BOOK: ‘MINI-FORESTS’ HELP COUNTER WARMING

Trees serve us better when they are planted with friends.

In “Mini-Forest Revolution,” a new book from Chelsea Green Publishing, 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 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 make a positive environmental difference in a space the size of about half a dozen parking spaces, such as an empty lot in an urban area.

That’s because planted in a group, trees shade and cool the land below and allow it to retain much more water, which helps all the trees and 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. Choosing the right trees for the location is critical. And with rising temperatures, the trees need to be adaptable to warmer conditions.

India, England, France and 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 where students will plant and learn.