Marine Biology

Salinity

They are capable of living in the salt water by separating the freshwater from seawater by reverse osmosis at the root level. Some species can exclude more than 90% of salt in seawater. Another method is to secrete salt through the use of special glands on the leaves of the tree, which are among the most active salt-secreting systems known. This mechanism usually comes with a high metabolic cost. Structural adaptations to reduce water loss due to the extreme saline environment are also found within the mangrove floral assemblage. Leaves with thick, waxy cuticles and stomata found only on their lower surfaces are examples of such modification. Finally, salt can in some instances be sequestered within special cells and is concentrated in bark or old leaves, and the old leaves will be withered to avoid excess salt in the plant.