KARACHI, Dec 30: Karachi’s tree cover stands at a mere seven per cent, with localities falling under various cantonment boards and the Defence Housing Authority being particularly bereft of greenery, says a new report.

Prepared for the City District Government of Karachi, the report stresses extension of the tree cover. Only seven per cent of the city’s total land area – which consists of 900,000 acres (3,600 sq km) of urban agriculture and built-up area -- has a vegetation cover.

For an atmospherically ideal condition, experts underline the need for at least one tree per person in the city. Karachi’s environmental health is deteriorating owing to untreated residential and industrial effluents flowing into the sea, air and noise pollution caused by rapid and undisciplined transport and unplanned settlements, commercial premises and industries.

Alarmed by their findings on air pollution, a group of scientists at the Pakistan Space and Upper Atmosphere Research Commission (Suparco) in their report of 2006 had urged the government to take immediate measures to check the factors responsible for the deteriorating environment.

The scientists stated: “The impact of a reduced oxygen level on roads is already apparent from the blood picture of the people residing in or making a living at various traffic intersections. Any addition of a polluting system or technology that may increase the concentration of the pollutants by a mere 1 micro gram per cubic metre (µg/m3) is likely to be catastrophic.”

For Suparco’s survey, the designated sites included 26 traffic intersections divided into five corridors. The peak SO2 concentration of 40ppb (parts per billion) was noted at the Garden Road-Preedy Street intersection and the Burnes Road intersections, while the maximum NOx concentration of 239ppb was recorded at the Burnes Road intersection.The maximum CO2 concentration of 615ppm (parts per million) was found on Korangi Road at the Baloch Colony bypass intersection, whereas the maximum CO concentration of 17ppm was noted at Empress Market.

Health professionals have noted that cancer and other diseases of the ear, throat and lungs have increased by 60 per cent, due to vehicular emissions, mainly containing carbon dioxide.

On the other hand, urban development experts feel that high-rise buildings blocking sunlight and insufficient allocation of space for plants in the government and private built-up area are among the causes behind the slow plantation or not up-to-the-mark greenery.

While successive governments failed to get rid of the factors that contributed to the overall mismanaged system, including faulty and dilapidated and smoke-emitting vehicles, experts find a potential remedy in an increased non-conventional forestry in Karachi, which now has a population of about 18 million.

The report says that the total vegetation cover of Karachi was assessed through satellite imagery in March, 2007 in all the 18 towns of the CDGK, cantonments and the Defence Housing Authority.

A maximum vegetation cover of 18.25 per cent was witnessed in North Nazimabad town, followed by Gulberg town (17.34 per cent), Lyari town (17.31per cent), Liaquatabad town (16.53 per cent) and Jamshed town (14.57 per cent). Cantonments have the cover rate at 10.31 per cent, while the DHA rests at the minimum of 4.92 per cent.

Total vegetation cover in Karachi as estimated through satellite images is 62,643 acres, which works out to be seven per cent of the total land area of 907,001 acres.

About the soil quality in Karachi, the report says a majority of the soil samples in the study were “none to slightly saline” in nature; a majority of soil samples were “poor to medium in organic matter and nitrogen contents”; the phosphorous content in a majority of the samples was adequate enough, the soil samples were slightly to medium alkaline in reactions; and were brown in colour and were mostly heavy textured.

Dr Mohammad Qaiser, a botanist and vice-chancellor of the Federal Urdu University of Arts, Science and Technology, said the soil in Karachi had the potential for planting trees and vegetation.

Replying to a question, he said Karachi should have a vegetation and tree cover of 15-20 per cent against his estimates of five per cent of the total land area.

Karachi had such a vegetation cover because trees hardly found an environment to survive amid unguided development activities, he said.

He went on to say that the selection of species for plantation also mattered very much. If the compatibility of plants and local climate were considered before the start of a tree-plantation campaign, the trees could play the crucial role of cleansing agents and not become a source of inconvenience or threat to human health or city life, he remarked.

A director of the Sindh Environmental Protection Agency, Naeem A. Mughal, said urban vegetation, besides affecting everyday moods, activities and emotional health, could filter air pollutants, sequester CO2, shade and shelter homes from the sun and wind, intercept urban runoff and provide habitat for wildlife.

The CDGK’s executive director for parks and horticulture, Liaquat Ali Khan, said urban vegetation was one of the important infrastructural components of any urban ecosystem and the existence of a well-distributed and abundant vegetation cover in cities could provide many benefits to the citizens, in addition to providing the cityscape an aesthetic appeal.

He said the present CDGK set-up was working towards the transformation of Karachi into a “green city” and since July about 300,000 trees had been planted on major roads such as Sharea Faisal, Karsaz Road, Rashid Minhas Road, University Road, Shahrah-i-Pakistan and M. A. Jinnah Road.

He said mostly the Conocarpus, a new and fast-growing tree, was being planted and the city would see the full growth of these trees with broad leaves by the end of June 2009.

He conceded that due to improper planning and ill-advised execution of development works, the city had to see felling of about 1,000 trees in recent years. He estimated that the city at present had 2.5 to 3 million trees in the urban areas, which was almost seven to eight times less than the world standards.

Replying to a question, he said he felt that about 20 per cent of the project cost should be reserved for greenery activities such as parks, green spaces and trees, which were more than lungs of the city or pollution scrubbers and guaranteed on the wellbeing of local citizens as well as visitors from outside.