This paper presents results from studies in 4 mountain regions in East Africa, 2 in Ethiopia (Simen Mountains, Bale Mountains), and 2 in Uganda (Rwenzori Mountains, Mount Elgon). The focus is on the ericaceous vegetation that forms the (upper) treeline ecotone at all sites. There is little evidence for climatic control of the patchy appearance of this belt in all afroalpine environments. Since traces of former fires were observed in all ranges, repeated burning is most probably responsible for the present appearance of the ericaceous vegetation in East Africa. The fires observed were almost exclusively lit by local people, who utilize the afroalpine zone for poaching, livestock grazing, and honey hunting. Although these fires are man-made and not strictly natural, they help to maintain a structurally and biologically diverse environment.