Interview with Francis Hallé, botanist

Capture d_écran 2017-03-30 à 15.03.53Francis Hallé is a botanist and co-author of the expedition project "The Raft of the Peaks".

The equatorial canopy is the richest natural environment in the world, and is only just beginning to be explored. The raft of the peaks is a project that allows the study of its biodiversity. We interviewed Francis Hallé at Biomim'expo 2017, before the event.

1) Presentation
2) The intelligence of plants
3) Effect of plants on humans
4) Plant biomimicry
5) Cooperation and competition
6) An invincibly destructive primate
7) The raft of the peaks

Mr Hallé, you are a botanist, you are an explorer, how can I introduce you?

No, no, no, botanist is more than enough for me, and I can tell you that it is enough to fill my life and even beyond. Life is too short for a botanist. No, no, it's enough for me, it's perfect.

Life is too short, because it is a largely unexplored universe?

Plants have not been studied for very long, other than to use them. Of course, if it's to make medicine or wood, oil or rubber, we know how to do that, but studying them in themselves is very recent, and consequently there is a huge delay.

We talk too much about animals, we talk too much about the four-legged creatures we can observe?

Yes, and it's easy to understand why, it's because we are ourselves, so it fascinates us. Whereas plants are much more intellectual to be interested in.

In fact we are interested in our peers, that's what you are telling us.

We are interested in our navels, it's not complicated. [laughs]
A scientist should not fall into this trap. I fall into it myself, it's impossible not to have a little tenderness for human beings.


Drawing by Francis Hallé

How did your passion for plants begin?

I started out interested in animals, I had gone quite far at university on animals, I had started to publish, I had good entrances to good laboratories, but all of a sudden it changed because I realised that plants are infinitely more interesting than animals and than us.
The plants must be thinking "poor animals, they have to move to get their food, or even go hunting for it, while we sit in the sun and wait".

Biomim'expo is an event that focuses on bio-inspiration. What do you think we can learn from plants?

I would be interested in a direct application of photosynthesis [to produce food, sugar]. Plants have photosynthesis and we do not. There's no reason why we shouldn't have it. We use photosynthesis because we eat food that comes from it, that's not what I mean, it's putting it to our service directly, a bit bypassing the plants [not going through them to feed ourselves].

Photosynthesis is not very complicated, we could do it. There would be no more food problems on this planet, I think we would all gain.

Photosynthesis explained in less than 30 seconds

There is a whole gallery of absolutely brilliant plants that can inspire architecture, urban planners... Sometimes you almost talk about the intelligence of plants and trees. How do you react to that?

Well, I'll tell you, I've changed my mind. For years I refused to use the term intelligence for plants. Why? Simply because if you look in a dictionary, even the best dictionaries, you see that intelligence is for us: you need a brain, you need speech, and you need to be able to move, so it didn't apply to plants. I was brought up to have the utmost respect for the dictionary, but I have changed my mind. I realise that whoever wrote the definition in the dictionary was definitely a human being. One should be wary of definitions that valorise the person who writes them.

How are plants intelligent?

So I'll tell you what, I can't stop talking about it. A little experiment to start with?
You plant an inert support, a bamboo. You put a vine with a tendril, a passion flower, or a vine, whatever: a plant that climbs with tendrils. So you know very well that it sees the support, it's obvious: it sends the tendril directly to it. Before it hits, you move the support 10 centimetres to the right. Then she sends another spin and just as it's about to hit, 10 centimetres to the right. You do it four times, and the fifth time she aims 10 centimetres to the right from the start. So there's a possibility of some kind of prediction, an idea of what the future is.

Learning from past experience, therefore. And they also communicate with each other?

Of course. It's not very old. We would have made everyone laugh if we had said that 40 years ago, but now the processes, the mechanisms of communication between plants, we know that it is incredibly rich.

A memory experiment. Do you see the sensitive? It's a little plant you find in supermarkets. You touch one of its leaves, it folds, and then it takes three-quarters of an hour to unfold again. You raise it at home, in good conditions but without rain. The day you take it out, it receives its first rain, and obviously it bends, because of this myriad of small shocks. But it gets the hang of it pretty quickly, by the third or fourth rain. It doesn't bend anymore, it's used to it.
You take it home, and you raise it for 4-5 years without rain, well the day you take it out, it gets a rain and doesn't bend, even though it's not the same leaves.

Now there are many books that deal with the intelligence of plants quite openly. I agree with them completely. I think they are more intelligent than we are.
I'm not saying that it's totally passed into the mainstream because there are still biologists who are bothered by it, but those I'm interested in, those I work with, have crossed that line.

Reaction of a sensitive plant to touch

What about the relationship between plants and humans?
In an interviewIn your article, you cited an experiment in Chicago. The presence of trees in the city obviously had an effect on the crime rate.

Personally, I wasn't surprised at all, but the Illinois academics were surprised because they didn't know what they were going to get.
Everyone I know who deals with plants knows very well that it makes people peaceful.
You have problems - everyone has problems - you go down to the garden. It doesn't take away the troubles, that's for sure, but it puts them into perspective, so plants are undoubtedly good for us.
There are similar statistics for school grounds - where plants are removed for safety reasons - wrongly because for discipline reasons it would be better to add them.

So when we talk about revegetation of cities? When we talk about urban forests?

This is essential. I go to great lengths to try and get trees planted in prisons. Because if I were in prison, what I would miss the most is walking between concrete and metal without seeing a leaf. I would find that monstrous. It's the worst kind of cruelty to a human being.
And I'm told that it's not possible for security reasons. I think they are too lazy to change.

Illustration-Principale-Paris-2050-de-Vincent-CallebautDrawing of Paris in 2050 by Vincent Callebaut, architect

Biomimicry is often a matter of interdisciplinarity.
Have your views on this changed over the last few years?
We are used to saying, especially in France, that it is difficult to break out of our silos.
Do you, as a botanist, feel that there is more porosity between disciplines?

Definitely. It depends on which disciplines you are talking about. With physics, for example, it goes extremely well. Biomechanics, we're really on an equal footing there. It's developing very, very quickly.
It's true that there are disciplines with which we are a little isolated.
As botanists, we are obliged to take an interest in chemistry. Animals, of course, I don't mention, that goes without saying. The distinction between zoology and botany is disappearing, not the distinction between plants and animals, it's not the same.
I believe that interdisciplinarity is very well accepted in our time. Moreover, the public authorities are pushing in that direction. The big newspapers, the communities of establishments...

What words of encouragement would you give to these young generations of researchers, or students, or entrepreneur-researchers, who are interested in the inspiration of life to optimise a whole range of things?

We have in front of us almost constantly models that have been tested in natural reality for millions of years, hundreds of millions of years in the case of plants. It would be completely foolish to wipe all that out and start from scratch.
It's very basic what I'm saying here, but we have the solutions in front of us.

Relationship between tropical forests and climate (video)

I have a biomimicry project, I would have liked to tell you a few words about it. A mobile animal, a dog, a man, these are centralised structures. We have vital organs, and therefore we are very easy to kill, our only salvation is to escape.

Plants are decentralised structures, so they are much more resilient, to the point of being almost impossible to kill. People say to me "you take a chainsaw, you cut the trunk of the tree, it will die", no it's not true, when the trunk falls it sticks to the ground and comes out with a series of reiterations on the back part. The trunk will eventually disappear but a perfectly straight line of trees will remain.
That's for what has fallen. The stump may give shoots, but it may not. If it doesn't, it will give hundreds of suckers, i.e. reiterations from the roots.
In other words: you wanted to kill a tree but you end up with a hundred trees. Whereas an animal is very easy to kill.

Also, an apple pie, a glass of Saint-Emilion, you know very well that it doesn't kill the apple tree or the vine. They are there to give you the same gift year after year.
Veal liver? A herring fillet? The animal must be involved. You can't take small pieces of an animal and feed on them. The plant is much more clever.


We have about a hundred organs, well individualised, and each of these organs has a function, it is not interchangeable. Plants have 3 organs: stems, roots, leaves.
Biologists have said to themselves that there are very few functions because there are very few organs. This is a complete misunderstanding of what a decentralised structure is.
Because everything is done in the plant at the cellular level. That is, they don't have eyes: they have eyes all over the body. They don't need a nose to smell, they smell with all their organisation.

In our human achievements, I think it would be very important to adopt, as a source of resilience, absolute decentralisation.

The first Internet networks were created by the American army. And from the beginning they thought: if we have an atomic attack, part of the network can be destroyed. And so they made a totally decentralised thing, so that even if half of it collapses, it still works.

Our resilience through decentralisation?

That's my general impression of biomimicry.
I live in the provinces and I can tell you that we are not decentralised. Parisians are perhaps less sensitive to this. [laughs]

There is work in bio-inspiration which is interested in human organisations, and which in a way flirts a little with what you have just said, based on the principle that in an anthill, in a termite mound, or in a forest, there is not a great leader in the middle of the forest who dictates everything.

Example of biomimetic innovations inspired by ant colonies

There is no need for a leader anyway, it works very well. Optimisation is generated from the start, as is resilience.
It's all based on cooperation. A plant cell is a huge example of cooperation.
You take a human cell and put it on a culture medium. This type of cell, but no more. Next to it, you take a plant cell: it is much bigger, much heavier, and much more complicated. If you culture this cell, the plant comes out. That will never happen with an animal or a human cell culture.

Is cooperation much more productive than competition?

For me, it is a pendulum movement, and we should find a middle ground.
Darwin went far too far in the role given to competition. "Struggle for life
Then people like Fabre in France, or Jean-Marie Pelt who died recently, went too far in the other direction. Competition no longer had a role, and it was only cooperation. This is also an extreme, because in fact both have their place and we need both, permanently, at all levels.

Finally, one point that either distresses or annoys you and another that on the contrary comforts you or gives you a little optimism about what you can observe?

What irritates me the most and what makes me suffer is the destruction of natural environments. It starts with the plants. My daily problem is the equatorial forests, and when I am in a logging site run by the French in our name, financed with our taxes, it disgusts me. It's disgusting. It's a kind of official rape. And this biodiversity that they are making disappear is ours. It's our common heritage. But the guys who do this don't care.
When you're in the money spiral, there's nothing stopping you, it's terrible.

How are the primary forests doing?

There is no more. We've been saying that for 40 years. I made a film not long ago with Luc Jacquet. As he is a very good filmmaker, he managed to make it look like we were in a primary forest, but I can tell you that it wasn't. It's just a one-off. It's just a one-off.

Trailer of Luc Jaquet's film "Once upon a forest

In Poland, the Bialowieza Forest ?

You know that it is being exploited by the Polish government. The last primary forest in Europe. And Europe does not react. I think they are saying some harsh words, that's it. But nothing... It's disgusting.

Is there a global awareness? Are things changing?

Perhaps this is where there is a reason for optimism.
Plants are of interest to the population, not only in France, in Europe. Much more than 40 years ago. You can fill a large amphitheatre with a conference on plants, never would have imagined that in the 1960s of the last century, never. The problem is that this indisputable awareness is not translated into action, it does not reduce the pressure on ecosystems.
I am very disappointed in humans as a zoological species.

Can we repair in part what we have destroyed?

Yes, it's even remarkably easy, and quick. It's just that you can't take it too far, because if there's no forest at all, you can't recreate it from scratch.

If it is broken up, can it be put back together? A bit like wounds.

It's always the same, if you leave it alone. It's just that humans are invincibly destructive primates.

That seed vault that was built up in Norway?

I find it ridiculous. I find it deeply ridiculous and even harmful. It is a vision of life that is totally disconnected from reality. That's not how it works.

Is this a sterile process for you?

Totally sterile. Besides being very expensive.

The Svalbard Global Seed Bank


And this famous raft of the summits, will it take off again?

We stopped talking about it in the media, because as soon as you have a presence in the media, donors think you have a lot of money. You don't get any more and they even come to beg you for it. So there is a complete misunderstanding.
We just celebrated our 30th anniversary. We're going to Asia now after exploring Africa, America, and Melanesia.


The Peak Raft is a scientific laboratory, a place to live, and the focal point of a series of expeditions set up from 1986 onwards, with the aim of studying the biodiversity of primary forests from the canopy, where most of it is concentrated.

What do you hope to discover in Burma in particular?

Burma excites me a lot. It's tiny what we found in the canopy. It's the liveliest place on earth. It's 75% of our terrestrial biodiversity. We're going back next year. Burma excites us a lot because it was a military dictatorship, there hasn't been any scientific research for 50-60 years, and now they're wondering what they've got in terms of biodiversity.

When you say "they wonder what they have", there is an awareness that they are sitting on an incredible wealth of biodiversity?

China comes in at any time of the day or night and all year round and takes the best timber. That's all that's being exploited in the Burmese forest at the moment, so we have to react before it's gone.

Interview by Alain Renaudin, Olivier Floch, and Victor Wastin.


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