Soil analytical and taxonomic data of 27 Observatories, being distributed along the BIOTA transects from Northern Namibia to the Cape Peninsula and produced with a standardised procedure for each site have been evaluated with respect to overarching factors for the soil genesis and pedodiversity. Of twelve soil reference groups found, Arenosols and Leptosols were dominant. Signifi cant trends between topsoil median values (pH, electric conductivity, organic carbon content) and annual precipitation could be described; nevertheless for all distributions some Observatories exhibit special conditions. For both rainfall regimes (summer and winter rainfall) the total organic carbon stored within the soil profi les seems to have the same positive correlation to annual rainfall, however for identical rainfall amounts the carbon pools are varying by a factor of three, among other factors controlled by soil clay content. The pedodiversity of the studied sites varies strongly (2–20 types of 25 possible). In general, soilscapes predominantly build up by aeolian sands are mostly homogenous whereas soils in mountainous areas exhibit the highest richness. Plains and salt enriched areas are of medium pedodiversity.