In his bestselling book,The Hidden Life of Trees, Peter Wohlleben argues that to save the world’s forests we must first recognize that trees are “wonderful beings” with innate adaptability, intelligence, and the capacity to communicate with — and heal — other trees.
As a student in forestry school, Peter Wohlleben was trained to look at trees exclusively as an economic commodity. But after joining a German forestry agency and managing a community forest, he soon became disillusioned with practices like clear-cutting, chemical use, and mechanical harvesting that put short-term profits before sustainability.
Wohlleben was eventually hired by the local mayor to look after the same forest in an eco-friendly way. Today, he manages the forest without usinginsecticides or heavy machinery, and the trees are harvested by hand and hauled out by horses. He also has started a “living gravestone” project in which townspeople pay the equivalent of the commercial value of an ancient tree to have their ashes interred at its base. The woodland has gone from a money-losing operation to a profitable one.
In an interview withYale Environment 360, Wohlleben, author ofThe Hidden Life of Trees, discusses how trees are sophisticated organisms that live in families, support their sick neighbors, and have the capacity to make decisions and fight off predators. He has been criticized for anthropomorphizing trees, but Wohlleben, 52, maintains that to succeed in preserving our forests in a rapidly warming world, we must start to look at trees in an entirely different light.
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Yale Environment 360:You write in your book: “When I began my life as a forester, I knew as much about the hidden life of trees as a butcher knows about animals.”
Peter Wohlleben:Forestry students are taught how to harvest wood, what machines to use, how to sharpen the blade of a chainsaw, how to sell the timber, what price to expect — that’s about it. As a young forester I was told to make clear-cuts, to use insecticides, and so on. I thought— “Wait, I am someone who wants to protect nature, and here I am being asked to destroy it!”
I visited some other districts that were operating in an eco-friendly way, and I thought, that’s the way woods should be managed. But the problem is I was still thinking of trees as a commodity, as something to sell, not as living beings. I had to learn from the people of the community where my forest is located how to take a closer look at trees, to see them as unique individuals. I also started reading the latest scientific research that began to present me with a new picture of trees as highly sensitive and social beings.
e360:Social beings?
Wohlleben:We all learn in school that evolution advances by pitting each individual against every other in the struggle for survival. As a forester, I learned that trees are competitors that struggle against each other for light, for space. But we are now learning that individuals of a species are actually working together, they are cooperating with one another.
e360:How exactly do trees cooperate with one another?
Wohlleben:One thing is that mother trees suckle their children, they feed the young tree just enough sugars produced by its own photosynthesis to keep it from dying. Trees in a forest of the same species are connected by the roots, which grow together like a network. Their root tips have highly sensitive brain-like structures that can distinguish whether the root that it encounters in the soil is its own root, the root of another species, or the roots of its own species. If it encounters its own kind, I don’t know if scientists yet know how this happens, but we have measured with radioactive-marked sugar molecules that there is a flow from healthy trees to sick trees so that they will have an equal measure of food and energy available.
“Parts of the forest that grew naturally were 3 degrees C cooler than those managed by humans.”
e360:How do the healthy trees that feed their sick companions benefit?
Wohlleben:If sick trees die, they fall, which open gaps in the canopy. The climate becomes hotter and drier and the environment becomes worse for the trees that remain. In the forest I manage, students from Aachen University did a study that shows that the parts of the forest that grew naturally were 3 degrees C cooler than those that are managed and disturbed by humans.
The world is trying to limit warming from climate change to 2 degrees, but undisturbed forests can do even better than that. Forests create their own microclimate. When we thin forests, the temperature rises, the humidity goes down, evaporation increases, and all the trees begin to suffer. So trees have a stake in supporting one another to keep all members of the community healthy.
e360:You tell one amazing story in the book about trees keeping neighboring stumps alive.
Wohlleben:This one beech tree was cut four to 500 years ago by a charcoal maker, but the stump is still alive — we found green chlorophyll under the thick bark. The tree has no leaves to create sugars, so the only explanation is that it has been supported by neighboring trees for more than four centuries. I made this discovery myself, and later learned that other foresters have observed this happening as well.
e360:Are there other ways that trees help each other?
Wohlleben:We know that trees also exchange information. When one tree is attacked by insects, we can measure electrical signals that pass through the bark and into the roots and from there into fungi networks in the soil that alert nearby trees of the danger. The trees pay for this service by supplying the fungi with sugars from their photosynthesis. And the fungi in turn protect their host trees from attacks by other dangerous species of fungi and contamination by heavy metals.
Trees also send chemical signals through the air when they are attacked by insects. Nearby trees receive these messages and have time to prepare their defenses. Scientists likeSuzanne Simard[who teaches forestry at the University of British Columbia in Vancouver] have labeled this amazing web of communication the Wood Wide Web.
e360:You have also written that trees remember their experiences?
Wohlleben:We had a heavy drought here. In subsequent years, the trees that had suffered through the drought consumed less water in the spring so that they had more available for the summer months. Trees make decisions. They can decide things. We can also say that a tree can learn, and it can remember a drought its whole life and act on that memory by being more cautious of its water usage.
e360:You’ve said that there are “friendships” between trees. What is the evidence for that?
Wohlleben:In about one in 50 cases, we see these special friendships between trees. Trees distinguish between one individual and another. They do not treat all other trees the same. Just today, I saw two old beeches standing next to each other. Each one was growing its branches turned away from the other rather than toward each other, as is more usually the case. In this way and others, tree friends take care of each other. This kind of partnership is well known to foresters. They know that if you see such a couple, they are really like a human couple; you have to chop down both if you chop one down, because the other will die anyway.
“Plants process information just as animals do, but for the most part they do this much more slowly.”
e360:You speak about trees as if they had personalities.
Wohlleben:Trees have just as much character as humans do. They also exercise independent judgments, which can differ. If trees lose their leaves too early, they many not produce enough food for a long winter. If they keep them on too long, they may get caught in an early snowstorm and the weight of the snow can break their branches. Some trees of the same species and age living right next to each other shed their leaves weeks before their neighbors. I’m not sure why some choose to do this earlier and others later, but it shows that there really are differences of character that we can’t easily account for.
e360:You have been criticized for attributing emotions to trees. Scientists usually avoid such language.
Wohlleben:We humans are emotional animals. We feel things, we don’t just know the world intellectually. So I use words of emotion to connect with people’s experience. Science often takes these words out, but then you have a language people can’t relate to, that they can’t understand. That’s one reason most scientific research has so little impact on people. If you only write technically about “biochemical processes,” people would quickly get bored and stop reading. We have been viewing nature like a machine. That is a pity because trees are badly misunderstood.
e360:How so?
Wohlleben:We just see them as oxygen producers, as timber producers, as creators of shade. I always ask people, “Who would think of, say, elephants in such terms?” We don’t look at elephants just as commodities or as mechanical and insentient objects. We recognize them as marvelous beings. On the other hand, nobody thinks about the inner life of trees, the feelings of these wonderful living beings.
e360:Plants are not generally thought to possess consciousness.
Wohlleben:We have this essentially arbitrary caste system for living beings. We say plants are the lowest caste, the pariahs because they don’t have brains, they don’t move, they don’t have big brown eyes. Flies and insects have eyes, so they are a bit higher, but not so high as monkeys and apes and so on. I want to remove trees from this caste system. This hierarchical ranking of living beings is totally unscientific. Plants process information just as animals do, but for the most part they do this much more slowly. Is life in the slow lane worth less than life on the fast track?
Perhaps we create these artificial barriers between humans and animals, between animals and plants, so that we can use them indiscriminately and without care, without considering the suffering that we are subjecting them to.
e360:How would understanding trees better change the way we manage forests?
Wohlleben:Humans are weakening ecosystems by indiscriminately cutting timber. We destroy tree social structures, we destroy their ability to react to climate change. We end up with individuals that are in a bad shape and susceptible to bark beetles, which can only infest trees that are already sick. A tree that is healthy can get rid of them. So the beetle is winning because we have degraded ecosystems to the point where they are unable to respond effectively to threats.Here in Germany, we have planted spruces to replace the beech trees. It is now too dry and warm for spruce, so those forests are failing in large parts of our country. It’s because we have planted the wrong species for the climate. We need to let nature heal itself and come back to balance with broadleaf species that are natural to our region, like oaks and beeches, which will help to cool the forests down and can survive climate change without too much harm.
“Faster growth makes trees less healthy and more susceptible to illnesses.”
e360:Do we need to manage forests at all?
Wohlleben:We are told that forests and woodlands need management, but it is just plantations that need management because they are unstable systems that can be destroyed by storms, by insects, by fire. It’s like a farm with hundreds of acres of corn. It is highly likely that insects or fungi will kill these plants because there is just one species. It’s the same thing with monoculture tree plantations. Natural systems, with a variety of species, are much more resilient.
e360:Managed forests and planted forests tend to space trees farther apart to encourage growth and prevent competition between the trees. Is this a good idea?
Wohlleben:Well, that is one mistake introduced by foresters. While it is true that trees may grow faster when we remove their comrades, because more sunlight means more photosynthesis, they actually grow too quickly for their own good. Trees should grow very slowly in the first 200 years, which we can call their youth. If they grow too fast in the beginning, they will waste all their energy in the rapid growth and will be out of breath, exhausted, and die early. It is similar to industrial meat production where a pig, for example, is fed too much so that it grows prematurely and in five or six months it can be sold and slaughtered. But the animals are unhealthy.
People on their home plots make the same mistake: They cut down some trees to encourage the growth of others. That would be like a family where they shoot the parents to give the kids more space. You slaughter their mother and the young trees will grow very fast, but they will be unhealthy and have short lives.
e360:Trees are growing faster now because of more CO2 in the air. Is that a good thing?
Wohlleben:Not at all. In Germany now, for example, trees are growing 30 percent faster than decades ago. But as I’ve said, faster growth makes trees less healthy and more susceptible to illnesses. The wood is also of lower quality, so the price we get for it is going down. The cells of these fast growing trees actually become bigger and more susceptible to fungi. A little wound can open them to rot, which kills them.
e360:Can foresters help protect forests from climate change and other environmental threats? I understand that in your forest, you still do things the old fashioned way.
Wohlleben:That’s right, we use horse-drawn carts to remove the wood. In between the trees, we don’t use any heavy machinery, which compresses the soil up to two meters deep andpushes the air out and makes it less able to soak up the water in winter that the trees need to use for growth in the spring.
e360:So the low-tech methods are actually more cost effective?
Wohlleben:Yes, they are working well all over the world — in the Amazon, even in the U.S, some forest owners are working with these methods. We recommend growing only tree species that are natural to the area. I also advise not to make any clear cuts, don’t kill the mother trees that are protecting their children, leave the families intact. Don’t use heavy machinery and cut out pesticides and other toxic chemicals that kill off beneficial insects and microorganisms in the soil. These are the keys to maintaining a successful and long-lived forest.
FAQs
Is a tree a sentient being? ›
Just like an organism, they help each other in times of need or to warn of a crisis. The tree trunk, for instance, vibrates to “scream” to alert its neighbours to a water shortage. Trees can also taste, touch, smell, hear and feel. And they exhibit these characteristics just the way animals do.
Are trees aware of their existence? ›While trees has some degree of outside awareness as they react to their environment, the level of self-awareness is highly debated. Defining consciousness is problematic for researchers because it encompasses so many variables.
What is the German title for the hidden life of trees? ›His 2015 book about natural forests, Das geheime Leben der Bäume:Was sie fühlen, wie sie kommunizieren – die Entdeckung einer verborgenen Welt, (The Hidden Life of Trees: What they Feel, How they Communicate: Discoveries from a Secret World) introduces readers to the world of trees, including Wood-Wide Web, through ...
Are trees living beings? ›Trees, similar to all living things grow, reproduce, and respond to their environment. Trees, like all plants, manufacture their food through photosynthesis.
Do trees feel pain when cut? ›Given that plants do not have pain receptors, nerves, or a brain, they do not feel pain as we members of the animal kingdom understand it. Uprooting a carrot or trimming a hedge is not a form of botanical torture, and you can bite into that apple without worry.
What qualifies as a sentient being? ›Abstract. Sentience means having the capacity to have feelings. This requires a level of awareness and cognitive ability. There is evidence for sophisticated cognitive concepts and for both positive and negative feelings in a wide range of nonhuman animals.
Do trees have soul? ›The reason for this is that, despite the lack of any kind of cognition, plants have souls too, according to Aristotle's widely-accepted theory: trees and flowers nourish themselves, they grow, and propagate, and so they have what was usually called a vegetative soul.
Are trees basically immortal? ›Amazingly, they can live for thousands of years. But while signs of deterioration from old age in trees might not be perceptible to humans in our lifetime, this doesn't necessarily mean they're immortal.
Do trees hold memories? ›Plant memory
A study published in 2014 took on that very question. It determined that plants can, indeed, make memories, and can display their memory recall though learned response.
In Norse mythology Yggdrasill is an enormous ash tree that connects the nine worlds, including the underworld (Niflheim), the earth (Midgard), and the realm of the gods (Asgard).
What does hugging a tree do for you? ›
“Hugging a tree increases levels of hormone oxytocin. This hormone is responsible for feeling calm and emotional bonding. When hugging a tree, the hormones serotonin and dopamine make you feel happier.”
What gender is a tree in German? ›Most trees and flowers are feminine. Der Ahorn (the maple) is masculine, though. All numerals used as nouns are feminine, as are motorcycles, ships and aeroplanes.
Do trees have feelings? ›They don't have nervous systems, but they can still feel what's going on, and experience something analogous to pain. When a tree is cut, it sends electrical signals like wounded human tissue.”
Can trees see us? ›Don't look now, but that tree may be watching you. Several lines of recent research suggest that plants are capable of vision—and may even possess something akin to an eye, albeit a very simple one. The idea that plants may have “eyes” is, in a way, nothing new.
Can trees hear us? ›But can they hear? They have no specialized structure to perceive sound like we do, but a new study has found that plants can discern the sound of predators through tiny vibrations of their leaves — and beef up their defenses in response.
Do trees scream when cut down? ›While they may not have brains like humans do, plants talk to one another through smell and even communicate with insects to maintain survival. Like any living thing, plants want to remain alive, and research shows that when certain plants are cut, they emit a noise that can be interpreted as a scream.
Do trees like to be touched? ›Your plants really dislike when you touch them, apparently. A new study out of the La Trobe Institute for Agriculture and Food has found that most plants are extremely sensitive to touch, and even a light touch can significantly stunt their growth, reports Phys.org.
Do lobsters feel pain when boiled alive? ›Most likely, yes, say animal welfare advocates. Lobsters belong to a family of animals known as decapod crustaceans that also includes crabs, prawns, and crayfish.
What living things are not sentient? ›Beings that have no centralized nervous systems are not sentient. This includes bacteria, archaea, protists, fungi, plants and certain animals.
What are the three rules of sentience? ›There are three general criteria for deciding whether a being is sentient. These involve considerations that are (1) behavioral, (2) evolutionary, and (3) physiological.
What animal is closest to being sentient? ›
Whether or not octopuses should be viewed as charming or terrifying very much depends on your personal perspective. But it's hard to deny their intelligence. Octopuses can squirt water at an annoyingly bright bulb until it short-circuits. They can tell humans apart (even those who are wearing the same uniform).
What do trees do spiritually? ›Trees play an important role in many mythologies and religions. They have been given deep meaning through the ages. They are seen as powerful symbols of growth and resurrection. In many of folk religions, trees are said to be homes of spirits.
What are tree spirits called? ›A dryad (/ˈdraɪ.æd/; Greek: Δρυάδες, sing.: Δρυάς) is a tree nymph or tree spirit in Greek mythology. Drys (δρῦς) signifies "oak" in Greek. Dryads were originally considered the nymphs of oak trees specifically, but the term has evolved towards tree nymphs in general, or human-tree hybrids in fantasy.
Do trees release energy? ›Through a process called photosynthesis, leaves pull in carbon dioxide and water and use the energy of the sun to convert this into chemical compounds such as sugars that feed the tree. But as a by-product of that chemical reaction oxygen is produced and released by the tree.
Is there a tree that never dies? ›The uses of the Moringa tree seem to be endless. Moringa Oleifera trees may survive despite high altitudes (up to 1500 meters) or very dry and arid deserts with less than 400 mm annual rainfall.
How long would Earth survive without trees? ›In one year, a mature leafy tree produces as much oxygen as ten people breathe. If phytoplankton provides us with half our required oxygen, at current population levels we could survive on Earth for at least 4000 years before the oxygen store ran empty.
Can a plant theoretically live forever? ›All plants die eventually. But according to researchers at the New York Botanical Garden in the Bronx, there is no specific lifespan for plants, except for the plants called “annuals,” which are plants that live for one growing season and then die. This is genetic.
What is the most intelligent plant in the world? ›Orchids are sometimes called "the smartest plants in the world" because of their ingenious ability to trick insects and people into helping with their pollination and transport.
Do trees feel lonely? ›Plants will definitely experience something like being “lonely” in pots because they miss out on underground connections. The majority of plants form symbioses with fungi underground, via their roots.
How intelligent are trees? ›We can debate the definition of “intelligence,” but we know that trees can identify and solve problems in ways that we can't. They remember that spring is coming, and when it does they'll be ready to sense the weather and make their decisions in response.
What religion is the tree of life? ›
The tree of life appears in Norse religion as Yggdrasil, the world tree, a massive tree (sometimes considered a yew or ash tree) with extensive lore surrounding it. Perhaps related to Yggdrasil, accounts have survived of Germanic Tribes honouring sacred trees within their societies.
What did God say about the tree of life? ›Jesus said that God's heavenly presence was arriving on Earth through him and his mission. And he often likened this to a huge tree, growing and spreading in surprising ways (Matthew 13:31-32). Jesus even claimed to be a tree of life, a vine that offers God's life to the world (John 15).
How many trees of life are in heaven? ›Marvin Meyer writes: "The "five trees" in paradise are mentioned frequently in gnostic texts, ordinarily without explanation or elaboration. In Manichaean Psalm Book 161,17-29, it is said that various features of life and faith are put together in groups of five.
Can trees feel you hug them? ›There is also fairly robust evidence that plant cells can perceive and respond to pressure waves, like the kind that are generated by sound in the environment and touch — like, say someone walking up to a tree and hugging it.
Can trees communicate with one another? ›Trees are "social creatures" that communicate with each other in cooperative ways that hold lessons for humans, too, ecologist Suzanne Simard says. Simard grew up in Canadian forests as a descendant of loggers before becoming a forestry ecologist.
What happens if you fall asleep under a tree? ›Final Answer: Sleeping under a tree is not advisable at night, since photosynthesis does not occur, oxygen is not being produced by the trees. In addition to this, the trees continue respiring thereby causing the amount of carbon dioxide to be increased and the amount of oxygen to be reduced.
Why does German have 3 genders? ›Genders in German were originally intended to signify three grammatical categories that words could be grouped into. The three categories were: endings that indicated that a word was of neutral origin. endings that indicated a group of people or things.
What are the 3 genders in the German language? ›German has three genders: masculine, m; feminine, f; and neuter, n. Most nouns have one gender or the other but a small number have two or all three.
Does German Have 3 genders? ›Three grammatical genders.
German nouns—for humans and objects—are all in one of three noun categories: masculine, feminine, or neuter.
Plants are qualitatively different from humans and sentient nonhumans in that plants are certainly alive but they are not sentient. Plants do not have interests. There is nothing that a plant desires, or wants, or prefers because there is no mind there to engage in these cognitive activities.
Why are trees sentient? ›
Trees in a forest of the same species are connected by the roots, which grow together like a network. Their root tips have highly sensitive brain-like structures that can distinguish whether the root that it encounters in the soil is its own root, the root of another species, or the roots of its own species.
Are plants actually sentient? ›Plants use groups of coordinated physiological activities to deal with defined environmental situations but currently have no known mental state to prioritise any order of response.
Are plants considered sentient? ›Scientific research shows that plants possess these same attributes. Plants are conscious, sentient beings. In 1973, The Secret Life of Plants, by Peter Tompkins and Christopher Bird documented experiments that showed plant sentience.
Do all trees have feelings? ›Trees — and all plants, for that matter — feel nothing at all, because consciousness, emotions and cognition are hallmarks of animals alone, scientists recently reported in an opinion article.
Can trees really hear you? ›They're listening. That's the overarching conclusion from multiple research studies: While plants don't have ears, they can “hear” sounds in their local environment. More importantly, they can react.
What is the most sentient plant? ›Orchids are sometimes called "the smartest plants in the world" because of their ingenious ability to trick insects and people into helping with their pollination and transport.
Are plants aware that they are alive? ›Both animals and plants are aware, and given the relation between awareness and consciousness, plants can be described as conscious organisms. The mechanisms involved however are very different. Awareness focuses on behaviour and its degree of complexity rather than arguments about the nervous systems and brains.
Can trees feel pain? ›As explained by plant biologist Dr. Elizabeth Van Volkenburgh, all living organisms perceive and respond to painful touch, but plants do not perceive or “feel” pain the same way that animals do because they lack a nervous system and brain.
Are living things sentient? ›Evidence from multiple scientific studies has helped us to understand that a wide range of animals are sentient beings. This means they have the capacity to experience positive and negative feelings such as pleasure, joy, pain and distress that matter to the individual.
Why are plants non sentient? ›Another argument is that plants do not have brains – the central system that contains and controls thoughts, emotions and responds to stimuli. Plants do not have this control system, so it is logical to think that plants cannot sense the stimuli and form emotions about them in response.
Do Buddhists believe plants are sentient? ›
Particularly in Tibetan Buddhism and Japanese Buddhism, all beings (including plant life and even inanimate objects or entities considered "spiritual" or "metaphysical" by conventional Western thought) are or may be considered sentient beings.