Concrete, violations take toll on national capital’s green giants
NEW DELHI: Two majestic Neem trees that stood tall for around 100 years, shadowing central Delhi’s APJ Abdul Kalam Road, fell in June this year. A survey report prepared by the New Delhi Municipal Council (NDMC) attributes their uprooting to shallow roots — a phenomenon that occurs when the root system does not get enough water or breathing space. Concretisation is a big reason for that. A dense pilkhan, also about 100 years old, on Dr Zakir Hussain Marg dried up and died this May. The survey cited gradual decay because of lack of nutrients and repeated injuries as the reasons for the tree’s death.
These towering trees, estimated to have been planted between 1920 and 1935 when New Delhi was being built, are among the 1,391 old and fullgrown trees that were uprooted or died between 2015 and July 20 this year. Of these, 199 fell or died between January 1 and July this year, shows the NDMC data consulted by HT.
According to NDMC officials, more than 30% of these trees were ‘heritage’ trees (more than 70 years old) with most of the neem and pilkhan trees aged more than 100 years.
Ageing apart, concretisation and digging of roads for various civic works are the other two top reasons for the uprooting of trees as these obstruct rainwater from seeping into the ground, which then lowers the water table and affects soil quality, say officials.
This is despite the 2013 National Green Tribunal order that prohibits any kind of digging or construction activity within a 1m radius of a tree trunk. “Among the 20-odd native tree species in Lutyens’ Delhi, neem and pilkhan are the most predominant victims of concretisation. On an average, at least 10 heritage neem trees die or fall off every year. These trees have heavy canopies and a girth measuring more than 2m. The tree trunks weaken as the roots do not get enough water and moisture... Eventually, it falls off as its weakened trunk cannot bear the weight of the canopy,” said a senior NDMC official.
During its survey, the municipal body found that more than 70% dead cells constituted the core region of the neem trees that died, indicating that the trunk almost had no strength to bear the weight of the canopy. Similarly, the root system became shallow in the pilkhans, which have the heaviest canopy.
“Both these species have a tap root system that goes deep into the soil vertically and have a stronghold... Most of these trees are about 100 years old and are now falling off because of concretisation,” said the official.
According to data accessed by HT, of the 1,391 trees, 783 were in the category of ‘dead and dry’; 559 were ‘fallen or uprooted’; and 47 were in the ‘dangerous’ category.
Most of these are ‘avenue trees’ (planted on both sides of the road), which experts say were planted keeping in mind the aesthetics of each stretch.
“It has also been observed that the number of trees in the ‘dead and dry’ category has been increasing. On an average, 110 heritage trees are dying every year. The absence of enough water and moisture reaching the roots facilitates their gradual decay. The wetness leads to infections, pest and termite attacks, eventually leading to the death of the trees,” said another official requesting anonymity.
Officials associated with the survey also said that Ganoderma,
a fungal infection in trees, was also responsible for the death and decay. “Over the past 5-7 years, this infection has been growing in the collar region of the trunk in many silver oak trees. The infection dries up the epidermal cells, crucial to growth,” said the second official.
S Chellaiah, director (horticulture), NDMC, said even with the utmost care, many trees, including heritage ones, are dying due to development activities. “Heritage trees have their own ecological value. What we need to do is have a strong policy to preserve trees and not allow repeated digging or trenching that damages the root system,” said Chellaiah.
He said all underground cabling should be done through a single duct that wouldn’t require digging every time a cable has to be laid. “So far, the duct system has been adopted only in Connaught Place,” Chellaiah said, adding that it would require heavy investment but will increase the life span of trees by at least 20-25 years.
C R Babu, professor emeritus at DU’s Centre for Environmental Management of Degraded Ecosystem, said avenue trees in Lutyens’ Delhi are dense and have immense ecological value as they help to keep pollution in check by trapping dust.
“These trees need to be preserved by minimising construction activity and maintaining a gap of at least two metres lengthwise,” he said.
He added when there is concretisation around trees, their root system does not get enough space to develop or take nutrients and water from the soil. “Besides, many trees in Delhi are dying of termite attacks. In most cases, these are concretised trees which are not able to draw enough moisture and oxygen from their roots and become susceptible to termites,” he said.