The Family Trees

An Essay on the Secret Lives of Trees.

Today I tried to befriend a tree. I walked along the wooded trails of my college campus shaded by ancient oak trees, waiting to pass a tree that would seem to call out to me. Not far outside of my apartment building, I stumbled upon an ethereal cottonwood tree. Its yellow leaves had fallen and littered the ground below me like a golden puddle. Its trunk was separated at the base and fanned out into four strong trees, so tall that their branches grazed the clouds. I felt a bit ridiculous as I situated myself within the nook of the trunk and began to whisper to it, darting my eyes around to make sure no one was listening- I presume they’d think I lost it. After a few minutes with the tree, the discomfort began to fade. It was so peaceful, meditative almost, to run my hands over the inch-deep grooves of the bark and talk to a being older than the state of Minnesota itself. I let the tree talk back, watching the branches wave and studying the singular leaf still attached to the body, its greenish veins mirroring mine. Trees have human-like qualities in the way they communicate, form relationships, and interpret the sensory world around them. Their human-like qualities are important because they help us to appreciate and conserve nature while remembering that we are a part of it.

In the Western world, we don’t appreciate how similar we are to nature, much less the fact that humans are a part of nature. I urge you to look at God’s greater design, and you will find humanity in every plant and animal, and wildlife in each human. Trees are a wonderful example of a human-like plant. Just like you and me, trees have mothers, friends, knowledge, and even unique quirks. Whether the human-like aspects of trees are simply a matter of intention or natural selection has yet to be uncovered in length, with many scientists refusing to so much as consider if there is any effort made in plant communication. While it may be considered foolish to entertain discussing plant communication through a lens of humanity, using emotional vocabulary can help us understand trees on a level that is yet to be accessed by most of the world.

You are likely wondering how trees can possibly talk to one another- they don’t have vocal cords or lungs, so where does this alleged voice come from? Trees can communicate in multiple ways, but the most commonly used method is via complex underground networks of roots and mycelium known as the mycorrhizal network (Lagomarcino, 2019). Mycelium is the body of the fungus, stretching both laterally and horizontally underneath the soil. Through the tangles of roots in mycelia on the Earth, trees send electrical, chemical, and hormonal signals of distress allowing them to warn nearby trees of danger. In response to the warning call, the neighboring trees are able to adjust accordingly to the issue and aid other trees (Simmard, 2021). A prevalent example of this type of conversation is an experiment done by Canadian scientist Suzanne Simard. In her groundbreaking 1997 discovery, Simmard discovered that two different species of trees with the same mycorrhizal network will aid each other in times of need. To do this, Simmard injected radioactive carbon-14 into the trunk of a birch tree and shaded a nearby fir tree with a tent; this resulted in the birch tree sharing its excess carbon dioxide with the birch that was unable to photosynthesize (Simmard, 1997).

Another way that trees can communicate is by sending pheromones through the air, much like a skunk that sprays chemicals at an oncoming enemy. For instance, when a giraffe begins to snack on a flat-topped acacia tree, the tree is quick to emit ethylene gas. The gas can travel up to around 100 yards without wind and warns the nearby acacias that they may become giraffe dinner if they don’t defend themselves (Wohlleben, 2015). In response to the signal, the trees pump tannic acid, a chemical that is poisonous to mammals into their leaves causing their predator to become sick upon ingestion (Furstenburg & Hoven, 1994). The conversations between trees that have been decoded by scientists thus far are always some type of message of distress, necessary for their survival.

The bonds formed between trees that are comparable to human relationships are built on the foundation of family and dependency. In the tree family, there are trees that are mothers, and then there are “mother trees”. Trees that produce offspring through their seeds are mothers. In another fascinating experiment, Suzane Simard discovered that parent trees can recognize their “babies” and will prioritize their health over the other saplings of the forest (Simard, 2018). “Mother trees colonize their kin with bigger mycorrhizal networks,” claims Simard, “they send them more carbon below ground. They even reduce their own root competition to make elbow room for their kids” (2022). Unfortunately, this experiment has not been recreated by other scientists yet; the concept of “mother trees” has more evidence behind it.

“Mother trees” are better known in the scientific community as Hub trees. They are usually the oldest and largest trees in the forest with the largest mycelium networks (Wholleben, 2015). These trees take on the maternal role of using their deep roots to nourish the shaded young trees of the forest. In addition to helping saplings photosynthesize with sugar water, “mother trees” also aid the grown-up trees around them. They donate water and carbon stored up in their deep roots to trees that are sickly, wilting, or stressed. Since “mother trees” mycelium networks are so vast, they do not discriminate between species of trees. Hub trees are a major contributor to biodiversity in forests, promoting trees to form “friendships” with trees of all species. The bonds between trees are extremely close-knit- forester Peter Wholleben has closely observed this relationship during his German forest expeditions. “(Trees that are friends) are very considerate in sharing the sunlight, and their root systems are closely connected (…) when one dies, the other usually dies soon afterward, because they are dependent on each other,” Wholleben states in a Smithsonian interview (2018). Essentially, trees help and rely on each other to the point that one cannot thrive without the other. If you have ever had a loved one pass away, you likely understand this relationship and how difficult it is to move through life with intense grief.

In addition to being similar to humans in terms of relationships and communication, trees are also like us in the way that they use their senses to take care of themselves. Trees are able to detect physical sensations and react accordingly to how much light they are receiving. In Charles Darwin’s book “Power of Movement in Plants”, he discusses how plants are sensitive to light. Much like us, when the sun goes down at night, plants sleep. For instance, the Porlieria tree leaves close at night and lose their moisture (Darwin, p. 322). This behavior is seen throughout the plant kingdom, and its purpose is to “limit transpiration and save water” (Costa et. al., 2014). Trees are less susceptible to this phenomenon than smaller plants that are close to the ground because they are able to get more resources during the day due to their size. Just as we can’t survive without sleep, light detection and subsequent rest periods are indispensable to the vitality of trees.

In addition to the ability to detect light, trees are also shockingly attuned to sound. They are able to pick up on vibrations, like the sound of an animal chewing their leaves (Appel, 2014). They are not defenseless against these attacks either- when a leaf is damaged by a caterpillar, for example, leaves emit the amino acid glutamine. This behavior overwhelms the leaves with calcium which is toxic to the worms in large amounts (Lunn, 2018), very similar to the aforementioned acacia tree that defends itself against giraffes in the savannah. Essentially, when trees hear danger approaching, they defend themselves just like us. Despite all these qualities trees share with us, it is often considered distasteful to claim that trees are human-like.

The practice of humanizing trees to describe their complex nature is a controversial tool. Suzanne Simard and Peter Wholleben are no strangers to scientists rolling their eyes at the outlandish idea of trees making friends and talking to each other. The main critique of emotionally-spoken scientists is that the sharing of resources between trees is simply evolution. For trees, competing with every neighbor is detrimental to their health. The mutualistic relationships between trees displayed through mycorrhizal networks are necessary for the survival and wellness of a forest. Scientists prefer to be as objective as possible when describing what they observe in nature, so personifying plants is seen as ridiculous. “Sometimes I think scientists’ (and my) negative reactions to certain types of science writing are not so much about factual integrity as they are about tone. Wohlleben turns science on its head by anthropomorphizing trees. No scientist would take that seriously”, says plant physiologist Erin Zimmerman in a critique of Peter Wohlleben’s book “The Hidden Life of Trees”. Zimmerman recognizes the merit Wohlleben’s research contains but, like most scientists, is unable to get past the way he humanizes trees.

Despite the distaste scientists have for metaphors in scientific writing, Wohlleben’s book holds its own when the readers understand the nuance of his writing style. Obviously, trees do not have neurons, voices, or hearts, but Wohlleben and Simmard make the literary choice to explain trees in an empathetic way. Some scientists go so far as to claim it is dangerous for people to humanize the flora and fauna of the world. They worry that the personifying claims that Wohlleben makes in his book about trees will be taken literally by an uneducated audience, thereby drowning out factual information. There was even a petition created in 2017 with the intent to label Wohlleben’s book as fantasy- a portion of the petition’s description reads, “It is very unfortunate that, through this book, so many people obtain a very unrealistic understanding of forest ecosystems because the statements made here are a conglomerate of half-truths, biased judgments, and wishful thinking derived from very selective and unrepresentative sources of information” (openpetition.org). This petition was never published, but as of October 2023, it has 4,561 signatures. There are no scientific papers that attack Wohlleben, so it is difficult to gauge what this petition is specifically talking about when they use terms like “half-truths” or “wishful thinking”. It can be assumed that these critiques are relevant to the way Wohlleben narrates in a way that portrays trees as his peers- discussing their “daily dramas and moving love stories”, as if trees act with emotional intention (Kingsland, 2018).

What these no-nonsense scientists do not understand is that Wohlleben intentionally speaks in a whimsical way to draw in an audience and intrigue them with the mysterious lives of trees, which he does very effectively. Wohllebend, Simmard, and other poetic foresters are getting people interested in plant biology and nature as a whole in an unprecedented way for Western society. Despite all the metaphors and personification, what they say is true and has been studied- trees do in fact protect themselves, their young, and the trees around them. They talk to each other, not with voices, but with chemical signals sent through mycorrhizal networks beneath the soil. They rest when the sun goes down and work during the day to get nutrients for themselves and their community. Although trees may not look anything like us from the outside, they share so many qualities and habits with humans.

Right beneath our feet, trees are engaged in robust conversations, their mycorrhizal networks linking them like underground telephone wires. They discuss trading resources, donating to the sick, nearby danger, and the weather. Trees that are near to each other talk the most and combine their resources, making them like the close friends we see in the human world. The family dynamics are similar to humans as well- like a suckling infant, young trees rely on their mothers for food and resources, unable to get their own until they are stronger and taller. Mother trees, the kind and gentle queens of the forest, look after their community and are watchful to make sure the trees around them are well-fed and happy. Although mother trees are hard workers during the day, they rest at night like all the other trees and us. Trees exhibit human-like characteristics as they engage in communication, establish relationships, and interpret their sensory environment. Next time you feel yourself getting sleepy as the sun goes down, think of the trees that feel the same way. When your mom cooks you a meal, remember the mother trees that feed their young sugar water. As you text your friend about an oncoming snowstorm, I urge you to recall that trees essentially do the same. Remember that trees are so much like us, and deserve to be treated with human respect.

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