Highlands in East Africa: Unstable slopes, unstable environments?

Mass movements are geomorphic processes affecting steeplands all over the w orld. Mass movement research is comprehensive, but has been concerned mainl y with temperate and periglacial areas, while tropical steeplands are still inadequately covered. This paper summarizes research on mass movements car ried out since the early 1990s in Nyandarua Range, Kenya and Uluguru Mounta ins, Tanzania. Research aspects include processes and causes, aspects of sc ar recovery, and effects on landscape morphology in a long-term perspective . It is argued that mass movement is the most common denuding agent in the highlands and that natural prerequisites for movement are ample, being of o verruling importance in comparison to human-induced movement. Landforms imp ly that mass movement has been paramount in long-term landscape sculpturing . Recovery of landslide scars is surprisingly fast. In Uluguru Mountains, s cars are brought back to agricultural production within about 20 years; in Nyandarua Range considerable physical and chemical recovery of scar topsoil has taken place within 10 years. Hence, land degradation by mass movement is of transient character.