The Infinite Monkey Cage - The Wonder of Trees - Dame Judi Dench, Tony Kirkham and Tristan Gooley

Episode Date: July 10, 2024

Brian Cox and Robin Ince leaf through the latest tree science with Dame Judi Dench, Tony Kirkham and Tristan Gooley. Dame Judi Dench shares her great love for treekind and describes how over time she has come to create a small woodland in her garden and how meaningful that is for her. Tony Kirkham, former head of Kew Arboretum and Gardens shares some of the amazing journeys he's been on to find unusual and rare trees around the world. Navigator Tristan Gooley, has spent a lifetime learning how to read trees, he explains how nearly everything on a tree can provide clues into the environment around it and how elements like leaf shape and colour can help us to use trees as a compass to navigate our way.Producer: Melanie Brown Exec Producer: Alexandra Feachem BBC Studios Audio production

This is the BBC. This podcast is supported by advertising outside the UK. I'm Sarah Milroy, Director of the McMichael Canadian Art Collection in Kleinberg. If you love Impressionism, you'll love what we have on view this summer at the Gallery. River of Dreams, Impressionism on the St. Lawrence, features more than 150 sublime works by some of Quebec's most beloved artists. Join us for a journey down the St. Lawrence and see how Impressionism flourished in this country a century ago. Buy your tickets today at mcmichael.com, home to the art of Canada.

Hello, I'm Greg Jenner. I'm the host of You're Dead to Me, the Radio 4 comedy show that takes history seriously. And we are back for Series 8, starting with a live episode recorded at the Hay Literary Festival all about the history of the medieval printed book in England. Our comedian there is Robin Ince. And then we'll be moving on to the life of Mary Anning, the famous paleontologist of the 19th century with Sarah Pascoe. And then we'll hop on a ship all the way back to Bronze Age Crete to learn about the

ancient Minoans with Josie Long. Plus loads more. So if that sounds like fun, just type in, you're dead to me, wherever you get your podcasts. BBC Sounds music radio podcasts Hello you're about to listen to the Infinite Monkey Cage. Episodes will be released on Wednesdays wherever you get your podcasts. But if you're in the UK the full series is available right now on BBC Sounds. Hello I'm Brian Cox.

I'm Robin Ince and this is the Infinite Monkey Cage back for a new series. The question of course is always if a tree falls in the woods and there's nobody there to hear it, does it make a sound? And if Robin Ince is invited to a Royal Institution Christmas lecture and his head is placed inside a giant magnetic pulse generator, does he make a sound? The answer to that is no, genuinely from experience. I had a magnetic pulse on the right hand side of my brain while doing Jabberwock towards Brillingham. The slidy toes did go on gimbling. The whir. And that was what happened.

And Brian now can't get hold of that machine, but he would love to shut me up with my motor region. Now, I know that even by the standards of the monkey cage, that's an avant-garde introduction But the reason we made it is today we are at the Royal Institution and we're talking about trees So you see it made sense And this is one of the most famous lecture theaters in the world and more than that some of it is made of wood as well Isn't it which kind of connects with the leave it now?

Leaf it that now when I said leaf it I'm gonna make this clear I didn't want to put that in the script but our producer loves puns so if you'd like to complain about that pun don't send them to me you'll hear the producer's name at the end of the show and we'll give you a home address throughout the first half of the 19th century Michael Faraday stood in this very spot and delivered lectures on electromagnetism the electric generator the electric motor which he invented in this building and which the BBC are still using today to power this show Humphry Davy so David Attenborough Carl Sagan of

all delivered lectures here so a wonderful place to begin the new series of the infinite monkey cage so today we are going for a walk in the woods, something that of course normally annoys Brian in particular in the spring, summer and autumn time because it gets in the way of all the really lovely stars. I can't see it because oh no look the yew tree's in the way. Oh. How do trees compete in the woods? How are trees adapted to the changing environment and indeed what is a tree? This is going to be a good question. 185 episodes of Finally We Ask What is a Tree. We're beginning to get somewhere with this

science business. Today we are joined by a reader of trees, a leader of trees and a queen of the trees and they are... My name's Tonic Urcombe. I'm retired after 43 years of managing the Arboretum at the Royal Botanic Gardens Q and my favourite tree is the Dawn Redwood, Metsochoia gliptostroboides. Ooh! I'm an actress, Judy Dench, and I have a passion for trees. Absolute passion. And my favourite tree is an oak. Also it is a family name of ours.

Alas, not my immediate family, but my cousins have all got oak in their name, which seems very suitable. I like it a lot. Hi, I'm Tristan Goole. I'm a natural navigator and author of books about clues and signs in nature, most recently How to Read a Tree, and my favourite tree is an unremarkable beach tree which taught me how to use bird poo as a compass. And this is our panel! Tristan, we have to bite, don't we?

How do you use bird poo as a compass? Well, my work is about observing, but in particular looking for asymmetry. So if I... Everything in nature that I've found is asymmetrical, whether it's a tree, the sun, or everything in between. And I noticed on one of my walks that there was bird poo, but mainly on one side of the trees. And I paused by one tree, and I tried to unravel the mystery. And by the time I'd solved it, I'd gone through astronomy, botany, ethology, forestry, meteorology, looked into the interconnectedness of nature.

And I feel ridiculous, so it sounds, got a small glimpse into the meaning of the universe. But to answer your question, the birds are perching on branches, and we get more branches on the side of the tree that gets most light. And in this part of the world, that is the south side, because the sun is too south in the middle of the day. There are lots more levels to it, but that was the start of that fun investigation. Brilliant. So next week's episode is,

What is Bird Pooh? We're going to keep moving. And well done, Tony, by the way. I think that was very impressive. You yet again found out that radio 4 listeners, they do love a bit of Latin. Oh, did you hear that sound when you got all Latin-y? They loved it. And that was the first tree that I learned at 10 years old. Someone gave me a book, knowing that I was interested in

trees, I went straight to the index, like you do, to look for the longest Latin name. I learned it off parrot fashion, didn't know what it was, I had no idea what the tree was and little did I know that in 1996 I'd see that tree in China growing on its own as a single specimen. Well if there's any lull in the show, you know the trick, just burst out into Latin, we'll be fine. Mexicoia.

Tony, everybody laughed with that, thought it was a joke, this question what is a tree, but I'm hoping you say, that's a good question. No, it is a good question. And there are lots and lots of definitions. Basically, a tree is a woody perennial that can do something that we call secondary thickening. So it produces annual rings each year and gets larger. It can be broadleaf.

It can be a conifer. It can be deciduous. It can be broadleaf, it can be a colifer, it can be deciduous, it can be evergreen and it can have several trunks. The Oxford English Dictionary suggests that there's only a single trunk but of course there are multi-stem trees and then they can vary in size from a from a birch in the Arctic that's about six inches tall to a coarse redwood which is the tallest tree in the world in California that's 115 meters tall so Woody like a woody hedge

Why is a really great name for a 1960s Why is a privet hedge not a tree? What is the rules it out? I thought this was a scientific program. Well that's a really good question Brian, because when is a tree a tree? When is it not a shrub? And so things like hollies, hazel, privet can be trees if they get large enough. So some of the shrubs we usually say if they get over several meters tall and start to put on a good trunk and live for, you know, maybe over ten years, then they can become a tree. So there's a lot of confusion between, you know, when is a tree a tree and when is a shrub a shrub and when do they change.

We're so close to being a philosophy programme. Judy, how do you feel about that definition of a tree? Because obviously anyone who saw the wonderful documentary you did, you have a real true passion for trees you have woodland I don't know why this happened but when I was really a small girl seven or eight maybe I used to get irrationally upset when I saw lorries with trees on them then I used I went through a stage where I thought I once remember saying to my parents I think we're in an upside-down world because I think they're the roots up in the air. They said, no, pull yourself together Judy, calm down.

But then it came to the fact that I went to Stratford in 1962 and walking through the Bancroft Gardens one day, I saw a tree and it had on it the name Vivien Lee and it said under it, alas unparalleled, which is a Shakespeare line, and I thought that this is the most marvelous thing to do, but I kind of put it in a notebook and it was only till, you know, 40 years ago when we moved to our garden that we suddenly thought this is it, this is what I must do, I must plant as many trees as I can and there was many different kinds and two friends who have died. And how do you choose them? Which trees do you decide to put them?

It's very hard. Sometimes I think they actually look like them, do you know? I just think you have to somehow match the character but I just find such delight in the fact of having trees in my garden or seeing them out everywhere, you know. You're very knowledgeable on trees, Judy. I remember you taking me around the garden and you showed me a tree and I remember you saying it was like the person that you'd planted it for because it was a birch with gray bark and you said he was very, he was always very gray. Tristan, how do, could you talk us through the lifecycle of a tree? How does it begin? How does it grow? How does it become a tree?

Well, in my work, I'm looking at things through quite a strict filter. So I'm not looking for the complete scientific chapter and verse. I'm looking for what helps me understand the clues I'm going to find. You know those time lapse videos we see when we see something growing incredibly sort of fast

and sort of working its way upwards? And perhaps when we were kids we grew sunflowers and we get this idea that the top of a plant moves upwards and it makes us think all the parts of a tree move upwards. But a big breakthrough for me, and all my work is I'm standing on the shoulders of giants and scientists and researchers, was when I discovered that trees have two main stages of growth. They have that time when they're working their way upwards and it is like the sunflower. That's the primary growth. They then have the secondary growth and that's when they put on bark. And at that point, the trunk doesn't move upwards at all. And the most sort of fun way of thinking of this is you know when you see graffiti on the trees,

quite often it's romantic and, you know, Leo for Gemma or something like this. And we shouldn't do it. It's not good for the trees but it's helpful for this particular example. That graffiti doesn't move and for me that was that was quite an eye-opener because I've always thought of all plants moving upwards but the second the bark is there it will grow fatter but it won't go upwards. So a branch for example doesn't move up. That was a really when I first when I was reading your book and finding out about that, it's such, because we've got a Christmas tree in my old dad's house and it was four foot tall.

And now it's terrible, it's an absolute nightmare and it's ruined the whole village green because it's all dark now because of the size of the tree. But I said, he put a pulley on it to put up Christmas lights until that was impossible. And I've realized when I was reading that, the pulley is still in the same position. So now it's halfway down the tree.

What was once at the top of the tree? And that is, as you said, it's such a counter-institutional idea of how we see the process of nature. Yes, we get these ideas at a very, very young age. And it takes a little bit of a shift to actually sort of overturn them. But when we do, it makes sense of so many things. It explains the shape and the patterns we see in the tree.

So we imagine that the branches start at the sort of ground level and moving upwards. But actually, what the tree is doing is constantly growing new branches higher up and then lopping off the ones it doesn't need lower down. And what we see is the end result. But we imagine an entirely different story. But the great thing about trees is that we can edge them

by these annual rings, because they produce one a year And we always over egg how old trees are you know word? I'll not say that we're competitive in the tree world But we are very competitive And in our in our gardens and our burrito we we always want the biggest we want the tallest we want the oldest And you know part of my enjoyment now in retirement is going around the UK, going around the world. It's come back from America, looking at trees, looking at old trees, looking at big trees, and looking at those record breakers.

And we have people in the UK who go around measuring trees as a job. And this information is gonna be really important as we go into this climate change, to see which trees are gonna be the best to grow in our climate which which are growing the fastest Which are growing the biggest which aren't growing at all and that will start to tell us which trees we need to be planting For the future you know given that you mentioned that the records So can you give us a sense of could you said the oldest tree the tallest tree?

So you should tell us if you ask my children I've got two children and I took them on a holiday to California to see The biggest tree in the world the oldest tree in the world and the tallest tree in the world After the second tree my daughter lost the will to live. I Mean she was only 13 14 and it cost me two days retail therapy in Macy's. But the tallest trees on that west coast of the Pacific west coast of North America, in California, just creeps into Oregon, and that's of course the redwood, Sequoia sempervirans. And the tallest tree, they have names, so the tallest tree is called Hyperion, and it's

115.7 metres tall. We love a very tall tree, you and I. We did. In Borneo. We must talk about that one in Borneo, yeah. But the biggest tree in the world is General Sherman, which is a giant redwood, Sequoia dendron giganteon, and that's over the Sierra Nevada in California.

And you know, these are huge trees. And just to give you an example, General Sherman lost a branch a few years ago. And that branch is bigger than any redwood outside of California. And it's still the biggest tree in the world. So, you know, these are monsters. And then the oldest tree in the world is a pine, the bristlecone pine. Pine is longieva, which means long-lived pine. And that's between 4,000 and 5,000 years old. And we know that because we've counted the

annual rings by doing what we call increment boring. So we can bore into the tree, take a core out, and then count the annual rings. And that's in the White Mountains or Death Valley, the only tree that will grow there. And what was the tree you climbed in Borneo? What was the name? Judy I thought you remember the Latin name Yellow Moranti was no it was a very very tall tree You know it was and you went 30 meters up it I did on the end of a rope. Yes hauled by a young man called unding I did. On the end of a rope?

Yes. Hauled by a young man called Unding. It was about fifteen I think probably. It was a wonderful day. We were looking at the biodive, all the different biodive types of biodiversity in the Borneo rainforest which was amazing. Hello, I'm Greg Jenner. I'm the host of You're Dead to Me, the Radio 4 comedy show that takes

history seriously. And we are back for series 8, starting with a live episode recorded at the Hay Literary Festival all about the history of the medieval printed book in England. Our comedian there is Robin Ince. And then we'll be moving on to the life of Mary Anning, the famous paleontologist of the 19th century, with Sarah Pascoe. And then we'll hop on a ship all the way back to Bronze Age Crete to learn about the ancient Minoans with Josie Long. Plus loads more. So if that sounds like fun, just type in, you're dead to me, wherever you get your podcasts.

Everybody gets excited by tall trees, as we should do. But in my strange world and strange perspective, the short trees are often telling us some interesting different stories. So the wind, when it buffets the trees, triggers, since you're having fun with words down that end, I'll join in. It triggers a botanical process called thigmomorphogenesis. Touched. Oh, man! APPLAUSE called thigmomorphogenesis, touched... Oh, man! APPLAUSE I heard a metal gauntlet slapping a cheek there.

Stand by. I believe I've gone a bit towards the Greek, not the Latin, but I might be wrong there. But the fun part of it is this is touch-change growth, because, again, trees don't know what the world they're growing into. So if they're in a sheltered valley, they grow taller than if they're on a windswept hill and in natural navigation we can use this because the

shortest trees will be on the southwest side of woodland because that's the side that gets the the prevailing gales so if you look at woods on a hill from a little distance look for the shortest side and that through figma morphogenesis forgive me will be the southwest side I have now got to work out how I can just drop figma morphogenesis into conversations And I presume that's why I'm going to have to start working for the Forestry Commission So it's but I wanted to ask you Judy there was something interesting was saying a little bit before Which was about you know this kind of self mutilating branches almost this this action that is going on with trees and when we look And you have this wonderful woodland

and I think people without you know without knowing a little bit more would just see a wood as a place that's almost stationary that there's a kind of you know silence and not much movement and yet when you hear these stories suddenly when you look at those woods they are a place of perpetual action. We might not be able to observe it but we know that something lies within it Yes, and I did a program about trees and something I absolutely never knew It was early spring couple of three years made four years ago. We went to a woodland where there were a lot of bluebells and The person I was with had bought kind of stethoscope Which they put against the trunk and I couldn't believe it.

I could not believe the force of water rushing up the trunk. Especially, it's very comforting when you look in the winter and it's all bare, and you think, oh, the trees have gone... It's very comforting now to me to know what's going on inside. They're... They're doing all the time. They're exhausted at the end of the day. It was a revelation.

Is there any limit to how long a tree could live in principle? You said that we're talking about 5,000 year old trees here. What determines the lifetime of a tree? I think it's a really difficult question to answer that Brian. The 5,000 year old bristlecone pine could live for another 5,000 years so we're gonna have to stay around for a bit to find out. And there are some trees like the London Plain which is a hybrid where we've crossed a North American species with a Mediterranean species and the originals are still growing and that was in the 1600s and we still don't know how big the London Plain will will get. So does it tend to be the environment and environmental factors that kills them ultimately or just being blown down in gales?

Or man. The threats are you know logging, illegal logging etc, pollution, climate change is going to be a determining factor. Judy, can I just ask you, just because Tony was there talking about the age of trees, and is that part of the connection? Because before we came out, I was talking about in the village, I was brought up in, there's an oak tree that's 500 years old, and from the time that I was very small, I could just imagine, you know, all of those different children that might have danced around there, and all those adventures adventures and all the climbing on the branches and it seems to me that trees are wonderful for helping us to get that sense of of all that time. I agree I mean I I just love the idea of planting trees

which I haven't got a woodland actually but I have six acres only but I just love the idea of planting trees that somehow represents the person you're missing. I think it's an important thing that you can, on a birthday or an anniversary, you can send a picture of that tree to the relative of where it is and say, look what's happened to your tree. You know, recently I sent a picture to Greg Doran because of Tony Sherdye a couple of years ago and I put such a small little tree into my orchard and it's now way above my height

and I think that's quite a comfort to somebody. I think it's a nun head cemetery has this in one of the corners of the wooded corner there's a tomb that has been broken open by a tree breaking through it. And you can't help but feel as though, not quite yet, I'm not quite ready yet. Tristan, your book is How to Read a Tree. When you see a tree, as Judy said, there's a history to the tree. How do you begin to look at a tree and try to understand what it's been through for those hundreds of, actually sometimes thousands of years, I suppose?

Yes, I love the idea and we can all do it now. Imagine a tree and then if you step out and look at the very first tree you meet and think, is that identical to the tree I imagine? And the answer will always be no. And there will probably be hundreds of small differences and every one of those differences is a clue because it is a reflection of the world that that tree has experienced, its story. So for example, if it has is a reflection of the world that that tree has experienced, its story. So, for example, if it has on one side of the tree the leaves might be smaller than you're expecting and that might be the south side, there's more light there, the leaves become smaller, thicker and lighter in colour, sun leaves on the south side. Or

we might find that the leaves have a very sort of pointed tip and that's telling us that the area is wet because leaves have evolved to shed rainwater because it's a burden. So there are hundreds of these little differences. I mean if you just sketch a tree it will not look like the tree you meet and so that's what I'm always thinking. So my work really is putting on the detective hat and thinking what is the reason? There is always a reason. Randomness sort of pops up in the quantum world and things like that but in terms of tree shapes and patterns, it really doesn't. I was going to say, honestly, I was going to say, have you ever met a tree that stumped you?

And I thought I can't say that. I really genuinely can't say that. Send your complaints to our producer. Even that was her using telepathy to get a pun in his head. Do you have any trees you've encountered where you say, I don't understand how this has come to be the way that it is? Yeah, I mean the joy for me is I follow the idea that there will be a reason and I actually now I'm at the point where I love it where it's a real mystery. Some of the the best ones come in actually in urban environments because we tend to sort of mess around with trees quite a lot when in towns and cities, but also you get quite fun patterns.

There was a tree I met on holiday once that was growing in the... We've been living together for many I brought it home. I'll tell you what it takes a lot for this audience to go that's weird. Well done. I am weird. And I looked at this tree that I'd met and it was growing the wrong way in inverted commas. Now nothing can grow the wrong way, but it took me ages to work out what was going on. It was picking up light that reflected off a mirror glass building on the other side of the road. So it was just doing the natural thing and growing towards the light, but the reason I was puzzled was because it was breaking all the rules.

Naughty tree. Is there such a thing as a... was puzzled was because it uh yeah it's breaking the rules naughty tree is there such a thing as a it was talked about the British Isles we think as Judy said the oak tree it's almost like a symbol the British Isles is this such a thing as a native tree to the British Isles what what are those native yeah I mean we have a very small number of native species in the British Isles actually you know what is a native that's question, but for me it's when Brexit first happened 8,000 years ago.

The Channel, when the Channel was formed. When the Channel was formed, yeah. Any tree that managed to get to the British Isles from the continent before the waters broke, that's a British native. And I suppose the Orc is the iconic tree of the British Isles. But the... And the yew is definitely the oldest tree in Britain. And we have trees that are thought to be between 2,000 and 4,000 years old. But the oak's been around a long time.

And the great thing about the oaks is how we relate them to historical events. So my favourite oak tree is the Queen Elizabeth the first oak in Cowdry Park and I usually make two pilgrimages a year to see that tree. It's a fantastic tree, totally hollow, thought to be almost a thousand years old and it's called the Queen Elizabeth the first oak because Queen Elizabeth the first is supposed to have sheltered in it while she was out hunting. Judy, do you remember the first time that you deliberately made a trip just to go and see a tree? Because you know there's that wonderful book, Meeting with Remarkable Trees, which I think helped introduce a lot of people as well. Was it was there something you saw or thought? I don't remember.

My first recollection was raking pears off a tree that was in our next door garden and being told off for it, quite right. But I don't remember. I'm going to boast a lot now because I have just been given, thanks to Tony, a shoot of the sycamore gap tree. Yes, indeed. Which I was overcome when Tony said this is going to be given to you. So it was going to be chosen, it's been taken away again till the autumn because it's got to grow a bit more and then it's going to come back and be implanted. I've decided I'm going to call it Antoninus because I thought that was Hadrian's son but somebody said to me that's not Hadrian's son that's Hadrian's lover and I said well either way, son lover I don't care that's who's going to come. That was such an interesting story because I think I

think people will have been surprised at how emotionally they affected they were because I remember the first time seeing Sycamore Gap and it really you did have an emotional you have an emotional reaction, the landscape of it, the beauty of it, the loneliness of it, you know that was an amazing connection. And it's a place where people used to meet and were engaged under, were probably buried under I don't know, but you know it was such a beautiful tree. It's the most photographed tree in Britain, it's so and of course the film Robin Hood with Kevin Costner and oh yes just past over isn't it I think in that film it's a short ride in the film at risk of making myself sound even weirder than I have done already there were a pair of yew trees on top of the Sussex Downs and they were chopped down by the land owner with good reason they were they were converting the the land for pasture and yew and new trees and animals aren't a great partnership,

but they assumed nobody would notice, I think. And I was bereft because I'd spent years teaching people using these two trees the way the wind and the sun shaped them. They were my classroom for over a decade. And I think that's, for me, that's the exciting thing, how we can build a relationship with trees, is instead of, I think it's fantastic when there are these landmark trees and we should all enjoy them, but the trees we see every day do become remarkable when we just start asking ourselves questions, like, why are the branches pointing that way and not that way? Why are the leaves, you know, only in this place and not in that place?

And then we start to see its story and the relationship develops and, yes, you then start talking about them like they're your friends. See we've talked about a lot about trees in the British Isles. So we go to the southern hemisphere. Yeah. Anyone who's been there will notice that they almost look alien. Can you give us an idea of the trees that you find if you go right to the other end of the earth? Right to the other, well I mean if you go down to the southern tip of South America, then you get the monkey puzzles. And the monkey puzzle, we call the Marmite tree.

Some people love it as a tree, some people hate it. But it is an incredible architectural plant. And Fibonacci's number sequencing is based on how that tree grows by, you know, that spiraling branch that gives it its strength to stand up. So, and then you can go across to Australia, you've got the eucalypts, the gums, and there are about a thousand different species of gums. So I could start and tell you how to identify each one, but we're going to be here for quite a few days. But the tree that I suppose captivated most people's attention is the

walla my pine that was discovered in Australia in 1994. We thought that become extinct two million years ago from fossil records of you know pollen grains and then suddenly in 1994 David Noble, a member of the Wildlife and Fauna organization in Australia, was canyoning in the Blue Mountains, 125 kilometres northwest of Sydney, and he came across this tree that he didn't recognise, broke a piece off, brought it out and showed it to all the botanists who'd never seen it before, apart from fossil records and descriptions, and asked him how, you know him how small was it, with a little shrub.

And he went, no, it's 42 meters tall. How had that evaded our attention for so long? There are only about 70 trees in this canyon. That's the only population that are being monitored and grown. But we flooded the market with young wallamai pine so that nobody had to go into that canyon to try and collect it and to raise money to, you know, to protect the habitat that it grows in because that's what we need to do. And it prefers to grow in England than it does in Australia. It's growing better with us than in Australia. So you could... So, Judy, if said you I'd like to plant one of those

I know what to get you for Christmas Would you go about getting one of those oh we can buy them over here They are available in all good nurseries. Yeah, you can buy them in garden centres. And it's well worth trying. It is a beautiful tree and its other closest cousin is the monkey puzzle. So at Kew, I planted them next to the monkey puzzle so they could catch up on two million years. Because they do communicate, so they could catch up on two million years.

You told me about the kind of communication. I'll never forget it. The trees have between themselves underneath the ground and they can signal if there's any kind of threat or something they can signal to another tree. That's right. The wood-wide web. We had... Underground for trees. Yeah. You're absolutely right, the wood-wide web. We had... underground for trees, yes. You're absolutely right, Judy, and we went into a woodland and looked at this. Microisal fungi that is like fiber-optic cables that run from tree to

tree and connect them all and send signals and tell each other, you know, what's happening. And if there's a tree that's feeling a little peaky, a bit under the weather, then the mycorrhizal fungi can help it out and share other resources with them. So, trees are amazing things. They've survived for a long, long time. And what we've got to remember is where they come from, from woodlands. And these woodlands are, you know,

like social enclaves for trees. There's quite a fun one above ground I believe with the acacias in Africa isn't there as well where they've evolved this incredible defensive response because when the the giraffe start grazing on the acacias they I forget the chemical is it is it a tannin I don't know do you know Tony? Yeah it's a tannin and and and like I think in most trees when they come under attack from insects or animals and they can increase the tanning levels in the leaves and the branches so they become very bitter and they can do it very quickly.

And what's amazing I found was that quite a few of the trees do that and the the giraffes have worked out that the trees are communicating through the hormones in the air. have worked out that the trees are communicating through the hormones in the air so the giraffes have Let frog that logic so they start at the downwind end of the roe vocations Yeah, there's a question here about what we mean by life Intelligence because you said earlier the tree wants to do this the tree and of course It's just a form of language. We don't think these agency is such. But the more we talk about Woodland, for example,

as you said, Judy, communication networks, it does begin to feel there's almost a layer of life, a way that things cooperate together, that we're just beginning to glimpse. But trees also send signals to us that we are totally oblivious to. And I think if everyone goes out tomorrow and walks around a tree, those trees give off something called a monoturpines and they trigger things in our brain that relieve stress,

relieve anxiety, improve our mental wellbeing and make us feel good. And there's evidence to show that if you've had an operation, say for example in hospital, and if you are in a recovery room and can see trees or be near trees, then your recovery will increase dramatically. Being amongst the trees reduces stress until you discover, as I did at Kew Gardens, that walking over the roots compacts them which then leads to trauma and branches falling. So if you find a path, a new path, most paths in the UK are older than the trees next to them, they're well established, but if you find a new path cutting through woodland, have a look at the branches above it and you'll

find they're really struggling because the path has compacted the roots, this leads to bubbles, cavitations, that kills off and one of the things I didn't realise until researching the book was that the roots on each side of the tree are supplying that side of the tree and that was for me, it was a real eye-opener when you realise you see a new path and you can see the actual branches suffering above that path. So that, after you've recovered from your illness, you can think about the... Judy, can I just ask about that six acres of woodland you've got, how much did it start off with a plan? It didn't. I think that the thing I said about seeing the tree in the Bancroft Gardens at

Stratford kind of triggered off something in my mind of how lovely it is to actually be able to plant something to somebody who's not with us anymore and see that. And Michael had felt exactly the same about that, and that's what started us. So I think we planted 80-something trees all over the garden, and there are, I'm afraid, many more to go in. But I can't begin to explain how unbelievably satisfying it is. Well, we all know because we appreciate them so much, but it is to see their growth. And it upsets me about the paths. That's very upsetting to know that the paths past the tree kind of upsets or worries them.

There is one positive spin which is that the roots have sort of two parts so there's if we think of the edge of the canopy that's that's the drip line that's very very sensitive and if people start walking or going over on mountain bikes and things like that the tree will suffer quite significantly but closer to the tree it's more structural roots and and there you can actually have an ancient path, which near where I live, there's an old Roman road, and there are these mighty beech trees.

And the two are right next to each other, and people are bombing up and down, walking and cycling, and the trees are absolutely fine. So if you get close enough to the trunk, you're sometimes doing the tree less harm. I love strange stories of trees. And there was one that I was reading in, I think it's Nicholas Fern's book of philosophy where

he starts off telling the story of someone who when they died they were considered very unpopular with the village so they were buried outside the churchyard. A hundred years later they went they checked the records when actually wasn't such a bad person we should put him in and then they dug down there was an apple tree that grew just near the grave and when they opened the coffin there was no body as, there was an apple tree that grew just near the grave. And when they opened the coffin, there was no body as such. There was just a human-shaped root of a tree, which I love as an idea. And the idea that all of those apples that had been eaten by those people, yeah. And I'm fascinated, you know, from any of your, those kind of moments again, another

bit of that connection. First, you asked, is that possible? Absolutely, yeah. I mean they'll look for the, you know, the easiest route. Sorry, another pun. The easiest area to break through soil. I've seen London plain routes that have been excavated in London of 90 degree angles where they've come and dug the road up to replace water pipes or you know gas pipes Put the soil back the soils a lot finer and looser than the compacted soil around So they've literally followed down the trenches and and then you get these roots with

90 degree corners. So yeah, they're opportunists and they'll look for the the easiest option. You know a lot about trees Tony. I think we can they'll look for the the easiest option. You know a lot about trees Tony I think we can... I always like to ask this question of real experts, are there questions that are burning questions that we do not understand? Is it about discovering new species or is there something about the about trees themselves that you would think I would love to know that? I'd love to know more about what goes on underground and how trees communicate. I mean, we know roughly how they communicate. I think I'd like to know a little bit more about,

you know, how they do and how they support each other and help each other and survive, you know. I'd love to be able to talk to a Methuselah in the White Mountains and just find out what it's seen and what it's experienced that we'll never know. What about for you, Judy? Yes, the things you'd still like to know about the trees. Oh, there's no end of things I want to know about trees.

I just love seeing the change of them. I love learning about them. I never get tired of it. And actually, we did have a wonderful afternoon once when Tony came down to the garden and we measured an oak that was in my garden and Tony said that would have been here during the Battle of Waterloo.

I just loved that fact about it. I mean, they're like people to me. Well, they're people, they represent people, but they are actually like people. They're all so different. They all behave in such extraordinary ways suddenly throughout something you know no idea about the shape of it changes may I ask about that one of my favorite actors was Ian Richardson and I believe you have and this from that

wonderful line in Tinker Tailor Soldier Spy where he's asking Smiley to give some money to a young man he's been having an affair with and he just says he was a cherub but no angel and just just for that alone is such, and I just, I know you have a tree for Ian Ricks. I do for Ian, yes, because we were at Stratford together in 1962. The wonderful thing is that sometimes the trees look like, I know it's daft to say, but they actually start to look like the people too. When my grandson was born, we put an oak in and Sammy is going to be 27 on Friday. Well this oak, I mean, it's so

representative, or Sammy is so representative of the oak, they just look alike. I don't think you'd be offended if I said that. It looks like a beautiful oak in my garden. You can have two, that's also what I love about it, you can have two trees exactly the same family of tree, they will grow completely differently. They look different. They look different in the surroundings there or whether they're with their own kind. I think that's the thing, a lot of what this side of things we've been talking about

is really you have to look at things for longer. Because the longer that you look at something, the more you go, I thought these were all the same. And that's, again, part of the beauty of science and curiosity played together, is you find the personality that can lie in so many things which we just morph together. Tristan, for you, where are the mysteries

left to be discovered? Oh, infinite, which is appropriate for this, isn't it? But I'd love to pick up on something that we've touched on there, which is that learning can, I don't think you use these words, but maybe it was this sense that kills the magic sometimes. And for me personally, and I think for a few others out there, you can get the magic back if we don't drown ourselves

in technicalities, but instead do what I believe very strongly we were born to do, which is to observe and understand, to find meaning. So what I mean by that is if you look at a river valley, for example, we can go in and try and identify down to species level every tree along that river, and that could be a satisfying exercise, but for me it's a lot more fun to step back and go oh it goes from pale to dark it's going from broadleaf trees to

conifers why broadleaf trees out compete conifers in moist environments so they're going to do well near the river and then as you look up the side of the valley up the hillside you see the broadleaf trees are getting shorter as you got the valley ah that's because the windaf trees are getting shorter as you go up the valley. Ah, that's because the wind is battering them as you go up, so they grow shorter to respond to that. And then they start to give up and the conifers do better, and you start with tall conifers and you look a little bit higher, they get shorter, and then they give up. So you've actually got a tree altimeter there without knowing the name of a single tree.

You've understood how the trees are competing, how they're making their home, what they're telling you about the environment. So for me, that's the happy zone. We're learning, we're observing, we're finding meaning, but we're not actually sort of beating ourselves up with technicalities. Oh, well, I hope everyone who's listening to this now, wherever you are, you know, go for a walk in the park and just, whatever tree it may be, you know, start that relationship. And I don't think that does sound weird. I think that is a beautiful thing. It does a bit.

It doesn't sound a bit weird. I'll tell you what the day I'm told that I'm weird by someone who can't relate to anything that's beyond subatomic is the day I'm more than happy about that. Now we asked our audience a question and today it was what tree would you like to climb and why? A small one because if because if I fall it's not far to fall. Gravity. I like our more nervous listeners. I would like, I would climb a poultry sentry holding pastry

in the wintry pantry because poetry. Head and tree. Because it takes 28.5 minutes to get to the punchline of this joke. An infinite monkey puzzle tree, as with Brian, I would appreciate the gravity of the experiment. A redwood tree, because it has strong branches and I could attach two ropes and a seat. After all, swings can only get better.

So, well done, everyone. Well done. Here we go. My family tree to stop those cousins marrying. Yes, I'm Irish. LAUGHTER Thanks to our guests, Tony Kirkham, Tristan Gooley and Dame Jeannie Dench. APPLAUSE See you then! APPLAUSE

Excitement doesn't end because next week's show is all about snakes. And ladders. We're doing a whole show about board games, and that's not a lie. Thanks very much. Bye-bye. Bye-bye. APPLAUSE Bye-bye. I'm not going to say it's a passion triangle In the infinite monkey cage Turn that nice again. I'm Helen Abonem-Carter, and for BBC Radio 4, this is History's Secret Heroes, a new series of rarely heard tales from World War II. None of them knew that she'd lived this double life.

They had no idea that she was Britain's top female code breaker. We'll hear of daring risk takers. What she was offering to do was to ski in over the high Carpathian mountains in minus 40 degrees. Of course it was dangerous, but danger was his friend. Helping people was his blood. Subscribe to History's Secret Heroes on BBC Sounds.

I'm Sarah Milroy, director of the MacMichael Canadian Art Collection in Kleinberg. If you love impressionism, you'll love what we have on view this summer at the Gallery. River of Dreams, Impressionism on the St. Lawrence, features more than 150 sublime works by some of Quebec's most beloved artists. Join us for a journey down the St. Lawrence and see how Impressionism flourished in this country a century ago. Buy your tickets today at mcmichael.com, home to the art of Canada.

Hello, I'm Greg Jenner. I'm the host of You're Dead to Me, the Radio 4 comedy show that takes history seriously. And we are back for Series 8, starting with a live episode recorded at the Hay Literary Festival, all about the history of the medieval printed book in England. Our comedian there is Robin Ince. And then we'll be moving on to the life of Mary Anning, the famous paleontologist the book.