KARACHI: After the launch of Karachi operation, as a part of National Action Plan (NAP), target killing and other crimes have almost halted in the city, but still environmental crime has not come to an end.Ruthless cutting of the indigenous trees almost everywhere in the city goes unnoticed everyday. But above all these crimes, the plantation of an alien species of plants, the Conocarpus, in the city, is considered to be one of the biggest environmental crimes by the nature conservationists.Conocarpus, an alien plant species for Karachi, which is basically a mangrove plant, is planted at mass level in Karachi. Almost all the parks, roadside species and major arteries have now conocarpus, which, according to experts, will bring an environmental disaster in the city in near future.Being Pakistan’s largest city and an industrial and commercial hub, Karachi needs more trees for balancing the ecosystem, but different civic bodies have continued to cut down trees, usually with a lame excuse such as the trees were hindering utility services, damaging footpaths or being an obstacle for electricity wires and sewerage lines or on the name of widening the roads and constructing bridges.Former Mayor of Karachi Mustafa Kamal led City District Government Karachi (CDGK), planted around 2.2 million conocarpus plants in almost everywhere in the city.Under Karachi Comprehensive Plan (KCP) 2008, CDGK was supposed to plant a variety of trees for better environment; it had instead planted only a single species, the Conocarpus.Forest experts are terming it as monoculture and warned of adverse impacts on city’s general atmosphere. Nature conservationists termed such mass level plantation of same species on plants as monoculture and they believe that monoculture creates a similar environment, hindering bird population, forcing them to migrate, since different birds have varying nesting habits and prefer different trees. The former City District Government Karachi (CDGK), as a part of its greener Karachi project, under the title “Forestation, Aesthetic Plantation and Landscaping Study-Karachi Comprehensive Plan”, made by former Conservator, Sindh Forest Department, Dr GR Keerio in October 2008 made proposals worth an estimated Rs8.34 billion.Three aspects were planned to be covered under the KCP including forestation, aesthetic-plantation and landscaping; in order to beautify the city, increase tree cover, apply modern landscaping techniques, encourage farm and social forestry in and around city to check green house effect, minimize threats to ecological integrity through carbon sequestration and improve bio-geochemical processes.The outputs of the plan were kept for substantial and sustainable environmental benefits besides beautification of city. The official documents, which this scribe acquired from the officials of the former CDGK, reveal that under the KCP more than a dozens species of different indigenous trees and shrubs were selected for plantation.The city government had planned to plant a variety of trees in the city, which include Plaksa tree (Pipal), Banyan, Coconut, Margosa (Neem) Tree and tropical tree species such as Siris, Rain tree, Ashoka, Amaltas and other Cassia species, Terminalia (Indian Badam), Peltophorum (Copper pod), Gulmohar, Palm trees, Molseri and also Lignum vitae. But instead of planting all these trees, the officials introduced only a single tree, a foreign species, the Conocarpus, which is actually mangrove specie and is imported from Ethiopia.According to experts, Conocarpus will bring adverse impacts on city’s general environment. Muhammad Moazzam Khan, the fisheries consultant for World Wide Fund for Nature (WWF)-Pakistan, quoting international studies said that Conocarpus is notorious plant specie for causing droughts in several regions. “In future Conocarpus will start releasing pollen, which will cause pollen allergy just like Islamabad,” he said.The foresters are terming such large number of the plantation of same species as ‘monoculture’.“Each plant species has its own time to grow, some are fast and others are slow growing trees, like Sheesham tree takes 22 years to be fully grown, while Eucalyptus can grow in four to six years. The problem in planting single specie is, in case of any plant disease, the entire lot will get affected. So it is better to introduce a variety of trees,” said an official of Sindh Forest Department.