The Salar was formed as a result of transformations between several prehistoric lakes. It is covered by a few meters of salt crust, which has an extraordinary flatness with the average elevation variations within one meter over the entire area of the Salar. The crust serves as a source of salt and covers a pool of brine, which is exceptionally rich in lithium. Lithium is concentrated in the brine under the salt crust at a relatively high concentration of about 0.3%. It is also present in the top layers of the porous halite body lying under the brine. However, the liquid brine is easier to extract, by boring into the crust and pumping out the brine. The brine distribution has been monitored by the Landsat satellite and confirmed in ground drilling tests.
The Salar is virtually devoid of any wildlife or vegetation. The latter is dominated by giant cacti (Echinopsis atacamensis pasacana). They grow at a rate of about 1 cm/a to a height of about 12 m. Other shrubs include Pilaya, which is used by locals to cure catarrh, and Thola (Baccharis dracunculifolia), which is burned as a fuel. Also present are quinoa plants and Polylepis rugulosa bushes.
Every November, Salar de Uyuni is the breeding ground for three species of pink South American flamingo: the Chilean, Andean, and rare James’s flamingos, their color presumably originating from feeding on pink algae. About 80 other bird species are present.
According to en.wikipedia