After MINIFOREST SUMMIT: Intern Suggests planting more & planting diversely To help restore Our ecosystem

Big thanks to one of our summer interns Jayden H. for all his work this summer and for this inspiration.

Last month, Jayden - a Sustainable Wellesley intern and rising high school senior - attended the Northeast Miniforest Summit, hosted by Biodiversity for a Livable Climate (Bio4Climate). The summit brought together foresters, soil biologists, environmentalists, and PhD students to talk about the Miyawaki Method, a Japanese approach to ecological restoration that uses extremely dense, native plantings to grow small forests quickly, even in tiny urban spaces.
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The summit opened with a keynote from Mio Urata, a Japanese forester who has worked directly with Dr. Miyawaki, the pioneer of the method, and closed with a keynote from Ethan Tapper, a Vermont forester and author known for his writing on forest stewardship. Urata's message came back to three core principles: amend the soil before you plant, plant densely, and plant what the land actually wants (not just native plants to the region, but native plants that would have historically been in those specific conditions and ecosystems).

Over the course of the summit, a common theme kept surfacing among the experts: the Miyawaki Method isn't a silver bullet. It's just one more tool to combat the climate and biodiversity crisis. Some concerns included that it has not been studied extensively over the long term; it's resource intensive: excavating and amending soil, sourcing enough native saplings to plant at high density, and accepting the relatively low survival rate of individual trees; and what works well in one spot may not translate directly to another depending on soil, species, and site conditions.

This method has become popular in recent years, with over twenty forests planted now in Massachusetts, due to its amazing claims of 10 times faster tree growth and fully mature forests in 20-30 years instead of 200-300 years. Many experts at the summit, however, refuted these claims, pointing out that in general Miyawaki forests are planted in urban areas, which already have faster tree growth due to increased heat, sun, and carbon, and that more data would need to be collected in order to verify these statistics. But there were some real benefits of the method that were talked about as well.

One point that came up a lot was the heat island effect. The air inside a miniforest measures noticeably cooler than the surrounding area, and even slightly cooler than the shade from a single large street tree covering the same footprint. For a town like Wellesley dealing with hotter summers, that may be a benefit worth paying attention to.

Another topic, and a more contested one, was community impact. Some speakers argued that miniforests are genuinely good for community building since planting day brings a lot of people out together. Others pushed back, pointing out that a planting is largely a one time event rather than an ongoing project, and that something like a ball field or another shared community space might do more for a neighborhood over the long run than a miniforest would, if the purpose of the project is community.

​None of this makes the method a bad option, especially somewhere like Wellesley. In small, densely populated areas, a corner of a yard, a strip along a public park, at a school for educational reasons, this method can pack in a surprising amount of biodiversity quickly, helping push back against pollinator and insect decline while pulling some carbon out of the atmosphere and cooling the immediate area. Maybe the real value of the Miyawaki Method isn't in following it exactly, but in the simple principle behind it: planting more and planting diversely, can help restore an ecosystem.