The results described are of the effects of fire exclusion since 1957 on a small area of close to the forest-zone boundary, on the northern Accra Plains, Ghana. A thicket has developed, with species in intimate association with nonforest species. The component includes healthy regeneration of the important timber species, Milicia (= Chlorophora) excelsa (Benth. & Hook.) Berg (nomenclature follows Hutchinson & Dalziel [1954-721 except where authorities are given) (max. 114 cm gbh) and Antiaris toxicaria Lesch. (53 cm gbh). Ceiba pentandra is the largest and most abundant canopy tree, with a maximum girth of 2 m (height 22 m). Other large trees were Albiziaferruginea (137 cm gbh) and the remnant trees Lonchocarpus sericeus (74 cm gbh) and the naturalized exotic Azadirachta indica (99 cm gbh). AFRICAN GUINEA SAVANNAS owe their distinctive physiognomy to frequent ground fires, and only to a lesser extent to the effects of climate and grazing. At one time it was proposed that, without fire, the savannas of West Africa would have supported vegetation, and that was therefore the result of human activity. This view is not generally accepted now largely because humans have been a natural biotic influence on vegetation development in Africa for many millennia. Nevertheless, it is clear from several studies that, if is protected from fire, trees become more abundant (Trapnell 1959, Charter & Keay 1960, Mensbruge & Bergeroo-Campagne 1961, Brookman-Amissah et al. 1980, Chidumayo 1988). In 1957, R. Rose-Innes (pers. comm.) established a fenced rectangular plot slightly larger than one acre (about 0.5 ha) in an area of in the northeast corner (0?04'E, 6?08'N) of the Accra Plains in SE Ghana. Woody plants at the time were no more than 3-4 m tall. The plot has since been protected from fire and grazing by the staff of the University of Ghana Agricultural Research Station at Kpong (ARS), on whose land the plot is located. The fence is now (1989) partly in disrepair, and fire has encroached on part of the plot in recent years. No proper control sample of the vegetation in the area was kept, but the surrounding land has been regularly burned and grazed since the exclosure was established. The exclosure is on flat ground, and the soil is a tropical black earth (vertisol). Outside the exclosure, the vegetation at Kpong is a fairly typical Guinea Savanna (Jenik & Hall 1976) with short, scattered trees up to about 6 m tall, and a continuous cover of grasses. This area is within, but close to the western limit of the Dahomey gap, the phytogeographical boundary between the forests of Upper Guinea to the west and those of Lower Guinea to the east (see Hall & Swaine 1981). The species are characteristic of over a wide area of West Africa. Tree species recorded in a small sample in 1979 are listed in Table 1. Because the Lonchocarpus is so successful in these coastal savannas it will be referred to as a tree in this paper, even though in some areas it is found also in forest. The grouping of species into forest or savanna species is based on relative abundance of the species in the two vegetation types as perceived by the authors and could be misleading, except that our conclusions do not depend on the distinction.