Difference between revisions of "Coastal Zones"

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==[[Mangroves]] ==
==[[Mangroves]] ==
==[[Saltmarsh]] ==

Revision as of 06:38, 20 October 2008

The coastal ecosystem is very complex with several very different zones, all of which are interdependent on each other. It is not possible to remove any part of the system without severely impacting on all remaining areas. Plants in this ecosystem are highly specialised, so when they are removed or destroyed there is great impact on surrounding flora, fauna, sand movement, nutrients and oxygen levels.

Coastal Zones 002.jpg

Fore Dune and Dune Crest

The fore dunes are essential barriers against extremely harsh oceanic conditions. They withstand ocean storms, extreme sun, strong winds and powerful waves. There has never been a man made equivalent of the fore dune area that has been effective in the long term. Vegetation in the dune area catches wind blown sand and binds it to the dune. Without plants to trap the sand, the sand is blown away and the dune erodes. Plants in this zone are extremely enduring with special adaptations that allow survival. They provide vital protection for fauna that live in this zone, such as crabs, and for other flora further back in the dunes. The dune crest is also subject to harsh conditions with plants in this zone prone to growing in patches to provide extra protection to themselves.

Beach Scrub and Hind Dunes

This area is relatively protected from the elements by the fore dunes and therefore more stable. There is more vegetation in this section, although these plants are still very hardy. Beach scrubs are vine forests growing in sand and often a denser thicket with older and larger trees. They are very valuable communities due to their high biodiversity (or number of different plant and animal species living together). Soil is still loose and sandy, but held together by the trees and shrubs. This zone is rapidly disappearing in many places due to coastal developments. Beach scrub in particular is now an endangered community, with over 70% of the original extent of beach scrub wiped out. Without this defensive hind dune zone, infrastructure has decreased protection from erosion, winds and cyclones.