Trees, Truffles, and Beasts

Also See: Table of Contents | Endorsements | Special Acknowledgments

FOREWORD

We depend on forests, yet we know less about them than we should. Forests are thought by many to be economic engines, providing wood for construction and fuel and wood chips for paper. Even as tourists, we view forests as a vista of trees, cloaking mountains and valleys. In this book, three wise men tell us there is much more that we should be seeing when we look at forests. Concentrating on their personal experiences in the Pacific Northwest of North America and southeastern Australia, they take us on an ecological and historical tour to open our eyes to the complexity of the ecological webs that support forests.
Ecologists have been like most people in ignoring the soil. It has been left to agricultural scientists and some foresters to begin to investigate soil ecology. The stimulus to these investigations has been largely practical—why are these crops not growing? And how can we increase tree growth for more wood production? The role that fungi play in plant growth was not understood in the 1800s when agricultural scientists began to investigate limiting factors in soils. Fungi were viewed as decomposers and disease agents, and not as essential players in the growth of living plants. An astute botanist, Albert Bernhard Frank, professor of plant pathology at the Royal College of Agriculture in Berlin, suggested in 1885 that mycorrhizae formed by certain fungi with tree roots were in fact beneficial to the plants. Many scientists rejected his idea for decades that the association of fungi with roots was a mutualistic symbiosis, or a win-win interaction, because it was against the conventional wisdom that fungi caused disease and decay. Clearly, some fungi might be nice to eat, but that was as far as it went.

Coniferous forest in the Pacific northwestern United States
During the last fifty years, ecologists have begun to appreciate the significance of fungal mutualisms to tree growth and survival. Coupled with this growing interest has been the application of aboveground ecological ideas to soil biology. Predator-prey dynamics, competition, dispersal, and community dynamics are all the subject of soil biology today.
We were even late to discover the importance of fungal foods to animals. Many examples in this book will capture your imagination because they seem so highly improbable. How do California red-backed voles in old-growth forests of the Pacific Northwest survive on a diet that is almost entirely composed of fungi? How does the long-nosed potoroo of eastern Australia locate the great diversity of fungal species in its diet when many of these species fruit below ground? Read on and you will discover a wealth of information on how animals use fungi as food sources.

Eucalypt forests in southeastern Australia
But it is events going on above ground that equally strongly affect the forests of the earth. Harvesting of trees has created a fragmentation of forests across the landscape, and we only dimly understand the implications of forest fragmentation for the plants and the animals dependent on them. We replant forests without always appreciating the fungal associations necessary for success. We suppress fires on the mistaken view that fire is a destructive economic force and must be minimized, with the result that our forests accumulate fuel loads that spell disaster if and when a fire is ignited.
The message of this book is that we must view forests as a complex system of interactions. The first message of complex system theory is that you cannot change just one thing. Humans operate with limited scope on the assumption that since they are doing only one thing, it will be easy to rectify if something unexpected happens. The second message of complex system theory is that you cannot easily undo mistakes. Management actions, like fire prevention or its opposite too frequent burning, unleash a cascade of biological interactions that we cannot predict. The eternal optimism of the manager that we know what to do to achieve a short-term goal must be replaced by an ecological realism based on the kinds of complexities you will discover in this book.
There is yet much work to do, and that is another message that flows from this book. The ecologist treats good news stories, like the recent methods for growing one of the world's most expensive fungus, Perigord truffles, in North America, with mixed happiness because the introduction of new species of fungi are not always ecological successes, even if they boost the economy. We should tread lightly on natural systems as we gather the detailed kinds of ecological insights that we find summarized in this book.
The ultimate issue of all of our human interactions with nature is whether what we do is sustainable in the long term. Many business leaders and politicians now use sustainability in "motherhood statements," but if we are serious about achieving this essential goal we must find out what human activities must be started and what must be stopped. Most now seem to agree that stopping the increase in carbon dioxide emissions is an absolute requirement of sustainability, but if we wish to sustain our forests, what do we need to change? This book is a start in answering this very large question on which the world depends more than it appreciates.
The last message of this very readable book is that science is a search of discovery done by interesting human beings turned loose in a new world in which too little is known. There is much more to the forests of the Earth than the Pacific Northwest and south-eastern Australia, and we see a good start here. But it is the tropical forests that remain the great challenge for this century, and I can only hope that some of the readers of this book will be challenged to carry these ideas into forests in other parts of the Earth. Science never stops, and this is a good progress report to see why.
Charles Krebs
Emerits Professor of Zoology
University of British Columbia
Vancouver, Canada;
Fellow Emeritus of Wildlife and Ecology,
Commonwealth Scientific and Industrial Research Organization
Canberra, Australia; and
Adjunct Professor
University of Canberra
Canberra, ACT 2601
Australia

TABLE OF CONTENTS

INTRODUCTION
Scope of This Book—From the Microscope to Infinity
Forests Are a Study in Complexity
Soil is Every Forest's Foundation
People and Forests Are Inseparable
CHAPTER 1: THE FOREST WE SEE
Composition, Structure, and Function
Pacific Northwestern United States and Southeastern Mainland Australia

CHAPTER 2: THE UNSEEN FOREST
The Genesis of Soil

Physical Weathering
Chemical Weathering
The Addition of Organic Material to Mineral Soil

The Living Community within the Soil

The Nitrogen Fixers
Scavengers, the Recyclers in the Soil
The Environment Is a Seamless Whole

CHAPTER 3: TREES, TRUFFLES, AND BEASTS—COEVOLUTION IN ACTION
In the Beginning
Mycorrhizae Enter the Scene
Fungal Nourishment: Decomposition and Symbiosis

Global Diversification of Organisms, Unification of Functions
Host Specificity and Forest Succession
Trees, Truffles, and Beasts: Spore Dispersal through Mycophagy

CHAPTER 4: OF ANIMALS AND FUNGI
Obligate Mycophagists
Preferential Mycophagists
Casual or Opportunistic Mycophagists
Accidental Mycophagists
Preferences in fungal diets
Invertebrate mycophagists

CHAPTER 5: THE IMPORTANCE OF MYCOPHAGY
The Fungal Feast: Nutritional Rewards of Mycophagy

Macroelements
Microelements
Proteins and Amino Acids
Carbohydrates
Fats and Fatty Acids
Vitamins
Nutrient Availability, Symbiosis, and Digestive Strategy
Truffle Diversity, the Key to Mycophagist Nutrition

Ecosystem Services of Mycophagy

Mycophagy Interactions with Soil Moisture
Mycophagy Initiates and Maintains Truffle Diversity

CHAPTER 6: LANDSCAPE PATTERNS AND FIRE
Landscape Patterns
The Role of Fire in Forests

Fire in the Western United States
Fire in Southeastern, Mainland Australia
Lessons from Byadbo, Mount St. Helens, Omeo, and Beyond

The Mycorrhizal Response to Disturbance
The Role of Spore Dispersal by Mycophagy
Emulating Fire Patterns

CHAPTER 7: FOREST SUCCESSION AND HABITAT DYNAMICS
Developmental Stages of the Forest

Autogenic Succession above Ground
Autogenic Succession below Ground

The Dynamics of Habitat

Food
Water
Shelter
Privacy
Space

Landscape Patterns
United States
Australia
Humanity's Fragmentation

Equality among Species

CHAPTER 8: OF LIFESTYLES AND SHARED HABITATS
A Glimpse of Two U.S. Forests
A Glimpse of Two Australian Forests
Ecological Services of Mycophagous Mammals

The Fungal Connection
The Fruit-Body Connection
The Squirrel and Potoroo Connection
The Pellet Connection
Mycophagy as a Basis of Infrastructural Relationships

Putting It All Together

Partitioning Habitat in the United States
Partitioning Habitat in Australia
Partitioning Food in the United States
Partitioning Food in Australia
Temporal Segregation in the United States
Temporal Segregation in Australia
The Importance of Ecological "Backups"

CHAPTER 9: LESSONS FROM THE TREES, THE TRUFFLES AND THE BEASTS
Shifting Our Focus
Products and Biological Capital

ENDNOTES

GLOSSARY

APPENDIX A: North American Common and Scientific Names

APPENDIX B: Australian Common and Scientific Names

Endorsements:
"Accurate and authentic, Trees, Truffles, and Beasts: How Forests Function makes a major contribution to the field of natural resource management. This is a clear and compelling argument that there's much more to forests than meets the eye."
Jim Furnish
Deputy Chief for National Forest System (ret.)
USDA Forest Service

"This book is an excellent introduction to the world of mycorrhizal fungi in forests and their importance in food webs as highlighted by truffles. This book should encourage readers to investigate further the intricate and essential interactions occurring in forests, which make them work."
Prof. John Dighton
Director
Rutgers University Pinelands Field Station

"Lucidly written and accessible to professionals and the general public alike, the authors adeptly tease out the intimate details and fascinating ecological interactions of a world hidden within the soil. I highly recommend this book for a fascinating glimpse into the wondrous web of life and complex ecological relationships that sustain our natural forests."
Alan Watson Featherstone
Executive Director
Trees for Life
Findhorn Bay, Forres, Scotland

"I just had the pleasure of reading—cover to cover—Trees, Truffles, and Beasts. An outstanding, well documented, and exceptionally written account of a snippet of Mother Nature. You continue to hoist the bar higher for us 'younger' lads, and I for one LOVE IT! It is superb. It should be a 'must read' for all natural-resouce students and managers."
Reese Halter
An award-winning
Conservation Biologist
Rancho Mirage, CA

Special Acknowledgments
"Trees, Truffles, and Beasts" is, without a doubt, the most complicated book I have every worked on, not only because of the subject's complexity but also because the forests occupy two continents so disparate in appearance that ecological commonalities would seem unlikely. Were it not for the scholarship, enthusiasm, and wit of my coauthors, Andrew Claridge and Jim Trappe, this book would never have come into being.

Andrew and Jim
Although authors tend to garner most of the recognition for a book, the adage, a picture is worth a thousand words, is indeed true. That said, creating such an illustration takes an excellent artist who not only understands the concept to be conveyed but also has the ability to render it in a way that is accurate, informative, and yet pleasing to the eye. Gretchen Bracher is such an artist. Hers are the beautiful illustrations that grace the pages of this book. It has been a privilege to work with her.

Gretchen
As is often the case, an apparently seminal piece of work rests on the shoulders of an unknown, but dedicated, group of people who remain anonymously in the shadows of an endeavor's precursive stages. This book is no exception.
The person in the shadows is my wife, Zane. Many years ago, when we were first married, she worked for Jim, who taught her to identify the spores from the fungi eaten by the mammals I had been working with. Zane spent countless hours peering through a microscope identifying the spores of mycorrhizal fungi from the many hundreds of samples of stomach contents and fecal pellets I had collected and preserved during my studies of mammals over more than a decade. Her work, although tedious to say the least, resulted in the 1989 publication of the first key to the spores of mycorrhizal fungi eaten by mammals: "Synoptic Spore Key to Genera of Hypogeous Fungi in Northern Temperate Forests, with Special Reference to Animal Mycophagy." As such, it forms the fundamental basis for this book. Without Zane's diligence, this book could not have been written.

Zane
Among the three of us, Andrew, Jim, and me, we melded 100 years of research experience in a number of countries and continents in writing this book. However, the birth of a book requires the midwife of a publisher, and we are fortunate indeed that Doreen Valentine, the acquisitions editor of Rutgers University Press, saw in our manuscript the germ of a global idea—namely, that in every forest, no matter how diverse, the commonalities of Nature's biophysical principles not only prevail but also are a critical part of the global commons, the birthright of every human being. Doreen shared the importance of this little-known aspect of the global commons with her colleagues in the Rutgers University book team, a turn of events that led to a much-appreciated contract.

Doreen
Fortunately for the reader, Doreen's contribution was far from over. She committed many hours to reading and editing the manuscript, which caused us to make numerous, painstaking revisions—all to the reader's benefit. Hers is the most thorough, general editing I have ever experienced, and among the very best.

A happy Grandma Marilyn
After Doreen's reorganization of our manuscript, it was passed to Marilyn Campbell, who is in charge of production and kept everything running smoothly. Marilyn, in turn, engaged Alice Calaprice, who did a superb job of copyediting, which is an absolute necessity with anything I write because dyslexia adds a definite novelty to my spelling and periodic reversal of words (as you will see if you read my essay, The "Book Team").

Alice and Albert, her helper
Beyond this, the professionalism of the Rutgers book team has made them a joy to work with. While many—but not all—publishers of today treat authors as little more than vendors, we have been accorded thoughtfulness and respect. In a world where mediocrity, speed, and the "bottom line" have seemingly banished the striving for genuine quality, Rutgers University Press is like a breath of fresh air. Moreover, the end result of the team's efforts will make us look far better as writers than we really are. In addition, Charles Krebs read the final manuscript, and wrote an excellent foreword, which succinctly highlighted our intended message. Who can ask for more than that?
I would be profoundly remiss if I failed to highlight the people and organizations who so generously came forward with the financial assistance to make this book as wonderfully illustrated as it is. Carl Ross (Save America's Forests), Henry Trione, Kieth Olsen, Mike Jani (Mendocino Redwood Company), Paul Harlan (Collins Pine, one of the Collins Companies), Sue Johnston, and Yvon Chounaird (Patagonia, Inc.) all consider the world's forests to be of such vital importance to humanity they were each willing to help fund our book. It is their generosity and commitment to a better world that is reflected in the illustrations and photographs enlivening the forest journey chronicled on its pages.