New Guinea mangroves

The New Guinea mangroves is a mangrove ecoregion that covers extensive areas of the coastline New Guinea, the large island in the western Pacific Ocean north of Australia.

The New Guinea mangroves cover an area of 26,800 square kilometers (10,300 sq mi), particularly among the river mouths of the island's south coast. This ecoregion contains the greatest diversity of mangrove species in the world and they are an important habitat for wildlife. Areas of mangroves on the northern coast of New Guinea can be found at the mouths of the Sepik and Ramu rivers on the eastern side of Cenderawasih Bay, and Dyke Ackland Bay and Ward Hunt Strait. However the largest areas are found on the south coast in the mouths of the Purari, Kikori, Flys as well as Bintuni Bay and other areas of the southern Bird's Head Peninsula. Some areas such as the Kikori delta have larger and thicker mangroves than others. The coast of New Guinea has a Tropical monsoon climate apart from the length of drier Trans Fly savanna and grasslands coastline on the south coast.

Mangroves depend on a complex series of dynamic natural tidal processes that create the conditions for their survival. Rivers depositing sediment, together with waves and coastal currents, reshape the tidal zone where mangroves thrive. There are several features that all species of mangroves have in common. These include tolerance to conditions of high soil salinity, tolerance to submergence in water, or waterlogged soil, and to low oxygen conditions. The use of water to disperse young plants is also very characteristic of mangroves. As a result of the water-logged soil that mangrove trees reside in, they have formed adaptations to help them survive. For example, black mangroves survive in water-logged soil by using special "root snorkels" called pneumatophores. These structures are covered with small holes call lenticels that allow the roots to breathe the same way a snorkel lets you breathe while underwater. When trying to overcome the obstacle of the salinity that these trees live in, they have a few adaptations. They can actually concentrate much of the salt concentration in older leaves, which are soon to fall off, taking the excess salt with them. Some species even have salt glands which excrete salt to the surface of the leaves allowing it to be washed away by rain.

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