That means it is okay to use wood as long as trees are allowed to live in a way that is appropriate to their species. And that means that they should be allowed to fulfill their social needs, to grow in a true forest environment on undisturbed ground, and to pass their knowledge on to the next generation. And at least some of them should be allowed to grow old with dignity and finally die a natural death.
What organic farms are to agriculture, continuous cover forests with careful selective cutting are to silviculture. In these forests (called Plenterwälder in German), trees of different ages and sizes are mixed together so that tree children can grow up under their mothers. Occasionally, a tree is harvested with care and removed using horses. And so that old trees can fulfill their destinies, 5 to 10 percent of the area is completely protected. Lumber from forests with such species-appropriate tree management can be used with no qualms of conscience. Unfortunately, 95 percent of the current forest practice in Central Europe looks quite different, with the use of heavy machinery and plantation monocultures.
Laypeople often intuitively grasp the need for a change in forest management practices better than forestry professionals do. The public is getting increasingly involved in the management of community forests, and they are insisting the authorities embrace higher environmental standards. We have the example of “forest-friendly” Königsdorf near Cologne, which reached a mediated agreement with the forest service and the regional ministry for natural resources and the environment that heavy machinery no longer be used and deciduous trees of a great age never be cut down.74 On the other side of the Atlantic, in Virginia, the mission of the nonprofit Healing Harvest Forest Foundation is to “address human need for forest products while creating a nurturing co-existence between the forest and human community.” The foundation supports community-based forestry initiatives and promotes the use of horses, mules, and oxen to remove felled trees and the practice of removing single trees that are struggling when harvesting timber, leaving the healthiest standing.75
In the case of Switzerland, a whole country is concerned with the species-appropriate treatment of all things green. The constitution reads, in part, that “account [is] to be taken of the dignity of creation when handling animals, plants and other organisms.” So it’s probably not a good idea to decapitate flowers along the highway in Switzerland without good reason. Although this point of view has elicited a lot of head shaking in the international community, I, for one, welcome breaking down the moral barriers between animals and plants. When the capabilities of vegetative beings become known, and their emotional lives and needs are recognized, then the way we treat plants will gradually change, as well. Forests are not first and foremost lumber factories and warehouses for raw material, and only secondarily complex habitats for thousands of species, which is the way modern forestry currently treats them. Completely the opposite, in fact.
Wherever forests can develop in a species-appropriate manner, they offer particularly beneficial functions that are legally placed above lumber production in many forest laws. I am talking about respite and recovery. Current discussions between environmental groups and forest users, together with the first encouraging results—such as the forest in Königsdorf—give hope that in the future forests will continue to live out their hidden lives, and our descendants will still have the opportunity to walk through the trees in wonder. This is what this ecosystem achieves: the fullness of life with tens of thousands of species interwoven and interdependent.
And just how important this interconnected global network of forests is to other areas of Nature is made clear by this little story from Japan. Katsuhiko Matsunaga, a marine chemist at the Hokkaido University, discovered that leaves falling into streams and rivers leach acids into the ocean that stimulate the growth of plankton, the first and most important building block in the food chain. More fish because of the forest? The researcher encouraged the planting of more trees in coastal areas, which did, in fact, lead to higher yields for fisheries and oyster growers.76
But we shouldn’t be concerned about trees purely for material reasons, we should also care about them because of the little puzzles and wonders they present us with. Under the canopy of the trees, daily dramas and moving love stories are played out. Here is the last remaining piece of Nature, right on our doorstep, where adventures are to be experienced and secrets discovered. And who knows, perhaps one day the language of trees will eventually be deciphered, giving us the raw material for further amazing stories. Until then, when you take your next walk in the forest, give free rein to your imagination—in many cases, what you imagine is not so far removed from reality, after all!
NOTE FROM A
FOREST SCIENTIST
THE UNDERGROUND SOCIAL networks of trees that Peter Wohlleben describes in his home woodlands of Germany were discovered in the inland temperate rainforests of western North America. In the early 1990s, when searching for clues to the remarkable fertility of these Pacific forests, we unearthed a constellation of fungi linking manifold tree species. The mycelial web, as we later discovered, was integral to the life of the forest. Peter’s account that these networks, as in our old-growth forests, are also important to the wellbeing of the beech, oak, and planted spruce forests of Europe is heartening.
My own search for this web in my home forests began as a quest to understand why weeding paper birches from clear-cut plantations went hand in hand with the decline of planted Douglas firs. In the rows of saplings, I would often see clusters of firs suffering from the loss of their birch neighbors. Yes, trees decline and die naturally—gracefully, beautifully, generously—as an essential part of the irrepressible life cycle of the forest. But this pattern of premature death had been concerning me for some time. The loss of synergy between broad-leaved trees and conifers, it turns out, was a concern of Peter’s, too. Across the forests of Europe, planting and weeding to create clean rows has been practiced for centuries.
With the web uncovered, the intricacies of the belowground alliance still remained a mystery to me, until I started my doctoral research in 1992. Paper birches, with their lush leaves and gossamer bark, seemed to be feeding the soil and helping their coniferous neighbors. But how? In pulling back the forest floor using microscopic and genetic tools, I discovered that the vast belowground mycelial network was a bustling community of mycorrhizal fungal species. These fungi are mutualistic. They connect the trees with the soil in a market exchange of carbon and nutrients and link the roots of paper birches and Douglas firs in a busy, cooperative Internet. When the interwoven birches and firs were spiked with stable and radioactive isotopes, I could see, using mass spectrometers and scintillation counters, carbon being transmitted back and forth between the trees, like neurotransmitters firing in our own neural networks. The trees were communicating through the web!
I was staggered to discover that Douglas firs were receiving more photosynthetic carbon from paper birches than they were transmitting, especially when the firs were in the shade of their leafy neighbors. This helped explain the synergy of the pair’s relationship. The birches, it turns out, were spurring the growth of the firs, like carers in human social networks. Looking further, we discovered that the exchange between the two tree species was dynamic: each took different turns as “mother,” depending on the season. And so, they forged their duality into a oneness, making a forest. This discovery was published by Nature in 1997 and called the “wood wide web.”
The research has continued unabated ever since, undertaken by students, postdoctoral researchers, and other scientists, with a myriad of discoveries about belowground communication among trees. We have used new scientific tools, as they are invented, along with our curiosity and dreams, to peer into the dark world of the soil and illuminate the social network of trees. The wood wide web has been mapped, traced, monitored, and coaxed to reveal the beautiful structures and finely adapted languages of the forest network. We have learned that mother trees recognize and talk with their kin, shaping future gen
erations. In addition, injured trees pass their legacies on to their neighbors, affecting gene regulation, defense chemistry, and resilience in the forest community. These discoveries have transformed our understanding of trees from competitive crusaders of the self to members of a connected, relating, communicating system. Ours is not the only lab making these discoveries—there is a burst of careful scientific research occurring worldwide that is uncovering all manner of ways that trees communicate with each other above and below ground.
Peter highlights these ground-breaking discoveries in his engaging narrative The Hidden Life of Trees. He describes the peculiar traits of these gentle, sessile creatures—the braiding of roots, shyness of crowns, wrinkling of tree skin, convergence of stem-rivers—in a manner that elicits an aha! moment with each chapter. His insights give new twists on our own observations, making us think more deeply about the inner workings of trees and forests.
DR. SUZANNE SIMARD
Professor of Forest Ecology
University of British Columbia, Vancouver
February 2016
ACKNOWLEDGMENTS
I VIEW THE fact that I can write so much about trees as a gift, because I learn something new every day as I research, think, observe, and draw conclusions from what I have discovered. My wife, Miriam, gave me this gift as she patiently took part in many conversations about what I was thinking, read the manuscript, and suggested countless improvements. Without my employer, the community of Hümmel, I would never have been able to protect the beautiful old forest that is my preserve, where I love to wander and which inspires me so much. I thank my German publisher, Ludwig, and publishers around the world for giving me the opportunity to make my thoughts available to a wide readership. And last but not least, I thank you, dear reader, for having explored some of the trees’ secrets with me—only people who understand trees are capable of protecting them.
NOTES
1. S.W. Simard, D.A. Perry, M.D. Jones, D.D. Myrold, D.M. Durall, and R. Molina, “Net Transfer of Carbon between Tree Species with Shared Ectomycorrhizal Fungi,” Nature 388 (1997): 579–82.
2. E.C. Fraser, V.J. Lieffers, and S.M. Landhäusser, “Carbohydrate Transfer through Root Grafts to Support Shaded Trees,” Tree Physiology 26 (2006): 1019–23.
3. Massimo Maffei, quoted in M. Anhäuser, “The Silent Scream of the Lima Bean,” MaxPlanckResearch 4 (2007): 65, www.mpg.de/942876/W001_Biology-Medicine_060_065.pdf, accessed February 16, 2016.
4. Ibid., 64.
5. M. Anhäuser, “The Silent Scream of the Lima Bean,” MaxPlanckResearch 4 (2007): 62.
6. Y.Y. Song, S.W. Simard, A.Carroll, W.W. Mohn, and R.S. Zheng, “Defoliation of Interior Douglas-Fir Elicits Carbon Transfer and Defense Signalling to Ponderosa Pine Neighbors through Ectomycorrhizal Networks,” Nature, Scientific Reports 5 (2015): art. 8495; and K.J. Beiler, D.M. Durall, S.W. Simard, S.A. Maxwell, and A.M. Kretzer, “Mapping the Wood-Wide Web: Mycorrhizal Networks Link Multiple Douglas-Fir Cohorts,” New Phytologist, 185 (2010): 543–53.
7. Susanne Billig and Petra Geist, “Die Intelligenz der Pflanzen” (“The intelligence of plants”), Deutschlandradio Kultur, July 18, 2010, www.deutschlandradiokultur.de/die-intelligenz-der-pflanzen.1067.de.html?dram:article_id=175633, accessed December 12, 2014.
8. Tyroler Glückspilze, “Was sollte ich über die Anwendung von Mykorrhiza-Produkten wissen?” (“What should I know about using mycorrhizal products?”), www.gluckspilze.com/faq, accessed October 14, 2014.
9. S.W. Simard, D.A. Perry, M.D. Jones, D.D. Myrold, D.M. Durall, and R. Molina, “Net Transfer of Carbon between Tree Species with Shared Ectomycorrhizal Fungi,” Nature 388 (1997): 579–82.
10. Ibid.
11. D.A. Perry, “A Moveable Feast: The Evolution of Resource Sharing in Plant–Fungus Communities,” Trends in Ecology & Evolution 13 (1998): 432–34, and D.M. Wilkinson, “The Evolutionary Ecology of Mycorrhizal Networks,” Oikos 82 (1998): 407–10.
12. N. Lymn, “Commercial Corn Varieties Lose Ability to Communicate with Their Own Defenders,” Ecological Society of America, October 27, 2011, www.esa.org/esablog/research/commercial-corn-varieties-lose-ability-to-communicate-with-their-own-defenders, accessed January 26, 2016.
13. Monica Gagliano, et al., “Toward Understanding Plant Bioacoustics,” Trends in Plant Science 17(6) (June 2012): 323–25.
14. Unpublished research from RWTH Aachen.
15. Knut Sturm, district forester, Lübeck, personal communication, 2015.
16. S. Dötterl, U. Glück, A. Jürgens, J. Woodring, and G. Aas, “Floral Reward, Advertisement and Attractiveness to Honey Bees in Dioecious Salix caprea,” PLoS One 9(3) (2014): e93421.
17. Maurice E. Dermitt, Jr., “Poplar Hybrids,” in Russell M. Burns and Barbara H. Honkala, tech. coords., Silvics of North America, vol. 2, Hardwoods, USDA Forest Service, 1990, www.na.fs.fed.us/pubs/silvics_manual/volume_2/populus/populus.htm, accessed January 30, 2016.
18. S.W. Simard, video, “Mother Tree,” in Jane Engelsiepen, “‘Mother Trees’ Use Fungal Communication Systems to Preserve Forests,” Ecology Global Network, October 8, 2012, www.ecology.com/2012/10/08/trees-communicate, accessed January 26, 2016, and S.W. Simard, K.J. Beiler, M.A. Bingham, J.R. Deslippe, L.J. Philip, and F.P. Teste, “Mycorrhizal Networks: Mechanisms, Ecology and Modelling,” Fungal Biology Reviews 26 (2012): 39–60.
19. Kenneth R.James, Nicholas Haritos, and Peter K. Ades, “Mechanical Stability of Trees under Dynamic Loads,” American Journal of Botany 93(10) (October 2006): 1522–30, fig. 9, www.amjbot.org/content/93/10/1522.full, accessed January 30, 2016.
20. Max Planck Institute for Dynamics and Self-Organization, “Unterscheiden sich Laubbäume in ihrer Anpassung an Trockenheit? Wie viel Wasser brauchen Laubbäume?” (“Are there differences in how deciduous trees adapt to drought? How much water do deciduous trees need?”), www.ds.mpg.de/139253/05, accessed December 9, 2014.
21. University of Western Australia, “Move Over Elephants—Plants Have Memories Too,” University News, January 15, 2014, www.news.uwa.edu.au/201401156399/research/move-over-elephants-mimosas-have-memories-too, accessed October 8, 2014.
22. Swiss Federal Institute for Forest, Snow, and Landscape Research WSL, “Rendering Ecophysiological Processes Audible,” www.wsl.ch/fe/walddynamik/projekte/trees/index_EN, accessed January 26, 2016.
23. Swiss Federal Institute for Forest, Snow, and Landscape Research WSL, “Grösster Pilz der Schweiz” (“Largest fungus in Switzerland”), www.wsl.ch/medien/presse/pm_040924_DE, May 27, 2010, accessed December 18, 2014.
24. A. Casselman, “Strange but True: The Largest Organism on Earth Is a Fungus,” Scientific American, October 4, 2007, www.scientific-american.com/article/strange-but-true-largest-organism-is-fungus, accessed January 26, 2016.
25. U. Nehls, “Sugar Uptake and Channeling into Trehalose Metabolism in Poplar Ectomycorrhizae,” dissertation, April 4, 2011, University of Tübingen.
26. SCINEXX, “Forscher belauschen Gespräche zwischen Pilz und Baum” (“Researchers eavesdrop on conversations between fungi and trees”), January 23, 2008, www.scinexx.de/wissen-aktuell-7702-2008-01-23.html, accessed October 13, 2014.
27. S.W. Simard, D.A. Perry, M.D. Jones, D.D. Myrold, D.M. Durall, and R. Molina, “Net Transfer of Carbon between Tree Species with Shared Ectomycorrhizal Fungi.” Nature 388 (1997): 579–82.
28. J. Fraser, “Root Fungi Can Turn Pine Trees into Carnivores—Or at Least Accomplices,” Scientific American, May 12, 2015, blogs.scientificamerican.com/artful-amoeba/root-fungi-can-turn-pine-trees-into-carnivores-8212-or-at-least-accomplices, accessed January 26, 2016.
29. “Wassertransport in Gefäßpflanzen” (“Water transport in vascular plants”), chemgapedia.de/vsengine/vlu/vsc/de/ch/8/bc/vlu/transport/wassertransp.vlu/Page/vsc/de/ch/8/bc/transport/wassertransp3.vscml.html, accessed December 9, 2014.
30. K. Steppe, et al., “Low-Decibel Ultrasonic Acoustic Emissions are Temperature-Induced and Probably Have No Biotic Origin,” New Phytologist 183 (200
9): 928–31.
31. “Haut—Das Superorgan” (“Skin, the super-organ”), June 17, 2014, www.br-online.de/kinder/fragen-verstehen/wissen/2005/01193/, accessed March 18, 2015.
32. Zoë Lindo and Jonathan A. Whiteley, “Old Trees Contribute Bio-Available Nitrogen through Canopy Bryophytes,” Plant and Soil (May 2011): 141–48.
33. J. Owen, “Oldest Living Tree Found in Sweden,” National Geographic News, April 14, 2008, news.nationalgeographic.com/news/2008/04/080414-oldest-tree.html, accessed January 26, 2016.
34. František Baluška, et al., “Neurobiological View of Plants and Their Body Plan,” in Baluška, Mancuso, Volkmann, eds., Communication in Plants (New York: Springer, 2007).
35. J. Copley, “Just How Little Do We Know about the Ocean Floor?” Scientific American, October 9, 2014, scientificamerican.com/article/just-how-little-do-we-know-about-the-ocean-floor, accessed January 26, 2016.
36. “Faktensammlung: Bodendegradation” (“Summary: Soil degradation”), desertifikation.de/faktensammlung/fakten_degradation, accessed November 30, 2014.
37. Klara Krämer, thesis defense, RWTH Aachen, November 26, 2014.
38. A. Fichtner, et al., “Effects of Anthropogenic Disturbances on Soil Microbial Communities in Oak Forests Persist for More than 100 Years,” Soil Biology and Biochemistry 70 (March 2014): 79–87.
39. National Fish and Wildlife Foundation press release, “NFWF Announces $4.6 Million in Funding for Restoration of Longleaf Pine Forest and Ecosystem across the Southeast,” June 30, 2015, nfwf.org/whoweare/mediacenter/pr/Pages/longleaf-pr-15-0630.aspx, accessed February 12, 2016.
40. E.-Detlef Schultz, coord., John Gash, Annette Freibauer, Sebastian Luyssaert, Philippe Ciaia, eds., CarboEurope-IP, An Assessment of the European Terrestrial Carbon Balance (Jena: carboeurope.org, 2009), ftp://ftp.bgc-jena.mpg.de/pub/outgoing/athuille/CE_booklet_final_packed/CE_booklet_Stand_02-03-09_screen.pdf, accessed January 30, 2016.
The Hidden Life of Trees: What They Feel, How They CommunicateDiscoveries from a Secret World Page 20
