Francis Hallé (1938-2025) : Le poète des arbres nous a quittés

Francis Hallé (1938-2025): The poet of trees has left us

" What matters in safeguarding tropical forests is not so much that we have an immediate need for these tropical forests, but that we need the human qualities necessary to save them; for these are precisely the qualities we need to save ourselves ."
— Francis Hallé


It is with deep sadness that I learned of the passing of Francis Hallé on December 31, 2025, at 11:00 p.m. He died at his home in Montpellier, surrounded by his family. The last day of the year has taken with it one of the greatest defenders of trees and primary forests of our time.

An eminent botanist, visionary biologist, passionate dendrologist, talented illustrator and above all, tireless defender of life, Francis Hallé dedicated his life to making us understand and love plants, these extraordinary beings with whom we share the Earth.

I met him three years ago in Alsace, in Krautergersheim, the sauerkraut capital, to hear his plea for preserving a primeval forest in Europe. The Swiss and French Jura mountains are well-positioned to allow for this type of project for the common good.
I could see Francis's humanity in his eyes when I told him about the workshops I was developing for children using plant sounds. I spoke of the power of reconnection through sound to the living world, because by giving plants a voice, we restore the subtle link between living organisms, through the symphony of life.

I would have liked to propose new exchanges with him in 2026 but like Jane Goodall, Francis left us too soon, he still had so much to share with us about plants.
We will share some of your wisdom with Naturasounds.


All smiles with Francis Hallé - April 2022

A canopy explorer

Born on April 15, 1938 in Seine-Port (Seine-et-Marne), Francis Hallé was the youngest of a family of seven children. His father, an agricultural engineer, and his mother, daughter of the painter André Dauchez, who "adored plants," instilled in him a passion for botany.

What he did with this passion defies imagination. Thanks to his invention, the canopy raft, he was able to conduct extensive research on the canopy and the incredible biodiversity it harbors for decades in several forests around the world. This airship, which allows for delicate landings in the treetops, revolutionized the study of tropical forests, granting access to a previously inaccessible world where the vast majority of forest biodiversity is concentrated.

Formerly a professor of botany at the University of Montpellier, he specialized in the ecology of tropical rainforests, settling in tropical regions to study primary forests, first from 1960 to 1968 in Ivory Coast where his children were born, then in Congo, Zaire and Indonesia.

"In Praise of Plants": A revolution in our view of plants

In 1999, Francis Hallé published what would become one of his most influential works: "In Praise of the Plant: Towards a New Biology" (Le Seuil). This seminal book lays the foundations for a radically different understanding of the plant world.

Plants: Beings with extraordinary abilities

In this essential work, Hallé methodically dismantles our anthropocentric view of plants. He shows us that Plants are not immobile and inferior animals , but organisms of astonishing complexity, endowed with capabilities that we are only beginning to understand.

Among its major teachings:

  1. Plant architecture as a language
    • Hallé developed a method for classifying trees based on their growth architecture
    • Each plant "writes" its story in its form
    • The 23 architectural models he identified reveal sophisticated evolutionary strategies.
  2. Modularity and potential immortality
    • Unlike animals, plants are modular They can lose 90% of their biomass and survive
    • They do not have programmed senescence: theoretically, a tree can live indefinitely.
    • This fundamental difference changes everything in our understanding of "what an individual is".
  3. Plant sensitivity
    • Plants perceive their environment with an acuity that we underestimate.
    • They detect light (phototropism), gravity (geotropism), and touch (thigmotropism).
    • They communicate chemically with other organisms
  4. A radically different way of life
    • Immobile, they have developed sophisticated chemical defense strategies.
    • Being autotrophs, they produce their own food through photosynthesis.
    • Being decentralized, they lack centralized vital organs.

Key quote from In Praise of Plants :

" Plants don't have brains, but they don't need them. They solve the problems they encounter in other ways. Their solutions are often more elegant than ours ."

"A Plea for Trees": Defending What Gives Us Life

In 2005, Francis Hallé published "A Plea for Trees" (Actes Sud), a vibrant call to recognize the intrinsic and essential value of trees in our lives and societies.

The tree as the infrastructure of life

In this passionate book, Hallé demonstrates that Trees are not simply "resources" , but the pillars upon which all life on Earth rests.

His main arguments:

  1. Trees create their own climate
    • They regulate temperatures
    • They generate and retain moisture
    • They protect the soil from erosion
  2. Trees are complex societies
    • A single tropical tree can host up to 10,000 different species
    • Trees communicate with each other via mycorrhizal networks
    • They help each other, feed their young, and share resources.
  3. The urgent need to protect primary forests
    • Francis Hallé points out that primary forests contain 75% of the world's biodiversity and that by 2020, those in the tropics will have disappeared.
    • Once destroyed, these forests take centuries, even millennia, to regenerate.
    • Their loss represents an irreversible catastrophe for humanity.

Memorable quote:

"Trees are our oldest and most faithful partners. Without them, we would never have appeared on this planet. Without them, we will not survive long."

Primary forests: a dream turned battle

In 2019, he launched a project to recreate a primary forest in France on a territory of 60,000 to 70,000 hectares yet to be defined. The Association for Primary Forests in Western Europe, established to gather support for the project, was created in March 2019.

What is a primary forest?

For Francis Hallé, a primary forest is not simply "an old forest". It is:

  • A forest never exploited by man
  • Where natural processes take place without human intervention
  • Where the biodiversity reaches its maximum
  • Where the cycles of life are complete and self-contained
  • Where the long time (several centuries) allows for the emergence of complex ecological relationships

Currently, the Białowieża forest is the only primary forest in Europe. It covers 5,000 ha out of the total 200,000 ha of the forest.

Francis Hallé's project was visionary: to recreate the conditions for a primary forest to be reborn in Western Europe , in a cross-border area (France-Belgium, France-Switzerland, or in the Vosges).

His message:

"We don't have to create a primeval forest. We simply have to let nature take its course, for long enough, without intervening. The trees know what they have to do."

The Francis Hallé Association for Primary Forests is more determined than ever to realize its dream: to create the conditions for a primary forest to be reborn in Western Europe. Its fight continues.

An artist in the service of science

Throughout his travels, spanning more than half a century, Francis Hallé meticulously recorded countless sketches of the specimens he studied in his notebooks. In this way, the botanist bequeathed to posterity more than 24,000 pages of hand-drawn sketches.

In a style close to the clear line, his explanatory diagrams often include a dose of humor that facilitates understanding.

His illustrations are not simply botanical drawings. They are... works of art which capture the essence, the life, the movement of plants. Each stroke reveals not only the anatomy, but the personality of the observed tree.

Major works illustrated by Hallé:

  • Atlas of Poetic Botany (Arthaud, 2016)
  • The Raft of the Summits (Actes Sud, 2021)
  • The Amazing Life of Plants (Actes Sud junior, 2021)
  • The beauty of life (Actes Sud, 2024)
  • The genius of the forest with Vincent Zabus and Nicoby (Albin Michel BD, 2025)

Communicating with plants: Hallé's vision

Francis Hallé never claimed that plants "speak" in the human sense. But he dedicated his life to showing us that they communicate , perceive , react And interact in ways infinitely more sophisticated than we imagined.

Forms of plant communication according to Hallé


1. Airborne chemical communication

  • Emission of volatile organic compounds (VOCs) in case of attack
  • Neighboring trees detect these signals and strengthen their defenses.
  • Attracting predatory insects to combat herbivores

2. Root and mycorrhizal communication

  • The trees are connected by underground fungal networks.
  • Nutrient sharing between trees, even of different species
  • The "mother trees" nourish their young plants via these networks
  • Information circulating on the health situation, environmental threats

3. Perception and reaction to the environment

  • Light detection (across the entire spectrum, including UV and infrared)
  • Perception of gravity, touch, temperature
  • Response to sound vibrations (some studies suggest a sensitivity to sound)
  • Short-term and long-term memory (adaptation to repeated stress)

4. Architecture as a language

  • The shape of a tree "tells" its story
  • Each branch, each node, bears witness to a decision made in response to the environment.
  • The tree "writes" its life in its structure

Hallé's position: respect for plant otherness

Francis Hallé was very clear: We must not anthropomorphize plants . They do not think like us, do not feel like us, do not communicate like us.

BUT — and that is the beauty of his thought — Just because they are different does not mean they are inferior .

Fundamental quote:

"Plants have solved life's problems differently than we have. Their solutions are not less good, they are different. And often, they are better."

This respect for plant otherness — recognizing that plants are radically different from us while also being complex and sophisticated — is at the heart of Hallé’s philosophy.

Towards interspecies bio-communication: Hallé's legacy

Francis Hallé's work opens up immense perspectives for the Interspecies bio-communication , this emerging field which studies the exchange of information between living organisms of different natures.

What Hallé taught us

1. Plants are partners, not resources

To build a true relationship with plants, we must:

  • Stop seeing them as passive objects
  • Recognize their agency their ability to act on their environment
  • Respect their temporality Plants live at a different pace than ours.
  • Accept their radical difference They are not green animals.

2. To observe is already to communicate

Hallé spent his life in observe Plants. This attentive, patient, respectful observation is already a form of communication.

When we truly observe a plant:

  • We perceive his needs
  • We understand its responses to the environment
  • We "read" his story in its form
  • We are entering relationship with her

3. Plants transform us

Francis Hallé liked to say that spending time with trees profoundly changes human beings. Primary forests have this power:

  • Slow down our pace
  • Calming our minds
  • Expanding our temporal perspective
  • Reconnecting with life

It is also a form of communication: Plants teach us, if we know how to listen .

Naturasounds and the legacy of Francis Hallé

At Naturasounds, we follow in the footsteps of Francis Hallé by seeking to making plant signals tangible via the sonification of their bioelectric activity.

Our approach: rigor and respect

Like Hallé, we believe that it is necessary to:

1. Be transparent about what we measure

  • We are capturing real electrophysiological signals.
  • We translate them into audible sounds (sonification)
  • We do not claim that "plants make music"
  • We clearly explain the translation process

2. Respect plant diversity

  • Plants do not "speak" in the human sense
  • The signals we detect are physiological processes.
  • Our work is a Mediation , not a revelation of a "secret language"

3. Create sensory bridges

  • Sonification allows for perceive the invisible activity of plants
  • It creates an emotional experience that can change our relationship with plants.
  • It serves as front door towards scientific understanding

4. To educate and amaze

  • Like Hallé with his drawings, we use sound to fascinate.
  • We hope that this fascination will lead to knowledge
  • And that knowledge will lead to respect and protection

Possible collaborations with plants

Francis Hallé showed us that plants are capable of Cooperation , adaptation , and learning . These capabilities open up possibilities for collaboration:

In agriculture:

  • Listen to plant stress signals to optimize irrigation
  • Early detection of diseases via bioelectrical analysis
  • Understanding nutritional needs in real time

In forestry:

  • Monitoring forest health via their signals
  • Identify the "mother" trees that need priority protection
  • Understanding the dynamics of forest communication

In scientific research:

  • Studying plant responses to environmental stimuli
  • Mapping underground communication networks
  • Understanding the mechanisms of plant memory

In art and mediation:

  • Creating sensory installations that make plant life "audible"
  • Developing interactive educational tools
  • Promoting emotional reconnection with nature

"The Tropical Condition" and "A World Without Winter": Understanding Life in its Fullness

In A world without winter: the tropics (Le Seuil, 1993) and The Tropical Condition (Actes Sud, 2010), Francis Hallé reveals to us that The tropics are not an exception, but the norm .

The tropics: a laboratory of life

For Hallé, rainforests are the place where:

  • Life reaches its maximum complexity
  • Ecological relationships are the most sophisticated
  • The evolution takes place most quickly
  • There beauty of life expresses itself fully

The tropics teach us:

  • That diversity is the rule, not the exception
  • Let cooperation take precedence over competition
  • That complexity emerges from long periods of time
  • That living beings, left to their own devices, strive towards greater wealth

The final message: "The beauty of life"

In 2024, Francis Hallé published his final work: "The beauty of life" (Actes Sud). This is his spiritual and philosophical testament.

An aesthetics of the living

In this book, Hallé develops the idea that there is a "environmental aesthetics" which enriches our relationship with living things.

The beauty of life is not superficial. It is:

  • A sign of health and vitality
  • The result of millions of years of evolution
  • An invitation to contemplation and respect
  • A reminder of our interdependence with the rest of the living world

Quote from The beauty of life :

"The beauty of life is a reminder of what we owe to life, of its grandeur that made us and keeps us alive; it is a call to find a more appropriate place on Earth."

The complete literary works: a treasure for humanity

Francis Hallé leaves behind a monumental body of work that will continue to inspire generations:

Major works

  1. A world without winter: the tropics (Le Seuil, 1993)
  2. In Praise of the Plant: Towards a New Biology (Le Seuil, 1999)
  3. The Raft of the Summits with Dany Cleyet-Marrel and Gilles Ebersolt (Lattès, 2000; Actes Sud, 2021)
  4. Essay on the architecture and growth dynamics of tropical trees with Oldeman (Masson, 2002)
  5. A Plea for Trees (Actes Sud, 2005)
  6. The Tropical Condition (Actes Sud, 2010)
  7. The words of botany (Actes Sud, 2011)
  8. The origins of plants Volumes 1 and 2 (Fayard, 2008)
  9. Atlas of Poetic Botany (Arthaud, 2016)
  10. Leonardo da Vinci and Nature with Patrick Scheyder and Allain Bougrain Dubourg (Ouest-France, 2019)
  11. The Raft of the Canopies: Thirty Years of Exploring Equatorial Forest Canopies (Actes Sud, 2021)
  12. The Amazing Life of Plants with Rozenn Torquebiau (Actes Sud junior, 2021)
  13. The beauty of life (Actes Sud, 2024)
  14. The genius of the forest with Vincent Zabus and Nicoby (Albin Michel BD, 2025)

Artistic collaborations

  • "There was a forest" (2013): A documentary by Luc Jacquet in which Hallé guides the viewer through the tropical forests.
  • Exhibition at the City of Science (2022-2023): "Fragile", on the fragility of living things
  • Exhibition at the Montreal Botanical Garden (2018): A portion of his 24,000 pages of drawings

A legacy for the future

Francis Hallé has left us, but his work, his vision and his struggle continue.

What he leaves us

1. A renewed understanding of plants

  • They are not inferior to animals, they are different
  • Their intelligence is distributed, not centralized.
  • Their lifestyle offers solutions to ecological challenges.

2. A call for the protection of primary forests

  • These cathedrals of life are irreplaceable.
  • Their loss would be an irreversible catastrophe
  • Protecting them is protecting ourselves.

3. An invitation to slow down and observe

  • Plants teach us patience
  • They show us the beauty of long periods of time.
  • They reconnect us to what is essential

4. An ethics of the relationship with living beings

  • Respecting otherness
  • Recognizing our interdependence
  • Act as partners, not as exploiters

The fight continues

The Francis Hallé Association for Primary Forests is more determined than ever to make its dream a reality: to create the conditions for a primary forest to be reborn in Western Europe.

How to honor his memory:

  1. Support the Francis Hallé Association for Primary Forests
  2. Read and share his work
    • Start by In Praise of the Plant And A Plea for Trees
    • Sharing one's books, ideas, and drawings
  3. Plant trees, protect forests
    • Each tree planted is a tribute
    • Every forest preserved is a victory.
  4. Observe and respect plants
    • Spending time with trees
    • Learn to understand them, not just to use them
    • Passing this respect on to future generations
  5. Supporting research on plants
    • Encourage studies on plant communication
    • Developing environmentally friendly technologies (such as bio-electric sonication)
    • Promoting agriculture that cooperates with plants

Conclusion: The spirit of the forest will always live on

Francis Hallé showed us that Trees are our masters . They were here long before us, and they will be here long after us. They have developed life strategies of a sophistication that we are only beginning to understand.

He taught us to to see things differently . To look at a forest no longer as a stockpile of timber, but as a living community of unparalleled richness. To consider each tree no longer as an object, but as a individual with his history, his relationships, his personality.

He taught us humility . Faced with a thousand-year-old sequoia, faced with the complexity of a tropical forest, faced with the evolutionary genius of a simple leaf, how can we not feel our smallness and our dependence?

And above all, he passed on to us a A message of hope . If we let nature take its course, if we give it time and space, it will regain all its splendor. The forests can be reborn. Life can reclaim its rights.

Francis Hallé, we will continue your fight.

We will continue to defend trees, to protect forests, to transmit wonder at living things.

We will continue to listen to the plants, with rigor and respect, knowing that we will never hear everything they have to tell us, but that each signal captured brings us a little closer to these extraordinary beings with whom we share this Earth.

Thank you, Francis, for everything you have given us.

May the trees you loved so much continue to grow, to communicate, to live, in homage to your memory.

To go further

Essential reading:

  • Francis Hallé, In Praise of Plants: Towards a New Biology , Le Seuil, 1999
  • Francis Hallé, A Plea for Trees , Actes Sud, 2005
  • Francis Hallé, The Beauty of Life , Actes Sud, 2024

Documentary:

  • Once Upon a Forest , Luc Jacquet, 2013 (with Francis Hallé)

Association :

At Naturasounds:

  • We continue our exploration of plant bio-communication with scientific rigor and respect for plant otherness, in the spirit of Francis Hallé.
  • Discover our sonification devices: www.naturasounds.org

"A tree is a living being that deserves our respect, our admiration, and our protection. It is not there for us, it is there with us." — Francis Hallé

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