The hot, barren, sandy images of deserts presented in movies has perpetuated a myth. Presented as wastelands in many land use inventories, deserts support irrigated agriculture, riparian forests, and extensive rangelands. Desert varnish Rock varnish coatings are not unique to arid climates but are a widespread phenomenon occurring in tropical and high-altitude environments. The orange, gray, brown, or black coatings have physio-chemical and biological origins. Salinity Not all aridic soils, especially the sandy soils, are high in salts and bases.
Sandy soils allow rapid infiltration of water and leaching of salts.
In areas of intense rainfall leaching, acidification can be significant, especially when the microbasins that are typical of sandy plains capture all the runoff. This can result in Alfisols occurring on the microhummics and Ultisols in the microbasins, a common occurrence in the sandy plains of Sahelian Africa. Closed basins in deserts are not always salty, as in Lake Chad of Saharan Africa which has a complex biological sink that maintains low levels of salts in its water. Geomorphology of desert environments. Management of problem soils in arid ecosystems.