What is a Miyawaki forest? Here's why volunteers are planting 4,000 trees on the University of Iowa campus this month

IOWA CITY — About 4,000 trees are being planted on a half acre of land near Hillcrest Residence Hall on the University of Iowa campus using a forestation method developed by a Japanese botanist.

The Miyawaki forest method involves planting native trees and shrubs in a dense area as a means to increase biodiversity and create a self sustaining forest.

“This forest, it's gonna be its own little ecosystem. This supports the fungi, the insects, the minutia that we don't always think about. It's gonna be its own little neat, unique ecosystem with native plants,” said Andy Dahl, urban forest supervisor and arborist with UI Landscape Services.

The Miyawaki method is to plant the trees very close to each other — one to two feet apart — as opposed to a more traditional forest where trees can be up to nine feet apart. Due to the dense nature of the forest, the trees will grow faster than normal.

  Buy Photo

“The competition for sunlight will cause them to all shoot up and grow really, really fast. And so you get really accelerated growth using the Miyawaki method, and research suggests that you can have a mature forest in 20 to 30 years,” said Beth MacKenzie, programming manager in the UI Office of Sustainability.

Once planted, the forest will need about three years of regular weeding and maintenance. The forest will contain a mix of more than 20 different trees and shrubs native to Johnson County. Dahl began selecting the mix earlier this year.

“I tried to pick native trees that wouldn't necessarily grow too fast, so things like cottonwood and Silver Maple might over top the other ones,” Dahl said. “You kind of want to find balance of species that have the same growth rate so they continue to compete at kind of the same level.”

The forest near Hillcrest is only the second Miyawaki forest in Iowa. The first is in Brookview Park in West Des Moines, which contains 1,200 trees. The University of Iowa’s forest will be the largest in the state once completed.

Office of Sustainability collaboration with students

Members of the Office of Sustainability and Dahl had talked about the potential for a Miyawaki forest for years before planting began. Last fall, things started to take shape

“We had a class that had come to us asking for project ideas, and we said, hey, we would love to if you could explore Miyawaki forest and get some more information about it and find out if the spots that we have in mind would be suitable for the Miyawaki method. And so the class dug in and got into the details and submitted its recommendations for its final project,” said MacKenzie.

  Buy Photo

After receiving the recommendations, the university picked a half acre on the northeast side of Hillcrest Residence Hall, 25 Byington Rd., on the west side of campus. The land is adjacent to a sidewalk and on a slope that leads to an existing woodland.

“We chose this spot because it's an area that's pretty dangerous to maintain, as far as mowing, with the slope it can be kind of tricky,” Dahl said. “It's like, why do we keep expanding our carbon footprint to mow this dangerous spot where someone's going to get hurt sooner or later? Let's put something like this Miyawaki forest instead.”

University looking for volunteers to plant forest

While planting of the 4,000 seedlings began Friday, the work will continue into next week.

  Buy Photo

The university is looking for volunteers to help complete the Miyawaki forest. The forest is being planted on the following dates and times:

Some planting days may be canceled due to bad weather or if planting is completed early.

The university plans to host a community celebration May 2 at 4:30 p.m. to honor the newly planted forest.

  Buy Photo

Comments: megan.woolard@thegazette.com

Get a weekly roundup of Johnson County news by signing up for my Johnson County Update newsletter.