Do trees talk to each other?

Image of a misty forest

What if the forest knows more than we think it does?

I love trees. Many people do, although most don't really think about them very much. People walk past them on the way to work, sit underneath them in parks, complain when their leaves end up in the gutters and occasionally swear at the one that drops a branch on the car.

But spend a little time looking at a tree. It's constantly responding to the world around it. It reacts to changes in light and temperature, responds to water availability, and even detects damage from insects and other animals. It can alter its chemistry when it's attacked by disease, and its roots are exploring the soil, interacting with fungi and microorganisms, and responding to what they encounter.

None of this means that a tree thinks in the way that you or I do. It doesn't sit there wondering whether it remembered to put the bins out. There's no evidence that an oak has an inner monologue complaining about the weather (though who knows?)

But it does raise an interesting question.

If an organism can detect what is happening around it and change its behaviour in response, how much information is being passed around that organism, and perhaps between organisms?

And that is where things start to get rather interesting.

Plants have ways of sending messages

Plants have no brains, nervous systems or ears, but that doesn't mean they are incapable of signalling. In fact, plants use a remarkably complicated collection of chemical, electrical and physical processes to detect changes in their surroundings and respond to them.

One of the most fascinating examples happens when a plant is attacked by something that wants to eat it. Damage caused by insects or other herbivores can trigger chemical changes within the plant, including the production of substances involved in defence. Some plants can also release volatile chemicals into the air, which can affect nearby plants and alter their own defensive responses.

It isn't a conversation in the way we understand it. There isn't a little tree standing on the other side of the hedge shouting, "Watch out, there's a caterpillar over here."

But information has travelled.

Something happens to one plant. That plant changes chemically, and molecules enter the surrounding environment. Then another plant detects a change and responded.

If you take the word "communication" to mean the transfer of information that causes a response, suddenly the plant world starts looking rather different.

And it gets even stranger when you go underground.

The world beneath our feet

A tree's roots don't simply sit in the soil collecting water. They exist within an extraordinarily complicated community of fungi, bacteria and other organisms.

One particularly important relationship involves mycorrhizal fungi. These fungi associate with plant roots, effectively extending the reach of the root system through their microscopic filaments. The fungus can help the plant obtain nutrients and water from the soil, while the plant provides the fungus with carbon produced through photosynthesis.

It is a partnership that has been around for a very long time.

And because fungal filaments can spread through the soil, sometimes connecting with the roots of more than one plant, scientists have become interested in whether information or resources can move through these underground relationships.

This is where you may have heard the phrase "the wood-wide web".

It is a wonderfully evocative name, and it has become extremely popular because it gives us an image that is easy to understand. Picture a forest floor covered in an invisible network, with trees connected to one another by fungal threads, quietly exchanging messages and resources beneath our feet.

It's a great story. The science, however, is more complicated.

Researchers have pointed out that some of the popular claims about the wood-wide web have run ahead of the evidence. The relationships between plants, fungi and the wider soil community are real, fascinating and extremely complex, but that doesn't necessarily mean that a forest functions like a giant underground internet, with older trees deliberately sending carefully selected packages of food to their offspring.

Nature is rarely quite that tidy. And I think that makes it more interesting because we don't need to turn trees into furry woodland characters having conversations around a campfire to find something remarkable happening (and I'm sure the last thing some trees would want is a campfire).

So what does "talking" actually mean?

Perhaps our problem is the word itself. When we say that two people are communicating, we normally imagine language. Words carry information from one brain to another. We can ask a question, give an instruction, tell a lie or explain that we've forgotten where we parked the car.

Plants don't need any of that. Their version of communication can be chemical. It can involve changes in electrical activity, or involve signals travelling through tissues or interactions between roots, fungi and microorganisms. A plant can detect a change in its environment and trigger a response somewhere else.

There is no reason that communication has to look like ours. Afterall, a smoke alarm doesn't understand the word "fire". It detects particular conditions and responds to them. A thermostat doesn't understand the weather forecast. It measures temperature and turns something on or off.

Nature is full of systems that detect information and respond to it without anything remotely resembling a human conversation. Once you start thinking about trees in those terms, the forest becomes a much more complicated place.

The tree beside you isn't simply standing there, it's sensing, responding, interacting with an enormous biological community that exists above, below and around it. And we are only beginning to understand exactly how much of that interaction is going on.

Now for the dangerous question

This is the point where my brain tends to get me into trouble. Because once you discover something genuinely interesting, there is always a temptation to ask the next question.

What if?

What if the signalling systems we've discovered are only part of a much bigger picture? What if plants can coordinate their responses to environmental changes in ways that we don't yet understand? What if the relationships between trees, fungi, bacteria and other organisms create patterns of information transfer that are far more sophisticated than we currently appreciate?

And, perhaps most importantly, what if the forest isn't simply responding to individual threats?

What if it can respond to a pattern?

This last question is where science gives way to fiction. I should make that distinction very clear. There is no evidence that forests are secretly holding meetings about humanity. There is no scientific basis for imagining that trees have suddenly decided we have been terribly naughty and need to be dealt with.

At least, not yet.

But I find the gap between what we know and what we don't know much more interesting than pretending we already have all the answers.

And that's where The Awakening came from

I've always been fascinated by the idea that the things we take for granted might be doing considerably more than we realise. Trees are a perfect example. We see them every day. We lean against them, climb them, cut them down, build around them, pave over their roots and fill the air around them with pollution. Most of the time, they simply stand there and take it.

Or at least, that's how it looks to us. So I started wondering what would happen if that changed.

What if trees didn't simply respond individually to the damage we were causing? What if something changed in the way they interacted with one another? What if the natural world reached a point where it no longer tolerated what we were doing to it? And what if, instead of humans discovering that the environment was changing, the environment decided to do something about humans?

That is the idea at the heart of The Awakening.

It's not a book about trees secretly having human thoughts, or that they can get up and walk like in Tolkien. It's not an attempt to suggest that the science has already proved forests are capable of organising themselves against us. And it's certainly not a prediction that the oak tree outside your house is currently plotting your downfall.

It's a "what if?" taken several steps further. Because sometimes the most interesting stories begin with something that's completely real, add one impossible question, and then refuse to stop asking what might happen next.

In The Awakening, the world's trees wake up and humanity discovers that being at the top of the food chain doesn't necessarily mean we're the ones in charge.

The Awakening is coming in April 2027. Discover The Awakening