Our Green Heart: The Soul and Science of Forests

by Diana Beresford-Kroeger

In this inspiring culmination of Diana Beresford-Kroeger's life's work as botanist, biochemist, biologist and poet of the global forest, she delivers a challenge to us all to dig deeper into the science of forests and the ways they will save us from climate breakdown—and then do our part to plant and protect them.

As the last child in Ireland to receive a full Druidic education, Diana Beresford-Kroeger has brought an unusual and ancient holistic attitude to the science of trees, which has led her to many fresh insights into how closely we are tied to one another and to the natural world. Her influential message is to pay rapt attention to trees, because they are the green heart of the living world. Forests are our lungs, our medicine, our oxygen and the renewal of our soil. Planting the right trees in the right places, protecting the last virgin forests and working to create new ones is our best means to ensure a future for our children and grandchildren on this burning earth.

Each of the essays gathered in Our Green Heart show us a slice of the natural world through Diana's unique lens, illuminating the way our health, individually and as a species, is tied to the health of the forest—a tie we ignore at our peril. She maps the science that still needs to be done—there is so much we don't know about the ways trees and forests work—but also, eloquently, shows us the path to survival that her own science has revealed, the "bioplan" or blueprint for the connectivity of life in nature. If we realize that even the flowerpot on our doorstep is a natural habitat, and plant it according to its bioplan, we will be aiding and abetting life rather than destroying it.

Genres: Nonfiction, Nature, Science, Audiobook, Environment, Ecology, History

216 pages, Hardcover

First published September 1, 2024

About the author

DIANA BERESFORD-KROEGER, a botanist, medical biochemist and self-defined "renegade scientist," brings together ethnobotany, horticulture, spirituality and alternative medicine to reveal a path toward better stewardship of the natural world. Diana's latest book is called The Sweetness of a Simple Life. A precise and poetic writer steeped in Gaelic storytelling traditions gathered from her childhood in Ireland, her previous books include The Global Forest, Arboretum Borealis: A Lifeline of the Planet, Arboretum America: A Philosophy of the Forest, A Garden for Life and a collection of stories, Time Will Tell. In 2010, Diana was inducted as a Wings Worldquest Fellow. The Utne Reader named her one of their Visionaries for 2011. She lives in Ontario, Canada, with her husband, surrounded by her research garden filled with rare and endangered species.

Reviews

[Jackie McGinnis · Rating 5 out of 5]

I love the mix of Druidic wisdom, science, and stories of her botanical experiments. The chapters can twist and turn with so much information, but you encounter wonderful surprises! One moment I’m reading the science of why aspen trees sound the way they do, and the next moment I’m discovering why the celts included this tree in the Ogham alphabet.

I’ve read other books by Beresford-Kroeger, and, while some stories are repeated, they put into perspective new findings and wisdom.

Don’t forget… plant a tree, care for your plants. They need us, and we need them.

[Jalene Johnstone · Rating 5 out of 5]

My husband and I have been doing a reforestation project on the public lands behind our house, planting natives, collecting our neighbors leaf bags and picking up free wood/logs off of Facebook marketplace to amend the soils, provide habitat and moisture for the soils. The land is along the second Welland canal, and has long been changed by human activity. We planted 230 trees in 2024; not something we had set out to do. We found that being amongst the trees that are there, doing something proactive in all the destruction and despair in the world, has been a great medicine for us. We joined a group called Arbor STC, and found that this small and new group made a big impact on poor decisions being made towards the city canopy, and stopped public arborist jobs from being privatized. Having not been raised in this city, we found that our planting of trees was where we really started to meet our neighbors. The project has been life changing for us.
I've always been fascinated with the Druids/Celts since I was a child, and whilst I'm an electrician, I have always had a great love of science. All of that to say, that Diana's book sung to me. Getting to learn about the scientific knowledge of how trees hear, why horses roll in the grass, and how our global forests provide a moisture umbrella that reflect radiation back into space, has been really eye opening. The beauty of how she writes, of how she merges her upbringing with botany, chemistry and medicine, is sublime.
Extremely inspiring read to kick off 2025.

[Zahra · Rating 4 out of 5]

Thank you to NetGalley for providing me an eARC of this book in exchange for an honest review.

At the start of reading Beresford-Kroeger’s work, I was hesitant, as I was worried that it would be based in less-than-scientific reasoning. I don’t know why I assumed that, now that I’ve finished reading it. Truly, this work is a reflection of the author’s hope. She leads the reader on a meandering path which brings you to a call to action. It is an easy call to answer, all things considered. Plant a tree once a year for six years. A native oak, if possible.

As I write this review, I’m sitting on a picnic blanket in the shade of a willow tree the author so often described. This book changed the way I view these trees. Mostly, it gave me a sense of peace and hope. Change is possible. Humans caused climate change, but humans can also undo climate change. We must protect our forests.

Please read this book if you have been unsettled by the recent news about our agricultural future. Diana will give you hope. You can make a difference in the world.

[Shirleynature · Rating 5 out of 5]

Much gratitude to Diana Beresford-Kroeger, publisher, and Libro.fm @librofm for generously providing access to an Audiobook Listening Copy (ALC)! With vast knowledge offered, I'll be revisiting this text and recommending to many more Earth & tree loving readers 🌏 🍁

[Lynn · Rating 4 out of 5]

Dr. Diana Beresford-Kroeger is a botanist whose ongoing mission is to clone and map the forests of the world. Think on that for a minute. This is a woman who is working diligently to save our rapidly vanishing forests. She is a tireless champion of nature and in this short book of essays she expounds on why healthy forests are essential for the life of all species on earth.

The writing is beautiful and the importance of her work can never be underestimated.

[Brooklyn · Rating 3 out of 5]

3.75 stars.
An intriguing read, and mix of Druidic perspective with biochemistry! Diana Beresford-Kroeger certainly knows her stuff, and her enthusiasm for revitalization of forests & human engagement in battling climate change was palpable.

I’m not sure if perhaps this was too busy a time for me to sink my teeth into this, or if the biochemistry was just too beyond my reach, but I struggled to really engage with this book. I found myself a bit disengaged when high-level chemistry or tree makeup was detailed, and at times found it hard to jump with Beresford-Kroeger to the next topic because of this. I will also admit, I struggled with some of the claims of tree aerosols preventing childhood cancer, or reducing chronic health conditions, and though I understand this relates to her Druidic perspective, I feel these topics warranted the scientific rigor she applied elsewhere in the novel.

Maybe I will want to revisit this in a time where I can really get into the scientific lens of this and learn more thoroughly, but for now, the highest value for me was learning from the personal stories Beresford-Kroeger’s early education, and travelling to learn from other environmental stewards.

[Nathaniel · Rating 5 out of 5]

What a powerful, poetic work. Reading the author talk about how much she loves poetry (near the end) made this whole book click because this is nature poetry wrapped up in science. The descriptions are lush and so good I could eat this book. I'm such a fan. I need to read more from Diana.

[Jennifer · Rating 5 out of 5]

Words can’t express how important this book is, and how much I think everyone needs to read it. We hear about climate change all the time - taxing billionaires, stopping greenhouse emissions, going vegan to help the environment, blah blah blah. But this book truly breaks down what is happening in our forests at a molecular level. Why the eradication of our forests is killing trees we don’t even fully understand yet. How the decreasing forests are impacting sunlight refraction and heating up our soil, which lacks replenishment due to lack of forest dead fall. How non-native tree species in areas like California are literally just a powder-keg waiting to explode in increasing temperatures. The science of how we’re killing our planet is terrifying. But there’s hope - and we can do it by planting trees, practicing safe and Indigenous-led forest maintenance, and preserving the virgin and vital forests we have, like the Boreal forest.

I love and appreciate the author’s history of growing up in Ireland under the tutelage of community in the old Brehon Druidic knowledge. I’ve come to my love and education of tree wisdom through ancestry and curiosity about Ogham and Irish folk magic, now finding myself delving into the wisdom and medicine of our forests. Diana’s last two books have woven the ancient and modern knowledge beautifully. She has so wonderfully given the trees a voice and expressed their soul.

[Mattie Kavanagh · Rating 5 out of 5]

That was beautiful! I have so much respect for the author. She so artfully weaves together history, personal narrative, and fact. The audiobook reading was like listening to music — her voice is beautiful. The writing educated me, entertained me, and inspired me. I can’t express how much I loved this book without being repetitive, but I look forward to reading more of her work.

[Meghan King · Rating 5 out of 5]

If you don’t have a background in Science this book will be a little tougher to follow, but it is AMAZING. I got so many goosebumps and a few tears were shed when it was finished. This is a must-read.

[Nathan Budd · Rating 4 out of 5]

Lovely mix of poetry and fact, culture and science. It fills a similar niche to Braiding Sweetgrass, but through a different cultural lens that values nature and trees just as much. Read this book and plant some trees

[Lolz · Rating 5 out of 5]

Fascinating facts that will amaze you. Clear vision that will inspire you. This book builds on ‘To Speak for the Trees’ and it was great 👏🏽

[rachkatreads · Rating 4 out of 5]

*3.5
This felt a bit repetitive at times but it was filled with fascinating information.

[Jolene Bear · Rating 2 out of 5]

This one was a slow burn for me. A few great chapters, but definitely not my favourite book on the subject.

[Margueritte · Rating 3 out of 5]

DNF. Too biologically in depth. Repetitive. The chapters are short and there is a lot of interesting information, but I couldn’t get into it.

[Candace Jackson · Rating 2 out of 5]

This book was just not gripping me at all. I gave it 1.5 hours of the audiobook but felt that I wasn't learning anything nor was it that interesting to me, even though I am an avid nature enjoyer. This may be better enjoyed by someone without a science background.

[Angelee · Rating 1 out of 5]

1.5 - I was really looking forward to this book. I don’t know what I was looking for in this book, but whatever was in this book was not it.

[Meggo · Rating 4 out of 5]

ho is u the Lorax

[Ray Diamond · Rating 4 out of 5]

(audiobook) I love when a scientist narrates their own work, you can feel how passionate they are

[Kelly Monk]

“Life is a vestment to be worn with grace and love.”

[Liesl · Rating 4 out of 5]

I loved this book so much I am listening to it all over again. It is fascinating, enlightening, and I want to plant some trees every year for the rest of my life.

[Nicole Bergen · Rating 5 out of 5]

Trees are phenomenal. I will definitely reread this book, probably more than once. It’s absolutely fascinating and the writing is engaging.

[Liz · Rating 5 out of 5]

4.5 stars

[The Adaptable Educator · Rating 5 out of 5]

In Our Green Heart - The Soul and Science of Forests, Diana Beresford-Kroeger masterfully intertwines the poetic reverence of a naturalist with the analytical rigor of a scientist. The result is a work that not only illuminates the ecological intricacies of forests but also ignites a profound moral and spiritual call to action. This book is not merely an exploration of trees but a meditation on the interconnectedness of all life—a hymn to the lungs of the Earth.

Beresford-Kroeger’s scientific acumen shines as she unpacks the biochemistry of trees, revealing their ability to sequester carbon, filter water, and emit phytoncides that promote human health. These insights are presented with clarity, striking a balance between accessibility and depth, making complex processes comprehensible without diluting their significance. Her discussion of the boreal forest, for example, is particularly evocative, as she describes its role as a global "carbon bank" and its precarious vulnerability to climate change.

Yet, what elevates this book beyond a standard ecological treatise is Beresford-Kroeger’s unique ability to weave cultural and spiritual dimensions into her narrative. Drawing on her Celtic heritage and years of cross-disciplinary research, she resurrects ancient forest wisdom, reminding readers that trees have always been more than their utilitarian functions. Forests are storied beings, repositories of myth, medicine, and meaning. In doing so, she bridges the chasm between Western scientific methodologies and Indigenous ecological philosophies, offering a holistic perspective that resonates deeply with contemporary environmental ethics.

Beresford-Kroeger’s prose is a luminous force in itself. Her metaphors are drawn from nature’s lexicon, creating a text that is as verdant and layered as the ecosystems she describes. Her descriptions of tree communication—a "wood-wide web" of mycorrhizal fungi—feel almost mythical, yet they are underpinned by rigorous scientific evidence. This duality of the poetic and the empirical is the book’s beating heart, embodying its central thesis: that forests are as much about soul as they are about science.

At its core, Our Green Heart is a call to arms. Beresford-Kroeger challenges her readers to embrace what she calls "bioplanning," a personal and collective commitment to planting trees and protecting the world's remaining forests. Unlike the detached despair that often characterizes environmental literature, this book is imbued with a rare sense of hope. The author believes in the power of individual and community action, and she equips her readers with both the knowledge and the inspiration to make a difference.

While the book is a triumph in many respects, its breadth may occasionally feel overwhelming. The wealth of information and the sheer scope of its themes—ranging from climate science to Celtic mysticism—demand a patient and attentive reader. Yet, this complexity mirrors the subject matter itself: forests are intricate, multilayered systems, and to do them justice requires an equally multifaceted approach.

In Our Green Heart - The Soul and Science of Forests, Diana Beresford-Kroeger has crafted a work that transcends genres, blending science, philosophy, and advocacy into a singularly impactful narrative. It is a book that educates as it inspires, urging us to recognize the profound interdependence between humanity and the forests that cradle our existence. In an era of ecological crisis, this book stands as both a clarion call and a love letter—a testament to the resilience of nature and the necessity of human responsibility.

This is not merely a book to read; it is a book to carry in your heart, a manifesto for those who wish to align their lives with the rhythms and wisdom of the natural world.

[Ryan Johnson · Rating 5 out of 5]

Our Green Heart

28/2025.

An ode to trees, the forest, and the plant life we are bound to in a timeless bond of life giving exchange. In short, plant trees and love them, for without them we are lost.

The author claims to be the last Druidic educated person in Ireland, and certainly she taps into that ancient knowledge. Clearly our pre-Roman, pre-Christian, pre-Enlightenment ancestors had much knowledge that was eradicated as too pagan, and later too unscientific. Recapturing that knowledge and blending it with our modern science is the best hope we have to survive the changes we have set off in our planet. A closing chapter, “Bioplan,” provides good guidance for climate change that amounts to “plant trees.”

Her perspective as a scientist and recipient of that ancient knowledge helps her see the interconnectedness among all living things, a view I share.

The book is really a collection of essays on interwoven topics. One concept I find interesting here is that of using epigenetic information from older trees to help young forests prepare for larger temperature swings caused by climate change. If she’s right about that, all the more reason to totally stop cutting of old growth forests. Likewise, she makes a compelling case for replanting forests with native tree species and removing the transplanted ones- the native species are better adapted to the local climate situation (as a former Californian who saw the fiery wrath of eucalyptus, I can attest).

More fundamentally, the book is about values. The value of centering our lives and our education and our senses to the world we were meant to inhabit: forests and savanna’s, not the concrete jungles that we falsely believe shield us from the worst of nature.

[Sandra · Rating 5 out of 5]

Tiny in size and chilling in impact. Our Green Heart is a personal look at the role of the forest in the health of our increasingly carbon choked world. It contrasts ancient Celtic belief about the sacredness of the natural world with the evolving science about the evolution of the forest and the primary role the forest has as our Earth's vast lungs. We learn about the loss of countless numbers of tree species through thoughtless greed. We see how the tree's wondrous, sometimes inexplicable abilities, not only to clean the air but bathe us (and all creature species) in healthful aerosols when we wander through a native forest. The author has made protecting our tree species a life's work and has her own arboretum and she explains how we each might participate in saving tree species for future generations.
I was entranced by the book and completely depressed by it. Our human greed despoils most that is good.

[Diane Dewing · Rating 5 out of 5]

This book's message will stay with me for a long time. I suspect it will become one of those books I go back to many times over the years.

Diana Beresford-Kroeger shares the culmination of her many years of botanical research. Her knowledge of trees is astounding. Throughout the book she shares both hope and despair regarding the state of our world. Deforestation has hurt the land, the oceans and the glaciers of north and south. Individuals are unnecessarily afflicted with poor health when the proximity of trees could heal them. The foolishness of monoculture planting is exposed.

What makes this scientist different from many is her ability to look at the world in a holistic way. Humans, beasts, plants and oceans are all interconnected. Her early training in the Druidic traditions causes her to ask questions and to look at living things in a distinctive way.

I highly recommend this book and suspect many of my friends will receive a copy over the holidays.

[Joanne Culley · Rating 4 out of 5]

In Our Green Heart: The Soul and Science of Forests, Diana Beresford-Kroeger explores how her early life in Ireland steeped in Druidic lore and ancient Celtic practices passed down from her ancestors, has influenced her approach as a scientist in the fields of medical biochemistry, botany and medicine. In her arboretum in Eastern Ontario, she is like a modern-day Noah, preserving and cultivating the seeds of rare trees. Through her studies, she has discovered that ancient remedies such as Irish moss have the same properties found in modern medicines such as antibiotics and cancer treatments. In this collection of essays, she discusses the importance of maintaining the purity of our water supply, fighting climate change by planting trees to sequester carbon dioxide, protecting old growth forests, and more.

[Judith · Rating 4 out of 5]

Beautifully poetic book about trees and forests, and their vital place in the health of our planet. The symbiotic relationship between the earth, plants, and animals all has its foundation in the carbon-oxygen cycle of trees. “We are made and re-made of the breath of trees, with sprinkles of stardust from the cosmos.”
Some interesting processes are revealed:
- iron leaching from tree leaves feeds abundant sea life near where fresh water enters the oceans
-the beneficial chemicals humans absorb when forest bathing
-the importance of oak trees
-how trees produce infrasound
-the importance of planting native trees to support reducing atmospheric carbon dioxide
A beautiful book of short informative essays.

[Vido · Rating 5 out of 5]

The chapters are short but filled with information that inspired me to tag pages and make notes of new information I learned and what I want to go back to, to gather more information. I work at a brand new school where some trees were planted. The students have been making observations naturally about these trees and as I head into the last week of school, this book has inspired me to work with the students to label and measure these trees so that we can monitor and compare growth each year and study each type of tree further. If we can instil respect and understanding for trees at an early age perhaps it will help to change the direction things seem to be going in.