This book contributes to the research into natural vegetation and land use in semi-arid areas, by providing a survey of forest types and individual species in the climatically vulnerable "Horn of Africa" - Ethiopia, Somalia and Djibouti. This research is needed in order to stop increasing environmental degredation and the spread of deserts, impoverishment and famine. The ecology and plant geography of the area is discussed and illustrated with the aid of species distribution and land use maps.