Mangroves may salinize the soil and in so doing limit their transpiration rate

Mangroves often grow in poorly flushed intertidal muds. When their roots extract water from these muds, they exclude almost all of the salt, so the solution becomes concentrated. The salt may concentrate until a quasi-steady state is attained, in which the flow of salt into the soil by convection in the water travelling to the roots is matched by diffusion of the concentrated salt back to the soil surface. The salt may become so concentrated that it will severely limit the rate of water uptake by the roots, and the limiting rate corresponds to a transpiration rate of about 1 mm day^-1, which is but a small fraction of typical potential evaporation rates. Mangroves thus may be adapted to low transpiration rates despite their growing with an apparently unlimited water supply, and they may be unable to sustain initially vigorous growth after colonizing freshly deposited muds. -from Authors