Yamuna Biodiversity Park: An Overview

Biodiversity—the diversity among living organisms—plays an essential role in ensuring the survival of life on earth. As far as cities are concerned, ecosystems provide three main kinds of service: firstly, the provisioning of food, fibre and fuels; secondly, purification and detoxification of water, air and soil, as well as mitigation of droughts and floods; and thirdly, enriching the spiritual, aesthetic and social life of urban dwellers. Our personal health as well as the health of our economies depend on the continuous supply of various ecologies. Protecting biodiversity is thus in our own interest.

India occupies the 11th position in the list of mega-diverse regions of the world and possesses 12 biogeographic zones with 16 biomes. Of these, the Indo-Gangetic biogeographic region faces the biggest climate threat, particularly in its Ganga-Yamuna basin, due to the rapid economic development that is transforming the region. Major industrial centres of north India, including Delhi, are also a part of this region.

Today, urban expansion in India is causing complex changes to the local and regional biodiversity, ecosystem services, and forest cover. As cities grow, vital habitat is either completely destroyed or reduced to fragments too small to support complex ecological communities. In cities, several species have become endangered or even locally extinct as areas that were previously wilderness areas have been swallowed up by the urban jungle.  In addition, biotic homogenization is another factor that has had a major contribution to the loss of biodiversity in urban areas. Biotic homogenization refers to the replacement of native (and often endemic) species with non-native, invasive and cosmopolitan species. This results in a decrease in the regional biodiversity, and also causes drastic alterations to the composition of urban biological communities. This happens either accidentally, or is done deliberately, so as to create additional sources of food or for aesthetic reasons. Non-native plants which are often planted in urban and suburban gardens, subsequently 'escape' into the wild. Thus, urban growth is often responsible for the introduction of non-native species. The trend towards global biotic homogenization of urban areas poses a serious threat to native species, which may not be so well-adapted to the urban environment.

Once the lifeline of many civilizations and cities that emerged along its banks, the river Yamuna suffers from inadequate waterflow and heavy pollution. The length of the river in the National Capital Territory of Delhi (NCT) of Delhi is 48 km with a total river bed of around 97 sq km. Apart from being a major source of water for Delhi, it is also one of the major sources of groundwater recharge and irrigation for the states of Uttar Pradesh and Punjab. Recently, however, rapid urbanization, overexploitation of natural resources and extremely high levels of pollution have taken a severe toll on the biodiversity of the river’s flora and fauna.

In order to rescue and restore the lost native biodiversity in urban areas, the creation of biodiversity parks is an innovative and novel approach. Biodiversity parks, which are assemblages of species in the form of biotic communities that belong to a particular ecological range, help promote urban biodiversity conservation as they serve as nature reserves within urban areas. They create a healthy ecosystem and also provide conservational, educational and recreational benefits to the cities.

The Yamuna Biodiversity Park was developed in two phases in two different areas— on the inactive floodplains of the river in Phase I and on the active floodplains in Phase II.

Phase I is spread out over an area of 157 acres near the village of Wazirabad. Once this area was acquired in the year 2002, the soil profile, physicochemical parameters and nutrient levels were estimated, and it was found that the soil was highly alkaline and nutrient impoverished. Around a 100 species of grass were planted as an early measure to ameliorate the quality of the soil. Initially, the area was highly alkaline with a pH of 9.8. Many species of grasses such as Leptochloa fusca, Vetiveria zizanoides, Bothriochloa species, Cenchrus ciliaris, Cenchrus setigerus etc. along with many native legume species such as Rhynchosia species, Indigophera tinctoria, Indigophera linifolia, Sesbania sesban were utilized not just to increase the nutrient levels but also to initiate microbial activities in the soil. Afterwards, plantation of seedlings of different forest species representing upper, middle and lower canopies was done each year during the monsoons in 30-35 biotic communities.  In addition, landscaping was also done in a few areas by creating mounds of different shapes, heights and sizes. It was anticipated that during rainfall the salt would leach down from the mounds and act as a specialized niche for several plant and animal species. Each mound represents a forest ecosystem found along the river Yamuna, from Vikas Nagar in Uttarakhand to the city of Allahabad in Uttar Pradesh, where it joins the river Ganga. To meet the ideal requirements for the creation of mounds, soil was excavated from areas which had the potential to develop as wetlands. For that, soil was used from areas with a presence of several indicator species such as Typha, Phragmites and Cyperus. Several marshy areas were restored and wetlands were de-silted.

The park is divided into two zones— the ‘visitor zone’ and the ‘nature reserve zone.’ The major components of the visitor zone are the ‘conservatory of medicinal plants', ‘butterfly garden', ‘rangelands', ‘sacred grove', ‘acacia woodland', ‘migratory ducks’ wetland', ‘resident ducks’ wetland’ and ‘conservatory of fruit-yielding species.’

The conservatory of medicinal plants consists of over 300 plant species known to have therapeutic values. Some of the most important herbs planted here are ashwangandha (Withania somnifera), artimisia, sarpagandha (Rauwolfia serpentine), nirgundi (Vitex negundo) and isabgol (Plantago major).  A climber grove was also created here for climbers of medicinal importance such as dama bel (Tylophora indica), gurmar (Gymnema sylvestre), antmool (Celastrus paniculata). A small lily pond in the medicinal garden houses aquatic plants such as brahmi (Bacopa monerii) and bach (Acorus calamus).

The conservatory of butterflies is a well-designed, open air, circular area whose outer periphery consists of host plants, while the inner portion has nectar-producing flowers. Small ponds have also been created to add moisture to the area. These ponds are also utilized for mud puddling of butterflies, an activity that enhances the strength of their eggs. Here, one can see all the stages in a butterfly’s life cycle— egg, larvae, pupa and finally adult.

The sacred grove houses plant species which have some religious significance. The conservatory of fruit plants, as the name suggests, has plant species that are specially grown in the Yamuna river basin for their fruits. Khirni (Manilkara hexandra), is an important fruit plant which was once found in Delhi but has now altogether disappeared from the wild. The other fruit plants are pomegranate, amla, cheeku, mulberry, kaith etc. The species in this conservatory yield a variety of fruits, which not only serve as a food source for the rich biodiversity of the park but also act as a conservatory of landraces (primitive cultivars). Birds such as green pigeons, peafowls, bulbuls and parakeets have carved their niches in this conservatory.

In the nature reserve zone, around 30 forest communities have been developed which offer multiple micro-niches and habitats for a diversity of animal species to live and breed in. The wetlands also harbour aquatic vegetation, fish, dragonflies and microorganisms that were once found in the river Yamuna but have now disappeared. When they were created, the wetlands were first inoculated with aquatic vegetation, fingerlings and sediments from well-known wetlands of nearby areas. Presently, these wetlands also receive flocks of migratory birds (around 5000) from Siberia and other Palearctic regions every year. Some notable species are the Red-crested Pochard, Northern Shovellor, Eurasian Wigeon, Gadwall etc. In addition, many resident birds have made the park’s wetlands their home. The Spot-billed Duck, Indian Moorhen, Lesser Whistling Teal, Purple Moorhen and grey and purple herons are a few such species. The darter, also called snake bird, is a near-threatened species which nests in the wetlands of YBP each year. The Tamarix-Phragmite forest all along the shallow wetlands has become one of the most important habitats for the nesting and breeding of the Black-crowned Night Heron, which was once found all along the Yamuna but latterly had disappeared due to habitat destruction.

Phase II of the Yamuna Biodiversity Park is spread out over an area of 300 acres on the active floodplain of the river and consists of a mosaic of wetlands together with grasslands and floodplain forests. The wetlands, which are in an area of around 100 acres, are presently under development and have already started attracting a diversity of resident and migratory birds such as Grey Herons, Painted Storks, Spoonbills, Open-billed Storks, Red-crested Pochards, Wagtails and Sandpipers. Once completed, this mosaic of wetlands will impound floodwaters to the extent of around 500 million gallon, recharge aquifers during dry months, minimize the impact of flood water on the Wazirabad barrage and reduce siltation of the reservoir.

Thus, the Yamuna Biodiversity Park harbours a wide range of ecosystems indigenous to the Yamuna river basin and supports more than 1,500 plant and animal species. The diversity of birds has shown a remarkable increase with specie numbers having risen from 37 to 196 since 2002, while reptiles have increased from 3 to 18. The nature reserve zone with different forest communities interspersed with sprawling grasslands and wetlands forms a fully functional ecosystem. Some forest communities already have developed canopies and have attracted animals like porcupines, civets, jungle cats and nilgai. As a result, mammal diversity has increased from 4 to 18.  

Biodiversity parks with their rich flora and fauna, managed and developed using scientific expertise are ideal instruments for promoting conservation education that will ultimately have a positive impact on environment quality and conservation ethics. These parks offer a wide range of opportunities for people to learn and adapt the ways and means by which they may live in harmony with nature. The Yamuna Biodiversity Park is also an open-air laboratory for a range of students and researchers. Groups are  led through the park on a predetermined nature trail and it has already become a location where education on environment, sustainable development and conservation is being imparted at a primary, secondary and tertiary level. Around 10,000 students/trainees/nature lovers from schools, colleges, institutions and NGOs visit it every year.

The chart below provides a glimpse into the biodiversity profile of the Yamuna Biodiversity Park over time.