Robertson Karoo low hills and flats covered in small succulent vegetation, usually growing on rocky shale-based soils. The climate is semi-arid due to the region lying in the rainshadow of the large mountain ranges to the south-west, but the rainfall does tend to occur mainly in winter. This vegetation type has a large number of endemic species and several endemic genera. Robertson Karoo Robertson Karoo is a semi-arid vegetation type, restricted to sections of the Breede River Valley, Western Cape Province, South Africa. It is a subtype of Succulent Karoo (geographically an extension of the "Little Karoo") and is characterised by the
Ryn Desert can drop to a low of . Many small towns are scattered throughout the Ryn Desert, and population density is between 1 and 15 people per square mile. The Ryn lies in a semi-arid climate zone, and receives very little rainfall. High winds sweep across the desert, and in 2001 a dust storm in the Baltic Sea was determined as originating in the Ryn Desert. A study of long-range dust transportation to the Baltic Sea region—by analyzing dust pollution in Scandinavia, showed that aerosol concentrations there were influenced more by the Ryn Desert region than the Sahara Desert in Africa.