What is the Miyawaki method?

• Miyawaki is a technique of growing dense plantations in a short time. This method originated in Japan and is now increasingly adopted in other parts of the world. It is named after the Japanese botanist and plant ecologist Akira Miyawaki.
• With this method of plantation, an urban forest can grow within a short span of 20-30 years while a conventional forest takes around 200-300 years to grow naturally.
• In the Miyawaki technique, various native species of plants are planted close to each other so that the greens receive sunlight only from the top and grow upwards rather than sideways. It helps in the prevention of the growth of weeds.
• As a result, the plantation becomes approximately 30 times denser, grows 10 times faster and becomes maintenance-free after a span of 3 years.

Process of Miyawaki

• In this technique, the native trees of the region are divided into four layers after identification and analysis of soil quality. The four layers include shrub, sub-tree, tree, and canopy. 
• The biomass is mixed with soil to enhance its nutrients, perforation and water retention capacity.
• Further, the seeds are planted on soil made mound at a high density i.e 3 to 5 saplings per square meter and a thick layer of mulch is used to cover the ground.

Significance

• The Bonn Challenge was jointly launched by Germany and IUCN in 2011 to restore 350 million hectares of degraded and deforested landscapes by 2030. 
• The World Economic Forum launched the One Trillion Trees Initiative in 2020.
• Trees can play a significant role in the challenging times of climate change and global warming. 
• These fast-shooting micro forests could cool concrete cities, clean the air, sustain wildlife, and form carbon sinks. 
• The method is quickly finding favour in government corridors and corporate boardrooms to restore urban spaces.

Concerns

• Some critics argue that the method is expensive and has unclear benefits.
• Furthermore, the selection of wrong trees can destroy native ecosystems, pushing plants and animals that depend on them to the brink.
• These forests lack a few qualities of natural forests like medicinal properties and the efficacy of the technique is questioned by several environmentalists that it could not match a forest’s complex ecosystem.
• However, this method is useful in restoring diversity and fighting climate change impacts in cities.

Why in news?

• Hyderabad is promoting India’s largest Miyawaki forest spreading over 18 acres.
• The self-sustaining urban forest has 126 species of native fruits and flowering trees besides 110 species of birds.