Bengaluru: The Garden City that was once home to a great variety of natural ecosystem has lost nearly 80-90 percent of its biodiversity since the 1960’s. From the world's most expensive red sanders to the makali roots that make a tasty pickle, the city has lost almost every natural product that was naturally found here. The rapid and unscientific growth of the city might put an end to even the last remaining species that have made Bengaluru their home, warns environmental experts.
Though the sight of uprooted or chopped trees heats up debates, what goes unnoticed and unmentioned is the loss of the rich biodiversity the city once had in plenty. Rapid urbanisation has not just led to the contamination of air, water and soil, but also triggered a serious threat.
The city that arguably got its name from the world’s most expensive wood – ‘Bengae’, popularly known as the red sanders, had a rich variety of biodiversity, including many species of climbers, creepers, crawlers and herbs. Tubers that grew 8-10 feet below the ground sustained the life of rodents, reptiles and amphibians.
While not many studies are being done recently to quantify the loss of the biodiversity of the city, former Environment Secretary, Dr A.N. Yellappa Reddy, estimates the loss of biodiversity to be around 80-90 percent. “Since the sixties, the city has witnessed a dramatic decline in the diversity of species. Unplanned development and the negligence has caused a huge loss species diversity,” he said.
The city, the world’s 19th largest in terms of population density, that was once made up of several villages has lost many tree groves that served as oxygen banks. “Each village had two to three groves that were rich in biodiversity. I recall about 50-60 varieties of trees, climbers, creepers and crawlers in just one tree grove, most of them wild. We have lost all of them. Now the authorities hardly give importance to the diversity of species while taking up tree plantation,” he said.
The groves were also home to many species of insects, like beetles, honey bees and birds that acted as pollinators.
The red sanders that was once abundant in and around the city and is a native tree species of Bengaluru is now the world’s most expensive wood, which costs around Rs 1-5 crore per tonne. Sandalwood, which too is a native variety, costs around Rs 50 lakh-1 crore per tonne.
The city has lost sarsaperilla, an excellent tuber (which when extracted produces a tasty beverage) and about 50-60 types of ficus trees. Nearly 1,200 species of small and medium-sized plants and trees, including the unique vegetation of xerophytes in and around the city that are known to withstand prolonged drought, have also vanished. The city has lost unique plant species, like Jalari, which blossom in February and March and are known for their unique ability to prevent spreading of viral diseases.
Makali that was once a common sight in the city is lost too. “Its roots penetrates deep into the ground and helps seepage of water in the hills, which helped the water gain medicinal properties of the root. Sadly, we have lost Makali hills too,” he said.
“Around 50 species of migratory birds arrived in lakhs in numbers and breed in lakes across the city. The forest department had documented about 40-45 migratory species of birds during 1985-87 in Bellandur. In Varthur Lake, we had documented around 10,000 birds of 30 species. The birds have stopped migrating here because of frothing and contaminated water,” he said.
The report by Madhav Gadgil on the diversity of species in Bengaluru shows that the city has lost 18 of the 22 species of lichens due to increased air pollution.
Dung beetles, one of the important decomposers in the ecosystem, are also seen going locally extinct in Bengaluru. Three species of dung beetles – Gymnopleurus cyaneus; Gymnopleurus Miliaris and Gymnopleurus Parvus – are not seen in the urban space anymore. However, there is still hope as the last few remaining green belts still offer a great variety of biodiversity.
The Bengaluru Biodiversity Park inside the Bengaluru University campus is home to around 300 different species of plants and trees, while the Ex-situ Evergreen and Semi Evergreen Arboretum in the Bannerghatta Park has more than 400 different species of plants and trees. While these are not open to the public and are only made available for scientific study, experts feel that attempts have to be made by the civic agencies to use these gene banks and take up planting of saplings across the city to get back its lost glory.