The ‘Miyawaki Method’ has found global fame but its afforestation promises may have limitations

The Miyawaki method for cultivating fast-growing groves of native vegetation has found eager practitioners all over the world. But some say the method promises more than it can deliver, and that, in some cases, restorers are planting Miyawaki groves where they don’t belong.

Developed in the early 1970s by the late Japanese forest ecologist Akira Miyawaki, the method involves the following steps: determine the plant species native to a given area; improve the soil by mixing in organic material; plant seedlings of native trees and understory plants in a dense, mixed manner (about three seedlings per square metre) meant to simulate a natural forest; remove weeds from the site for up to three years after planting, if necessary.

After that, the grove is left to its own devices. Due to the dense planting, the seedlings grow quickly as they compete for sunlight.

Although originally implemented in Japan, Miyawaki collaborated with Japanese multinational companies to apply his method overseas as well. This led Miyawaki in 1999 to claim that “quasi-natural forests can be built in 15-20 years in Japan and 40-50 years in Southeast Asia”.

Over the past decade, the Miyawaki method’s popularity has reached new heights, including projects in Jordan and Brazil, among other locations.

However, two ecological restoration practitioners in India recently criticised the Miyawaki method, saying it doesn’t deliver on the promise of “native, natural forests”.

Japan’s era of industrial pollution

Born in 1928 in Okayama prefecture, Miyawaki’s early work on weeds caught the attention of German botanist Reinhold Tüxen, who invited Miyawaki to study in Germany from 1958.

Tüxen introduced Miyawaki to his theory of “potential natural vegetation,” the native vegetation a given area has the ability to support – in other words, the vegetation that existed before human intervention. The theory would become a cornerstone of the Miyawaki method.

Due to centuries of human activity, “potential natural vegetation” is nearly impossible to find in today’s Japan. Still, inspired by Tüxen, Miyawaki devoted himself to cataloging his country’s native plants when he returned in 1960, using the protected forests around Shinto shrines as key reference points.

It was these surveys that first connected Miyawaki to the Japanese business world, as companies would request his team to survey specific sites, according to a lecture Miyawaki gave upon being awarded the Asahi Glass Foundation’s Blue Planet Prize in 2006.

Japan was rapidly developing in the 1950s and ’60s, with, at first, little thought for the environment.

“Forests and satoyama” – woods used for small-scale agriculture and forestry – “were rapidly cleared to make way for residential areas, and air and water pollution was so severe that there was strong momentum to do something,” said Fumito Koike, a professor of ecology at Yokohama National University, where Miyawaki spent most of his career.

In the 50s and 60s, industrial pollution in Japan was causing serious illness such as Minamata disease and Yokkaichi asthma. Japan established its environmental agency, now the Ministry of the Environment, in 1971.

Miyawaki’s lab suddenly had many industry visitors.

“I thought their only real interest in coming was probably just to ask us to plant some greenery to atone for the pollution they had caused,” Miyawaki remembered in the same lecture, saying he refused to plant greenery as a temporary cover-up. “I would, though, be very happy to cooperate in creating a real, native forest based on the potential natural vegetation of the area.”

In 1971, Japanese steelmaking giant Nippon Steel’s newly formed environmental division hired Miyawaki to create forests at the company’s production sites. This was Miyawaki’s chance.

“[In Japan], department heads are usually transferred after three years, so Dr Miyawaki devised a method for establishing a forest in three years,” Kazue Fujiwara, a former Yokohama National University professor who worked closely with Miyawaki, wrote in an email to Mongabay.

A representative from Nippon Steel, whose 840 hectares of Miyawaki forests now boast trees up to 30 metres tall, said the company “aimed for coexistence between humans and nature”.

A few years later, Miyawaki planted groves at the new campus of Yokohama National University, built on a former golf course.

Koike, who guided Mongabay around the campus in May, noted differences between the groves planted in 1967 and one in 2006. “The first groves consisted mainly of tall, [broadleaf] evergreen trees, and there wasn’t as much variety of species as there is now,” he summarized later over email.

“In the 1970s, ecologists believed that if a forest ‘skeleton’ was created by tall evergreen trees, other organisms would naturally expand their distribution,” Koike continued, explaining that unexpectedly low seed dispersal distance measurements in the 2000s may have prompted Miyawaki to include more shrubs and deciduous trees.

In 1973, Japan enacted a new Factory Location Law, which stipulated that factories of a certain size must make 20% of their total land into green areas. With the beginnings of a proven track record at Nippon Steel, Miyawaki went on to work with Tokyo Electric Power Company and other major utilities, as well as companies such as textile and chemical manufacturer Toray, Honda Motor Company, and real estate developer Mitsui Fudosan.

Japanese retailer AEON had just launched its own tree-planting program in 1991 when its current honorary chairman, Takuya Okada, connected with Miyawaki, according to AEON’s public relations department. Okada, who had seen the effects of serious industrial pollution in Yokkaichi decades earlier, “was deeply impressed by Dr Miyawaki’s ideas,” and the company adopted his method.

To date, AEON has planted more than 12 million trees in 11 countries, with the majority – 9.9 million – in Japan, according to its website.

Restoring tropical forests?

Thanks to Japanese companies with a global reach, the Miyawaki method quickly went international.

In the late 1980s, Miyawaki received a proposal from Mitsubishi Corporation to try regenerating a tropical forest in Malaysia, the first such project in Southeast Asia, according to his 2006 Blue Planet Prize lecture. He had been surveying Southeast Asian vegetation over the previous decade.

Nik Muhamad Majid, a retired professor at Putra Malaysia University, recalled meeting Miyawaki in Kuala Lumpur. The Japanese ecologist briefed Nik on the proposal and told him, “Mitsubishi is going to fund everything.”

In 1991, Putra Malaysia University planted 300,000 seedlings under Miyawaki’s direction across 50 hectares (124 acres) of land at its campus in Bintulu, Sarawak state – then just a “logging town,” according to Nik. With further planting festivals held annually, the site now contains 126 species of native vegetation.

According to Mitsubishi’s website, the Miyawaki project aims “to demonstrate the feasibility of restoring degraded forest land to conditions that closely resemble a natural forested ecosystem within 40 to 50 years.”

However, a 1993 paper from Friends of the Earth didn’t look so kindly on the Miyawaki project in Bintulu, arguing that “Malaysia’s natural forests are being depleted by Mitsubishi’s subcontractors at rates faster than any reforestation can take place.”

The article noted that Japan imported 6.7 million cubic metres of logs from Sarawak in 1989 and cited Sarawak Forest Department statistics that roughly 3 million hectares of primary forest had been logged (including by other actors) by that year.

‘There is no bullet train’

“I’m an industrial engineer,” began Shubhendu Sharma in a TED Talk that helped make the Miyawaki method famous to the English-speaking world. “The goal in my life has always been to make more and more products in the least amount of time and resources.”

After meeting Miyawaki in 2009 at the Toyota plant in India where Sharma then worked, Sharma was inspired to found Afforestt – an Indian “service provider for creating natural, wild, maintenance free, native forests” using the Miyawaki method. In his talk, Sharma said Miyawaki forests grow 10 times faster, 30 times denser, and are 100 times more biodiverse than a “conventional plantation”, and that his company had “standardised the process of forest-making”.

“The first and the most important thing about the method that I found extremely important is the philosophy of Dr Miyawaki himself,” Sharma told Mongabay, highlighting Miyawaki’s “optimistic” message of how “human creativity can be aligned with nature” and his emphasis on native species.

To date, Afforestt has planted 450,026 trees in 44 cities across 10 countries, according to the company’s website.

Although urban Miyawaki groves are common, there have been fewer large-scale rural rewilding projects. Sharma recommended that, due to the method’s relatively high cost, 10-20% of a larger rural site could be planted Miyawaki-style via “tiny pockets of forest … so your effective coverage is 100%,” with other areas including native shrubs, grasses and bodies of water.

Sharma also mirrors Miyawaki’s stance on working with industry. Although companies such as oil and gas giant Shell are among Afforestt’s clients, Sharma said his company’s role planting Miyawaki forests is to give the land back to nature, “through a process that we call business”.

However, the Miyawaki method’s popularity in India isn’t universal.

In April 2023, ecological gardeners Fazal Rashid and Somil Daga published an op-ed in Indian media outlet Science: The Wire, arguing that Indian iterations of the Miyawaki method often ignore ecological niches, incur unnecessarily high costs, and are an “easy way to make money” via corporate social responsibility budgets.

Their article touched on the method’s almost mythological status, thanks in part to Japanese cultural capital: “Apparently these ‘forests’ grow at a breakneck pace, no less than a bullet train slicing its way into the future. All of this sounded nice and marketable: grow a forest with Japanese speed and Japanese efficiency,” Rashid and Daga wrote.

Lacking formal education in ecology, the authors became interested in ecological restoration while working at an urban farming startup. They started a native plant nursery in Delhi, which was able to break even due to the Miyawaki boom in the city. (The relative scarcity of native plant nurseries is one factor contributing to the Miyawaki method’s high cost.)

The pair even tried selling a Miyawaki grove to a major gutka chewing tobacco company, but the experience made them doubt the method. Visiting varied restoration projects across India cemented their views.

“You can make a generalised native tree list of a region, but while planting, you ideally shouldn’t just plant anything anywhere. Each tree has its own specific needs,” Rashid said in an interview with Mongabay, highlighting soil type, drainage, salinity, proximity to water, and other factors.

In addition, some climax ecosystems – which the Miyawaki method claims to create – may be grasslands, or have a limited number of tree species. “I mean, all of these questions are completely glossed over by any kind of Miyawaki-type thinking.”

Acknowledging that most Miyawaki groves in India are small-scale urban greening projects, Rashid added, “But then don’t call it a native forest, you know?”

Rashid and Daga recommend a much slower approach to ecological restoration: a thorough examination of site-specific ecological niches and how the surrounding community depends on them.

Before planting, “first try to understand the context and put yourself in the shoes of everybody and everything around you, and then draw up plans to work with the community to restore ecological integrity,” Daga said. In his view, even with human assistance, ecological restoration is a process that can take up to hundreds of years: “There is no shortcut method for this. There is no bullet train.”

In Malaysia, Putra Malaysia University professor Zamri Rosli said he uses the Miyawaki method, albeit with some modifications, for projects outside the campus and to test which species will thrive at “difficult” sites. The Putra Malaysia University team’s research, some of which was funded by Mitsubishi, found that the Miyawaki method accelerated growth and carbon storage compared to forests regenerating without any human intervention.

Although Nik acknowledged the method’s expense, he maintained that the seedlings’ high survival rate and “zero maintenance after planting,” as well as forests’ benefits for a clean environment, make the high initial costs worthwhile.

For him, though, method is secondary to objective: “Miyawaki method or whatever method – go ahead. Plant that forest. Don’t destroy our forest, because the forest takes care of the air, the water, the animals, everything. Our security depends on the forest.”

Symbolic capital or practical collaboration?

“In modern Japan, [tree planting] is one of the most significant examples of a nature-making practice that serves to provide powerful actors with symbolic capital and, hence, legitimacy,” culture studies scholar Aike P Rots wrote in a 2019 paper. Such “symbolic capital” may be one lens through which to view the Miyawaki method and its entanglement with corporate interests.

Stories of environmentally-minded corporate actors, such as the AEON chairman who saw the harm caused by industrial pollution with his own eyes, may offer a less cynical view.

Yokohama National University’s Miyawaki groves, planted 47 years ago, offer a view of what the world’s young mini-forests may grow into. The strips of trees, which don’t cover a particularly large area and probably shouldn’t be called “forests,” nevertheless provide shade for students and screen parking lots and aging buildings.

They’ve helped make the campus a home for tanuki racoon dogs (Nyctereutes viverrinus) and other wildlife. Recently, according to a member of the university’s general affairs department, some branches were trimmed to keep the peace between crows’ digestive systems and the humans below.

Still, whatever its charms, the Miyawaki method shouldn’t prevent us from thinking critically about ecosystems and their endless variety, nor about the pressing need to protect Earth’s remaining “native, natural forests” before we need to engineer copies.

This article was first published on Mongabay.