Amid the constant hustle and bustle of activities that keep Kotturpuram buzzing, the Miyawaki forest located near the Kotturpuram MRTS is a peaceful sanctuary, a pleasant burst of green and fresh air for all who pause here.
The urban forest, which turned one in early February, was created in 2019 after cleaning about 1,600 tonnes of waste. More than 2,000 saplings of different varieties were planted that now yield hibiscus flowers, papaya and drumstick pods among others in the 2211.87 sq m** plot of land.
The Miyawaki method of raising forests has gained immense popularity across cities. Since the first project in Kotturpuram, the Greater Chennai Corporation (GCC) has created urban forests in 20 other locations within the city limits, including Sholinganallur, Mugalivakkam, Omandurar, Anna Institute of Management Greenways, Madhavaram. NGOs like Thuvakkam and Inner Wheel Club of Madras, private entities and residents living in the respective localities have all come together to help in the creation of these forests.
Recently, the GCC Commissioner inaugurated a Miyawaki Forest opposite the Secretariat that spans 3,000 sq. ft and has a total of 837 trees belonging to 30 native species.
What is a Miyawaki forest?
It is a plantation technique conceptualised and popularized by Japanese botanist Akira Miyawaki, where a clump of saplings of native trees are planted close to each other in a piece of land, resulting in dense forests. In this method, the growth of trees is 10 times faster than the traditional approach and gives 30 times denser green cover.
Why does Chennai need urban forests?
The total green cover of Chennai now stands at 19%. This falls well short of the mandated 33% tree cover considered necessary for urban areas.
While constant efforts are on to increase green cover, the city lacks enough space to plant trees. In such cases, vacant lands and spaces in government buildings can be used to create dense Miyawaki forests within the city limits.
Besides contributing to the green cover, the presence of urban forests also aids in strengthening the biodiversity in the neighbourhood.
Although Miyawaki forests cannot replace original forests, this is often the most practical solution for a city like Chennai that undergoes constant urbanisation. The city’s pollution levels may not be as bad as Delhi’s, but having such urban forests can help mitigate the pollution caused by vehicles and the urban heat island effect.
What is the minimum area required for Miyawaki forests? How much does it cost to maintain the forest?
A minimum of 1,000 sq ft is required to set up a dense Miyawaki forest where 250 saplings can be planted. However, it is also possible to create forests in an area as small as 100 sq ft, but that would be much less dense. Thus, Miyawaki forests can also be created in one’s backyard or a private space.
The creation and maintenance cost per tree for two years would roughly be around Rs 300.
The cost also varies from one locality to another, depending on the plant species and soil type. “For instance, in places like Thiruvanmiyur, the soil texture is different and the annual cost per tree is Rs 100,” says P Manojkumar, a volunteer with Chennai Trekking Club’s green wing, Ainthinai.
How should the saplings be selected?
Native trees, always.
NGO Thuvakkam, which works at the intersection of environment, education and other such causes, has been creating miyawaki forests for a few years now. They usually conduct some background research to start with, in order to identify native plant varieties for particular neighbourhoods.
“After selecting the land, we speak with people who have been residing in the neighbourhood for more than three decades, to find out the kind of trees that grow here. Based on the findings, we select the saplings for the forest,” says Krishna Kumar Suresh, founder-CEO, Thuvakkam.
How is the land prepared?
There are broadly three main phases involved in the creation of a Miyawaki forest — land scoping and readiness, land preparation, and plantation and mulching.
Land scoping and readiness
In the first phase, soil from the selected land is tested and documented. The pH value of the soil should range between 6.3 and 7.2. After the soil test, suitable soil enrichment nutrients and saplings for plantation are chosen. Once the documentation is done, the land area is marked and existing soil is excavated and stored. The soil has to be dug to a minimum depth of 3 ft and this excavated soil is used in the second phase for enrichment.
Once the land is deemed fit based on the results of the soil test, soil enrichment nutrients are added to the land in the required proportions. This is mixed with existing soil or red soil in the excavated pit, based on the type of sand/soil available at the location. The materials which are usually used for soil enrichment are:
- Perforator – rice husk/wheat husk
- Water retainer – coco peat/saw dust/bagasse
- Fertilizer – cow dung, manure and vermicompost
- Mulching material – straw
Once this is done, the plantation is designed and the locations of each sapling fixed for plantation. No tree belonging to the same family are planted together as the trees may fight for sun and water and that dents their growth.
Plantation and mulching
A Miyawaki forest is typically designed to accommodate both shrubs and trees. For a land area of approximately 1000 sq ft, a minimum of 250 trees to a maximum of 300 can be planted.
This plantation is distributed layer-wise as below:
- Shrub layer (up to 6 m height): 8 to12 %
- Sub-tree layer (6 to 15 m): 25 to 30%
- Tree layer (15 to 30 m): 40 to 50%
- Canopy layer (above 30 m): 15 to 20 %
This has to be accompanied by mulching, a process where the topsoil layer is covered with organic materials like straw or grass. This process helps to preserve the soil moisture, improve fertility and health of the soil. Direct sunlight will make the soil dry and make conditions difficult for the young saplings. The mulch should be evenly laid out on the soil, in a 5-7 inch layer.
How should the forests be maintained?
- For two continuous years, the urban forest needs careful and meticulous attention to ensure protection against threats.
- Real-time status should be documented by making regular visits to the urban forest.
- The trees should be supported with sticks to ensure the shoot grows upright.
- The forest should be watered every day with a hose pipe. A water drainage system should also be installed to prevent water accumulation around the saplings/trees.
- The forest must be kept free from any kind of waste and guarded against human intervention and grazing.
- Inorganic fertilisers should not be used.
- Pruning and cutting of trees should be avoided.
Can any interested person volunteer in Miyawaki forest projects in the city?
Yes. The civic body collaborates with various NGOs to carry out this project. Here is a list of NGO contacts that are engaged in setting up urban forests.
Alternatively, one can contact the Regional Deputy Commissioner’s (RDC) office for volunteering:
- RDC North: 044 2520 0025 or email@example.com
- RDC Central: 044 2664 0224 or firstname.lastname@example.org
- RDC South: 044 2442 5981 or email@example.com
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** Errata: The area of the Kotturpuram Miyawaki forest plot was mistakenly mentioned as 2211.87 sq km (instead of sq m) in the first published version. We apologise for the inadvertent error.