Urban green belts are considered the lungs of the cities as they act as a sink for some of the harmful gases released by vehicles and industries operating in the city area. Whether sprawling over a large area or a small belt, these green belts are found in all cities and play a very important role.
Today, urban areas in India are faced with excessive population along with the pressure of unplanned economic development, industrialization, and vehicular emissions. This has led to a considerable rise in urban pollution, affecting air, water, and land. Air pollution has increased rapidly in many cities and metropolises, especially due to vehicular traffic and industrial emissions. Over the years rising population has led to a decrease in open spaces and green belts in the cities. These green belts serve as lungs for cities and towns. They serve as a sink for pollutants, check the flow of dust and bring down noise pollution level. Plants provide innumerable environmental benefits and considering the steady increase in air pollution it has become imperative to increase the green belts in and around the cities.
The Delhi ridge forests are considered the lungs of the capital, the main areas being the central or the new ridge, and the northern or the Old Delhi. The green belt in this area was not completely a gift of nature. Earlier, there were only Kikar (Acacia) trees found growing sparsely among the hard rocks. According to the municipal records after 1857, the British ordered the planting of thousands of Neem and Babul trees. In 1912, when Delhi became the capital of the British Empire, Lutyens, the architect of the new city, ordered the large-scale afforestation of the ridge. Under his leadership, this area was declared a ‘Reserved Forest’ and no tree could be cut without permission. By the time India attained independence, this area was covered with diverse vegetation of plants and trees.
Since ancient times, the ridge has been of strategic importance to the city. All the seven cities that were built and destroyed in the area that is today the city of Delhi were located in the triangle between the ridge and the river. The river gave them water and the forest its products and cool air.
The ridge is under severe threat as it is being gradually destroyed over the years. This has mainly been due to increasing human activities. Most of the animals of this area have ‘vanished’. yet even today it is a bird watchers paradise. There are at least 200 hundred species of birds that have been sighted in the ridge. There are many organizations working for the preservation of this green belt and are trying to restore it to its past glory.
The Sanjay Gandhi National Park is commonly known as the Borivili National Park and serves as the lungs of Mumbai. It is situated about 40 km away to the north of the island of Mumbai and about 8 km from the Arabian Sea. This forest has a history dating back to the 4th century BC. The trade route connecting Greece and Middle East to the ports of Sopara (Nalasopara) and Kalyan passed through this forest. The rock cut caves of Kanheri were ancient Buddhist settlements dating back to the 1st century. They also served as rest houses for travelers. When the forest department came into existence in 1945, the forests were surveyed and brought under proper management.
The area of the park is approximately 104 sq. km. This national park is one of the very few, perhaps the only one of its kind that is situated so close to a city. Despite thishas a large population of a variety of animals. This rich and diverse forest holds more than thousand species of plants, and a large species of mammals, birds, migratory, land and water birds, reptiles, and amphibians besides a large variety of fishes, insects and other life forms. The animal population consists mainly of panther, leopard, Sambar (deer) spotted deer, Chowrsingha (four horned antelope), wild boar, mongoose, civet cat, jungle cat, Languars, monkeys Macaques, etc. The park is also very rich in insect life, especially butterflies.
The forest area forms the catchment area for Tulsi and Vihar lakes, which are among the important sources of water for Mumbai and help in keeping down the pollution levels of Mumbai by acting as a sink. The natural vegetation of the park also influences the climate of the city in a big way. During the monsoon, this park and the adjoining areas receive the maximum amount of rainfall, implying is a high volume of rainwater stored which can later on be used to fulfill the heavy demand of water for the citizens of Mumbai.
The Guindy National Park is commonly referred to as the lungs of Chennai. It has the unique distinction of being one of the only forests to be located within a metropolitan city. The Guindy National Park is undoubtedly the lung of the city. The people living around the park know that the temperature they experience even in summer is lower than that experienced in other parts of the city.
Like all national parks today, the Guindy Park was originally a game reserve. It was in 1958 that the area of 400 hectares was handed to the Tamil Nadu Forest Department. Today the National Park has only 270.57 hectares.
The biodiversity within the Guindy National Park is quite amazing, despite the fact that it is a very small area surrounded by houses and habitation. The vegetation is mainly of the tropical dry evergreen type, and over 350 species of plants have been found including trees, shrubs, climbers, herbs and grasses. There are large numbers of Chital and Blackbuck that graze in the open grassland on the northern end of the park. Nocturnal animals include the toddy cat, civets, jungle cat, pangolin, and hedgehog. The dense forest, grasslands, and water bodies provide an ideal habitat for a large species of birds, some not seen anywhere else in Chennai. Apart from snakes, certain species of tortoise and turtles, lizards, geckos, chameleons and the common Indian monitor lizard are also found here.
Other than the Guindy National Park, the Arignar Anna Zoological Park , popularly known as the Vandalur Zoo (spread over a lush green forest area of about 510 hectares) also acts as a lung to the city.
The Maidan is located in the heart of the city and acts as its lungs. It is an ideal place for a morning stroll or even for a break from the hustle-bustle of the city. The Chowringhee road, the Victoria memorial and the Eden Garden are located around the Maidan while the Raj Bhawan overlooks it. On one side of the Maidan is the Calcutta Race Course. This Maidan was originally used as a practice range for the British soldiers based at Fort William. The forest around this fort was cleared to give a clear shot to the cannons. It is about 3 kms in length and 1 km. in width. It is dotted with various sporting and cultural clubs.
The botanical garden of Kolkata is perhaps the most important garden in India and also serves as a lung to the city as it has a large variety of flora and fauna. The 250-year-old Banyan tree is a special attraction. It is said that the tree has spread its area so much that it is difficult to say which one is the original trunk. The botanical garden is located on the banks of Hooghly.
The Alipore Zoo in Kolkata is perhaps the largest in the country and is spread over an area of 45 acres. This zoo was established in 1876 and is the one of the oldest zoo gardens in India. It is also famed for the winter migration of birds to this zoo.
Bangalore was once a Garden City with tanks, lakes and vast green spaces. But the growing population and the rapid pace of expansion has made it one of the most polluted cities in the country. It is to halt this destructive march that some individuals and organizations have been petitioning the government and the courts to save what is left of the water bodies, parks, and forests. India’s biggest urban forest is being nurtured in the heart of Bangalore on 400 acres of land belonging to the Army Supply Corps.
There are more than 1.8 lakh saplings that have been planted, including Gul Mohur, Jacaranda, Mahogany and Flame of the Forest. When the saplings begin to mature into trees within the next two to three years, the forest will act as a huge carbon sink cleansing the polluted city. Water bodies in the area will be developed to attract birds and animals. In a few years time this area will be one of the most sought after places in the city. It will also serve as the lungs of a city that has an ever-growing population and increasing habitation.