How a 2 hectare forest in Bangalore’s heart has lowered temperature and raised its water table
The summer temperatures in Bangalore this year have been cause for particularly high concern among its residents, with some claiming that daytime temperature shot up to 41 degrees Celsius one day in April. This summer has surely felt hotter than most old Bangaloreans remember them ever being.
But, there are some parts of the city that have kept the unrelenting heat away. Walk around the lush Indian Institute of Science (IISc) Campus and you will encounter several species of trees, native and exotic. The 400 acre campus is home to 112 species of trees and 45 species of grasses. There are gulmohar lined avenues, large, raintree-shaded bowers, and colourful bursts of laburnum, jacaranda, and tabebuia.
And then you walk past the Centre for Ecological Sciences department (CES) and you stop short! The vegetation here is unlike anything you’ve encountered on the rest of the campus so far. Gigantic, woody vines weave endlessly like lace through a lush canopy, the trees are thick and dense, letting only a modicum of sunlight through, and all around you, in the cool air is the hum of insects and birds. If you feel like you are in the rainforests of Agumbe, you’re not alone.
You are in IISc’s mini-forest, a forest planted by a team of researchers led by senior faculty member Dr. T.V. Ramachandra (Energy and Wetlands Research Group). The man-made forest began as an experiment to study the adaptability of tree species endemic to the Western Ghats to a habitat and conditions considered alien to these species. It was also done to conserve native woodland trees and study their adaptability to afforestation programmes in urban spaces.
To do this, 500 saplings of 49 species were planted in 2 hectares land in the late 1980s. The region chosen was scrub jungle infested with parthenium weed and an annual rainfall of just 850 mm compared to the 6000 mm received by the Western Ghats.
In less than 25 years, the mini-forest transformed into a lush jungle of dense fruit and flowering trees which have had a positive impact on the micro-climate of the campus. Some of the species thriving there include mahua, arjuna, hirik, ylang-ylang, and the lovely liana, found only in the moist tropical forests of the Ghats.
Says Dr. Ramachandra, “Temperature in the IISc campus is lower by 2 degrees Celsius compared to the rest of Bangalore city and it experiences increased humidity. The soil has enriched humus content owing to the many moist evergreen species and their good canopy cover. The forest has also raised the formerly 200 — foot deep water table of IISc to just 10 feet as trees have helped the percolation of water and aquifer recharge.”
Because the mini-forest is free from human disturbance, it shelters 4 families of the elusive Slender Loris, many bird and reptile species, and smaller flora such as mosses, algae, fungi, and ferns. “The entire plot is amazingly transformed into the type of a habitat that prevails in the moist forests of Western Ghats”, says the scientist.