For example: Iran falls within the Middle East arid zone, with some 13% of the country receiving less than 100 mm mean annual rainfall, an additional 61% receiving less than 250 mm and only 9% receiving more than 500 mm.
<em>First we have to know exactly what is the meaning of niche construction: ( Niche construction is the process by which an organism alters its own (or another species') local environment. These alterations can be a physical change to the organism’s environment or encompass when an organism actively moves from one habitat to another to experience a different environment. Examples of niche construction include the building of nests and burrows by animals, and the creation of shade, influencing of wind speed, and alternation of nutrient cycling by plants. Although these alterations are often beneficial to the constructor they are not always (for example, when organisms dump detritus they can degrade their own environments).</em>
