Perhaps the most conspicuous and characterizing adaptation of mangroves is their development of aerial roots. As the soft sediment in which they grow are usually poorly drained, rich in organic matter, and is always saline to some degree, an extensive root system is necessary to provide stability, and obtain the oxygen which are vital for plant growth. Despite belonging to many different families mangroves have come up with surprisingly similar solutions to overcome this obstacle. The Avicennia marina grows a series of snorkels or pneumatophores which project through the sediment surface to aid gas exchange between underlying roots and the atmosphere. Stilt/prop roots grow downwards from the trunk and branches, providing gas exchange in the exposed sections and w

Most plants have a very low tolerance for salt, but in mangroves, twice a day, the high tide rushes in and covers the majority of plants in saltwater. To defend themselves against the daily onslaught of salt, mangroves exclude salt by filtering it out at the roots; Rhizophora stylosa, Brugueira gymnorrhiza and Ceriops tagal are all salt excluders. Some salt, however, still enters the root system, and is stored within the plant in its leaves, stems and roots. Consequently, there are often very high concentrations of salt in mangrove plant leaves. In some species salt is secreted from special leaf glands which can be seen and/or tasted on the surface of the leaves, such as that of Avicennia marina and Aegiceras corniculatum. Species such as Avicennia marina and Ceriops tagal may also store excess salt in bark or special succulent leaves which drop and form part of the food chain. Conserving water is essential for mangroves, and many of the plants have thick, waxy skins or dense hairs on their leaves to reduce transpiration ¡V the loss of water. As evaporation loss occurs through stomata (pores in the leaves), some species can restrict the opening of their stomata while in others they are often sunken below the leaf surface where they are protected from drying winds while. In addition, the leaves are often fat and succulent as water is store

Some topics in this essay:
Species Avicennia, , avicennia marina, ceriops tagal, rhizophora stylosa, root system, aegiceras corniculatum, brugueira gymnorrhiza, avicennia marina aegiceras, stylosa ceriops tagal, gymnorrhiza ceriops tagal, anaerobic conditions, leaves species, marina aegiceras, seeds germinate, rhizophora stylosa ceriops, brugueira gymnorrhiza ceriops,