There aren't many scientists raised in the ways of druids by Celtic medicine women, but there is at least one. She lives in a forest that she helped grow. She has been using a pencil to bewitch humans to save some of the oldest life-forms on Earth.

Diana Beresford-Kroeger is an author and developer of artificial blood. Her main focus has been to convey to the world the wonders of trees.

The goal of Dr. Beresford-Kroeger is to combat the climate crisis by fighting for what is left of the great forests in the Northern Hemisphere. She said that trees are the best way to fight climate change and do it fast.

The breadth of her knowledge is what sets Dr. Beresford-Kreoger apart. She can talk about the benefits of trees and their connection to humans in a single breath. Jane Fonda was moved to tears by her. She inspired Richard Powers to base a central character of his Pulitzer-prize winning novel on her.

An arboreal Noah's Ark of rare and hardy specimen that can best survive a warming planet has been cultivated by Dr. Beresford-Kroeger. She said that the native trees she planted on her property sequester more carbon and better resist storms and temperature swings, and that they also produce high quality nuts. If industrial logging continues, soil fertility will plummet and Dr. Beresford-Kroeger is haunted by the prospect of famine.

She wanted freedom to study and spread her ideas without any restrictions because she was an independent researcher who was funded by her writings and the sale of her rare plants.

Ben Rawlence, an English writer who found himself sitting at her feet doing a master's degree, said that brilliant pioneers are often outliers who don't play by the rules.

He said that people like her are important.

Dr. Beresford-Kroeger did not set out to be an outlier. She was born in England and raised in Ireland, but came to America in 1966 to study organic and radionuclear chemistry at the University of Connecticut. She moved to Canada three years later to study plant metabolism and cardiovascular research at the University of Ottawa.

She said she faced sexism, harassment and anti-Irish sentiment in that part of Loyalist Canada. She left academia in 1982, as much repelled by the toxicity as she was drawn to a deeper calling, a childhood that was both Dickensian and folkloric.

ImageA childhood portrait of Dr. Beresford-Kroeger, painted by her father, in her home.
A childhood portrait of Dr. Beresford-Kroeger, painted by her father, in her home.Credit...Nasuna Stuart-Ulin for The New York Times

At 12 Dr. Beresford-Kroeger was orphans. Her mother, who was related to ancient Irish kings, died in a car crash. Dr. Beresford-Kroeger spent her summers with her relatives in the countryside after being taken in by a kindly if neglectful uncle.

She was taught ancient Irish ways of life by her maternal grandaunt. She learned that trees were seen as beings that connected the Earth to the heavens. She was familiar with the properties of local flora, such as wildflowers that warded off nervousness and mental ailments, and seaweed that could treat Tuberculosis.

Dr. Beresford-Kroeger discovered that the teachings were true when he was a student at the university. The wildflowers were named St. John's Wort. The seaweed had strong antibiotic properties. The blood flow was increased by the flavonoids in the shamrocks. The course for Dr. Beresford-Kreoger's life was set by this foundation. She discovered that the relationship between plants and humans extended far beyond the life-giving oxygen they produced.

She wrote in her most recent book, "To Speak for", that she has little grasp of all that we depend on for our lives, because of the unseen or unlikely connection between the natural world and human survival.

She said that deforestation was a suicidal act.

We've taken down too much forest, that's our big mistake, Dr. Beresford-Kroeger said during a recent chat with her husband.

The Beresford-Kroegers lived on a 160-acre parcel of land they bought decades ago. Their house is filled with well-thumbed books, fingers of sunlight, thriving plants and their rescue cat. Dr. Beresford-Kroeger doesn't have a computer or a social media account. She uses a public desktop when she needs to zoom.

Dr. Beresford-Kroeger’s husband, Christian Kroeger, read aloud from “Under the Cedars and the Stars,” by the Irish author and Catholic priest Patrick Augustine Sheehan.Credit...Nasuna Stuart-Ulin for The New York Times

Outside the house, her trees grow, all climate- change resistant to varying degrees: the kingnut, blue-needled fir and a rare variant of the bur oak. She began creating her arboretum after learning that many of the key tree species that were prized by the First Nations people had been destroyed by colonizers centuries ago.

She said that the trees have fed the continent before.

Card 1 of 3

She painstakingly tracked down rare seeds and saplings native to Canada.

If plants and trees were shared far and wide, they would no longer be lost. She and Christian started giving away native seeds and plants to anyone who asked. The local Hell's Angels were among the tens of thousands of people who received black walnuts. They were very nice to me.

It took a decade for Dr. Beresford-Kroeger to find a publisher for her first manuscript. She has published at least a couple of Canadian best sellers. One was about gardening and the other was about living a simpler life. The importance of trees was her main focus.

Oxygenates the atmosphere under the toughest conditions imaginable for any plant, and she wrote about the irreplaceability of the boreal forest. She wrote about how a trip to the forest can boost the immune system, ward off disease, and lower blood pressure.

Skeptics have been present. She said a publisher admonished her for being a scientist who described landscapes as sacred. The head of a foundation introduced her after a screening of a documentary about her life, but he didn't believe what she said.

When Dr. Beresford-Kroeger offered a biological explanation for why he felt so good after walking through redwood groves, he initially had reservations. She said that his sense of well-being was due to fine particles.

She said the aerosoles go up my nose and that makes me feel good.

Some of the claims have been supported by outside research. Studies led by Dr. Ling found that forest bathing reduced stress and activated cancer-fighting cells. A study from Italy suggested that immunity- boosting aerosols from trees and plants could be to blame for the lower rates of Covid-19 deaths in forested areas.

Dr. Beresford-Kroeger said her Irish accent was still strong.

Dr. Beresford-Kroeger is in great demand because of mounting fears about the environment and a hunger for solutions.

She received a doctor of law degree and a doctorate in biology from the university. She was a guest on one of Jane Fonda's climate action teach-ins. She gives virtual talks to universities and keynote addresses to organizations, and the person who moderated her talk at the InternationalHerb Symposium said she had goose bumps talking to her. She is working on a new book about how people are connected to nature and is helping to plan some healing gardens.

During a tour of her forest and gardens, Dr. Beresford-Kroeger spoke about the similarities between Celtic cures and those of Indigenous peoples.

She told the reporter to lean against the tree. She said that people should look at forests as the sacred center of being.

She said that the trees laid the path for the human soul.

Dr. Beresford-Kroeger in a grove of dwarf bird’s nest spruce on her property.Credit...Nasuna Stuart-Ulin for The New York Times