Atlas of the potential vegetation of Ethiopia

Abstract

A new map of the potential vegetation types of Ethiopia has been produced at the scale of 1:2,000,000. It is published here as an atlas with 29 map plates. The map shows the distribution o f twelve potential vegetation types that can be mapped using environmental parameters and GIS-methodology. In the accompanying text these vegetation types have been described and further divided into a number o f subtypes. The types and subtypes are: (1) Desert and semi-desert scrubland. (2) Acacia-Commiphora woodland and bushland (with the subtypes (2a) Acacia-Commiphora woodland and bushland proper and (2b) Acacia wooded grassland of the Riß Valley). (3) Wooded grassland of the western Gambela region. (4) Combretum-Terminalia woodland and wooded grassland. (5) Dry evergreen Afromontaneforest and grassland complex (with the subtypes (5a) Undifferentiated Afromontane forest, (5b) Dry single-dominant Afromontane forest of the Ethiopian highlands, (5c) Afromontane woodland, wooded grassland and grassland, (5d) Transition between Afromontane vegetation and Acacia-Commiphora bushland on the Eastern escarpment). (6) Moist evergreen Afromontane forest (with the subtypes (6a) Primary or mature secondary moist evergreen Afromontane forest, and (6b) Edges of moist evergreen Afromontane forest, bushland, woodland and wooded grassland. (7) Transitional rainforest. (8) Ericaceous belt. (9) Afroalpine belt. (10) Riverine vegetation. (11) Fresh-water lakes, etc. (with the subtypes (na) Fresh-water lake vegetation (open water) and (nb) Freshwater marshes and swamps, floodplains and lake shore vegetation). (12) Salt lakes, etc. (with the subtypes (12a) Salt lake vegetation (open-water) and (12b) Saltpans, saline/brackish and intermittent wetlands and salt-lake shore vegetation). The taxonomic revision of the Ethiopian flora for the Flora of Ethiopia and Eritrea has been completed, and intensive field studies of the flora have been carried out over nearly the entire country, after the publication of two previous detailed vegetation maps of Ethiopia, by Pichi Sermolli in 1957 and by Frank White in 1983 - both at the scale of 1:5,000,000; this new information has been incorporated in the present map. New ideas about the classification of Ethiopian vegetation have also been put forward on maps produced on smaller scale. Here, the vegetation types used for the last two vegetation maps in 1:5,000,000 and the later maps on smaller scales are reviewed and discussed, and the definitions of most previously accepted vegetation types have been revised. Definition of a characteristic forest type, Transitional rainforest, in south-western Ethiopia has been completely reworked, and, for the first time, it has been attempted to classify saline vegetation on a vegetation map o f Ethiopia. The vegetation atlas has been produced using a digital elevation model with a resolution o f 90 x 90 metres in connection with GIS technology; it is based on information from previous literature, field experience of the authors, as well as on an analysis of information about approximately 1300 species of woody plants in the completed Flora of Ethiopia and Eritrea.