Review: ‘Mini-Forest Revolution’ shows how to mimic nature

This cover image released by Chelsea Green shows "Mini-Forest Revolution: Using the Miyawaki Method to Rapidy Rewild the World" by Hannah Lewis. (Chelsea Green via AP)

This cover image released by Chelsea Green shows “Mini-Forest Revolution: Using the Miyawaki Method to Rapidy Rewild the World” by Hannah Lewis. (Chelsea Green via AP)

Mini-Forest Revolution: Using the Miyawaki Method to Rapidly Rebuild the World,” by Hannah Lewis (Chelsea Green)

Trees serve us better when they are planted with friends.

In “Mini-Forest Revolution,” author Hannah Lewis shows how a forestation method developed by Japanese botanist Akira Miyawaki is helping groups around the world restore ravaged areas to dense forests that create green zones and help mitigate global warming by absorbing carbon.

Mention the word “forest” and many people think national park in scope, but a forest planted in the Miyawaki method can thrive and make a positive environmental difference in a space the size of about half a dozen parking spaces. That’s because planted in a group, trees shade and cool the land below and allow it to retain much more water, which not only helps all the trees but it also allows beneficial insects and animals to thrive.

On a forest floor, temperatures can be as much as 20 degrees cooler than the surrounding area. Replace an asphalt surface with a mini forest and the temperature differential can be 50 degrees or more.

In Miyawaki plantings, monocultures are out; natural variety is in. Forests contain a mixture of tree species in nature, Lewis explains.

Critical to the Miyawaki method is choosing the right trees for the location. And with rising temperatures, the trees we plant need to be adaptable to temperatures that may be much warmer.

At least two groups have sprung up to advance the Miyawaki forestation method: Afforestt in India and National Urban Forests in Seattle. Natural Urban Forests founder Ethan Bryson was inspired after seeing a TED talk by Shubhendu Sharma, founder of Afforestt.

India, England, France and especially the Netherlands are leading the world in creating Miyawaki forests, many of them small enough to replace what were hardscrabble play areas at schools.

By year end, Lewis reports, the Netherlands will have 230 mini-forests; each associated with a school or nursery school where students will plant and learn.

Planting trees is regularly offered as a solution to global warming because trees absorb carbon; in the atmosphere, carbon dioxide absorbs and holds heat. But the solution is not as simple as planting any available tree – some tree species are far better than others at absorbing carbon.

In a tidy 185 pages, Lewis simplifies the science of planting trees in a manner that produces the maximum benefit.

And that’s an urgent issue in the United States, where Lewis notes that we have just one-fifth of the original forests that were here when Europeans first arrived.