When I began my career as a forester in western Germany’s Eifel mountains, I knew as much about the hidden life of trees as a butcher knows about the emotional life of animals. The forestry industry produces lumber; it fells trees and then plants new seedlings. If you read the professional literature, you quickly get the impression that the wellbeing of the forest is only of interest insofar as it is necessary for optimising the lumber industry.
But about 20 years ago, I began to organise survival training and log-cabin tours for tourists. In conversations with the many visitors, my view of the forest changed.
Visitors were enchanted by crooked, gnarled trees I would previously have dismissed because of their low commercial value. I began to notice bizarre root shapes, peculiar growth patterns and mossy cushions on bark. Suddenly, I was aware of countless wonders I could hardly explain, even to myself. At the same time, RWTH Aachen University began conducting scientific research programmes in the forest I manage.
During this research, many questions were answered, but many more emerged. I will never stop learning from trees, but even what I have learnt so far under their leafy canopy exceeds anything I could ever have dreamt of.
Trees live in communities
Years ago, I stumbled across a patch of strange-looking mossy stones in one of the preserves of old beech trees in the forest I manage. Carefully, I lifted the moss on one and found tree bark. These were not stones, after all, but old wood; it was obviously attached to the ground in some way. I scraped away some of the bark until I got down to a greenish layer. This indicated the presence of chlorophyll, which makes new leaves green: this piece of wood was still alive! I suddenly noticed that the remaining “stones” were arranged in a circle. I had stumbled on the gnarled remains of an enormous ancient tree stump. The interior had rotted long ago – a clear indication that the tree must have been felled at least four or five hundred years earlier. But how could the remains have clung on to life for so long? It was clear that the surrounding beeches were pumping sugar to the stump to keep it alive.
Trees share food with their own species for the same reasons as human communities: there are advantages to working together. On its own, a tree cannot establish a consistent local climate. It is at the mercy of wind and weather. But together, many trees create an ecosystem that moderates extremes of heat and cold, stores a great deal of water and generates agreat deal of humidity. And in this protected environment, trees can live to be very old.
To get to this point, the community must remain intact. If every tree were looking out only for itself, then quite a few would never reach old age. Regular fatalities would result in many large gaps in the tree canopy, which would make it easier for storms to get inside the forest and uproot more trees. The heat of summer would reach the forest floor and dry it out. Every tree, therefore, is valuable to the community and worth keeping around for as long as possible.
Trees warn each otherof danger
Four decades ago, scientists noticed something on the African savannah. Giraffes there were feeding on umbrella thorn acacias, and the trees didn’t like this. It took the acacias mere minutes to start pumping toxic substances into their leaves. The giraffes got the message and moved on to other trees – but they didn’t start nibbling until they were about 100 yards away. The reason for this behaviour is astonishing. The trees that were being eaten gave off a warning gas (specifically, ethylene) that signalled to neighbouring trees of the same speciesthat a crisis was at hand. Right away, all the forewarned trees also pumped toxins into their leaves to prepare themselves.
Similar processes are at work in our forests. Beeches, spruce and oaks all register pain as soon as a creature nibbles on them. When a caterpillar takes a bite out of a leaf, the tissue around the site of the damage changes. In addition, the leaf tissue sends out electrical signals, just as human tissue does when hurt. However, the signal is not transmitted in milliseconds, as human signals are; instead, the plant signal travels at the slow speed of a third of an inch per minute.
When to shed your leaves is a question of character
On the country road near my home stand three oaks. They grow unusually close together: mere inches separate the 100-year-old trunks. That makes them ideal subjects to study because the environmental conditions for all three are identical. This means that if the oaks behave differently, it must be because of their own innate characteristics. And they do, indeed, behave differently.
In winter, when the trees are bare, or in summer, when they are in full leaf, the driver of a car speeding by wouldn’t even notice three separate trees. However, with autumn comes a different story. When the oak on the right is already turning colour, the other two remain completely green. Ittakes a couple of weeks for the two laggards to follow their colleague into hibernation. But if their growing conditions are identical, what accounts for the differences in their behaviour? The timing of leaf drop, it seems, really is a question of character.
As we know, a deciduous tree has to shed its leaves. But when is the optimal moment? Trees cannot anticipate the coming winter. They don’t know whether it is going to be harsh or mild. All they register are shortening days and falling temperatures. If temperatures are falling, that is. There are often unseasonably warm days in the autumn, and now the three oaks find themselves in a dilemma. Should they use these mild days to photosynthesise a while longer and quickly stash away a few extra calories of sugar? Or should they play it safe and drop their leaves in case there’s a sudden frost that forces them into hibernation? Clearly, each of the three trees decidesdifferently.
Young trees are kept in check by their mothers
Young beech trees are so keen on growing quickly that it would be no problem at all for them to grow about 18in taller per season. Unfortunately for them, their own mothers do not approve of rapid growth. They shade their offspring with their enormous crowns, and the crowns of all the mature trees close up to form a thick canopy over the forest floor. This canopy lets only three per cent of available sunlight reach the ground and, therefore, their children’s leaves. With that amount of sunlight, a tree can photosynthesise just enough to keep its own body fromdying.
But what purpose does this restriction serve? Don’t parents want their offspring to become independent as quickly as possible? Trees, at least, would answer this question with a resounding no, and recent science backs them up. Scientists have determined that slow growth when the tree is young is a prerequisite if a tree is to live to a ripe old age.
Dr Suzanne Simard, who helped discover maternal instincts in trees, describes “mother trees” as dominant trees widely linked to other trees in the forest through their fungal-root connections. These trees pass their legacy to the next generation and exert their influence in the upbringing of the youngsters. “My” small beech trees, which have by now been waiting for at least 80 years, are standing under mother trees that are about 200 years old. The stunted trees can expect another 200 years of twiddling their thumbs before it is finally their turn. The wait time is, however, made bearable. Their mothers are in contact with them through their root systems, and they pass along sugar and other nutrients. You might even say they are nursing their babies.
Why trees 'scream' and other fascinating facts
- Whereas it is generally accepted that we know less about the ocean floor than we know about the surface of the moon, we know even less about life in the soil. There are more life forms in a handful of forest soil than there are people on theplanet.
- Think that treescannot communicate? Scientists from the University of Western Australia have registered the roots of grain seedlings crackling at a frequency of 220 hertz. When other seedlings’ roots were exposed to crackling at this frequency, they oriented their tips in that direction.
- When trees are really thirsty, they begin to “scream”. If you’re out in the forest, you won’t be able to hear them, because this all takes place at ultrasonic levels. Scientists at the Swiss Federal Institute for Forest, Snow and Landscape Research explain these sounds as vibrations occurring in the trunk when the flow of water from the roots to the leaves is interrupted.
- Over the course of their lives, trees store up to 22 tons of carbon dioxide in their trunks, branches, and root systems.
- Walnuts have compounds in their leaves that deal so effectively with insects that garden lovers are often advised to put a bench undera canopy ofwalnuts if theywant a comfortable place to relax, because this is where they will have the least chance of being bitten by mosquitoes.
- To grow its trunk, a mature beech needs as much sugar and cellulose as there is in a 2½-acre field of wheat. Every five years, abeech tree produces at least30,000 beechnuts. Assuming it grows to be 400 years old, it can fruit at least 60 times and produce a total of about 1.8 million beechnuts.
This is an edited extract from The Hidden Life of Trees, What They Feel, How They Communicate by Peter Wohlleben (Greystone Books, £16.99; audiobook, £8.49). Order for £14.99 plus p&p: call 0844 871 1514 or visit books.telegraph.co.uk.
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.”How intelligent are trees? ›
Plants are much smarter than we give them credit for. They sense their environment, process information, communicate, and problem solve to some extent. Nevertheless, there is a limit to how smart or aware they can be without the nervous systems we animals thrive on.Can trees remember you? ›
They can count, learn and remember; nurse sick neighbors; warn each other of danger by sending electrical signals across a fungal network known as the “Wood Wide Web”; and, for reasons unknown, keep the ancient stumps of long-felled companions alive for centuries by feeding them a sugar solution through their roots.Do trees have memories? ›
During their lifetime, trees are not only able to adapt quickly to new conditions but can even pass on the 'memory' of such environmental changes to the next generation. This amazing ability has been proved for the first time by researchers at the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).Do trees experience consciousness? ›
Within that system, all the plants are consciously and continually communicating with each other, sending chemical communications along the mycelial network to other plants in the community.Can trees feel when you touch them? ›
Scientists already know that plants are highly sensitive to touch of any kind, and even have a word for this phenomenon, “thigmomorphogenesis.” If you've ever touched a Mimosa pudica (also known as the “sensitive plant”) you have already witnessed this phenomenon first hand—the Mimosa's fan-like leaves close up like, ...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.Do trees have personalities? ›
Nursery school: Trees have personalities and are able to learn. Young trees don't just grow; they develop a personality and, as the years pass, learn more about their environment and how they should best behave in it. Personality, just as among people, varies among trees.Do trees have empathy? ›
Trees lack a nervous system, so they can't experience emotions that we feel, like happiness or excitement.Can trees respond to you talking to them? ›
Can trees hear when spoken to? Kind of. Of course, trees don't have ears as we do, but tree spirits can pick up the message of our words when we talk to them. This means that when you talk to a tree, it can understand the message of what you're telling it.
Plants are surprising organisms—without brains and central nervous systems, they are still able to sense the environment that surrounds them. Plants can perceive light, scent, touch, wind, even gravity, and are able to respond to sounds, too.Can you be friends with a tree? ›
Some Trees Form Friendships
I have known trees that I am certain were friends, even if they don't go out for coffee with each other. Wohlleben agrees: In about one in 50 cases, we see these special friendships between trees. Trees distinguish between one individual and another.
Do Plants React to Human Voices? Here's the good news: plants do respond to the sound of your voice. In a study conducted by the Royal Horticultural Society, research demonstrated that plants did respond to human voices.Do trees perceive time? ›
Plants keep track of the time of day with a circadian clock. This internal clock is synchronized with solar time every day using sunlight, temperature, and other cues, similar to the biological clocks present in other organisms.What is the most intelligent 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.Can plants interact with our thoughts? ›
He conducted interviews with people, instructing them to lie part of the time, and the plants told him when they were lying. He showed that plants have a memory for different people, and that plants read the minds of their “caretakers” even from thousands of miles away.Do plants love their owners? ›
They conducted all sorts of experiments with plants – playing music, talking to plants, vibrations, etc. But their findings were discredited. Now fast forward nearly 50 years, and it has never been scientifically proven that plants have feelings.Is planting a tree someone's memory? ›
Plant a Tree in Memory
A tree planted in someone's memory is a living tribute that benefits present and future generations, and is perhaps the most fitting memorial gift of all. Your memorial trees planted in National Forests will be honorable monuments and active participants in nature's plan for decades to come.
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.What happens to a tree when you hug it? ›
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.
Recent studies show that touching plants alters their genome, reducing their growth by upwards of 30%. It's crucial to avoid unnecessary contact as much as possible to prevent your plant from getting stressed.Can trees hear us? ›
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.Why do I feel so connected to trees? ›
People have a trunk; trees have arms. And so we innately feel a deep connection to them. Many people say they can feel a tree's vibrational energy when placing their hand upon its bark. With their deep roots, trees carry significant grounding energy.Do trees have DNA? ›
Plants, like all other known living organisms, pass on their traits using DNA. Plants however are unique from other living organisms in the fact that they have chloroplasts. Like mitochondria, chloroplasts have their own DNA.Do trees enjoy life? ›
TREES may have vibrant inner lives that aren't so different from ours. They thrive in families, form underground social networks and may even feel pain.Can trees feel stress? ›
Trees are a lot like people: they experience stress and they get infected with bugs or diseases and they can be attacked by fire, windstorms, floods, and droughts.Do trees affect mental health? ›
Spending time around trees and looking at trees reduces stress, lowers blood pressure and improves mood.Does touching a tree give you energy? ›
So, like everything & everyone else in the universe, you are vibrating & creating energy. Quite literally this means that the energy that flows through us, flows through all living things including all plants & trees. So, there you have it when you hug a tree you connect to it through its energetic vibration.Do trees give out 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.Do plants have thoughts? ›
Plants don't have a central nervous system, so thought (as we normally define it) isn't possible. But plants can sense their environment, respond to insect attacks and are even capable of limited movement.
While connecting with a tree, cultivate a quiet and receptive state. Tune into the tree, listen deeply, and see what comes. Or guide the communication by holding an intention, asking a question, or speaking directly to the tree.What is a tree spirit 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.Why do plants like when you talk to them? ›
Plants respond to the vibrations of nearby sound which turns on two key genes inside of them that influence their growth. Plants also increase photosynthesis production in response to carbon dioxide, which is a by-product of human speech.Do plants have memory? ›
Although they do it differently than humans, plants also have memories. This so-called "epigenetic memory" occurs by modifying specialized proteins called histones, which are important for packaging and indexing DNA in the cell.Do plants have consciousness? ›
Plants can sense and react to more aspects of their environments than we can, and they maintain bustling social lives by communicating with each other above and below ground. They also interact with other species.Do trees have a frequency? ›
Recent theoretical work has suggested that tree natural frequency is an important indication of tree stability in windy conditions.Do trees recognize their children? ›
And it turns out they do recognize their kin. Mother trees colonize their kin with bigger mycorrhizal networks. They send them more carbon below ground. They even reduce their own root competition to make elbow room for their kids.Can trees touch the house? ›
As a general rule, trees should be at least 10 to 20 feet from your home, but the exact distance depends on the size of the tree, its canopy and its root system. Ideally, no part of a tree should touch your home, and branches that hang over your roofline should be trimmed regularly.How do you make friends with a tree? ›
The idea is that, whilst blindfolded, you are guided by a companion, to walk through a cluster of trees until your guide stops you, positioned close-up to a tree of their choice.Can a plant see you? ›
Plants detect visible and invisible electromagnetic waves. Unlike plants, we can only detect visible electromagnetic waves. Although plants can see a much larger spectrum than we do, they don't see it in images. The photoreceptor which receives red light is called red photopsin in the case of humans.
In a Mythbusters experiment involving seven plants — two received positive speech, two received negative speech, one listened to classical music, another to death metal and the last was left in silence — the plant left in silence fared the worst. Surprisingly, the one to flourish the most was the death metal plant.Does yelling at plants affect their growth? ›
“But some research shows that speaking nicely to plants will support their growth, whereas yelling at them won't. Rather than the meaning of words, however, this may have more to do with vibrations and volume. Plants react favourably to low levels of vibrations, around 115-250hz being ideal.”What emotions do trees show? ›
Some of the findings of the tree-whisperer Peter Wohlleben are the following: Trees can feel pain, and they have emotions, such as fear. They like to stand close to each other and cuddle. Trees adore company and like to take things slow.What time do trees sleep? ›
One hour after sunset, tree branches start dangling and continue doing so throughout the night, reaching their lowest point about 9-11 hours after sunset, new research published in the journal Frontiers in Plant Science has found.Does a tree fall if nobody hears it? ›
If sound is vibrations, then the falling tree certainly does make a sound, because it produces vibrations in the air. Even if there's no person or other animal around to hear the sound, a recorder with a microphone could certainly record those vibrations—as sound.What is the most intelligent living thing on Earth? ›
For years, dolphins have been heralded as the smartest animals on Earth, second only to humans—though some would even contest that ranking. Aside from humans, dolphins have the greatest brain-to-body ratio among animal species, including primates.
Welwitschia mirabilis: The world's toughest plant.What is an emotional tree? ›
The Emotions Tree is an image that I've used to help students identify how they're feeling about a situation. Once they can associate with the feeling of a person on the emotions tree, we can work together to find the words to describe the feeling.Can trees feel vibrations? ›
“This research also opens the window of plant behavior a little wider, showing that plants have many of the same responses to outside influences that animals do, even though the responses look different.” So while it may not exactly be hearing, plants do sense sound vibrations.Can trees sense danger? ›
Botanists have long known plants are capable of sensing their environments and responding to them. They can grow differently in response to shade or drought, or release noxious chemicals to fend off predators, even as a caterpillar is mid-way through chewing on a leaf.
When trees are starved of water and other favourable conditions required for growth, they suffer and make a noise. Unfortunately, because it is an ultrasonic sound, too high for us to hear, it goes unheard. Thanks to researchers!What does a tree represent in psychology? ›
Trees are symbols of strength, individuality and expression, calmness, growth and the interconnectedness of everything.Can trees feel hugs? ›
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 feel pain? ›
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.Can trees hear my thoughts? ›
He conducted interviews with people, instructing them to lie part of the time, and the plants told him when they were lying. He showed that plants have a memory for different people, and that plants read the minds of their “caretakers” even from thousands of miles away.Can plants hear my thoughts? ›
Here's the good news: plants do respond to the sound of your voice. In a study conducted by the Royal Horticultural Society, research demonstrated that plants did respond to human voices. In this study, there were 10 tomato plants, 8 of which had headphones placed around their pots.Can trees hear us talk? ›
Can trees hear when spoken to? Kind of. Of course, trees don't have ears as we do, but tree spirits can pick up the message of our words when we talk to them. This means that when you talk to a tree, it can understand the message of what you're telling it.Can trees hold trauma? ›
Many troubled trees suffer from the same long-term trauma: They were planted too deep. “It's the most common underlying cause of tree problems,” said Sharon Yiesla, plant knowledge specialist at The Morton Arboretum in Lisle.Do trees avoid touching? ›
Trees avoid touching each other due to "crown shyness." The results are beautiful webs of leaves. Did You Know? Trees might be tall and strong, but they are still a bit sheepish. Crown shyness describes the phenomenon of a tree's leaves withdrawing from the leaves of other trees.