It is not only the urban structures, monuments and infrastructure that reflect the changing face of a city. Though seldom recognised in the pages of history, trees too tell stories about the past and the present. While Visakhapatnam’s natural green spaces support a number of native plant species, the city is slowly moving towards a different verdant look. The beautification and plantation drives taken up by the GVMC and AP Urban Greening and Beautification Corporation may have significantly given a lift to the beauty of the city, but it has also triggered a deep concern among environmentalists and experts on the rapid introduction of non-native species in the city in the recent past.
At several locations, rows of a beautiful non-native species of Conocarpus erectus have been planted in medians on the roads. This ornamental species which has rapidly grown over a short span of time has transformed the city’s look. However, what may seem an innocent plant can grow out to become a monster.
According to taxonomists and horticulturists, the tree’s roots have the ability to break into water and sanitation systems, grow inside them forcing them into strange shapes. The enormous roots of this species are strong, aggressive and in search for any source of water. While these trees grow rapidly and are suitable as a wind buffer, they have proved to be eager water absorbers with horizontally extending roots. “This species has the capacity to grow very rapidly, which makes it highly unsuitable for plantation in medians. If not pruned at regular intervals, it can obstruct the view of commuters,” said botany researcher of Andhra University Prakasa Rao Jonnakuti. Around 865 Conocarpus erectus plants, including 10,800 shrub plantation, was carried out recently by the GVMC from Sagar Nagar to Bheemunipatnam along the median.
As part of its plantation initiatives for 2017-18, the GVMC has marked 22.65 km stretch of new medians with landscaping works and plantation of species of Spathodea and Tabebuia, both of which are non-native varieties. Similarly, at several stretches in the city, for instance the Ramnagar area, non-native species of royal palms have been planted.
While researchers and botany experts say that we should prioritise managing the “worst” introduced species and worry less about innocuous ones, knowing which actions to take is the difficult task. Some introduced species cause significant damage, but are so abundant or resilient that they are essentially unmanageable.
“Instead of planting Cornocarpus erectus on the road medians, native species like Memycylon edule is a far better option. This species grows slowly and gives beautiful blue flowers. It is abundantly found in the forests of Kambalakonda and Visakhapatnam Agency areas,” said Associate Prof. S.B. Padal of Dept. of Botany, AU. Incidentally, when cyclone Hudhud hit the city it was the non-native species like copper pod which were uprooted on a large-scale.
Bowing to this growing demand from activists, researchers and environmentally conscious citizens, the GVMC this year is focussing on native species as far as the avenue and block plantation drives are concerned. Speaking to The Hindu, GVMC Commissioner M. Hari Narayanan, said: “For block and avenue plantation, we are focussing on native species. Here, there won’t be any species of hybrid or ornamental plants. While we take the advice of AP Urban Green Corporation on matters of beautification, the GVMC has taken an independent decision to take up only native species for block and avenue plantation. Around 80 % of our plantation drives are native species.”
The GVMC’s greening efforts along the medians has so far covered 105 km. However, on these, the corporation is taking up plantation of ornamental species like Conocarpus erectus and Terminalia mentally. “While we don’t want to spend much on exotic species, we want to bring a balance,” Mr Narayanan added. Only for greenery development along central medians and block and avenue plantation, the total expenditure cost is estimated to be ₹4 crore to ₹5 crore.
Additionally, for the beautification drive to be carried out at road central median at 22.65 km stretch in the city is estimated at ₹5 crore which includes pipelines, borewells, flowering and plant material. “We are trying to bring a balance between native and ornamental species for the purpose of beautification. In the medians, not all the species planted are exotic ones. We are spacing it out. This year, we have given a lot of importance to using native species as many of the residents have given us advice on the importance of native species. In future in the next phase of development of medians, we will look at only native species,” said Mr Narayanan.
According to environmentalists, flowering varieties and the ones that support bird population are being given less importance in plantation drives in the city. “For example, planting of Terminalia mentally won’t benefit bird or other animals except giving a nice look. Its counterpart T. bellarica (badam) is not only fast growing, but also animal friendly,” says Lohitasyudu, Director, AP State Forestry Academy, Rajamahendravaram.
Several members of city based groups like Mana Harita Vizag have been propagating the need to grow native plant species by taking up plantation by seed balls.
Native species suitable for road central median plantation
Caryota urens (Fish tail Palm): It is growing in Araku and Paderu forest (local tree)
Ficus benjamina: Local tree, needs to be pruning in rainy season
Ficus microcarps: Local tree, needs to be pruning in rainy season
Butea monosperma: (Flame of the forest) Tree with beautiful bright red flowers
Ougenia oojeinensis: Adavi Chikkudu chettu ; flowering tree
Memecylon edule: Beautiful blue flowers, small evergreen tree
Ficus arnottiana: Kalla ravi
Native species suitable for block or avenue plantation
Wrightia tinctoria : It is locally called as Ankudu, slow growth tree with white flowers
Cassia fistula: Local name Reela, with yellow flowers, medium sized tree
Saraca asoca : Real Asoka, it is Endangered tree, described in Ramayana , with bright red bunches of flowers
Anogeissus acuminata: Localy called as Pasi chettu, large timber yielding tree
Anogeissus latifolia: Local name is Sirimanu, Large tree , timber yielding tree
Terminalia alata: Nalla maddi, large tree , timber yielding tree
Terminalia arjuna: Tella maddi, large tree , timber yielding tree