Mangroves have evolved to have a number of adaptations to live in their very specific environment:
- Avoidance of toxic NaCl. Depending on the species of mangrove adaptations range from salt exclusion to full halophytic strategy, which includes taking up the salt but storing it away from sensitive enzymes. The Mangroves in Dubai have a Halophytic strategy.
- Drought tolerance: The sea water the roots of mangroves are exposed to has an osmotic pressure of 25 bars, this could go much higher if the sea water evaporates and becomes more concentrated. The permanent wilting point for crop plants (the maximum drought they can stand) is around 15 bars. To take up water plants must have a water potential below that of the environment, generating this is a bigger challenge for mangroves. Mangroves have a range of adaptations to take up and restrict the loss of water.
- Low oxygen in the soil: The silt in which mangrove roots grow lacks airspaces and is low in oxygen. Mangroves have evolved root adaptations to avoid the anaerobic conditions.
- Toxins in the soil: Anaerobic conditions can cause normally beneficial nutrients to be converted into toxic versions. Mangroves growing under low oxygen conditions have evolved metabolic responses to tolerate these compounds.