Would you like to plant a forest in your garden?

Monday, 17 august 2020 | Redacción CEU

Could you imagine having a dense and lush forest in the center of your city? What if you could have one in your garden or in a park near your home? We are not talking about an urban garden or a landscaped garden. Nor are we talking about letting the weeds that appear in the most unsuspected places grow wild. What we are referring to is fast- growing urban mini-forests. This idea, inspired by the Miyawaki method, is beginning to be developed in some European countries, and is being presented as an interesting alternative in the fight against global warming. What exactly does this proposal consist of? Can a forest really grow in an environment as reduced as a garden? How can these mini-forests help reduce the rise in global temperatures?

There are many dangers that forests are facing nowadays: excessive logging, fires, droughts, pests, soil exploitation, etc. On the other hand, the existence of forests is key to our survival: they protect hydrographic resources, prevent soil erosion, boost biodiversity, regulate local weather, provide oxygen to the planet and mitigate the effects of climate change. Thus, how can we ensure that forests do not disappear?

Being blindingly obvious, one could say: "Why not plant more forests?" Sometimes, simple proposals may turn out to be the right ones. Reforestation is a strategic part of the fight against global warming. Nevertheless, the idea of planting more forests on the planet is not without challenges. It may take these wooded areas a hundred years to grow. In addition, they must grow on suitable lands, which, in turn, are becoming increasingly smaller.

What if we could avoid these problems? This is what Miyawaki’s method sets out. Following this model, their followers claim that it is possible to grow dense and lush forests in less than ten years. In fact, forests can grow in the most unexpected places, since it is not necessary to have extensive and particularly fertile spaces in order to do so. For example, Shubhendu Sharma, one of the main promoters of this method, explains in a Ted talk how he planted a forest in his house garden.

Fast-growing mini-forest 

The promoters of this type of urban forest, which is already beginning to be a trend in Europe, have been inspired by the work of Akira Miyawaki: the Japanese botanist who gives his name to this method and who has planted more than a thousand forests of this type in countries like Japan and Malaysia.

This expert in plants and seed ecology observed the great diversity of vegetation that is found in temples, cemeteries and sanctuaries in Japan, and how it grew, giving shape to a resistant and diverse ecosystem. Hence, in the 1970s, his proposal to combat the fragility of forests and accelerate the growth cycle of these plant areas emerged. His model focuses on two key ideas: planting native seeds that can best adapt to local weather and terrain conditions and the high density of planted species. Thanks to these and other indications, the plants can grow in a system of high vertical competition that leads them to growing faster. This density also contributes to the soil being wetter and protected and having a higher quality layer of humus.

These forests may grow ten times faster, becoming mature ecosystems in 20 years. In addition, they do not need special care after a first stage of growth. Another advantage of urban mini-forests is that biodiversity also increases exponentially in these plant areas, more than in other types of forests.