A Walk Through the Mangroves

Adaptations, Ecosystem Services and Climate Change Threats

Mangroves grow in coastal intertidal zones and are prevalent in Equatorial regions. The environment they live in is hot, saline (NaCl), tidal and subject to storms. Why not take a virtual visit to a mangrove in Dubai?

Self-Guided Tour of the Mangroves

Adaptations

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.

Benefits (Ecosystem Services)

The extensive root system of mangroves stabilises the soil and buffers the effects of storm damage.
Mature mangroves create an environment which is home to a range of organisms and increases the biodiversity, including acting as a nursery for commercial fish.
Mangrove roots capture and filter suspended particles, increasing water quality and improving the environment for marine organisms, including coral.
Mangroves can take up nutrients from agricultural runoff, reducing eutrophication.
Mature mangroves capture significant amounts of CO₂ through photosynthesis and biomass deposition, so-called ‘blue carbon.
Mangrove forests are valued by local people and are important culturally.

Threats

Changes in weather patterns due to climate change can increase sea level and the frequency and intensity of storms.
Habitat loss through coastal development can reduce the area and regeneration opportunities of mangrove forests.
Industrial activity and agriculture on land can lead to nutrient and pollutant runoff impacting negatively on the growth of mangroves.