<span>An indicator species is an organism whose presence, absence or abundance reflects a specific environmental condition. Indicator species can signal a change in the biological condition of a particular ecosystem, and thus may be used as a proxy to diagnose the health of an ecosystem. For example, plants or lichens sensitive to heavy metals or acids in precipitation may be indicators of air pollution. Indicator species can also reflect a unique set of environmental qualities or characteristics found in a specific place, such as a unique microclimate. </span>
There is a U-shaped region called The Fertile Crescent.
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Either the first one or second one
Star dunes are mountains that can form in areas with relatively sparse sand and ever-changing winds.
<h3 /><h3>Where is the star dune easiest to find?</h3>
They are easily found in deserts, and will be formed with the transport of sediment by changing the direction of strong winds.
Therefore, the dunes are ecosystems formed by fine grains of sand from the action of the winds, forming mountains and hills of different shapes.
Find out more about dunes here:
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