D.7. Mangroves
- These unique plant formations are typically found along the sheltered tropical and subtropical coastlines within the littoral zone.
- They consist of trees and shrubs that grow below the high-tide line of spring tides and display an exceptional ability to tolerate saline water.
- Essentially, they are evergreen terrestrial plants specially adapted to thrive in coastal, salt-rich environments.
- Growing on sheltered shores, typically on tidal flats, deltas, estuaries, bays, creeks and the barrier islands.
- Require high solar radiation and have the ability to absorb fresh water from saline/ brackish water. Produces pneumatophores (blind roots) to overcome respiratory problems in the anaerobic soil conditions.
- Leaves are thick and contain salt secreting glands.
- Exhibit viviparity mode of reproduction, i.e. Seeds germinate in the tree itself (before falling to the ground). This is an adaptive means to overcome the problem of germination in Saline water.
- Crystals of salt on the back of the leaves; others block absorption of salt at their roots.
- The mangroves of Sundarbans are the largest single block of tidal halophytic mangroves of the world.
- Famous for the Royal Bengal Tiger and crocodiles.
- The mangroves of Bhitarkanika (Orissa), which is the second largest in the Indian subcontinent, harbour high concentration of typical mangrove species and high genetic diversity have (additional) special roots such as prop roots, pneumatophores which help to impede water flow and thereby enhance the deposition of sediment in areas (where it is already occurring), stabilize the coastal shores, provide breeding ground for fishes.
- Protects coastal lands from tsunami, hurricanes: and floods release oxygen back to the atmosphere, along with a little methane gas