Depleting green cover, a grey area of concern

Last Updated 24 March 2019, 05:25 IST

Trapped in a vicious green-grey debate, can Bengaluru afford to surrender the last vestiges of its once green heritage? As the development brigade marches on with its concrete monster projects of dubious utility, here comes an alarming piece of statistics: By 2025, grey will dominate 98.5% of the city’s landscape.

Tracking the city’s dangerous descent into climatic chaos for decades, the Indian Institute of Science (IISc) should know what it is in store. Years ago, its arresting imagery of eight Bengaluru maps from 1973 to 2020 had shocked everyone. The 1973 map, with its 68.2% green expanse had morphed into a ‘built-up’ mosaic of 78.7% red by 2017.

But this will not prick the conscience of the bull-dozers, ready to chop down over 3,500 trees for an elevated corridor project that aids none but the car-owners. On the chopping line are 120 Cubbon Park trees, even if the corridor beku brigade contends that the Queen’s Road median is outside the park boundary.

A 1998 government notification had clearly defined the Park’s boundary as up to and along the Queen’s Road and Kasturba Road. The stress on ‘along’ meant the medians were part of the park, and nobody had the right to construct anything there without the Karnataka High Court’s consent. A 2001 court ruling had ratified the boundary notification, clearing all doubts.

The potent threat to Cubbon Park is an arresting symbol of a deeper, far bigger malaise: An ostrich-like disregard to the wanton destruction of Bengaluru’s green heritage. The demolition continues when citizen activists, environmentalists and institutions, the IISc in particular, have left the warning bells continuously ringing.

Critical green roles

Landscapes with tree cover, reminds Dr T V Ramachandra from IISc’s Centre for Ecological Sciences, recharges the groundwater, moderates the micro climate, sequesters the carbon emitted in urban environment, maintaining the natural balance.

In 2016, a study led by Dr Ramachandra had conclusively established this: Bengaluru witnessed an astounding 1005% increase in paved surfaces. This coincided with a deeply troubling 88% decline in green spaces and 79% drop in water spread regions.

Overlaying the administrative boundaries of 198 BBMP wards on the vegetation distribution maps from 1973 to 2012 revealed an interesting trend: The least vegetation cover (less than 1 hectare) was found in Chickpete, Shivajinagara, Kempapura agrahara, Padarayanapura and surrounding areas.

Highest vegetation

Varthur, Bellandur and Agaram wards had the highest vegetation cover (of over 300 ha). In quantitative terms, wards such as Varthuru, Bellanduru, Agaram, Aramane Nagara had over 40,000 trees. Chickpete, Padarayanapura, Shivajinagara, Kempapura Agrahara, and Kushalnagara wards had less than 100 trees.

But is this slide irreversible? Hardly so, say IISc scientists. They have proof right inside their campus: A mini forest raised from 500 saplings of 49 native species, planted in the 1990s. “The groundwater table that was as deep as 150ft now stands at 10-15 ft. The temperature inside the miniforest is at least two degrees lower than the surrounding area,” informs Dr Ramachandra.

Scaling up

Can this be replicated and scaled up for the rest of the city? Yes, if one to two hectares of land is set aside for such miniforests in every ward. “When the government can acquire land for elevated corridor and similar projects, they should find land for this as well.”

For the Bruhat Bengaluru Mahanagara Palike (BBMP), afforestation is all about planting saplings. Earlier this month, the Palike unveiled one such plan to plant one lakh saplings across its eight zones with support from various Non Governmental Organisations.

Sapling response

The Palike’s Deputy Conservator of Forests, M K Cholarajappa informs that the saplings are ready at BBMP’s four nurseries. Tenders have been finalised for 75,000 saplings. A sum of Rs 5 crore was earmarked in the recent budget for the project.

Native species are often preferred for the saplings, those valued for timber, honge and mahogany. The Palike, he says, will also make available hole dasavala, huvarasi, sampige, basavana pada, tabebuia, jacaranda and tabebuia guayacan. Also figuring in the list are fruit-bearing trees kadu badami, jamun, gooseberry, cherry and medicinal trees such as neem, simarouba and tapasi.

The saplings could take years or even decades to offer a canopy anywhere near the fully grown trees being felled for multiple projects. But what about the green behemoths that disappear without a trace from official records?

Tree tracking

To digitally track the city’s tree cover and keep a tab on every tree, Bengaluru’s tree doctor Vijay Nishant had recently launched a tree census in Jayanagar. The objective is simple: To develop a verifiable database of trees, freely accessible in the public domain. As Nishant notes, this will help citizens and all stake-holders keep a strong vigil on indiscriminate tree-felling.

The tree census might help call the bluff on planting claims. But, as Harini Nagendra, professor of Sustainability, Azim Premji University, points out, a qualitative analysis of the trees being planted is critical in the long-term.

Species matter

Trees are planted for shade, promotion of bio-diversity and reduction in air pollution. The choice of plants should reflect these objectives. “The old trees, tamarind, mango, banyan and the raintrees, had a lot of canopy. Our studies in recent years show a lot of honge and neem trees are preferred now while the old species are abandoned,” notes Harini.

She cautions that this fixation with only a few species could lead to mono-culture. “In case of any pest attack, for instance, the entire lot can get wiped out. The need of the hour: A judicious mix.”

(Published 23 March 2019, 17:56 IST)

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