Ageing ornamental trees behind mass uprooting during rains in Bengaluru

Despite the forest cell conducting an audit of dangerous trees in the city and clearing over 1,200 of them, around 515 trees were uprooted and more than 1,500 branches snapped during the rains last week, according to the Greater Bengaluru Authority (GBA) data.

The data also revealed that over 90% of the trees uprooted during the rains were ornamental trees. Experts argue that these trees required a focused management approach, including pruning and removal, which has not been carried out over the years, leading to such massive uprooting.

The highest number of uprooted trees included Indian cork trees, Gulmohar, copper pod, Spathodea campanulata, Jacaranda mimosifolia, rain trees, and Tabebuia rosea, among others.

Noted environmentalist A.N. Yellappa Reddy pointed out that these are ornamental trees with soft to moderately soft wood, making them vulnerable as they age. “In Bengaluru, the administration initially prioritised planting ornamental trees, particularly exotic species, which are now old and vulnerable to strong winds and rains,” he explained.

Ganesan Rengaian, adjunct fellow at ATREE and former member of the Tree Expert Committee, explained that the pattern clearly shows that most uprooted trees are ornamental species, which also have a definite lifespan. “Most of the uprooted trees have a lifespan of about 30 to 50 years, and many of them have already completed that period. Besides, tree management has also not been adequate,” he said.

He pointed out that concretisation and development further compounded the issue by restricting the natural growth of roots, thereby weakening the trees. He noted that cutting roots and laying roads over them naturally limited the stabilisation of trees.

Mr. Reddy stressed that the problem is further aggravated because trees grow stably in their natural habitat, as they are genetically adapted to the environment. However, most of the ornamental trees prioritised in the city are exotic species, making them more vulnerable.

He also suggested that future tree plantation plans must include a mix of species. He recommended more native species such as Saraca asoca and Kadamba trees, a point that Mr. Ganesan also reiterated, noting that indigenous species generally have a longer lifespan.

Civic neglect

Dattatraya Devare, an environmental activist, pointed out that the civic body and its parastatals have failed to manage the city’s green cover effectively. “Roots of most of these trees are cut for drain construction; improper pruning causes imbalance in the trees; and, most importantly, concretisation around tree bases has been a major issue. These factors make trees hollow from inside,” he said.

As Mr. Devare pointed out, the civic body has neglected the National Green Tribunal (NGT) order to free tree bases from concrete and leave adequate soil space during the construction of roads and footpaths.

In this regard, the Special Commissioner of Forests, Environment, and Climate Change Management had also written to corporations, directing them to ensure adequate soil space for trees during road construction. However, the civic bodies have barely followed these rules.