What is the trendy Miyawaki method for creating forests?

A forest seen from the sky under the colors of autumn.

(Photo illustration).

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• Special attention to the soil, a dense plantation of trees, a selection of a large number of local species.

  Here are summaries of the three main principles of the botanist Akira Miyawaki's method.

• A global specialist in seeds and forest naturalness, the Japanese have developed a method to quickly grow resilient forests on degraded soils.

• It is emulated in France, where more and more projects to create mini-forests are emerging claiming to be Akira Miyawaki.

  In town, to bring freshness and biodiversity… But also in the countryside.

  A good idea ?

"There will be beech, cécile oak, country maple, charm, hazelnut ..." To describe the forest he wanted to create on a small piece of land owned by his grandparents, near Champagnole, in the Jura, Xavier Dommange stops at the five dominant species so as not to embark on an endless list.

"There are twenty more," he warns.

Bushes, shrubs, trees to reconstruct the different levels of the forest.

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The whole should give a nice concentrate of biodiversity.

Xavier Dommange plans to plant 900 trees on just 300 m².

“The equivalent of twenty-four parking spaces,” he says to help us get an idea.

The project is called “Jurassic Forest” and is always looking for funding on the web.

Xavier Dommange's idea is to create the first forest inspired by the method of Japanese botanist Akira Miyawaki in the Jura.

"With the hope of inspiring others, and me to make it a professional activity", he slips.

Miyawaki's precepts are in any case in fashion.

It is also from this botanist that the Boomforest association is inspired to create its mini-forests at the gates of Paris, as well as the “Micro-forest collective of Toulouse in transition” in the heart of the Pink City, the association Sylva project in the Tarn since 2018, or “Sowers of forests” in Juvignies, in the Oise….

helps you see more clearly.

Who is this Akira Miyawaki?

The Japanese have accumulated 92 springs, of which nearly 70 are devoted to the study of the seeds and naturalness of forests, of which he has become a world specialist.

Xavier Dommange focuses especially on the three years he spent in Germany, between 1958 and 1970, as a visiting researcher at the German Institute for Vegetation Mapping [1958-1960].

“With other botanists, he worked on natural plant potential,” he says.

In other words, what are, for a specific location, depending on its terrain and its climate, the plants that will naturally occupy the land in a stable manner, over time.

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Back in Japan, Akira Miyawaki continues her research.

He thus notes that the vast majority of the archipelago's forests, made up of species introduced over the centuries by foresters to produce timber, are not the most resilient [which resist shock], nor the most effective in dealing with climate change.

Unlike the trees that the Japanese traditionally let grow around temples, tombs and cemeteries.

Modest forests certainly, but composed of species which would have naturally developed on this plot if Man had not urbanized it, and which then form a stable ecosystem.

He then developed a method for planting and restoring more natural forests, especially on degraded soils.

Industrial sites, urban or peri-urban areas… Akira Miyawaki has thus been loaned to the restoration of 1,300 sites in Japan and in various tropical countries since the 1970s.

What does the Miyawaki method say?

“The general idea is to get as close as possible to what the forest would be at this precise location, if it had never been touched by humans”, summarizes Xavier Dommange.

Hence the term “native” forest [to be distinguished from “primary”, not created by man] which often comes up to describe projects inspired by the Japanese botanist.

Once that has been said, the method then comes down to three main principles, which Boomforest summarizes on its website.

• Particular attention to the soil, which must be sufficiently rich and loose for the young roots to take root well.

• A dense plantation of trees, with three trees per m² in our latitudes, to promote root communication and limit the growth of weeds and create a situation of virtuous competition for light.

• A selection of tree and shrub species adapted to the location.

  Which amounts to choosing local species.

David Buffault, vice-president of Sowers of forests, and Xavier Dommange add yet another, which is to intervene as little as possible in these forests.

"The first three years in the event of climatic hazards, but otherwise we leave the forest as quickly as possible in free evolution", indicates the first.

The method to follow in the cities?

Many “tiny forest” projects, inspired by Miyawaki, have emerged in recent years in urban areas.

Sometimes in improbable pocket squares.

Boomforest thus planted a door to Montreuil, in March 2018, on a 400 m² embankment adjacent to the Paris ring road.

Then another Porte des Lilas, a year ago.

It is also in this logic that the “Collective Micro-forest of Toulouse in transition” is part, which has already planted 1,200 trees on a plot of 400 m2 in the heart of the Pink City, last March, and plans new ones again.

It is also the idea of ​​Xavier Dommange, who recalls that his mini-forest in the Jura is to be seen as a demonstrator.

"I will rely on it to convince municipalities to establish Miyawaki mini-forests in the heart of town or on their outskirts," he predicts.

With several benefits.

These forests are already growing up to ten times faster than conventional plantations, Boomforest assures us.

They also help to cool cities - a major problem in these times of repeated heatwaves -, capture their share of CO2, bring biodiversity, adds Xavier Dommange.

A method that can also be used in the countryside?

This is the conviction of "Sylva Project" and the "Forest Sowers".

The first association planted 5,000 trees of thirty species in two meadows of around 5,000 m² in the Tarn.

As for the Forest Sowers, they bought a pasture of 1.4 ha in October 2019, on a part of which they plan to plant more than 3,000 trees, "hoping that Nature - the wind and the animals - will do the same. rest of the work by swarming the seeds, ”explains David Buffault.

Working on this scale involves taking some liberties with the Miyawaki method.

In particular on the rule of three trees per m², quickly too expensive.

On the other hand, there is no question of procrastinating on the need to work on a large number of species - 30 for the two associations - and all of them indigenous.

This is the very heart of the approach of the two associations: breaking with the lack of diversity in French forests.

If these have doubled in area in two hundred years to now cover a third of France, Yann Roques, founder of Project Sylva, calls on us not to forget that “84% of these woods have only one or two essences.

The most striking example is the Landes forest, which covers a million hectares, including 950,000 maritime pines.

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“This lack of plant biodiversity does not promote animal biodiversity, continue Yann Roques and David Buffault.

It also promotes the spread of diseases, which usually attack a single species and then only have to jump from tree to tree.

This is yet another advantage of the Miyawaki method, which complicates the path of pests by allowing species to coexist.

Sarah Katib, forestry project manager at France Nature environnement, is a bit ticking about the variation of the Miyawaki method in rural areas.

“It was designed and proven to grow forests in a few years where there can be no natural regeneration because the soils are too degraded, she recalls.

Elsewhere, nature can do the job itself and will do it better than anyone else, ”she continues.

And if at FNE, we agree on the need to introduce more diversity into French forests, "there are techniques widely known to foresters and less expensive than that of Miyawaki to do it on a large scale", resumes Sarah Katib for whom the Japanese botanist's method "has nothing to do in the forest".

This is not what Yann Roques or David Buffault want to do either.

“The idea is much more to create here and there oases of biodiversity,” sums up the first.

One day even leaves to create corridors.

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