Konnagar municipality of West Bengal has become the country’s first civic body to issue “identity cards” for 28 species of commonly found trees as part of a move to create awareness about their ability to absorb carbon dioxide.
The cards, which were issued on Tuesday, contain pictures of the trees, species name, location and the amount of carbon dioxide absorbed by the trees.
Fifty students and more than 30 teachers from nine schools, over a dozen staff of the municipality and a team of scientists of Konnagar, located about 30 km from state capital Kolkata, worked for nearly one-and-half months to prepare the identity cards.
“We are the first municipal body in India, and probably in Asia too, to undertake such a project. There are 20 wards in our municipality and the project took into account all the major trees in these wards,” said Bappaditya Chatterjee, chairman of the civic body.
“Just like your office identity card mentions your name and reveals the position you hold, these ID cards mention the tree species, its location and mention how much carbon dioxide it absorbs to mitigate the effects of air pollution,” said Abhijit Mitra, the former head of Calcutta University’s marine science department who is leading the project.
Experts said such identification has become important because trees are being felled in the name of development while authorities are indiscriminately planting trees without knowledge of the ability of species to clean the air.
“If we know which species absorb more carbon dioxide than others and plant only those species, we can better tackle the problem of carbon dioxide. Carbon dioxide is a greenhouse gas which triggers global warming,” said Mitra.
Trees such as Gulmohar (Krishnachura), Subabul, Kadam, Jamun and Bakul have been found to absorb the maximum carbon dioxide and store it in their woody trunks.
Other large trees such as Neem, Banyan and Peepal absorb less carbon dioxide. Neem and Banyan are useful when it comes to the absorption of lead.
Next, the researchers plan to carry out a similar study on the trees in Kolkata. Similar studies were earlier conducted in Keshtopur, Sector V of Salt Lake and Kalinganagar in Odisha.
The team will measure the volume of trees with laser technology. From the volume and density of the wood, the tree’s biomass will be ascertained. The results will be fed into a hi-tech CHN analyser machine to ascertain the carbon content.
A few cities around the world, mostly in the US, have done similar studies to ascertain the carbon content in trees.
“A full grown Gulmohar tree was found to store nearly 180 tons of carbon. This means if we plant a Gulmohar sapling, it will absorb more than 650 tons of carbon dioxide a year when fully grown,” said Nabonita Pal, one of the team members.
“On the other hand, it would also mean that if we cut down a full grown Gulmohar tree, we are allowing around 650 tons of carbon dioxide to be added to the air.”