Deserts beyond the sand dunes
Deserts are regions where limited precipitation strongly influences the landscape and its living communities. They are not all hot, and they are not all covered in sand. Some contain broad gravel surfaces, exposed rock, dry valleys, or salt flats. Others include cold uplands or coastal areas. Their shared feature is a shortage of moisture relative to the demands of the environment, rather than one particular appearance. Wind and occasional flowing water both help shape desert landforms. Loose sand can accumulate in dunes where suitable material and wind conditions occur. In...