A forest is a complex ecosystem or assemblage of ecosystems dominated by trees and other woody vegetation. The living parts of a forest include trees, shrubs, vines, grasses and other herbaceous plants, mosses, algae, fungi, insects, mammals, birds, reptiles, amphibians, and microorganisms living on the plants and animals and in the soil and their interaction with one another and with the non-living part of the environment. The type of forest in a given area depends on many elements, including climate, soil, water source, rainfall patterns, seed sources and human influence. Forests provide habitats to diverse animal species, livelihood for different human settlements, watershed protection, timber and non-timber products, and various recreational options. They prevent soil erosion, help in maintaining the water cycle, and check global warming by using carbon dioxide in photosynthesis. Pakistan forest resources are limited, covering only 4.8 percent of total land area, which is far below then the optimal standard of 25%, forest cover for a country. However scarce, forests of Pakistan are very rich in terms of biodiversity and present a unique blend of tree, shrub, grass and animal species, living across various ecological zones from sea level in the south, to high altitude alpine pastures of the north. Pakistan consists of alpine forests, temperate forests, sub-tropical forests, dry tropical forests and mangrove or coastal forests. Mangroves are ever green forests between land and sea, found essentially in the intertidal zone and occupying large tracts along the shallow coasts, estuaries and in the deltas where they are influenced by tides, widely differing conditions of saline. The coastline of Pakistan spans a total area of about 1000 km, of which 241 km covers the province of Sindh on the south eastern side and 660km within the province of Baluchistan (western side) with 22,820 square kilometers of territorial waters and an Exclusive Economic Zone of about 240,000 square kilometers.
In the Sindh, mangroves are found along Karachi in the Indus Delta which occupies approximately 600,000 ha extending from Korangi Creek in the north to Sir Creek in the South (FSMP 1992).The mangrove forests lie between 24° 10′ and 25° 37′ latitude North and 61o 38′ and 68° 10′ longitude east. Indus Delta comprises 17 major creeks, numerous minor creeks and extensive mudflats and constitutes 97% of total mangrove forests found in Pakistan. In Baluchistan, mangroves are found in Miani Hor, Kalmat Khor and Gwader bay with total area of about 7,500 ha. Indus Delta mangroves, one of the largest tracts of arid mangroves in the world, used to cover an approximate area of 2,50,000 to 2,83,000ha till early 1980s but the area dropped drastically to 1,60,000 ha in 1990s. A recent study by WWF - Pakistan (2006) has estimated the existing cover of the Indus delta mangroves around 129,000 ha. The focus of this management plan is mainly on the rehabilitation of mangroves of Karachi. Mangroves of Karachi are unique in being the largest arid climate mangroves in the world. As a result of continued and uncontrolled deforestation and reclamation, Karachi which was made up of several islands with fringing mangroves in the seventeen century, is now limited to a very sparse growth of mangrove. There is a need for rehabilitation of these precious forests for our survival, food security, flood protection, sustainability and for scenic beauty.
The mangroves are very important ecosystem both economically and ecologically. Although mangroves play protective and productive roles but their protective role is more effective than productive. Some of the functions of mangroves are as under: Ecological:
•As pool of diversity they support diverse forms of plants and animal life. •Provide food, shelter and breeding ground to prawns, shrimp, several fin fish, crabs and other marine life. •Protect seaports from cyclones and...