Wednesday, April 13, 2011

Mangrove Forest

             

P
akistan contain Mangrove Forests which are the world’s 5th largest continuous mangrove area, known as the Indus delta mangrove ecosystem, stretched over some 600, 000 hectors between Karachi and the south-western border of India on the coast of Arabian Sea. Major mangrove forests are found on the coastline of the provinces of Sindh and Balochistan. Pakistan's mangrove ecosystem is one of the largest found in an arid climate.



Those trees which grow in shallow marine waters are called mangrove trees. Mangroves line 60-75% of the earth¹s tropical coastlines. These areas are tough places for plants to grow. Mangrove trees live life on the edge.  Mangroves trees grow in tropical and subtropical inter tidal zones. During low tides inter tidal zones are exposed to air. During high tides they’re covered by salt water. Each mangrove has an ultra filtration system to keep much of the salt out and a complex root system that allows it to survive in the intertidal zone. Some have snorkel-like roots called pneumatophores that stick out of the mud to help them take in air; others use prop roots or buttresses to keep their trunks upright in the soft sediments at tide's edge. They flood frequently. The soil is poor. But mangrove trees survive and even thrive in these harsh conditions.



Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics.  Big groups of mangroves and other plants that live here are called mangrove swamps, mangrove forests, and sometimes simply Mangal.  . There are some 70 species from two dozen families—among them palm, hibiscus, holly, plumbago, acanthus, legumes, and myrtle. They range from prostrate shrubs to 200-foot-high (60 meters) timber trees.
The mangroves forests are among the most productive and biologically complex ecosystems on Earth.  Birds roost in the canopy, shellfish attach themselves to the roots, and snakes and crocodiles come to hunt. Mangroves provide nursery grounds for fish; a food source for monkeys, deer, tree-climbing crabs and a nectar source for bats and honeybees. Many different birds depend on the mangrove forest. The birds build nests on the mangrove branches. The tangle of mangrove roots offers safe habitats for fish, shrimp, and oysters. . Many animals and plants depend on mangroves and cannot survive without them. The unique ecosystem found in the intricate mesh of mangrove roots offers a quiet marine region for young organisms. In areas where roots are permanently submerged, the organisms they host include algae, barnacles, oysters, sponges, and bryozoans, which all require a hard surface for anchoring while they filter feed. Shrimps and mud lobsters use the muddy bottoms as their home. Mangrove crabs mulch the mangrove leaves, adding nutrition to the mangal mud for other bottom feeders. In at least some cases, export of carbon fixed in mangroves is important in coastal food webs.

Millions of people in developing parts of the world where mangroves flourish rely on the mangal for a huge portion of their daily needs. They use mangrove wood for fuel and to build boats and furniture. They use the bark for dye and medicine. They use leaves for tea and animal feed and the fruit for food.

Another important part of Mangroves is that it’s roots help stop erosion by anchoring the ground and also lessening the effects of the waves. They prevent silt from damaging reefs and sea grass beds. These coastal swamps protect property and lives during storms and hurricanes by acting as a buffer against the winds and waves. Mangroves protect coastal areas from erosion, storm surge especially during hurricanes, and tsunamis. The mangroves' massive root systems are efficient at dissipating wave energy.

Mangrove trees are threatened from pollution and industries. Human destruction of an environment can come in many forms: cutting forests, air pollution and littering. Garbage thrown into the mangrove polluted water and harm animals. Sewage, weed-killers, and spilled oil are extremely unhealthy for the mangroves. As human activity around mangroves increases, more and more mangrove forestland is lost. The land where mangroves live has often been sold cheaply to businesses, which cut down many of the trees.

The objectives of the WWF - Pakistan project include rehabilitation of mangrove-degraded areas at Sonmiani and Jiwani in Balochistan, and Sandspit in Karachi, Sindh. WWF - Pakistan initiated a two-pronged approach in this area, i.e. mangrove plantation and community mobilization, simultaneously. Four mangrove nurseries, established at three sites, have been stocked with 40,000 saplings. An average survival rate of new plantation is around 81%.

The local community is being mobilized by enhancing awareness on the significance of mangroves for livelihood and by persuading the local people to take responsibility for conserving mangroves. Once destroyed Mangroves do not recover quickly.

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