F. W. M. R. Schwarze, J. Engels, C. Mattheck Fungal Strategies ofWood Decay in Trees Springer-V erlag Berlin Heidelberg GmbH Francis W.M.R. Schwarze Julia Engels Claus Mattheck
Fungal Strategies of Wood Decay in Trees
With 63 Figures,43 in Color, and 4 Tables
i Springer Dr. Francis W. M. R. Schwarze Translated by: University of Freiburg Dr. William Linnard Institute for Forest Botany and Tree Physiology 7, Ffordd Las Bertoldstr. 17 Radyr 79085 Freiburg i. Br. Cardiff CF4 8EP Germany UK
Dr. Julia Engels 2, rue du cimetiere 7313 Heisdorf Luxembourg
Prof. Dr. Claus Mattheck Research Center Karlsruhe Institute for Material Research II P.O. Box 3640 76021 Karlsruhe Germany
Title of the original German edition: "Holzzersetzende Pilze in Biiumen - Strategien der Holzzersetzung", published by Rombach Verlag 1999 Ist edition 2000, 2nd printing 2004 ISBN 978-3-642-63133-7 Library of Congress Cataloging-in-Publication Data Schwarze, Francis W.M.R., 1962- [Holzzersetzende Pilze in Băumen: Strategien der Holzzersetzung. English] Fungal strategies of wood decay in trees / Francis W.M.R. Schwarze, Julia Engels, Claus Mattheck. p.cm. lncludes bibliographical references (p. ). ISBN 978-3-642-63133-7 ISBN 978-3-642-57302-6 (eBook) DOI 10.1007/978-3-642-57302-6 1. Wood-decaying fungi. 2. Trees--Diseases and pests. 1. Engels, Julia, 1969- II. Mattheck, C. (Claus), 1947- III. Tide. SB 761 .S29713 2000 634.9'64--dC21
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© Springer-Verlag Berlin Heidelberg 2000 Originally published by Springer-Verlag Berlin Heidelberg New York in 2000 Softcover reprint oftlte hardcover Ist edition 2000 The use of general descriptive names, registered names, trademarks, etc. in tiris publication does not imply, even in ilie absence of a specific statement, tltat such names are exempt from ilie relevant protective laws and regulations and ilierefore free for general use. Cover design: design & production GmbH, Heidelberg Typesetting: cicero Lasersatz, Dinkelscherben Printed on acid-free paper SPIN: 11364085 31/3111 5 4 3 Foreword
Interest in trees, whether in our streets, parks or forests, has in• creased considerably in the last 20 years or so. One reason for this has been the decline and dying of forests, which caused great concern about our environment during the 1980s. Because of the prominence of this event, which is now blamed on abiotic factors, it is all too easy to forget that the life of trees is also affected by a multitude of biotic factors: viruses, bacteria, fungi and animals. These may have very different relationships with trees, but are usually deleterious. The fungi playa particularly important part, and during the course of their evolution they have developed various abilities and strategies in order to obtain nutrients and energy by decomposing wood. On the other hand, the tree has 'learned' to react to external and internal infections. The various interactions between fungi and trees form the main theme of this book. In reviewing this new book I was involuntarily reminded of a work by Robert Hartig over a century ago, entitled Die Zerset• zungserscheinungen des Holzes der Nadelbiiume und der Eiche in forstlicher, botanischer und chemischer Richtung, which laid the foundation of mycological and pathological research on wood. This new book by Schwarze, Engels and Mattheck deserves a place in the ranks of similar works. Moreover, almost comfort• ingly, it shows that progress in biology can still be achieved with• out necessarily resorting to High Tech. This is a book that has been conceived by using classical methods, and which delibera• tely presents the background knowledge essential for expert tree care. It is a happy synthesis of scientific research and practical experience. Accordingly, this book should find wide readership amongst scientists and practitioners, and help us towards a better understanding ofhow our trees co-exist with fungi.
Wolfenbiittel, Germany Heinz Butin Prefaces
During my study on tree care at Merrist Wood College, I was fre• quently faced with the question of whether the stability and safety (fracture resistance) of a fungus-infected tree was impai• red or not. It proved to be extremely difficult to make a reliable decision purely on the basis of fungus identifications. The availa• ble identification books are usually excellently produced, but they provided only inadequate information and assistance for many of the problems arising in practical tree care. They gave scarcely any information on why many fungi cause dangerous damage to trees and others do not. These obvious deficiencies induced me to investigate these questions myself. In my work at the Forest Botany Institute of Freiburg University, these studies have progressed sufficiently to produce this book on the practical requirements of tree care. This book reflects the enormous diversity of fungus decay pat• terns in the wood of living trees. Probably the most important finding is that fungi are extremely adaptable, and can switch from one type of wood decay to another, depending on the pre• vailing conditions. For the tree-care practitioner this means that, when assessing a fungus-infected tree and making a prognosis on its stability, he must make himself familiar with the wood• decay pattern, i.e. the type and manner of degradation of the wood and the individual cell-wall structures. Here, again, it is essential to be familiar with the structure of wood. With nume• rous model drawings and detailed descriptions ofwood degrada• tion by fungi, this book will give the reader a better understan• ding of the effects of decay patterns on the mechanical properties of wood. Such information is also indispensable for interpreting the measurements made during detailed investigations on trees. This book explains various host-fungus interactions for the very first time. Selected examples show what mechanisms fungi use to overcome reaction zones, and why decay by the same fun• gus progresses at different rates, depending on the tree species. Such information will permit improved prognosis of the future development of wood decay in living trees. The intuition of the tree-care expert is important in estimating the threats posed by a fungus-infected tree. This intuition is usually based on a wealth of accumulated knowledge and prac- VIII Prefaces
tical experience. This book will offer much assistance to the inte• rested practitioner by filling gaps in his or her knowledge, and by improving understanding and assessment of the way decay fungi act. This will give new scope for assessing a tree's condition more reliably, and making decisions with greater certainty. My thanks are due to the Karlsruhe Research Centre for fruit• ful collaboration. Over the years, many people have, knowingly or unknowingly, stimulated my enthusiasm for wood-decay fungi. I should like to thank the following in particular for their support in this work: Prof. Dr. Heinz Butin, Wolfenbuttel; Prof. Dr. Sieg• fried Fink, Freiburg; Dr. David Lonsdale and Dr. John Gibbs, Alice Holt Lodge; Ted Green, Windsor Great Park; and Prof. Dr. Ottmar Holdenrieder, Zurich. Various people have kindly supplied or produced photographs and drawings for the illustrations. Special thanks are due to my colleagues, Erwin Franz and Diploma Forester Sebastian Baum, who provided many drawings.
Freiburg, Germany Francis W.M.R. Schwarze
•••
Numerous trammg institutions in the field of tree-care state clearly that practitioners want to give their clients competent advice and answers, so that measures may be decided upon the basis of sound expertise and good background knowledge. However, appropriate and relevant literature is evidently lacking. Also, it seemed timely to summarize in an appropriate form the results of the long-term cooperation between the Karlsruhe Research Centre and Freiburg University in the field of tree care. Accordingly, there are excellent reasons for compiling a syste• matic book, tailored to the needs of practitioners, covering the life and wood-degradation behavior of the commonest and most dangerous wood-decay fungi. In contrast to other comparable studies, this book is distinguished by the fact that it explains the methods of investigation introduced by our colleague Francis Schwarze, and also contains descriptions of probable safety risks. Here, we have also used the latest publications of many expert colleagues. My contribution to this book is the work on the way oflife and wood-decay patterns of root fungi. I was also responsible for the editorial work. A special concern here was to deal with the various aspects in a comprehensible form, and to find a harmo• nious balance between the necessary presentation of professional knowledge and the demands ofbrevity. It is to be hoped that many practitioners will consult this book successfully in their various tasks, and will find in it soundly- Prefaces IX based aids to decision-making. Conversely, we also hope that many colleagues will send us comments from their own practical experience.
Heisdorf, Luxembourg Julia Engels
•••
This book is basically the work of the main author, Francis Schwarze. I am no mycologist. My contribution is modest: a few drawings, and assistance in looking at things from a biomechani• cal standpoint, which is what distinguishes this fungus book from others. For the practitioner facing a fungus-infected tree, the Latin name of the fungus is not so important. Of more interest is how the fungus is affecting the host as regards wood decay, what pro• gnosis emerges from this, and what tree-care measures will result from it or are no longer worthwhile financially. Someone using this book and short of time will probably read Chapter 3 (wood anatomy and kinds of wood decay), first for the mechanical evaluation of decay, and then will turn to Chapter 4 (host-fungus interactions) for making prognoses. The descrip• tion of the individual fungi and the decay they cause can then be studied when one is confronted with the fungus on a particular host. This book is the result of many years of multidisciplinary re• search, and is also a well-formed product of the collaboration be• tween the Karlsruhe Research Centre and Freiburg University.
Karlsruhe, Germany Claus Mattheck Contents
1 Introduction 1
2 Fundamental Aspects...... 5 2.1 Wood Anatomy 5 2.1.1 Structure of the Lignified Cell Wall...... 5 2.1.2 Middle Lamella 6 2.1.3 Primary Wall...... 8 2.1.4 Secondary Wall...... 8 2.1.5 New Information on the Structure of the S2 Layer. . 10 2.2 Mechanical Model for Wood 13 2.3 Types ofWood Decay 16 2.3.1 Brown Rot ...... 17 2.3.2 White Rots: the Whole Spectrum of Diversity...... 22 2.3.2.1 White Rot 22 2.3.2.2 White Rot: Selective Delignification 22 2.3.2.3 White Rot: Simultaneous Rot ...... 25 2.3.3 Soft Rot...... 26 2.3.3.1 Soft Rot in Living Trees Caused by an Ascomycete .. 30 2.3.3.2 Basidiomycetes as Facultative Soft-Rotters 30
3 Examination, Importance and Mechanical Effects ofWood-Decay Fungi in the Living Trees 33 3.1 Fungus Identification 33 3.1.1 Basidiomycetes ...... 34 3.1.2 Ascomycetes 36 3.1.3 Differentiation and Asexual Reproduction of Mycelium 37 3.2 Classification ofWood-Decay Fungi According to Their Main Occurrence in the Tree...... 37 3.2.1 Colonization Strategies of Stem-Decaying Fungi. .. 40 3.2.2 Colonization Strategies of Root-Decaying Fungi ... 43 3.2.2.1 Number of Fungal Fruit Bodies and Their Predictive Value 46 3.2.2.2 Fungus Species Which Invade the Stemwood as Well as the Roots...... 47 XII Contents
3.2.2.3 Root Fungi Found Mainly Only in the Roots ...... 48 3.2.2.4 Wood-Decay Patterns Observable in the Roots..... 48 3.2.3 Factors Influencing Wood Degradation 49 3.2.4 Symptoms of Damage by Fungal Pathogens 51 3.2.4.1 Symptoms of Damage by Stem and Root-Decaying Fungi 56 3.3 Fungus-Host Combinations ...... 59 3.3.1 Fornes fomentarius ...... 59 3.3.1.1 Distribution and Hosts ...... 59 3.3.1.2 Fruit Bodies 59 3.3.1.3 Possibilities of Misidentification...... 61 3.3.1.4 Useful Information 61 3.3.1.5 Appearance of the Decay 61 3.3.1.6 Pattern ofWood Decay by Fornes fomentarius (on Beech and Oak) ...... 62 3.3.2 Inonotus hispidus ...... 64 3.3.2.1 Distribution and Hosts ...... 64 3.3.2.2 Fruit Bodies 65 3.3.2.3 Useful Information 65 3.3.2.4 Appearance of the Decay 65 3.3.2.5 Pattern ofWood Decay by Inonotus hispidus (on London Plane and Ash) 67 3.3.3 Laetiporus sulphureus ...... 70 3.3.3.1 Distribution and Hosts ...... 70 3.3.3.2 Fruit Bodies 71 3.3.3.3 Useful Information 71 3.3.3.4 Appearance of the Decay 73 3.3.3.5 Pattern ofWood Decay by Laetiporus sulphureus (on Robinia and Oak) 73 3.3.4 Fistulina hepatica 76 3.3.4.1 Distribution and Hosts ...... 76 3.3.4.2 Fruit Bodies 76 3.3.4.3 Useful Information 78 3.3.4.4 Appearance of the Decay 78 3.3.4.5 Pattern ofWood Decay by Fistulina hepatica (on Oak) 80 3.3.5 Ustulina deusta ...... 81 3.3.5.1 Distribution and Hosts...... 81 3.3.5.2 Fruit Bodies 82 3.3.5.3 Useful Information 84 3.3.5.4 Appearance ofthe Decay by Ustulina deusta ...... 84 3.3.5.5 Pattern ofWood Decay by Ustulina deusta (on Beech and Lime) 85 3.3.6 Polyporus squamosus ...... 89 3.3.6.1 Distribution and Hosts ... .. 89 3.3.6.2 Fruit Bodies 89 Contents XIII
3.3.6.3 Useful Information 89 3.3.6.4 Appearance of the Decay 90 3.3.6.5 Pattern ofWood Decay by Polyporus squamosus (on Lime and London Plane) 90 3.3.7 Phellinus robustus 94 3.3.7.1 Distribution and Hosts ...... 94 3.3.7.2 Fruit Bodies 94 3.3.7.3 Possibilities ofMisidentification ...... 96 3.3.7.4 Useful Information 96 3.3.7.5 Appearance of the Decay 96 3.3.7.6 Pattern ofWood Decay by Phellinus robustus (on Oak) 98 3.3.8 Fomitopsis pinicola 98 3.3.8.1 Distribution and Hosts ...... 98 3.3.8.2 Fruit Bodies 99 3.3.8.3 Useful Information 99 3.3.8.4 Appearance of the Decay 99 3.3.8.5 Pattern ofWood Decay by Fomitopsis pinicola (on Spruce and Beech) . 101 3.3.9 Heterobasidion annosum . 104 3.3.9.1 Distribution and Hosts . 104 3.3.9.2 Fruit Bodies . 104 3.3.9.3 Possibilities ofMisidentification . 106 3.3.9.4 Useful Information . 106 3.3.9.5 Appearance of the Decay . 107 3.3.9.6 Pattern ofWood Decay by Heterobasidion annosum (on Spruce and Pine) . 107 3.3.10 Meripilus giganteus . 110 3.3.10.1 Distribution and Hosts . 110 3.3.10.2 Fruit Bodies . 110 3.3.10.3 Useful Information . 112 3.3.10.4 Appearance of the Decay . 113 3.3.10.5 Pattern ofWood Decay by Meripilus giganteus (on Beech and Lime) . 113 3.3.11 Armillaria spp . 116 3.3.11.1 Distribution and Hosts . 116 3.3.11.2 Fruit Bodies . 117 3.3.11.3 Useful Information . 117 3.3.11.4 Appearance of the Decay . 118 3.3.11.5 Pattern ofWood Decay by Armillaria (Armillaria ostoyae on Spruce; Armillaria mellea on Maple) . 120 3.3.12 Ganoderma spp , 122 3.3.12.1 Distribution and Hosts . 122 3.3.12.2 Fruit Bodies . 122 3.3.12.3 Useful Information . 123 3.3.12.4 Appearance of the Decay . 124 XIV Contents
3.3.12.5 Pattern ofWood Decay by Ganoderma spp. (Ganoderma pfeifferi on Oak; Ganoderma applanatum on Broad-Leaved Lime) 124 3.3.13 Grifola frondosa 128 3.3.13.1 Distribution and Hosts 128 3.3.13.2 Fruit Bodies 129 3.3.13.3 Useful Information 129 3.3.13.4 Appearance of the Decay 129 3.3.13.5 Pattern ofWood Decay by Grifola frondosa (on Oak) 131 3.3.14 Inonotus dryadeus 131 3.3.14.1 Distribution and Hosts 131 3.3.14.2 Fruit Bodies 133 3.3.14.3 Useful Information 133 3.3.14.4 Appearance of the Decay 136 3.3.15 Pholiota squarrosa 138 3.3.15.1 Distribution and Hosts 138 3.3.15.2 Fruit Bodies 138 3.3.15.3 Useful Information 138 3.3.15.4 Appearance of the Decay 138
4 Host-Fungus Interactions: Development and Prognosis of Wood Decay in the Sapwood ...... 139 4.1 Introduction ...... 139 4.2 The CaDIT Model ...... 141 4.3 Host Response Mechanisms in the Sapwood ...... 143 4.4 Different Response Mechanisms in Heartwood and Sapwood ...... 147 4.5 The Importance ofWalls 1-3 from the Mycological Standpoint ...... 148 4.5.1 The Importance ofWalls 1-3 of the CaDIT Model in Heartwood and Ripewood and Their Anatomical Interpretation ...... 148 4.5.2 The Importance ofWalls 1-3 in Sapwood: the Reaction Zones ...... 151 4.6 Reaction Zone Penetration, as Exemplified by Inonotus hispidus ...... 153 4.6.1 Inonotus hispidus in a London Plane Tree ...... 153 4.7 Example of Strong Compartmentalization of Ustulina deusta in a Healthy Beech Tree ...... 155 4.8 Examples ofWeak Compartmentalization of Ustulina deusta in a Weakened Beech Tree ...... 156 Contents XV
4.9 Ustulina deusta in Lime Trees 158 4.10 The Behavior ofStrong and Weak Compartmentalizers in the Host-Fungus Interaction ...... 158 4.11 Xylem Rays as the Tree's Achilles Heel in Host-Fungus Interactions 160 4.12 Cracks as 'Motorways' for Fungi 162 4.13 The Importance of the Barrier Zone (Wall 4) 163
Postscript 169
References 171
Index 183