DELHI RIDGE
by:- Siddhant Bhardwaj
It is a ridge in the National Capital Territory of Delhi in India. The ridge is a northern extension of the ancient Aravalli Range, some 1500 million years old (compared to just 50 million for the Himalaya). The ridge consists of quartzite rocks and extends from the Southeast at Tughlaqabad, near the Bhatti mines, branching out in places and tapering off in the north near Wazirabad on the west bank of the river Yamuna, covering a distance of about 35 kilometers.
The Delhi Ridge is said to be the green lungs for the city and protects Delhi from the hot winds of the deserts of Rajasthan to the west. It is also responsible for earning Delhi the tag of the World's Second most bird-rich Capital city after Kenya's Nairobi.
Delhi Biodiversity Foundation
In order to develop these nature reserves, and retain the ecological, aesthetical and cultural quality of Biodiversity sites in the National Capital Territory of Delhi, the Delhi Development Authority has set up the Delhi Biodiversity Foundation. The foundation, in turn, is setting up Biodiversity parks, which are being developed by DDA technical inputs by team of scientists who have specialized in the areas of field biology, ecology, wildlife, taxonomy, conservation, habitat restoration, natural resource management and nature education. Besides these experts, trained technical supporting staff oversees the development and management of these parks. The Foundation has a Governing body and an Executive Committee.
Aravalli Biodiversity Park
The Aravallis are among the oldest mountain ranges having evolved about 1500 million years ago.
The spurs of the Aravallis are popularly known as the Delhi Ridge in Delhi which is divided into the Northern, Central, South Central and Southern Ridge.
The Aravalli Biodiversity Park is located on the South Central Ridge and spreads over an area of 692 acres.One can approach to the Aravalli Biodiversity Park, at present, either from Vasant Vihar- Poorvi Marg gate located at about 4 km south west of Moti Bagh, and 2 km west of Jawahar Lal Nehru University (Munirka) or from the Vasant Kunj Institutional gate which is about 3.5 km north of Mahipalpur and one km west of Vasant Kunj Malls.
The Park features two major zones - the visitor zone and the nature reserve zone.
The first community that is encountered at the Poorvi Marg gate is young plantation of the moist deciduous forest community represented by treelets of species such as Diospyros melanoxylon (Tendu) Adina cordifolia(Haldu), Madhuca longifolia (Mahua), Mitragyna parviflora (Ken)and Sapindus laurifolius (Soapnut, Reetha) under a canopy of Prosopis juliflora (Vilayati kikar).When fully developed, the top canopy of this native forest community will attain a height of 40 to 50 feet. You may also find a few uncommon birds like the Black-breasted Redstart, the red whiskered bulbul, and the Ashy Prinia.
The moist deciduous forest community merges with a luxuriant Acacia dominated forest community with species such as Aegle marmelos, Prosopis cineraria and Cordia garaf interspersed with grass patches.
A side trail leads to the Fernary, a conservatory developed in a pit with rugged cut slopes having crevices of varying dimensions that provide ideal niches for ferns such as Phymatosorus lucidus,, Lycopodium wightii andDrinaria propinqua.
To the south east of the Fernary, is the Conservatory of Orchids, one of the high points of the Park. The trail from the Orchidarium runs through a young plantation of the Wrightia dominated community which merges with the rangelands. The rangelands, spread over an area of 150 acres composed of a mosaic of grasslands and woodlands, are rich in avifauna and carnivores sprinkled with termite and ant mounds on its grounds. The trail that runs through the rangelands enters in to the visitor area which is being developed and will showcase Aravalli plant communities, a rock garden, a bulbous garden and conservatories of butterflies and medicinal plants.
The moist deciduous forest community merges with a luxuriant Acacia dominated forest community with species such as Aegle marmelos, Prosopis cineraria and Cordia garaf interspersed with grass patches.
A side trail leads to the Fernary, a conservatory developed in a pit with rugged cut slopes having crevices of varying dimensions that provide ideal niches for ferns such as Phymatosorus lucidus,, Lycopodium wightii andDrinaria propinqua.
To the south east of the Fernary, is the Conservatory of Orchids, one of the high points of the Park. The trail from the Orchidarium runs through a young plantation of the Wrightia dominated community which merges with the rangelands. The rangelands, spread over an area of 150 acres composed of a mosaic of grasslands and woodlands, are rich in avifauna and carnivores sprinkled with termite and ant mounds on its grounds. The trail that runs through the rangelands enters in to the visitor area which is being developed and will showcase Aravalli plant communities, a rock garden, a bulbous garden and conservatories of butterflies and medicinal plants.
On the way from the visitor area back to Poorvi Marg gate, one can approach to habitats, which harbours a wide range of communities native to Aravallis, distributed on either side of the main trail. Before reaching to the office complex there is a side trail with a water body in the centre surrounded by a rugged and undulating landscape with a mixed deciduous forest. The water-body supports aquatic vegetation and a few native ducks. Adjacent to the office complex, one can find a trail, which passes from the conservatory of herbal plants, goes towards a shallow valley, through stairway, called amphitheatre. Adjacent to the amphitheatre is a conservatory of butterflies. Being a saucer shaped depression with slopes harbouring native bush vegetation; it holds thousands of butterflies belonging to 30-40 species.
A systematic planting program is carried out and every year native trees and bushes are planted to remove unwanted weeds, i.e. Prosopis juliflora. Scientists from Centre for Environmental Management of Degraded Ecosystems, University of Delhi have so far got over 10 ecosystems reintroduced with over 40 biotic communities.
Yamuna Biodiversity Park
Yamuna Biodiversity Park is spread over an area of 457 acres and is located along the floodplains in the upstream of river Yamuna near Wazirabad village. This project is being developed in two phases. Phase I was initiated in the year 2002 and today it has fully functional wetland ecosystems and well developed forest ecosystems characteristic of the river Yamuna basin. The wetlands of Yamuna Biodiversity Park are biologically productive and harbour luxuriant flora and fauna. These wetlands are known as important birding area of Delhi and attract large number of bird lovers, naturalists, educationists and civil societies every year.
Yamuna Biodiversity Park Phase II started in the year 2009 and it is being implemented
in the same manner as an extension of the project Yamuna Biodiversity Park: Establishment &
Management. Delhi Development Authority is the funding agency of the project.
The front portion of the Yamuna Biodiversity Park, a 220m southward and 140m northward stretch from the main entry gate with 20-30m width is demarcated as Domesticated Biodiversity Zone. Enclosed by a hedge of poplar, it features plants like Ailanthus, Butea and Bauhinia that have a continuous seasonal interest due to their long flower production throughout the season. The outer iron fencing is embraced by multi-coloured climbers like Jasmine and Quisqualiswith the same theme of continual luxury.
On the left, the landscaping provides two shallow valleys representing rangelands
with 10 mounds representing different ecosystems present from the foothills of the Himalayas (Siwaliks) through the Yamuna basin, till the point of confluence of the Yamuna and Ganga. The first rangeland i.e. Rangeland 1, corresponds to an exclusiveSporobolus diander dominance while the second one i.e. Rangeland 2 showcases a mixture of native tropical grasses such as Dichanthium, Chrysopogon, Vetiveria,and Bothriochloa. These two rangelands are bordered by a serpentine trail. The first loop of the trail connects Rangeland 1 with Herbal garden, sacred groveand Rangeland 2 while the other loop leads to the butterfly conservatory and amphitheatre. Subtropical mixed evergreen forest ecosystem
Top canopy - Toona ciliata, Dalbergia latifolia, Mitragyna parvifolia, Syzygium cumini
Middle storey - Trewia nudiflora, Artocarpus lakoocha, Cinnamomum camphora,
Shrub layer- Dillenia indica, Coffea benghalensis, Murraya paniculata, Bauhinia malabarica,
Herbs and Grasses- Barleria cristata, Flemingia bracteata, Desmodium triflorum
Climbers- Vigna capensis, Combretum decandrum, Vitis paniculatum
Moist tropical deciduous forest ecosystem with Teak as a dominant species
Top Canopy- Tectona grandis, Pterocarpus marsupium, Diospyros melanoxylon,
Middle storey- Buchanania lanzan, Albizia lebbeck, Bauhinia variegata
Shrub layer- Flemingia rugosus, Vitex negundo, Nyctanthus arbortristris, Zizyphus mauritiana
Herbs and grasses- Desmodium triflorum, Crotolaria juncea, Bothriochloa pertusa,
Climbers- Pueraria phaseoloides, Asparagus racemosus
Tropical dry decuduous forest ecosystem with Sal as a dominant species
Top canopy – Shorea robusta, Diospros melanoxylon, Putranjiva roxburghii,
Middle storey – Erythrina indica, Cassia fistula, Albizia sp., Sterculia urens
Shrub layer – Carissa spinarum, Zizyphus oenoplea, Nyctanthus arbortristris
Herbs & Grasses – Chloris, Eragrostis, Fimbristylis ferruginea, Indigofera tinctoria,
Climbers – Smilax zeylanica, , Clittoria turnatea, Marsidenia, Cocculus hirsutus
Tropical Dry Deciduous forest with Teak as a dominant species
Top Canopy – Tectona grandis, Butea monosperma, Sterculia urens, Terminalia chebula,
Middle storey – Emblica officinalis, Bauhina variegata, Cochlospermum religiosum
Shrub layer – Gardenia turgida, Randia dumetorum, Grewia asiatica
Herbs & Grasses – Barleria prionitis, Bothriochloa pertusa, Dicanthium HetropogoClimbers – Abrus pulchellus, Cocculus hirsutus
Tropical thorn forest
Top Canopy- Acacia sp., Prosopis cineraria, Anogeissus pendula
Underwoods- Zizyphus mauritiana, Maytenus emarginatus, Wrightia
Herbs and Grasses- Vicovestata, Vico auriculata, Desmostachya bipinnata,
Climbers- Valletia, Leptochloa fusca, Tinospora cordifolia
Scrub jungle
Top Canopy- Acacia catechu, A. senegal, A. leucophloea
Underwoods- Euphorbia neriifolia, Cassia auriculata, Maetenus emarginatus
Herbs- Tephrosia purpurea, Justicia simplex, Cyperus rotundus, Eragrostis tenella
Climbers – Cocculus laurifolius, Rhynchosia minima
Goals of Biodiversity Parks
The prime goal of the parks is conservation and preservation of ecosystems of the two major landforms of Delhi, the river Yamuna and the Aravalli hills. They seek to conserve keystone species and other threatened plant and animal species, preserve the biodiversity of any habitat that is likely to be converted into urban infrastructure, establish field gene banks for threatened land races and wild genetic resources, promote education on environmental awareness and nature conservation, establish native communities of the Aravalli hills and the River Yamuna basin particularly of the Delhi region, develop mosaic of wetlands that sustain the rich aquatic flora and fauna of the Yamuna and monitor short term and long term changes in the ecology of the Delhi region.
Thus, Biodiversity Parks act as heritage sites and repositories of the approximately 50, threatened communities of the Yamuna river basin and Aravalli hills, provide ideal alternative habitats for migratory and resident bird species, enhance ground water recharge and augment fresh water availability, act as sinks for CO2 and other pollutants, ameliorate local weather conditions and buffer ambient temperatures, promote eco-tourism and social connectivity across the urban community, serve as gene pools, and represent unique ecological models possesing not only wildlife and natural values but also aesthetic, environmental and educational values.