The demolition of the Supertech twin towers in Noida August 28, 2022, is expected to affect the local flora and fauna in more ways than one, experts have told Down To Earth.
Many birds and mammals will leave the area for some time, while long-term effects are difficult to assess at the moment and will require examination, they added.
The demolition has produced large amounts of dust. Heavier dust particles will settle down soon but the light particulate matter will probably remain in the air for weeks, Shourabh Gupta, senior research associate, Clean Air, Centre for Science and Environment, Delhi, said.
The settling of the dust particulate will also depend on wind speed and wind direction. Dust will also remain in the air because of loading and unloading of trucks for clearing the debris, he added.
But most worryingly, the local flora is going to suffer.
“The towers were located in a residential neighbourhood with large green spaces and significant tree cover. The post-demolition dust has engulfed nearby trees and vegetation.
Sprinklers are being operated, water has been sprinkled on trees, vehicles and smog guns were being operated to settle down the dust which may have localised benefits but seem inadequate to douse the dust and other fine debris,” Gupta said.
Dinabandhu Sahoo, director of Centre for Himalayan Studies, Delhi University (DU) and senior professor, Department of Botany, DU, explained how flora would be hit.
“When you have such fine particles that form in the aftermath of the implosion, all leaves and the canopy will be covered completely. So, the rate of photosynthesis will come down. Once that happens, the plants’ productivity will reduce,” he told DTE.
If there was continuous rain, the dust would be washed away and percolate into the soil and remain there for some time.
“But it will take a long time for the plants and trees to be rejuvenated. Birds and insects, especially pollinators will be affected. The only way this situation can be changed for the better is sprinkling water continuously,” Sahoo noted.
He also stressed that since the demolition was a first-of-its-kind event in India, multiple studies should be undertaken to gauge its impact not just on biodiversity but also humans.
The area where the implosion took place is home to several types of birds and some mammalian species as well. Most experts DTE spoke to, said these would leave the area for some time and come back later.
“That place will become devoid of any kind of biodiversity. There will be a drastic collapse in populations,” Sohail Madan, assistant director with the Bombay Natural History Society, said.
He added that it was difficult to talk about long-term impacts at the moment. “I am not sure if materials like asbestos or other harmful substances were used in the construction of the buildings. If arsenic and mercury were used, there would be long-term impacts on humans as well as wildlife,” Madan said.
The area where the implosion took place as well as those in its vicinity are very rich in bird life, Madan said. “There are mostly normal garden birds there. Owls, barn owls, spotted owlet, scops owls as well as water birds, will all be impacted,” he added.
Faiyaz Khudsar, Delhi-based wildlife biologist, pointed to the noise created by the implosion.
“Studies have shown that birds living within cities change their vocalisation due to the noise around them. Vocalisation is used by birds for breeding and protection. But they change the pitch and quality of their vocalisation due to noise pollution,” he said.
Khudsar added though that the noise in this case was short-term hence birds and mammals in the area would leave for some time.
Certainly, mammals would be affected like their avian counterparts. Murali Krishna Chatakonda, assistant professor, Amity Institute of Forestry and Wildlife, Amity University, Noida, talked about the impact on rodents like squirrels.
“There will definitely be a negative impact on squirrels though they are more used to urbanisation. Squirrels have respiratory systems similar to humans. So the particulate matter floating for weeks will affect them as well,” Chatakonda said. He added that squirrels too would leave the area but would come back once the dust settled.
Khudsar said jackals were common in the vicinity of the Yamuna, which is located quite near the demolition site.
“Here, they get plenty of food in the form of rodents, berries called locally as jharberi (Ziziphus nummularia), the fruit of the wild jujube plant as well as carrion,” Khudsar said.
“The nilgai antelope is also found in the area as it is a denizen of the Yamuna floodplain, where there are hardly any natural predators to hunt it,” he added.