delhi

Updated: Jul 16, 2018 13:30 IST

With the onset of monsoon, the forest department is set to start its offensive against vilayti kikar (Prosopis juliflora) from central ridge this month.

The central ridge spreads over 864 hectares, around half of which (423 hectares) comes under the forest department. In the first phase around 100 hectares belonging to the forest department would be taken up by the forest department to replace the kikar with other indigenous varieties of plants.

“The forest department has roped in ecologist CR Babu and a plan replace the kikar has been cleared by the Ridge Management Board. A fund of Rs 12 crore has been allocated. The project would span over the next five years,” said a senior official of the state forest department.

Hindustan Times takes a look at the forest department’s plan that targets bringing back the pristine nature of the central ridge and turn it into a multi-canopy forest within the next five years. This, experts said, would also help to bring several birds, insects and animals back to the ridge.

The terrain

The strip of land that has been selected is located along the Sardar Patel Marg. The undulating terrains of the ridge, most of which have become denuded because of lack of vegetation, slope towards the Sardar Patel Marg. While the hill tops and slopes are mainly dominated by Lantana and sida plants and vilayti kikars are mostly found in the valleys of the central ridge.Lantana, sida and vilayti kikars are exotic and invasive species of plants.

Preparing the ground

The kikars, with their deep roots, have sucked up much of the groundwater leaving the land dry. Scientists hence said they will first have to bring back the moisture in the soil.

“For this we are planning to develop small water bodies. While on one hand rain water coming down the ridge’s slopes would be harvested, run-off water from the roads during the monsoon would be channelized with the help of pipes towards the ridge, which in turn would percolate and recharge the ground water,” said Babu.

Aquatic plants would be introduced in the water-bodies and flowering and fruit bearing shrubs would be planted on the banks.

Developing green cover

At present the slopes and hill tops are mostly covered with lantana plants. While on one hand the lantana would be manually removed, various grass species — such as cenchrus, heteropogon and dichanthium — will be planted to make the ridge greener. They would also help to retain the moisture in the soil.

“At least 20–25 species of grass will be planted along with flowering and fruit bearing shrubs, including grewia, lyceum and rush. Some of these are critically endangered. The grass will help to attract insects and birds,” said Babu.

Taking over the open areas

As the kikar has a thick canopy, which doesn’t allow sunlight to reach the forest floor, the scientists will first target those areas where kikar population is less and the forest floor is open.

Indigenous varieties such as mitragyna, tecomella and butea would be planted in the open areas so that they can form communities. These would be planted mostly along the slopes after removing the lantana.

Final assault on the kikar

The final step of the plan is removing the kikars. At first the scientists will trim the kikar and create holes in its thick canopy so that sunlight can reach the forest floor. This would ensure that the saplings of indigenous varieties that are planted get enough sunlight to grow.

“While on one hand saplings of trees like jamun, arjun, siras will be planted at a distance from the kikar tree, a few varieties of vines, such as the geloi, makora (jackal jujube) and Asian bushbeech (gmelina asiatica) will be planted close to the kikar,” said Babu.

These vines have been found to be killing and replacing the kikar in the Kamla Nehru Ridge area. It is a kind of biological control of the kikar, which the researchers had stumbled upon and now plan to use in the central ridge.

“Kikar, like any other plant, needs sunlight for photosynthesis — a process through which they manufacture food. The sunlight is needed to produce glucose from CO2 and water. These vines, once they reach the top of the kikar, gradually engulf the entire canopy. As a result the kikar doesn’t get sunshine and can’t photosynthesis. Eventually they die,” said AK Singh, scientist in-charge of the Kamla Nehru Ridge.

By the time the fast growing fruit bearing indigenous varieties come of age, these vines would help in strangulating and killing the kikar. Finally, the indigenous varities would take over the area.

Time required

Forest officials said that it would take at least two to three years before the kikar can be replaced with indigenous varieties in first 100 hectares.

“The entire 423 hectares will be taken up in phases and it would take at least five years to replace the kikar. Within ten years we expect to see a multi-canopy forest free of kikar,” said a forest official.