THE AFTERLIFE OF A TREE The authors of appendices at the end of the book are: A. Bobiec, B. Jaroszewicz, A. Keczyński, A. Szymura, K. Zub Photographs by: J. Walencik, J.M. Gutowski, K. Zub, A. Bobiec, J. Korbel, J. Baake, C. Bystrowski, M. Czasnojć, W. Janiszewski, Z. Kołudzki, K. Sućko Drawings by: M. Bobiec, M. Waszkiewicz, P. Galicki Andrzej Bobiec (editor) Jerzy M. Gutowski Karol Zub Paweł Pawlaczyk William F. Laudenslayer THE AFTERLIFE OF A TREE 4 This publication is one of the actions taken by WWF Poland to help safeguard the largest remnant of natural forests in Europe – the Białowieża Primeval Forest. We thank the photographers for their authorisation for use of their pictures without charge. Without their courtesy, the cost of the publication would have been much higher and we would not have been able to publish at this time. © copyright by: WWF Poland Warszawa – Hajnówka 2005 ISBN 83-920712-1-2 Publisher: WWF Poland with: Foundation of Environmental and Natural Resources Economists Project co-ordinator: Stefan Jakimiuk – WWF Poland English revision: Johanna Willi Editorial revision: Simon J. Grove Rewiews: Janusz B. Faliński , Mark E. Harmon, Sven G. Nilsson, Czesław Okołów, Ludwik Tomiałojć Photographs on the cover: J. Korbel Graphic and typographic design: Andrzej A. Poskrobko Pre-press: Pracownia Składu Komputerowego i Usług Edytorskich w Białymstoku Print: BIELDRUK Drukarnia Wiewiórcza 66, 15-532 Białystok POLAND www.bieldruk.pl THE AFTERLIFE OF A TREE 5 CONTENTS Chapter 1. INTRODUCTION ______________________________________________________________________ 7 1.1. How long do trees live? _____________________________________________________________ 12 1.2. What is wood? ___________________________________________________________________ 13 Chapter 2. DYNAMICS OF DEAD WOOD 2.1. Dead wood in forests ______________________________________________________________ 18 2.2. Dead wood in parks and groves _______________________________________________________ 24 Chapter 3. LIFE AFTER DEATH 3.1. Stages in and consequences of the death of trees ________________________________________ 30 3.2. How does life continue in dead trees? Colonisation of dead trees and dead wood ________________ 36 Chapter 4. DYING AND DEAD WOOD IN LIVING FORESTS 4.1. Dying and dead wood as a wildlife habitat _______________________________________________ 44 4.1.1. Vertebrates __________________________________________________________________ 44 4.1.2. Invertebrates ________________________________________________________________ 62 4.1.3. Algae, bryophytes, liverworts and vascular plants _____________________________________ 94 4.1.4. Fungi ____________________________________________________________________ 107 4.1.5. Slime moulds: myxomycetes ____________________________________________________ 129 4.1.6. Lichens ____________________________________________________________________ 130 4.2. From forest fuel to stream course modification __________________________________________ 134 4.2.1. Forest ‘fuel’ _________________________________________________________________ 134 4.2.2. Stocking organic matter _______________________________________________________ 134 4.2.3. Carbon and nitrogen accumulation _______________________________________________ 137 4.2.4. Dead wood as a water reservoir _________________________________________________ 140 4.2.5. Role of dead wood in tree regeneration ___________________________________________ 141 4.2.6. Stabilisation of steep slopes by dead trees _________________________________________ 149 4.2.7. Role of dead wood in surface water retention and stream course modification _____________ 150 4.2.8. Role of uprooted and dead wood in soil processes ___________________________________ 152 THE AFTERLIFE OF A TREE 6 CONTENTS Chapter 5. DEAD WOOD IN FOREST MANAGEMENT AND NATURE CONSERVATION 5.1. Dead wood in forests – time to rethink the paradigm _______________________________________ 158 5.2. Dead wood and conservation _________________________________________________________ 167 5.3. Fire: an alternative mechanism of reducing dead wood to its components ________________________ 176 Chapter 6. DEAD WOOD IN SCIENCE AND THE ECONOMY ______________________________________________ 185 Chapter 7. WOOD AS A RAW MATERIAL ____________________________________________________________ 195 Chapter 8. SUMMARY ____________________________________________________________________ 203 APPENDICES I. Methods of qualitative and quantitative assessment of dead wood ______________________________ 210 II. Educational workshop: “What are dead trees for?” ___________________________________________ 217 Index of animals, plants and fungi - scientific and English names __________________________________ 227 THE AFTERLIFE OF A TREE Chapter 1 INTRODUCTION 8 Chapter 1 Below, like wrecks of cities, on the ground Vast, fallen oak-trees spread their ruin round; A trunk like shattered walls and columns seems; Here are branched stumps and there half-rotted beams, Hedged in with grass. (...) For when to pass the outskirts you are able And the dense tangled copses, you will come Upon a mighty rampart, in the gloom, Of stumps, logs, roots, defended by a mire, A maze of streams, a net of weeds and briar, And anthills, nests o wasps and hornets keen; And slimy coils of serpents there are seen. (“Pan Tadeusz” Adam Mickiewicz, translated by W. Kirkconnell The Polish Institute of Arts and Sciences in America, New York, 1962) A forest ecosystem is comprised not only of an assemblage of living trees or ‘a stand’ which provides the most significant part of the forest biomass, but it also includes all other plants and organisms living within this environment. This space includes the soil, with areas overshadowed by the trees’ canopy, as well as open, treeless patches such as glades and gaps overgrown by shade intolerant vegetation and inhabited by specific fauna often different from that occupying the shaded areas of the stand. A forest such as the one described is a dynamic system, in which the growth and development of trees and their death and decay determine the temporal and spatial patterns of a variety of continuously ongoing processes. This network of interdependent species and their associations means that a change in any single element in the system can result in changes to other components, while the entire stand remains in a dynamic quasi-equilibrium for long periods of time. Polish forests exhibit great variability in terms of species composition, structure and human impacts, from single-species plantations and multiple use managed fo- rests, through to forests almost excluded from direct human activity and retain- ing many characteristics typical of natural systems. The present book is devoted to dead wood, mainly in forests subjected to minimal management. Despite the focus of the book on semi-natural forests, dead wood is also necessary in ma- naged forests and amounts generally found there ought to be increased. Dead wood and old, hollow trees are essential to a functioning forest ecosystem and necessary for the conservation of a myriad of species including some that are endangered. In recent years the value of dead wood for a variety of forest organisms and its function in the ecosystem have been identified. However, these discussions usually address the value of dead wood to only a few organisms and rarely is the significance of dead wood to the entire system explored. Perhaps more impor- THE AFTERLIFE OF A TREE INTRODUCTION 9 tantly, very little information on the value of dead wood has been communicated to the general public. The goal of this book is to provide the general reader with sufficient knowledge to understand the processes that create and remove dead wood as well as the value of dead wood to forests and their inhabitants. We have provided references for more specialised literature at the end of each chapter and hope that the inquiring reader will utilise this information. Dead wood – what is it? Wood, in general, is the basic structural material that supports trees and shrubs. It is mainly composed of dead tissue (more than 90% of the total weight), but it also contains living cells. “Dead wood” is not a precise term, but is used to communicate the ideas about dead wood in a more under- standable fashion. To be more accurate, one should speak about decaying wood J. Walencik J. Photo 1. Białowieża Primeval Forest THE AFTERLIFE OF A TREE 10 Chapter 1 of dead woody plants or of their parts. When we talk about dead wood, we do not mean growing, living trees, but dead specimens (standing or fallen trees) or their parts (fragments of stems, branches, roots, stumps, etc.). We rarely mean the wood, living or dead, of a living tree or shrub. It would therefore be sufficient to refer to “wood” without additional descriptions, however, we have decided to use the adjective “dead” to avoid any misunderstanding. Biodiversity: Forests are the most complex and structurally rich as well as the most abundant is the variety of forms of life in a given area, usually considered at three levels of the terrestrial vegetation assemblage on earth in terms of organisms. Of all terres- ecological hierarchy: genetic or the variety of trial organisms, half of the species are associated with forests and this number genes within given populations; the variety of is expected to climb as knowledge about organisms found in tropical forests species (species richness), and the assemblages increases. Dead trees and shrubs and their parts are integral components of a of ecosystems