The Brihanmumbai Municipal Corporation’s (BMC) 2008 tree census revealed that the city is home to 19.17 lakh trees of 364 species.
Interestingly, among the 20 trees with the highest population, six are exotic trees, not native to the city. The six trees — Subabhul, Sonmohar, Deshibadam, Gulmohar, Rain Tree and Bottle Palm — alone account for 4.08 lakh trees in the city.
Green activists claim that planting exotic trees in large numbers is not conducive to the local ecology and also points to lack of planning in maintaining the green cover.
“When you have a dynamic environment, you should choose your trees wisely. Exotic trees work better at places where nothing grows owing to their rapid growth. In the local ecology, birds are the biggest beneficiaries of native trees, depending on the fruits and insects which comprise their food,” said Dr CS Lattoo, former botanist, Institute of Science, Colaba.
The Subabhul tree is viewed as a nuisance by many since it is essentially grown in semi-arid lands where it grows fast and also contributes to the local economy. Environmentalists claim, that the food preferences of birds, butterflies and other organisms do not change for centuries, which necessitates large presence of native trees.
“Humans can adapt to different cuisines, but birds cannot. For instance, owls feed on tamarind (chinch) trees, which are shrinking in number. Hornbills, that are rarely seen in Mumbai, feed on jackfruit and jamun,” said Anand Pendharkar, ecologist and director, Sprouts, a non-profit organisation.
The 2008 census data shows that there are 7,138 tamarind (chinch) trees in the city.
“Exotic trees are occupying a lot of land, depleting ground water and plus other organisms cannot make optimum use of them. They are good at places where its ornamental value is best utilised and where it can give ample shade,” said Avinash Kubal, deputy director, Maharashtra Nature Park.