The large scale plantation of the Conocarpus trees by the City District Government Karachi (CDGK) in 2009 is at the crux of one such dilemma. The successful pilot plantation of Conocarpus in Bagh Ibne Qasim and its survival in the tough coastal-urban conditions encouraged the district government to plant 300,000 new plants around the city. The parks and horticulture department claimed that Conocarpus was chosen because it needs no water after six months of plantation, it quickly matures into a tree and is flexible enough to be moulded into a variety of shapes.
While this plantation was in its initial stages, a scientific research conducted by Karachi University botanists, revealed that massive release of pollen from Conocarpus in the months of October and November can cause asthma and eczema among humans. The imported alien species, originating from South America, depletes water and soil along with giving rise to pollen and seasonal allergies when transplanted in Karachi.
The authorities however, justify their action on the basis that every plant releases pollen and claim that the Conocarpus plants will not be allowed to mature to the stage where it starts to release pollen. Their plan to trim one million trees every year only to stop the natural process of pollination seems nothing short of impractical.
Shahida Kausar Farooq, chairperson of an NGO devoted to environment and public health, has always voiced that planting of the right trees is as important as not cutting the trees. Experts are at a loss as to why indigenous plants (a plant can be called indigenous only if it has been growing naturally in that particular area for at least 400-500 years) are not opted for.
Dr Surayya Khatoon, Chairperson of the Botany department at Karachi University, believes that our people have a psychological complex and prefer imported things as opposed to native ones, even, it seems, in the case of trees.
She cites the example of the large scale plantation of eucalyptus trees in the mid-’90s by the KMC as an effort towards forestation.
However, just as these trees, which originate primarily from Australia, started reaching maturity the problems of excessive transpiration of water became evident which simply added to the problems of an already arid region like ours.
Eucalyptus also dominated the other indigenous plants and did not allow them to thrive and its insidious roots got tangled in the underwater pipeline network. Its pungent scent repulsed birds and animals, thus, robbing them of shelter.
When environmentalists raised a hue and cry they were initially ignored but as the menace got out of hand, the government went on a rampage to cut down these trees.
Learning no lessons from the eucalyptus debacle which took place in the not very remote past, the million tree target of the Conocarpus plantation was initiated. When asked why indigenous plants are not given preference over exotic ones, Dr Surayya commented that it may be because they require more effort. “Our horticulturists and foresters would have to collect their seeds from the wilderness, tend them carefully and they would definitely take longer to grow. They prefer plants that grow quickly, thus they opt for exotic plants, which in an unfamiliar ecosystem, dominate the other indigenous species which continue to grow at their normal pace.”
The lives of at least 15 species of plants, herbs, birds or insects are attached to a single tree; planting an exotic variety rather than an indigenous one often means hastening the death of these species.
The rule of thumb is that ecological hazards are bound to be posed by fast-growing plants, as they consume a lot of ground water, as well as by plants which produce a lot of seeds, as they consequently crowd out the native species.
Dr Surayya also elaborates on pollen allergies saying, “Plants like Conocarpus are wind pollinated thus they produce excessive pollen as they depend on the indiscriminate wind to carry it to its destination.
Not only are allergies caused by this excess pollen but the pollen is also a carrier of other environmental pollutants.” She fears that just as the paper mulberry’s hazardous ecological repercussions became apparent decades after its plantation in Islamabad, Karachiites too, might be faced with a similar plague.
“Monoculture is against nature as nature does not favour uniformity. But our planners are intent on selecting one kind of plant and then planting only that. The check list is simple: the plantation must be diverse, indigenous plants must be given preference and exotic plants must be welcomed too but those which have large and bright flowers so that they are insect-pollinated,” she says.
While on the one hand century-old trees are cut down in the name of development, on the other dubious and alien species are transplanted here by the thousands. It is obvious that the powers that be learn nothing from the paradigm: failing to plan is planning to fail.