Ringing out the old

Bangalore has the privilege of being home to two historic gardens, Lalbagh, which dates back to Hyder Ali’s administration and created in the 18th century, and Cubbon Park, formed in the 19th century by the British administration. The diversity of plant species that these parks harbour dates at least as far back as 1891, when a book written by John Cameron, Catalogue of Plants in the Botanical Garden, Bangalore (Second Edition) lists a mind-boggling 3,222 species of plants found in Lalbagh. These include as many as 258 varieties of roses, and 122 varieties of crotons! Lalbagh and Cubbon Park occupy a specific place in the city that is unmatched by other public gardens, because of their size, the age of the trees, and the rich diversity of plant species. What of the city’s other parks, though?

Old vs new

Bangalore hosts a number of other public green spaces. These range from tiny one-meter circles around traffic islands, to small neighbourhood parks used as community spaces and areas for exercise and recreation, to these historic parks. Old parks tend to look wooded, with large canopied trees that bring a more “wild” or natural look to them, while the recent neighbourhood small parks have a greater amount of lawn area, with attractively manicured hedges and carefully arranged clumps of herbs and shrubs. Thus, following up on our study of street trees (discussed in an earlier issue of Spectrum), we were interested in understanding and studying the distribution of trees in the city’s various parks, from young to old.

City parks, quite unlike their “wild” counterparts (wildlife parks like Bannerghatta Wildlife Sanctuary), are crafted green spaces. The type of vegetation you encounter in a park are directly and strongly shaped by the attitudes and preferences of the people who placed them there. Based on the history of horticulture in Bangalore, we grouped city parks into three sets that indicated the period in which they were planted, and the attitudes that shaped them. The first group had parks largely created before Independence, and planted by British and British-trained horticulturists. In addition to Lalbagh and Cubbon Park, this includes many iconic older city parks like Krishna Rao Park in Basavanagudi, Silver Jubilee Park, and Coles Park. These parks are frequented by birdwatchers, naturalists and regular visitors who want some relief from their concreted surroundings, and well known for their rich bird life and insect diversity. The second set of parks, intermediate in age, are parks established between the 1970s and 1990s, during periods of intense planting by Indian administrators – and includes parks like the Laxman Rao Park in Jayanagar (now threatened by the Metro), and Defence Colony Park in Indiranagar.

The third group of parks are largely small sized, local parks established widely across the city in the 1990s, in most localities. Established largely for recreation, exercise, and as community spaces, they tend to show a preference for landscaped lawns, with trees planted at the periphery, and perhaps at the centre of the park as well.

We studied the tree composition of these parks across the study, investigating 98 parks in total. We sampled a total of 1,423 trees belonging to 80 species in our study, and found that the composition was overwhelmingly dominated by non-local species. The most common tree is Polyalthia longifolia or the mast tree – also called the false Ashoka as it is often mistaken for the Ashoka tree. This is a tall evergreen tree commonly seen planted along the outer periphery of parks, as it grows fast, and screens the park from the noisy city exterior. This tree species alone accounts for 20% of all trees planted in parks! Other common trees include the honge (Millettia pinnata), royal palm (Roystonea regia), Nile tulip (Markhamia lutea), orchid tree (Bauhinia variegata), copper pod (Peltophorum pterocarpum), gulmohur (Delonix regia), golden bell (Tabebuia aurea), Indian cork (Millingtonia hortensis), and African tulip (Spathodea campanulata). These ten tree species together account for as much as 63% of the entire park tree population. This is similar to our findings for street trees, where the ten most common tree species accounted for 65% of all trees.

Old parks had more introduced species, while parks of intermediate age (those planted between the 1970s and 1990s) had the highest proportion of indigenous species, and the most canopy cover. Old parks had fewer trees, but the trees were larger and came from a more diverse species set, containing large canopied tree species such as copper pod and gulmohur. In contrast, recent parks had more trees, but small canopied, fast growing species like the mast tree and royal palm. This is similar to findings for Beijing and Berlin.

Changes in planting patterns

We also found clear changes in planting patterns over time. The tall Indian cork and African tulip trees are the only species which appear to have been planted in the past as well as in recent years. The  large sized iconic trees that hitherto visually dominated the park landscape, such as gulmohur and copper pod, are no longer being planted and gradually giving way to trees like honge, mast trees and royal palms.

These trends are similar to the changes in planting preferences we observe for street trees, where large canopied species are being replaced with small sized tree species. Large trees form a better habitat for other species including birds and insects, store more carbon, provide more shade, and are more effective in reducing air pollution. Although many of these species such as gulmohar and copper pod are considered exotic, they have been part of the Bangalore landscape for over two centuries, and have become an integral part of the city’s landscape, depended upon by a range of birds and other urban wildlife for their survival. At a time when the city is becoming increasingly concretised, hot, and devoid of bird and insect life, it is worrying to observe a consistent change in planting preferences away from these large, shade bearing broad leaf trees towards palms and other narrow canopied species. Unfortunately, it seems as though our city lacks a consistent, well formulated tree policy that specifies an appropriate mix of tree species to be planted.

The trees in Bangalore’s older parks are being threatened by infrastructure activities. Our research indicates that older parks have a unique place in maintaining Bangalore’s ecology and biodiversity. They need to be recognised as unique, irreplaceable heritage areas, and conserved as such.

(The author is the Urban Ecology Coordinator at ATREE & the Asia Research Coordinator at centre for the Study of Institutions, Population, and Environmental Change (CIPEC), Indiana University. )