Along Canal Bank Road at Kotturpuram is a dense forest set up by the Greater Chennai Corporation using the Miyawaki method. The green of the grove in which java plum, neem, false ashoka, and mahua trees stand is a pleasant sight, albeit from a distance. The gate of the Corporation’s first Miyawaki forest remains locked to prevent trespassers from causing damage to the ecosystem. However, one can see strewn litter and alcohol bottles from outside the gate.
The Miyawaki method, named after its creator Akira Miyawaki, a Japanese botanist, helps forests grow quickly. It involves planting different types of native trees in close proximity. Typically, the vegetation is grouped as shrub, sub-tree, tree and canopy. The expected result is that plants grow 10 times faster and the forest becomes 30 times denser than usual. The method is known for regulating surface temperature, sequestering carbon, increasing green cover, and offering a zero-maintenance mechanism after three years.
In December 2020, the then Corporation Commissioner, G. Prakash, had said Miyawaki urban forests would be developed at 1,000 locations across the city. For the local body, the more number of trees that can be planted in a small space and the ‘no maintenance’ aspects may seem like a win-win. However, conservationists have pointed to the drawbacks of the method: the trees, which are not allowed to grow to their full capacity, are not ecologically beneficial. The Corporation, too, seems to have slammed on the brakes on Miyawakis as there are fewere than 40 such forests in the city now.
‘Tree abuse’
Simply put, T.D. Babu of Nizhal, an environmental non-profit, says a Miyawaki forest is actually tree abuse. “The execution is incorrect. Trees such as Vaagai [Albizia lebbeck] whose crowns can grow up to 40 metres are packed together in pigeon holes. The trees might grow faster, but they aren’t normal as they don’t support associated fauna,” he explains.
The method has raised questions about the trees’ ecological efficiency as it brings down their sequestering capacity to insignificant levels because of the reduced surface area. Instead, ‘micro forests’, wherein native trees are planted not too close and are allowed to grow wider along with other creepers, are being recommended.
According to official data, 38 Miyawaki forests have been set up by the Corporation. R. Vijayalakshmi, Superintending Engineer, Greater Chennai Corporation, says there are no plans to set up new Miyawaki forests as of now. Despite the hum around the inadequacies of the Miyawaki method, it has not yet been completely avoided. The Water Resources Department recently announced a Miyawaki forest around the Red Hills reservoir where 55 native species are said to have been planted.
