A lot, it seems.
For humans, communication normally equates to talking. Trees don’t talk by using language or forming words and so for many years, people have believed that it means that trees don’t say anything to each other. How wrong we were.
Tracker Rob Hlatshwayo explains the medicinal uses of a weeping wattle tree to a Londolozi guest. One of the ways he does this is through language but, like with trees, there are many different ways to communicate.
What researchers have since discovered is that trees communicate not by sound but by scent. The first place they noticed this was in Africa by watching the way that giraffes feed. When the tree becomes aware that it is being browsed upon, it starts to pump tannin into its leaves, which make the tree unpalatable and drives off the hungry ungulate. What is fascinating though is that the giraffes the researchers were watching tended to walk upwind or a distance of about 100 meters before resuming their feeding. What was happening was that the tree was also releasing a warning gas called ethylene, which was carried on the wind and would warn other trees of the same species nearby to start producing tannin too.
Not only could they communicate but it seems they were looking out for each other’s wellbeing. This is something we’re beginning to understand more deeply with terms such as “forest wisdom” and “mother trees” being coined by forest researchers.
The problem though is that this form of communication, although fast, is weather dependent. What if trees wanted to say something to one another and there wasn’t any wind to carry their message? Well, that’s where some help comes in in the rather bizarre form of fungus. Dr. Suzanne Simard of the University of British Columbia discovered that they warn each other using chemical signals as well as electrical impulses sent through the fungal networks around their root tips. As the trees’ root systems grow together and overlap, it allows them to share information with their neighbours. These electrical impulses travel at about a third of an inch per second, which compares to that of a jellyfish or a worm. It seems that trees also share valuable nutrients with one another through their root tips, helping to care for sick or young neighbours.
A giraffe reaches up to feed off the sweet leaves of a knobthorn tree. This tree uses it’s highly knobbed bark and very thorny branches to protect its leaves from being over-browsed. Because animals like giraffes have developed special ways to handle these thorns, the trees uses another defense too. When it feels that it is under threat, the tree will start to produce tannins that will cause the giraffe to move off, preventing it from eating all available leaves.
It is interesting to note that in cultivated fields, crops have lost their ability to communicate with one another. In a natural forest like this one on Londolozi though, the trees will be communicating both above and below ground, helping to keep each other safe and healthy.
What happens if there are loner trees in an area though? Does this block the alarm signal being passed through the forest? Luckily not. As described by Peter Wohlleben in his extraordinary book The Hidden Life of Trees, fungi act like “fiber-optic internet cables”, disseminating news around the forest. As Wohlleben says, “over centuries, a single fungus can cover many square miles and network an entire forest”. They share information about insect, droughts and other dangers, even between competing species of trees as well as with shrubs and grasses.
This is rather comically referred to as the “wood wide web”.
A group of guests walk through the leadwood forest on Londolozi. Underground, the soil is alive with fungi, which act as fiber-optic cables spreading news around what tree researchers refer to as the wood-wide web.
What fascinates me is that if trees are weakened, they seem to lose their communication skills, which results in them being unable to defend themselves. It seems that insects listen to the chemical warning signals and then test a tree that doesn’t pass the message on by taking a bite out of its leaf. Because the tree has been unable to hear the rest of the forest warning it, it will not have produced any tannins and will become inundated with hungry insects wanting to devour its sweet leaves.
This fact is pertinent to us as a social species. It reminds us that we too are designed to look out for one other and to share information, resources and support. Trees that stand alone are weakened and the same can be said for humans. It’s a reminder too that communication doesn’t always mean talking. Like trees, our imaginary root systems are connected in weird and wonderful ways and regardless of physical distance, language or even the ability to speak, we should protect and care for our neighbours.
Lovely blog Amy. Interesting facts. Trees are my favourite living organisms in nature. I planted my garden full of trees. Mostly indigenous. It is so important to our wellbeing to care and protect trees.
It really is Marinda. They form the basis of it all! And often go unnoticed because they live at such a different pace to us. I’m so happy to hear that gardens in urban areas are still so full of life!
Very nice, very wise, Amy. Thanks. A biologist and writer at the University of the South in the United States, David George Haskell, has written a book called “The Songs of Trees.” He delves into the subjects you mention here. It’s a delightful book.
Thanks Dave, I’m going to check it out! Have you read the Hidden Life of Trees as well?
Yes, Amy, I did. About a year ago, in fact. For what it’s worth, here’s what I wrote on my Goodreads dot com review: “Some great insights into trees, and an interesting anthropomorphic spin. Unfortunately, the author (or translator) fails to write like a tree. The sentences tend to jerk in a Brownian motion fashion rather than flow, weave, and wave gently like a tree. Still an interesting book. Long live trees.”
I remember reading about this in Wohlleben’s book too! He also talks about how trees in the vicinity of a damaged or felled tree will keep it alive by sending their own sugars and water to it: a community of trees.
It’s incredible hey Callum! It points to such a high level of consciousness and community support!
It really is! It does, some of the content just blew me away! There are a lot of lessons we can learn from trees!
Also, who took the photo of the giraffe sunset? It’s spectacular!!
Hi Callum. It was taken by Guy Brunskill 🙂
Thanks Amy!
What a wonderful essay Amy. Your knowledge of nature, beyond the boundaries of the animals that inhabit Londolozi never ceases to amaze me. Who would have thought trees have such a detailed communication system. Now I wonder what the 85 ft redwood tree in my backyard is saying to the other trees in the neighborhood and its resident squirrels and birds.
Hi Denise,
I’m sure redwood trees, being so huge, have more to say than most… 😉
I would also love to know Denise!!
Hi, interesting blog! But……….. not all trees in the rest of the world have lost contact. The trees that are grown commercially like palmoil trees, yes, they did and with them all other trees planted like them.
But there is a not so new system that is catching on, called Permaculture and Foodforests etc. These systems imitate the bush and other wild situations, meaning that the life in the ground comes back so that the whole www is back!!
Hi Irene,
Indeed. I’m sure there are going to be some fascinating discoveries in the next few years when it comes to communication in nature, and not just between animals but far more between organisms whose communication is beyond the realms of human detection!
This is a really interesting blog. On UK tv in the next week or so Dame Judi Dench, the celebrated actress, is presenting a documentary on her lifelong love of trees and how they communicate with one another. It should make really fascinating viewing.
Hi Gillian,
We’ll look out for that program on our side. do you happen to know what it’s called?
http://www.telegraph.co.uk/science/2017/12/07/dame-judi-dench-life-now-just-trees-trees-champagne/
Hi James This is the link to the article I read. The programme is called Judi Dench: My Passion for Trees and is being shown on BBC 1 on 20th December.
Thank you, Gillian! Can’t wait to see this. I love that there are big names out there giving good publicity to trees 🙂
This is one of the most special stories we have heard in 20 years of being on safari.
Thanks for the comments Jeff!
Amy’s on leave for a few days but she’ll be thrilled to hear that!
Best regards
Thank you so much Jeff! What was it that you found particularly special?
After almost 20 years of going on safari and countless numbers of game drives, I worry about how many Rangers still focus on the Big 5 (a term I don’t like and never use in my social media postings). This story about the trees touched my heart. Trees are living entities and why shouldn’t they communicate with one another. Thank you for being the sensitive being that you are. See you in two months.
Hi Amy, Thanks for a truly inspirational piece on trees. Yes, we are all inter-connected so will send you some messages when we plan a visit to Londolozi.
You opened a whole new world to me this morning, Amy! Proof that trees DO talk and react is amazing to me. Thank you for opening yet another door that in turn expands, nurtures and educates my own inner spirit. All life, be it animal or plant, is interesting in this small world of ours!
Fabulous piece! It’s so important to emphasize how all life is connected to one another regardless of species. Londolozi does a marvelous job of reiterating that through its blogs and very existence.
Wow, intriguing ….
Just now reading this and what a gift to open on Christmas morning. Thank you for opening our eyes to the immense intelligence and connectedness of nature. Much love to you and everyone at Londoz.
Very interesting article! Never knew this about trees!