Should we create miniature forests instead of parks in the world’s megacities?

    10 Jul 2021

    The Japanese botanist has figured out how to quickly grow a forest in the middle of the city. Now his services are in full swing in cities around the world, The Economist reports.

    Wild forests, which are described below, no longer need to be ennobled: in the world, fashion recommends creating the forest in the middle of the city instead of the park. We need to keep this advantage especially vigilant right now, in times of climate change.

    The air of cities is in deplorable condition. It is dirty and hot. Pollution on the streets, according to the WHO, kills 4.2 million people each year. At the same time, concrete and asphalt absorb more sunlight than reflect it and replace plants that would cool the air by evaporation.

    The relentless proliferation of buildings and roads is turning cities into heat islands, creating discomfort for their residents and intensifying heat waves, which will become more frequent as the planet heats up.

    Trees are a possible solution to mitigate the effects of the twin problems – pollution and heating. Their leaves destroy at least some of the chemical contaminants, and they reliably retain small solid particles from the air, which are then washed into the ground by rain.

    In addition, the trees are cooling the air. In addition to evaporating moisture, thereby physically lowering the temperature – they simply provide shade. Their leaves, finally, evolved precisely to capture sunlight – the engine of photosynthesis.

    However, for effective cooling of a particular space there should be a lot of plants. Researchers from the University of Wisconsin in 2019 found that American cities should be covered with trees by 40% to reduce the heating of urban areas. Unfortunately, not all cities (especially those now in the world’s poorer countries) have enough parks, private gardens, or even trees along the streets to make it enough. And the problem is likely to get worse. Today, about 55% of people live in cities, and by 2050 this share is projected to increase to 68%.

    Under a leaf canopy

    A group of botanists believes that they have at least a partial solution to the problem of lack of urban vegetation: to plant miniature copies of natural forests, designed to grow quickly. The group’s leader, now 93-year-old Miyawaki Akira, an ecologist at Yokohama National University who has been working since the 1950s, has developed a way to do so even in the most hopeless, seemingly abandoned areas. Dr. Miyawaki retired from the university in 1993 – but has only intensified his career since then.

    The Miyawaki method, as it is now called, is becoming increasingly recognized among relevant circles around the world.

    Even the example of individual houses shows how trees condition the air:

    Dr. Miyawaki’s method is to artificially (and therefore accelerate) reproduce the process of ecological sequence through which, in nature, bare lands are gradually transformed into mature forests.

    Usually, herbaceous plants come first. Then there are bushes, followed by small trees, and finally, large trees. Thus, mature forests are composed of a system of different species of plants. The Miyawaki method allows you to immediately plant a complete species of species in the wild mature forest.

    Using the Miyawaki method, people who often call themselves gardeners first analyze the soil in which the future forest will grow. If necessary, the soil is improved with appropriate fertilizers. They don’t have to be expensive. Very effective and often free – chicken manure or pulp, which remains from the processing of sugar plants.

    After that, botanists choose about a hundred local species of plants – this is not done by textbooks, but by walking around the area: the books are often outdated or just wrong.

    It is essential to use a wide range of species – not just trees.

    Most tree plantations created for commercial purposes are monocultures. Instead, the natural forest coexists with many trees, shrubs, and grasses that cover the undergrowth – and that’s why they are all present in the Miyawaki forests from the beginning. It allows roses to contain more greenery in a particular space and encourages plants to grow faster because there are many positive ecological relationships in the natural forest. For example, vines need trees to grow around them. Trees provide the necessary shade for certain shrubs. Beneath the earth’s surface, the roots of various plants interact with each other, as well as with fungi – all of which promote metabolism, which we are only now beginning to understand.

    Having chosen the species, gardeners collect seeds and plant them randomly – not in rows. And they sow densely. Therefore, seedlings have to fight for sunlight, and only those that grow best survive. Trees planted in this way grow 14% faster than usual. For the first three years, gardeners water and nurture them. Then they leave it to themselves. In a few decades, the forest reaches maturity.

    Miyawaki coordinated the planting of more than 1,500 such forests, first in Japan and then worldwide. Others are now following in his footsteps. India was especially noted.

    More than 200,000 trees grow in and around the Miawaki forests in Mumbai. In Bangalore – more than 50 thousand. In the photo below – “before and after,” the forest planted around Bangalore airport.

    “Oh, how you grew up!”: Miyawaki Forest, three months after planting

    A group of gardeners in Chennai (formerly known as Madras) planted 25 such forests. The authorities in Tirunelveli in southern India use the Miyawaki method to create a green cover in the cities of the district. Hyderaban began growing the largest such forest of four hectares in 2020.

    West of India, in neighboring Pakistan, people are doing the same. The country’s climate change ministry says 126 Miyawaki forests have already been planted in the country: 51 in Lahore, 20 in Islamabad, and 5 in Karachi. And in Nepal, the city of Janakpur is also planning a biennial Miyawaki.

    This method is also gaining popularity outside Asia. In Europe, there are Miyawaki forests in Belgium, France and the Netherlands. There are several similar places in Latin America. No matter what they plant, gardeners do not follow nature to the letter. Miyawaki forests can be adapted to local requirements. For example, it is popular to include more fruit trees in forests than in natural forests, creating gardens that do not require human care.

    One of the supporters of this method is Schubgend Sharma. Through his company Afforest, founded in 2011, Mr. Sharma became one of the leaders of the Miyawaki method. He was once an engineer at the Toyota plant in Bangalore – and used his car-picking experience to plant trees. He pays special attention to time and movement: Sharma measured how much each seed or seedling needed on average and used this information to mathematically model and create a sowing graph. Afforest has made 138 forests in ten countries in a decade and is now creating four more. The company has produced at least 15 imitators in different countries such as Australia, Chile, and Iran.

    The insight came to Mr. Sharma in 2009 when Dr. Miyawaki arrived to plant a forest around his plant. Sharma was so impressed that he decided to grow his own garden, particularly planting a forest with guava trees. At first, only seven species of birds arrived in the forest, but two years later, there were already 17. Before planting the forest, the rain gathered in the yard in a puddle, forming a breeding ground for mosquitoes. But after the trees sprouted, the puddles disappeared. The forest also successfully cooled the air. Sharma measured that the temperature under the trees was 5 degrees lower than around. As for guava, she began to give birth so much that Sharma’s mother began distributing them to neighbors.

    What Mr. Sharma and others like him offer is reminiscent of the modern version of the nineteenth-century movement, which began to pay attention to the benefits of urban parks for the health of people in the West, which was undergoing rapid industrialization. Simultaneously, the approach of “taming” nature dominated, and parks became controlled, formally designed. Landscaping and the environmental movement are in vogue today, and Miyawaki’s approach to wildlife reproduction fully reflects this. The goal is the same as before: to introduce nature into cities.

    The Miyawaki method will not work for afforestation on a large scale: it requires too much work. It is likely that afforestation of large areas will need reliance on nature and the passage of time. This applies to once cut-down forests. Technophiles dream of speeding up the process by sowing drones. But if your goal is to quickly improve your area, not to save the planet from global warming in general, then Miyawaki is your man.

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