Updated: Sep 25, 2020
Urban areas are highly exposed to climate risks due to their heavy infrastructure and population density. In order to reduce risks such as heavy rains and extreme heat, planting forests with the Miyawaki method allows the rapid reintroduction of mini ecosystems that help regulate the urban climate.
TLDR: We need to protect our cities and neighbourhoods from the effects of climate change. Very simple actions based on nature can already bring great benefits. Urban forests are lifelines to be scattered throughout our cities, even in the smallest corners.
The Miyawaki method was created by Akira Miyawaki, a Japanese professor and botanist who developed an expertise in plant biology. He has developed and put into practice the reforestation method called "senzai shizen shokysei", meaning "natural potential vegetation".
This technique begins with selecting a variety of plants native to a region. It is important to choose plants that present the right requirements to thrive in the conditions offered by the environment. The seeds are then planted and germinated in nurseries. When the plants are one or two years old, they are replanted on prepared land. Soils are fertilised upstream with natural materials such as bark, decaying plants, addition of earthworms, and more.
What makes this method impressive and gives very fast results is the diversity and density with which these forests are planted. Between 30 and 40 different species are planted on each plot, in order to maximise the biodiversity that can be established there. The tree species range from shrubs in the bocage to canopy trees for optimal occupation of the vertical space and greater carbon storage.
The "Miyawaki" technique is a unique methodology that has proven itself worldwide, regardless of soil or climate conditions. Thousands of such forests have already been successfully created, and unlike conventional tree plantation, they can reach a density 30 times higher. The Miyawaki forests grow faster (about on metre per year) thanks to the interaction between plants and the synergies they develop between them. They only require human intervention during the first 3 years to water if necessary and remove any grasses that might grow and prevent the young plants from evolving. After these three years, they are independent and maintenance-free.
In return for the effort dedicated to planting these forests, they provide many benefits to cities. They foster biodiversity, benefiting to all the neighbouring green spaces and gardens. They keep their surrounding fresh during heatwaves. They help to clean up the polluted air by capturing particules and carbon dioxyde, and providing oxygen in return. And their soil can store excess rain water when needed, preventing the flooding of sewing systems.
You can support mini forests in your area by joining an association, suggesting the idea to you local government or by simply planting one in your backyard to protect yourself from climate change risks. In any case, you will find plenty of resources to walk you through step by step.