Vast expanses of grass fields that make up most city parks and residential lawns don’t offer much in terms of mitigating climate change. They don’t soak up a lot of carbon, and they don’t provide significant habitat to wild birds and insects.

That’s why a group of students is helping lead a “tiny forest” movement at their school outside west Portland, where they’ve squeezed about 600 plants and trees into a plot the size of a tennis court.

“A tiny forest tries to be a whole forest: It has the canopy, the understory, and all the little shrubs as well,” said Nico Howlett, a senior at Catlin Gabel, a private school for kindergarten through 12th grade students. “It has all the layers of the forest in this compact area.”

The idea: If you plant trees and shrubs close together, they will grow faster as they compete for sunlight. It’s called the Miyawaki Method, named after the Japanese botanist Akira Miyawaki, who came up with the tiny forests concept in the 1970s.

Since then, thousands of tiny forests have been planted in Japan, and hundreds in India. Others have popped up in Europe, Africa and South America. The trend has caught on in the United States in recent years, including in Portland.

This model allows cities to squeeze miniature ecosystems into plots around urban areas, offering some habitat for birds and other wildlife. As they grow, these clusters of trees and plants can lower surrounding temperatures.

“They have a really great cooling effect,” said junior Ari Wilda. “Part of this is about how we can mitigate our own impact on the environment, but also adapt to the ever-changing climate.”

Catlin Gabel’s tiny forest began when social studies teacher Patrick Walsh heard about the Miyawaki Method on a BBC Radio program in 2021. For Walsh, the concept offered some hope during a difficult period for students and educators.

“With COVID, there was a lot of time when we weren’t laughing — where we were all on screens, staring at each other and feeling isolated,” Walsh recalled. “This is the opposite of that.”

Walsh had his students research which native plants would work best, and he applied for grant funding to help purchase them. The red alder, red cedar and cottonwood trees arrived as sticks with bare roots. The holly-leaved Oregon grape plants, wild strawberries and sword ferns came in pots.

“The way we built it wasn’t an exact science,” said senior Julia Chun, explaining how over 100 volunteers showed up to shovel dirt. “People were just kind of planting things constantly wherever they could.”

That was February 2022. Now, almost three years later, the trees have grown nearly 20 feet tall. Ferns and snowberries thrive around them. Layers of leaves and mulch retain moisture, so not much watering is needed.

“We essentially do no upkeep,” Walsh said. “We pull out the odd Himalayan blackberry, and we put down more wood chips, but that’s about it because these plants really know what to do.”

Catlin’s forest is still relatively young, but students say it has already grown into a peaceful refuge.

“It just really allows students to come up here and immerse themselves in nature while also learning about something that’s really interesting and cool,” said junior Luna Flores.

Teachers across grades and subjects find ways to integrate the forest into their curriculum. Walsh uses it in social studies classes to teach students about how tribes used native plants. Art teachers have had their younger students decorate the forest’s fence line with painted placards.

The forest also gives teachers an excuse to bring their classes outside, something the students seem to appreciate.

“It’s impactful to be hands-on with the environment and not just be learning about it in a classroom at 8:30 in the morning,” said Atharva Deepak, a sophomore.

Walsh sees tiny forests as more than just an educational opportunity; they can also bring people together under a common cause — particularly when it comes to dealing with the effects of climate change, including the rapid depletion of forests from wildfires, pests and logging.

“I think we owe it to young people to not say to them, ‘Your generation is going to fix it,’ but to take young people outside and work with them,” Walsh said.

For the students who helped grow this forest, they hope their work inspires future students for years to come.

“We wanted to teach them about engaging with their environment,” said junior Luna González González. “And help them grow compassion and inspire them to take action for climate change.”

News Source : https://www.opb.org/article/2025/01/02/portland-students-caitlin-gabel-grow-tiny-forest-school-compact-ecosystems/