How Trees Communicate
The secret lives of trees and fungi 🌲
A forest holds all the secrets of nature, and humans will never know. A tree whispers encoded messages to its neighbors while it solemnly rests upon clusters of fungi. Beyond their stoic presence is a network of chattering plants and saplings awaiting the latest news concerning their habitat. The “Wood Wide Web” was coined by forest ecologist Dr. Suzanne Simard in her 1997 dissertation, which explored how trees of different species exchange carbon and nutrients with one another. She found that beneath a forest’s soil lies a mycorrhizal network of fungi communicating with each other to anticipate pest attacks, coordinate growth, and disperse resources (1). But how exactly do trees communicate? Is there another world of botanical dialect? Let’s explore a language foreign to all humans.
A mycorrhizal network is a web of incredibly tiny mycelium threads from a greater fungal organism that wrap around tree roots. These threads connect trees together and are the heart of their communication. Chemical signalling and electrical signals are utilized to send messages for help or rescue. Infochemicals from plants that wish to grab a forest’s attention include hormones, amino acids, or RNA.
It’s easy to confuse plant hormones with the hormones in our bodies, as they both act as chemical messengers. Plants produce simpler molecules from all around their anatomy, while animal hormones are secreted from complex glands and travel through the bloodstream. Ethylene is one example of these plant signalers, triggered by flooding, wounding, or drought. It also doubles as a pheromone, which is airborne. Nearby plants may react to ethylene as a warning or danger sign and will ramp up their own defenses to prepare for attack (2).
To understand how plants send electrical signals to each other, let’s first dive into ion flow across membrane channels, action potentials, and variation potentials. Ion flow is often triggered by any stimulus: light, a bite, or touch. Channels like calcium or chloride channels will open, allowing ions to rush into or out of cells. An ion is any atom or molecule with an electrical charge. Because of this sudden rush, an electrical potential is created; one side of the membrane is more negative than the other. Action potentials are faster-acting than variation potentials and are used to trigger rapid systematic responses to light. By contrast, variation potentials are used when a plant is wounded and are a slower, stress response (3). One example of a plant working with these electrical potentials is with osmosis. Osmosis is the movement of water to less saturated areas. It seeks to equalize water diffusion and is swayed by differences in electrical potential. Conveniently, this water will move to plants or trees in need of water because there is a lack thereof (4). Unlike hormone secretion, electrical signalling is much faster and works more rapidly. It’s like the forest’s nervous system (3)!
Like Dr. Simard’s work, The Hidden Life of Trees, written by Peter Wohlleben, debunks misconceptionsdebunks the misconceptions and stereotypes about trees. Much of society had believed that trees needed to be thinned out, replanted constantly, and maintained to build a healthy forest. A “younger forest” was prized, and many villainized older trees, worrying that they could leech off of their counterparts like parasites. With his publication, Wohlleben revealed how an untouched tree and its ecosystem are more productive. They do not need any human intervention or environmental micromanaging. While trees are complex, they are often underestimated and even infantilized by humans (5). So no, the Lorax does not need to “speak for the trees”; they speak for themselves!
Bibliography:
Simmard, Suzanne. (1997). Mother Trees in a Wood Wide Web, Awakin. Retrieved from: https://www.awakin.org/v2/read/view.php?tid=2518&sso_checked=1
Are Yew Talkin’ To Tree? (n.d). Species Spotlight - Tree and Plant Communication, National Park Service. Retrieved from: https://www.nps.gov/articles/species-spotlight-tree-and-plant-communication.htm#:~:text=Trees%20and%20plants%20communicate%20in%20a%20variety,*%20Water%20*%20Hormones%20*%20Alarm%20signals
National Library of Medicine. (2001). How Ionic Movements Produce Electrical Signals, Sinauer Associates. Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK11054/#:~:text=Electrical%20potentials%20are%20generated%20across,ionic%20movements%20across%20neuronal%20membranes.
BBC Bitesize. (n.d). Supplying the Cell - OCR Gateway, BBC. Retrieved from: https://www.bbc.co.uk/bitesize/guides/zwkn7p3/revision/4
Lamp’L, Joe. (2022, January 27). The Hidden Life of Trees, with Peter Wohlleben, The Joe Gardener Show. Retrieved from: https://joegardener.com/podcast/hidden-life-of-trees-peter-wohlleben/
This is an interesting read! I have been wondering whether and how plants interact each other, thanks for the eyeopening knowledge!
This was fascinating! Especially the idea of the forest functioning almost like a nervous system through electrical signaling. I’m curious how much of this communication is species-specific versus shared across an entire ecosystem. Do different trees “interpret” signals differently, or is the language more universal? Really compelling way to rethink forests as cooperative rather than competitive