dif ferences within a species often being strongly genetically influenced. The book will concentrate on the possible methods of producing more uniform and usable wood. The greater the uniformity of wood available for manufacturing, the greater will be the efficiency of pro ducing a specific product, and the quality of the final product will be much improved. When forests are well managed, wood is truly a renewable resource. As explained in the text, when the best forest management practices and genetic manipulation currently available are used, it would appear that wood production can be easily quadrupled on a world basis. It is our opinion that it should be possible to again dou ble the wood produced in the world as improved biology and better forest management, along with better utilization methods, are devel oped. Although not the major objective of this book, the subject of the effect of differing wood qualities on manufactured products will be briefly covered throughout the text. This is done to illustrate the im portance of wood variation and its control. No attempt is made to cover completely the effects of different woods on manufactured products. The book should be of value as a reference to the practicing forester and wood utilization specialist. It summarizes results of methods to produce more valuable wood in forestry practice. It helps the user to understand the magnitude and importance of wood varia tion so that manufacturing can be more efficient. It is written in such a way that it can be used as a textbook both in forestry and in wood science; both solid wood and fiber products are included in the discussions. January 1989 Bruce J. Zobel J. P. van Buijtenen Acknowledgments It is only through the generous help of many others that this book was made possible. The authors are most grateful to those persons who made suggestions and corrections, edited chapters, and supplied data, graphs, and photographs. The authors thank Dean Eric Ell wood, School of Forest Resources, North Carolina State University, Raleigh North Carolina for financial help in preparation of the book. Following is an alphabetical listing of those who contributed to the development of the book: Name Organization Location Jeanne Adams Office Options, Inc. Cary, North Carolina Pieter Baas Rijksherbarium l.eiden, Netherlands l.eop01do Brandao Aracruz Florestal Rio de Janeiro, Brazil Edgard Campinhos Aracruz Florestal Aracruz, Brazil J. A. Cisconetti Aracruz Celulosa S. A. Vito ria, Brazil Ergilio Claudio-da Aracruz Celulosa S. A. Vito ria, Brazil Silva Jr. Dean Einspahr The Institute of Paper Appleton, Wisconsin Chemistry J. Maddern Harris Forest Research Rotorua, Institute New Zealand Ted Hillis CSIRO Melbourne, Australia J ara Ikemori Aracruz Florestal Aracruz, Brazil Wolfgang Knigge Universitat Gottingen Gottingen, Germany Phillip Larson U. S. Forest Service Rhinelander, Wisconsin William Ladrach Zobel Forestry Asso- Cary, North Carolina ciates, Inc. Siegfried l.ewark Institute fUr Forst- Universitat Gottingen, nutzung Germany w.J. Lowe Texas Forest Service College Station, Texas Hal Martin Omni Engineering Raleigh, North Carolina X Acknowledgments Name Organization Location Craig McKinley Texas Forest Service College Station, Texas Ted Miller Professor Emeritus North Carolina State University, Raleigh, North Carolina Gerard Nepveu Station de Recherches Nancy, France sur la Qualite des Bois Ted Palmer Tropical Products London, England Inst. Hubert Polge Centre Nat'l de Nancy, France Recherches Foresteres Beatriz Vera Companhia Florestal Monte Dourado, Pozzi Redko Monte Dourado Brazil Tony Shelbourne Forest Research Rotorua, Institute New Zealand Hank van der Sijde South African Pretoria, South Forestry Research Africa Institute John Talbert University of Seattle, Washington Washington Fred Taylor Mississippi State Starkville, Mississippi University Tore Timell State University of Syracuse, New York New York Gerrit van Wyk South African Forest Pretoria, South Research Institute Africa Michael Veal Weyerhaeuser Co. Tacoma, Washington Alvin Yanchuk University of Alberta Edmonton, Alberta, Canada Barbara Zobel Zobel Forestry Asso- Cary, North Carolina ciates Contents 1 Wood Variation and Wood Properties 1.1 What Is Wood? .................................... 1 1.2 Kinds of Trees and the Wood Produced by Them. . . . . . . 3 1.3 Important Wood Properties . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.4 Wood Specific Gravity (Wood Density) . . . . . . . . . . . . . . . . 8 1.4.1 What Determines Wood Specific Gravity? . . . . . . . 9 1.4.2 The Importance of Specific Gravity ............ 15 1.5 Cell Length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.6 Other Wood Characteristics . . . . . . . . . . . . . . . . . . . . . . . . .. 20 1.7 Cell Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23 1.8 Factors Controlling Wood Properties . . . . . . . . . . . . . . . . .. 25 1.8.1 The Change from Earlywood to Latewood ...... 26 1.9 Different Woody Tissues. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28 1.9.1 Reaction Wood... . . .. . ... .... . . .... . . .... . .. 29 1.9.2 Juvenile Wood............................... 30 1.10 Relationships Among Wood Properties.. ...... . ....... 30 1.11 The Literature Related to Wood Variation ............. 32 2 The Effect of Provenance Variation and Exotic Plantations on Wood Properties 2.1 The Effect of Differing Environments on Wood Properties ......................................... 33 2.2 Provenance Variation in Wood from Natural Stands Within the Range of a Species ....................... 37 2.2.1 Examples of Provenance Variation in Wood Properties in Natural Stands. . . . . . . . . . . . . . . . . .. 38 2.2.2 A Summary of Provenance Variability in Wood from Natural Stands.. .. . ... .... . . . .... . . ..... 46 2.3 Wood Variation Related to Species and Provenance in Plantation-Grown Trees. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 47 2.3. . 1 Examples of the Effect of Provenance upon Wood Properties of Trees in Plantations ........ 49 2.4 Wood Properties of Trees Grown as Exotics. . . . . . . . . . .. 56 2.4.1 General Considerations. . . . . . . . . . . . . . . . . . . . . .. 56 2.4.2 Changes of Wood Properties in Exotics . . . . . . . .. 58 2.4.3 Wood Properties of Exotic Conifers - General .. 58 2.4.3.1 The Tropical Pines - Pinus caribaea Example. .. 59 2.4.3.2 Conifers from Temperate Regions. ..... . . . ..... 65 2.4.3.3 Summary - Wood Properties of Exotic Conifers 66 2.4.4 Wood Properties of Exotic Hardwoods. . . . . . . . .. 67