Hannah Lewis on the Burgeoning “Mini-Forest Revolution”
Writer Hannah Lewis says she practically fell in love with Japanese botanist Akira Miyawaki when she first read the 2007 book The Healing Power of Forests, which he co-authored with ecologist Elgene O. Box. The book introduced the Miyawaki method, a reforestation technique that involves planting native trees close together in vacant lots and backyards to restore biodiversity in urban areas and towns. According to advocates, these tiny forests, even with footprints as small as six parking-lot spaces, can grow up to 10 times faster and generate 100 times more biodiversity than forests planted using conventional methods. The concept resonated with Lewis’s own efforts to raise awareness about sustainable ecosystems—including her work as editor of the Compendium of Scientific and Practical Findings Supporting Eco-Restoration to Address Global Warming, a bi-annual, open-access compilation of scientific studies, industry and government reports, and journalistic investigations that outlines the benefits of repairing degraded or destroyed natural ecosystems as part of society’s response to the climate crisis. Reading Miyawaki and Box’s book led her to write an article about the approach for The Guardian in 2020, and a just-released book of her own: Mini-Forest Revolution: Using the Miyawaki Method to Rapidly Rewild the World (Chelsea Green Publishing).
In the book, Lewis chronicles her own investigation of mini-forests, which span locations from a small coastal village in Brittany, France, to sprawling metropolises all over the planet. (Lewis lived in France while she was writing Mini-Forest Revolution, and has recently returned to the U.S.) She explains not only the science behind Miyawaki’s genius, but also the trials of her own mini-forest project, which she planted in Roscoff, France. Like Miyawaki, she doesn’t shy away from digging her hands into the soil. And like the benefits of a mini-forest—from establishing wildlife corridors and habitats for pollinators, to bolstering soil health and sequestering carbon—the seeds Lewis’s story leaves behind are varied and quick to sprout, resulting in a book that is part personal narrative, part mini-forest ledger, part how-to manual, and part call to action.
Lewis also highlights how various mini-forests, informed by the Miyawaki method, are germinating rapidly across the globe. She writes of school children in France who slosh through mud, eager to submerge saplings into the ground, and tiny-forest advocate Shubhendu Sharma, who has planted a forest in his backyard in India. In Beirut, she spotlights traumatized survivors of an ammonium nitrate explosion, who have turned an abandoned park into a budding mini-forest, burying there the names of those lost in the blast.
We recently spoke with Lewis about the surging popularity of the Miyawaki method. Here, she talks about how mini-forests have the potential to help heal the planet as well as the people who plant them.
What initially drew you to the Miyawaki method?
I came across a project in Nantes, France, that was doing the Miyawaki method. That was the first time I heard about it. They were planting a small, dense native forest in response to the expansion of a road near their house, so that it would block the sound and filter out some of the pollution. I called them and asked for more information. The concept seemed ecologically sound: They were thinking about the species composition that would be growing there if the area hadn’t been cleared for agricultural development.
It was a completely different approach than what you normally see, where people plant a tree here, a tree there. And it seemed doable, because they weren’t trying to take on several hundred acres—they were just taking on two hundred square meters near their house. If two people can do something like that with the help of friends and their community, I thought, then that’s something that can ripple out. Little groups of people could do something of that size everywhere.
How do the environmental benefits of the Miyawaki method differ from other reforestation techniques?
There are lots of different goals when we plant anything. The aim may be decorative, to produce a product or a crop, to create shade, to stop erosion, or even to capture carbon. But Miyawaki’s goal was to regenerate whole forest ecosystems. When you have many plants growing together, as his method proposes, the organisms are mutually reinforcing.
By creating a forest, you create a microclimate inside of it that is cooler, and more humid. That creates a more mild environment for everything growing there. It blocks wind, extreme temperatures, and sunlight to the interior, and all the plants benefit from that and grow well. It also creates a habitat that animals that live in forests need. So you’re creating a snowball effect by bringing all the species that would normally grow together into the same spot.
The Miyawaki method is extremely effective. For instance, a few years ago, researchers at Wageningen University in the Netherlands and citizen scientists began monitoring biodiversity in a very small forest created using the Miyawaki method. The community had planted a couple dozen species of plants, but within a few years, they counted hundreds of plant and animal species. Mini-forests are like magnets. They create homes for animals that didn’t have homes before.
The other upshot of having plants growing in a community together is that you stimulate the soil, and get its mycorrhizal network—a microscopic network of fungus intertwined with the tree roots—going. When it rains, this underground sponge-like structure can absorb more water, which is handy not only in floods, but also in droughts. It’s a stockpile of nutrients that can continue to support the plants growing there.
The more productive the ecosystem is, the more carbon drawdown, photosynthesis, oxygen production, and all the other things we like about trees, result. They’re fortified in an ecosystem, versus being planted on their own and having to fend for themselves.
Why do you think the Miyawaki method is surging in popularity right now?
Part of it has to do with the fact that there was this 2016 Ted Talk by eco-entrepreneur Shubhendu Sharma, which simply disseminated the idea broadly. The timing of it was really good. It was right around the signing of the Paris Agreement, and people everywhere were becoming aware of how urgent the climate crisis was. We’re seeing the decline of nature so intensively, and that is accessible and really helps take care of the planet.
Some of the mini-forests you wrote about in your book, such as those planted in Beirut and the Yakama Nation in Washington state, were created as spaces for healing, both in an ecological sense and for the local communities. How did healing emerge as a theme of the so-called mini-forest revolution?
One thing Miyawaki emphasizes is that people are part of nature. That’s easy to forget in the middle of a city, when the things we depend on have corners and sharp edges and plug into the wall.
Miyawaki wanted to restore the earth’s ecosystems, and the reason he wanted to do that was for people. We’re happier and healthier when we’re connected to nature, which is where we come from and what we still depend on today.
Where do you think the Miyawaki method fits into the global effort to find solutions amidst the climate crisis?
We hear a lot about technological solutions and reducing consumption, but the Miyawaki method is an approach that connects people to nature, and that works. You can engage your whole community in learning about what biome they live in. It’s a way to learn about the species that normally live in the same area as you, and to take care of them and to create a space for them again.
Once the planting starts, you don’t need any machines; you just need people. They can be small children or older folks, because the plants are not heavy. It’s a great way to establish a direct connection between a local ecosystem and local people. They’re the ones who plant it, and they’re the ones who are going to watch it grow.