For decades now, tree lovers and environmentalists across the country have been campaigning against a tree species. The vilayati kikar, Prosopis juliflora, allows no other species to thrive. The Delhi government recently gave its nod to clearing the Central Ridge of the non-native tree in the hope that the area’s original flora — which are called the lungs of the city — as well as fauna can be restored.
Vilayati kikar and its weedlike properties — fast growth in arid conditions, killing any competition and water-table depletion —have been documented by several scientists and activists in Delhi, Haryana, Rajasthan, Gujarat, as well as Tamil Nadu, where it is called karuvelam and is used as firewood. The Madras High Court, in 2016, passed an interim order clearing removal of these trees as they were depleting the water table in areas already struggling for water. In 2017, the court started monitoring the removal of the kikar.
Delhi’s fight against the tree gained ground in the 1990s with court cases, representations to government, and research papers. The transformation of the Yamuna Biodiversity Park in Wazirabad, however, is what gave the forest department faith that the plan could work.
According to C R Babu, who heads the Centre for Environmental Management of Degraded Ecosystems (CEMDE), the organisation that will conduct the first phase of the removal over 100 acres between Dhaula Kuan and Chanakyapuri, the tree was brought to Delhi by the British in the early 1930s. By the end of the decade, it had taken over the Ridge completely, killing the native acacia, dhak, kadamb, amaltas, flame-of-the-forest etc. Along with the trees disappeared the fauna — birds, butterflies, leopards, porcupines and jackals.
Cutting down vilayati kikar and waiting for the other plants to grow is a counterproductive move for two reasons. First, the tree can regenerate from the root; second, leaving the Ridge barren and waiting for native species to grow will leave the city with barely any green cover, and invite encroachers.
In a plan made for Delhi but one that could well be replicated elsewhere, CEMDE has taken the stumbling blocks into account.
“The first step is to cut the trees’ branches and reduce the foliage cover so that sunlight can reach the ground. This cuts the tree’s capability to produce food and it starts to wither. Alongside, it gives enough sunlight and water to saplings,” Babu said.
Another method being used to expedite the process is planting parasitic, but native, vines that will cut the access of vilayati kikar to sunlight while taking away nutrients.
“The vines are native to Delhi. They quickly spread across the foliage and cut off the tree’s access to light, slowly killing it,” a senior forest department official said.
Replacing the vilayati kikar, a crucial part of the project, will have to be a scientific exercise to make sure Delhi gets the Ridge of the early 1900s. “We have identified 30 tree communities such as butea, Sterculia, and Acacia and others that are all native to India. Some of these have a canopy that is three storeys tall and will dwarf any remaining kikars when full-grown. We will plant the saplings when they are 3 to 6 feet tall to give them a good chance of survival,” Babu said.
Sourcing the saplings is another challenge. Since many of these species have been eradicated from the wild in Delhi, the city is looking to communities in Haryana and Gujarat for help. “Once the trees reach fruit-bearing age, propagation will be unassisted,” Babu said.
A reassurance is the similar model that has yielded results already, although on a smaller scale. Work started on developing the Yamuna Biodiversity Park in Wazirabad in 2002. Spread over 457 acres, the park is home to native tree, shrub, and creeper species, and houses several small water-bodies and boasts a healthy water table. Its most famous visitor, perhaps, was a young leopard that was spotted in November 2016.
For the scientists who run the park, it was a sign that what they had set out to do was being achieved. The leopard stayed for close to a month. Leopards only stay in an area for long if they find a suitable habitat — enough prey, water resources and some anonymity.
While the leopard was shifted out, the biodiversity remains — something CEMDE hopes can be replicated on the Ridge.