Located right next to the Jawaharlal Nehru University (JNU) in South Delhi, and accessible from the southern side of Vasant Vihar on Poorvi Marg, and also from the Mehrauli-Mahipalpur road, is a veritable treasure trove for Delhiites?the Aravalli Biodiversity Park! Biodiversity parks are unique landscapes in urban centres; they are natural heritage sites which serve as repositories of vanishing gene pools of plants, animals and microbial life. They have educational and cultural value, besides their all-important role in environmental conservation, serving as sinks for carbon dioxide and other gas emissions, acting as dust traps, recharging ground water, and promoting cloud formation and local precipitation.
The Aravallis are one of the oldest mountain ranges in the world, having evolved about 1,500 million years ago. The projections of the Aravallis in and around Delhi are popularly known as the Delhi Ridge. Historically, the river Yamuna and the Delhi Ridge have been the two vital life supporting systems of Delhi, both of which have degraded over time and lost their resilience.
The Ridge once occupied about 15% of Delhi?s area, but much of it has been flattened because of increasing demand for urban space by the densely populated Delhi, and the increasingly urbanised townships of Gurgaon, Faridabad and Noida. Thanks to citizens? action resisting encroachment, 7,770 hectares (ha) or about 19,000 acres has been protected legally. This is scattered in 4 distinct forest patches, i.e. the Southern Ridge known as Asola Wildlife Sanctuary (15,320 acres), the South Central Ridge (1,564 acres), the Central Ridge behind Rashtrapati Bhawan (2,135 acres), and the Northern Ridge next to Delhi University (215 acres) which is a favourite jaunt for students. This is a small part of the original area but significant enough to make a difference to Delhi?s environment. However, these once contiguous patches are still not immune from pressures or claims from other uses.
As recently as in 2005, the South Central Ridge was a barren and degraded area suffering from the effects of extensive mining of mica, sandstone, china clay, badarpur and gravel over several decades. Once covered with dense forests and supporting a wide range of ecosystems (tropical moist forests, scrubs and grasslands), the area was subsequently reduced to pits and denuded hillocks. Construction activity and encroachment led to further deterioration of this natural treasure. In a landmark judgment by Justice Kuldip Singh, the Supreme Court issued an order in 1996 prohibiting the Delhi Development Authority (DDA) from allowing any construction activity in 560 acres out of the total area of 778 acres owned by them. In 2004, DDA decided to develop a Biodiversity Park at this location. This, the Aravalli Biodiversity Park, is one of the first steps in setting right the damage that has been done over a long period to this unique natural heritage of Delhi.
The Park has been developed by a dedicated team of scientists from Delhi University, under the impassioned leadership of Prof CR Babu at the Centre for Environmental Management of Degraded Ecosystems (CEMDE). The project is still a work in progress. An area of 450 acres has already been successfully converted to create the right environment for biodiversity in an urban landscape.
In a short span of 7 years, the Park has grown into about 20 distinct forest communities with 1,000 species of plants. Each community has 5 to 6 species in the top layer, 15 to 20 species as underwood and a native ground cover with several grasses and herbs. Many species provide timber and products of industrial value. All the communities have 3 trophic (food chain) levels?autotrophs (plants), herbivores and carnivores. There are abundant insects attracting as many as 190 bird species to these communities. About 24 types of reptiles, including monitor lizards and snakes, are also found in these forests. Mammals such as jackals, blue bulls, porcupines and others are very common.
One can walk through these forest communities using 6 different nature trails which criss-cross the Park. All this has been accomplished without altering the topography of the land. About 300 acres or so of the area in the Park harbours forest communities, and is open to students and the public for guided tours; the Park receives about 2,000 persons on average every month.
A programme of planting native trees and bushes is carried out in a systematic manner, with a concerted effort to remove Vilayati Kikar and other unwanted weeds. The Kikar was brought from Rajasthan and introduced in the area by the British through aerial seeding. Prof Babu pointed out that Kikar has very long roots (over 20 metres into the ground) which suck water from deep down and drive other vegetation away. As a result of its introduction, the Ridge lost close to 480 species of its native plants. The Biodiversity Park is now undoing this damage.
We started our walk through the broad leaf community of trees such as the three-leafed Dhak or Tesu which is popularly known as the flame of the forest because of its orange and red flower. Dhak is used for making colours for the festival of Holi. Porcupines feed on the roots of Dhak or Tesu, and they even explore the bark of Dhak in winter. Another variety of trees in abundance in this community is Bel, its fruit typically used for making cool sharbats in summer. Kadamb, associated with Lord Krishna, and shrubs such as Lisora, which offer their fruit to birds and monkeys to feed on, are also part of the broad-leafed community.
A little further down from the Dhak-dominated community, we encountered trees and shrubs with narrow and smaller leaves. Our attention was drawn to Doodhi, Sheesham and Khejdi. Doodhi produces beautiful white flowers and yields wood used for making toys. Sheesham produces the finest all-round timber of India for making furniture; its leaves are used for fodder. Khejdi or Jhand, the tree of life, is a vital resource in deserts. We learnt that the flour made from its sweetish bark had saved lives in the Great Rajputana Famine of 1868-69. Indeed, every part of Khejdi is used in arid areas.
We also found Arlu or Ullu, which is a medium sized tree. It is conspicuous with its large compound leaves and long sword shaped hanging fruits used for offering in Buddhist temples. There was also the Safed Tekar which produces beautiful fragrant white flowers with its bushy crown acting as cover for wild animals like Nilgai. We also saw the Khair tree that yields kattha used in paan and in medicines, and the Amla tree, its fruit famous for its high Vitamin C content.
Further down, the trail took us to the 100-acre rangeland or grassland which had a large number of small bodied birds such as munias and primias, happily chirping away. It also harbours insects such as grasshoppers and mantis, which are food for many birds. We also saw a gentle slope of hilly tract covered with a closed canopy forest consisting of Chilbil or Kanju, which provides fodder and light wood, and Ronjh or Kareer, which provides fodder and pasture for herdsmen and also yields fibre for making fishing nets.
A spectacular Orchidarium in the middle of the Park was an unexpected treat. A 50-metre deep and 100-year-old badarpur-mined pit has been transformed from a pit to an orchid garden. Camouflaged by the surrounding vegetation, this pit is now a beautifully landscaped conservatory. It has a gradient of light and relative humidity that provides an appropriate environment for orchids to grow on the branches of trees with aerial roots hanging in the air. More than 10 species of orchids are growing in this conservatory which is first of its kind in Delhi, producing beautiful blooms with vase life of up to 3 months.
Within the serene environment of the Orchidarium, we looked at the mouth of a cave (50 feet long, 40 feet wide and 12-15 metre deep) which is home to thousands of bats. Our guide entered into the cave ecosystem and brought out the little flying mammal, and explained to us how bats eat insects and fruits, and help in pollination of trees.
From the Orchidarium, the trail took us to a saucer shaped shallow valley which was an abandoned amphitheatre created by Scindia Potteries which mined china clay prior to the ban. The abandoned amphitheatre has been turned into a natural conservatory for butterflies. There are at least 100 species of butterflies and about an equal number of host plants that provide food to butterflies and their infants. In the conservatory, we saw eggs, caterpillars, pupae and the fluttering butterflies.
The once barren landscape has been transformed into a thriving wilderness of Delhi. I was told Delhi is the only city to have a biodiversity park inside it. Cities often have parks and impressive ones at that, but these are not biodiversity parks. Typically, city parks are manicured with walks, grass lawns, and flower-beds, etc, for recreation. Biodiversity parks as natural reserves are a special feature for Delhi, but it should be possible to replicate these in cities where geography permits.
Dr Isher Judge Ahluwalia is Chairperson, ICRIER, and also former Chairperson of the High Powered Expert Committee on Urban Infrastructure Services