Taking Root: Mini Forest at the Zoo

Eighth graders from Urban Community School planting trees.

Last September, your Zoo worked with Paul Abbey, founder of the local nonprofit Rooted in Trees, Zoo horticulturists, the Holden Aboretum’s Green Corps, and eighth graders from Urban Community School to plant the first ever mini forest in a United States zoo. The 850 trees and shrubs will grow rapidly in their 2,500 square foot plot due to their dense planting method. This small but mighty space located just down the hill from Rosebrough Tiger Passage will not only represent the value of forests, it will be a functioning forest ecosystem on a tennis court-sized plot.

What is a mini forest, exactly? Distinct from other small arboreal installations such as “pocket parks,” a mini forest employs the Miyawaki Method of forestry to create a multi-level forest community quickly. This method, developed in the 1970s by Japanese botanist Dr. Akira Miyawaki, aims to reforest degraded areas quickly, rejuvenate the soil, sequester carbon, and create habitat for native wildlife.

(L to R) Cleveland Zoological Society CEO Sarah Crupi, Rooted in Trees Founder Paul Abbey, and Zoo Horticulture and Grounds Manager Leigh Anne Lomax at the mini forest site.

Forests planted in this manner grow ten times faster than typical forests as the trees compete with – and support – one another. “In three years, the forest will be self-sufficient, and the trees will share nutrients and fungi,” Abbey said. In the meantime, Zoo horticulturists will monitor the site, remove weeds as needed and protect the growing trees and shrubs with leaf mulch and fencing.

Abbey recalled that he originally met with Zoo Executive Director Dr. Chris Kuhar to discuss planting trees around the entry to Primate Forest, but he found himself pitching the idea of a mini forest instead. “I thought the Zoo was a perfect spot. There may be a million people walking by the mini forest – that's a special opportunity.”

It was kismet. Kuhar had visited a mini forest in the Netherlands just a couple weeks prior, during a layover on his return trip from Rwanda. He was keen to illustrate the Zoo’s dedication to healthy ecosystems and supporting tree canopy as plans for Primate Forest took shape. “When trees reach maturity, that’s when they’re best at sequestering carbon, producing oxygen, providing shade, absorbing water, and filtering air. So this is really a demonstration and an opportunity for us to talk about the importance of trees for both wildlife and people,” he said.

Students helping plant trees.

Planning the mini forest was no ‘mini’ feat. “It’s all about logistics,” Abbey said. “Planting is easy, but the logistics are mind-boggling.” The process looked to the Cleveland Metroparks Tree Selector, a publicly available online tool that helps identify appropriate trees by height, soil type, shade level, and more. For the mini forest, it was important to select native trees that will continue to do well in Cleveland as climate conditions and agricultural regions shift. Once the team made its selections, trees and shrubs were sourced from Ohio, Pennsylvania, New York, Michigan, and Indiana.

On planting day, eighth graders from Urban Community School joined with Zoo horticulturists, the Rooted in Trees team, and Holden Arboretum’s Green Corps to put 850 trees and shrubs in the ground, following a meticulous plan drawn to a grid. The students, who had to write an essay to apply for the opportunity, were eager to share their love of trees.

“It was very meaningful to the kids,” said Zoo Horticulture and Grounds Manager Leigh Anne Lomax. “I love working with kids, and to be able to work with young people and see them plant and make a real impact on something here at the Zoo was pretty great.”

Abbey was also elated by the students’ involvement. “There’s an opportunity for those eighth graders to connect with the Zoo,” he said. “Maybe in a few years, they become volunteers at the Zoo and engage with other visitors about the mini forest they helped plant.”

Zoo visitors will start to see distinct changes in the mini forest as the trees and shrubs get established this year, and soon, different birds and insects making use of the space. Many of the mini forest’s benefits, however, may be harder to detect by simple observation.

Lomax explained, “We’ve set out some great technology arrays that will measure noise, temperature, soil moisture, humidity – we can track these over time and see how they change in this site over the next few years.”

Be sure to take a look at the mini forest each time you visit and try to note how it changes!