Not just another crack in the wall

The Lower Parel road overbridge located in one of the busiest nodes of the heart of Mumbai has had to shut down for a new one after authorities found it had considerably weakened. It is a space teeming with office-goers and the closure for both vehicular and pedestrian traffic has inconvenenienced thousands. Apart from its age (shy of three years for a century), many think it's the steady growth of pipal and banyan trees in its nooks and crannies are the root cause behind the structural damage.

Dr Suchandra Dutta, professor at the Botany Department, National College in Mumbai, explains how tree growth is helped by birds who consume their fruits and help in germination. "The seeds pass through their gut and are dropped in their excreta. The moisture [in that spot] helps them not only sprout but grow into sturdy nascent plants. Helped on by their roots, these spread into the wall and in the process, widen the gaps."

This phenomenon is widely seen across the subcontinent. Entire structures like old temples have been completely engulfed by roots of the banyan and branches of the peepal. Examples can be found in Hampi, Karnataka; Bhubaneshwar, Odisha; historic mansions in Ahmedabad and some of the Mughal tombs in Delhi.

As their presence in often difficult-to-access spots weakens the structure, everything from chopping them off, harsh chemicals like acids to burn them and even fire is used to destroy these hardy plants. Dr Dutta says people should get rid of such plants before they come under the classification of tree (6cm in girth). "After that, it is illegal to destroy/cut any tree, and can attract penalties."

It is here that Jeroo Katrak, a nature conservationist from Pune, differs. "Nature is trying to help us as we wantonly destroy our tree and forest cover. These species are endemic to our land and we can help conserve them," she says, suggesting that instead of uprooting these plants, gently remove them with their roots intact and transplant them elsewhere. "The fact that they have grown in such adverse conditions shows how sturdy they are. We should especially opt to plant trees like acacia, eucalyptus and others, which are not from this climate."

Along with a group of nature enthusiasts, she goes around gathering such plants and young trees from edifices to transplant. "On the outskirts of Pune, along Nagar Road, we've been planting these trees and keep going to check on them. I am happy to say that over 40 per cent of them survive." According to her, every city and town in India needs to do this.

The BMC's tree department begs to differ. "Growing these trees after extracting them from their original location might not be cost effective," says Jitendra Pardeshi, who heads the department. "We have enough nurseries to provide us with saplings to grow."

Katrak feels people must be educated and encouraged to prefer these saplings over those from a nursery. "Holistically, that is a more environment friendly practice."