This May, temperatures in Delhi peaked to a scorching 52.9 degrees Celsius and the heatwave lasted for weeks. Respite came in the form of last week’s heavy downpour but it flooded the city. The obvious culprits were blocked and poorly maintained drainage and sewage infrastructure. Waterlogged streets to suffocating levels of air pollution, followed by biting cold — each year, there is an exponential rise in the severity of these calamities. The value of trees in this scenario cannot be overstated; they offer shade, reduce temperatures, improve air quality, and help manage water runoff, mitigating some of the severe impacts of climatic extremes.
On June 28, after the first heavy showers, the NDMC received complaints of the uprooting of 24 trees and 17 with broken branches. Trees native to Delhi such as shahtoot, neem, banyan, siras, milletia, imli, and pilkhan are reported to have fallen. These are merely official numbers just from the north and south NDMC areas or Lutyens’ Delhi — the only area of the city for which the Union government has, since 2009, given a tree ambulance.
In April, a revamped version was launched. The ambulance team checks tree health and attends to complaints related to pest infestation, and to those of hollowing out or drying up of trees; it also washes trees, in order to clean them up, on the basis of information it receives from its field staff on a regular basis. On an average, the team saves around 50 trees per month, including diseased and fallen trees. The team managed to replant at least 15 trees that fell during the May windstorms. But the extreme heat has made trees more prone to mites and mealybug infestations; they thus require frequent treatment, a huge job for the team. Since the past 15 years, the upkeep of approximately 1.80 lakh trees in the area has been managed by six members of the team with only one ambulance.
What heatwaves, thunderstorms do
“More trees are lost in thunderstorms than in the rainy season. When it does happen during the rains, it’s usually because the soil that supports the upper parts of the root system has been disturbed or has become waterlogged,” says Pradip Krishen, author of Trees of Delhi: A Field Guide. “Some trees, like the fig trees (such as banyan) of Delhi, tend to have root systems that don’t run very deep, so if the soil around their bases is washed away or becomes waterlogged, it’s possible that they will keel over.”
A higher number of trees may have been lost during the thunderstorms following the May heatwave, he surmises. There are no official figures on this. Krishen recalls that after a big windstorm, some years ago, he was surprised to see neem trees made up a hugely disproportionate number of arboreal casualties. “Though neem can thrive in multiple areas such as the rocky Ridge and the old floodplain, they struggle near the Yamuna and Najafgarh jheel. Gulmohars, on the other hand, are not native to Delhi. They also fell because they’re brittle and unbending. The two main causes other than external hindrances that cause trees to keel over are brittleness of the trunk and dense crowns. The latter makes them inflexible so while they may resist the force of the wind, they fall down.”
There are guidelines for pruning the dense growth of foliage under the Delhi Preservation of Trees Act, 1994. “Many a time incorrect pruning mechanically destabilises the tree, making it more prone to cracking and falling,” adds Vallari Sheel, an urban ecologist.
No replantation plan
When a tree falls, it is not just its shade that is lost but many birds and animals lose their habitat and food resources. Delhi trees that have become a rare sight are Palash, Doodhi, Barna, Peelu, and Roheda, which is also in the International Union for Conservation of Nature’s Red List of Threatened Species, says Sheel to paint the scale of biodiversity being lost. Planting native trees isn’t part of the landscape patterns covering the city and has not been enforced by civic agencies despite Delhi High Court orders. Native plantations are not only attuned to climate and can adapt better but also require less water and resources.
There is a “lack of penetration of this knowledge” among forest officers, municipalities, bureaucrats, and built environment practitioners, she says. She tells TMS that many times authorities refuse to plant native species not in the horticulture department’s rate list as that increases the work involved in the process of procurement. “Since there is no mandate to promote native species, the nurseries also do not stock them. There is also an aesthetic problem since everyone wants green trees with big leaves; native trees generally have thin leaves. We have so many native species with medicinal value, flowers, and fruits that are ignored,” she adds.
Trees in city planning
While concretisation, poorly done pruning, climatic calamities, and lack of promotion of native species are the four main reasons behind trees falling in the city, structural changes are urgently required in city planning. As is the change in urban lifestyles that are widening the gap between humans and the natural world. Says Nidhi Batra, urban designer and founder at Sehreeti Development Practices:
“To save trees there is a need to look beyond trees in isolation. We have overly concretised pavements, neglecting softer infrastructure and nature-based solutions, which should be integrated into city planning. By-laws for municipalities to incorporate these solutions are lacking. EIAs often fail, leading to extensive tree-cutting or ineffective transplantation. The 74th Constitutional Amendment Act’s ward committees are inactive, and structured planning processes are absent. As urban citizens, we prioritise cars and hard pavements over trees and softer pavers.”
“At the by-laws level, what are we promoting?” she also questions. “Builder flats don’t plan with street-avenue trees in mind, often removing trees and planting palms — which are non-native — leading to 100 percent floor coverage with barely any space left around the building.” Our relationship with plantations, food ecosystems, and biodiversity needs radical rethinking and re-prioritising so that we live in harmony with the ecosystem that feeds us and keeps us alive. From a time of growing up with a tree in the courtyard, today we no longer have houses with courtyards, should we let the trees go as well?