Re: How do sand dunes help the enviroment?

Dear Laura,

Sand dunes are an integral part of the world around us.  They "help" the 
environment by being part of it, inseparable from any other feature of the 
landscape. What probably motivated you to ask your question, is the fact 
that in many parts of the United States sand dunes are located within 
protected lands.  Even at the beach here in Rhode Island, we put fences 
around sand dunes to keep people and their pets off of the dunes.  Why do we 
do this? Or, as you put it, "Why are sand dunes important?"

Every part of the earth is important. Scientists are just beginning to 
understand how each element of the earth works with other elements to form 
what we call ecosystems.  Sand dunes are important because they support, or 
provide for, very sensitive ecosystems.  When a dune forms, the sand is 
always moving, therefore making it difficult for grass and other plants to 
grow.  This is called an "active dune".  Active dunes are great places to 
play, not only because the sand is fun to play in, but also because the wind 
will "heal" a dune surface very quickly by blowing sand to the holes your 
feet make in the surface.  

At this point the dune is really just a pile of sand, and does not support 
much life.  However, with time and the right conditions (for example, slower 
wind speeds and more rainfall) plants can begin to establish on the dunes.  
While it may take a long time to occur, eventually the dune support many 
different types of plants and animals.  The more plants growing on the dune 
surface, the more the dune is stabilized, thus making it a better place for 
plants and animals to live.

When we walk or drive our cars over the surface of a dune we disturb these 
plants and animals, often killing them.  By removing the plants, we allow 
for winds to again pick up the sand and move it about.  This means the dune 
is active again.  The sand blows across the desert or beach, getting into 
people’s homes, or washing out to sea. 

I just did a quick search on www.google.com (key words: sand dunes 
environment) and the first 5 links were all about sand dunes and the 
environment.  It was interesting to see what specific communities all over 
the world are doing to protect sand dunes.

Cheers,

Andrew