Mangrove shorelines

Mangroves are trees or shrubs that occur in the upper

intertidal zone on many low-energy tropical shorelines.

Globally they cover 137,760

km

2

(Giri et al., 2011). Salt

marshes and other coastal wetlands may occur landwards

of mangrove vegetation, and seagrass may be extensive

seawards. Mangroves are not a single taxonomic group,

but comprise a diverse range of plants with adaptations

enabling survival in this otherwise inhospitable saline and

anaerobic environment. Mangrove forests are highly pro

-

ductive ecosystems that support both terrestrial and

marine biodiversity. They are important habitats for fish

and crustaceans on which humans are dependent. They

also provide many other ecosystem services; both direct,

in terms of timber and fuel; and indirect, by supporting

biodiversity, providing physical protection of coasts,

retaining sediments, and regulating nutrient and carbon

exchange between terrestrial and marine environments.

Mangrove forests are best developed where extensive

near-horizontal topography occurs close to sea level. They cover substantial areas where there is a large tidal range;

however, there are instances where isolated stands of

mangroves persist inland where they are not influenced by

tides. Wave energy has to be sufficiently low to allow

establishment and growth of plants, but mature forests

also act to attenuate wave energy.