Montane rainforest with wild Coffea arabica in Bonga region (SW Ethiopia): plant diversity, wild coffee management and implications for conservation

The montane rainforests of Ethiopia are the center of origin and genetic diversity of Coffea arabica L. (Rubiaceae). They form part of the Eastern Afromontane biodiversity hotspot due to the high threat of deforestation. Concepts for conservation of these forests and their wild coffee populations are urgently needed. For the present study, vegetation surveys were carried out in four forest fragments in the Bonga region (southwestern Ethiopia) situated between 1,560 and 2,280 m asl. A total of 309 vascular plant species including 16 endemics were recorded; 36 % of the species occur in all forest fragments, while 43 % are present in one fragment only. Ordination methods reveal that plant species composition is strongly influenced by the altitudinal gradient. The forest fragment Koma, which is located above 1,800 m asl, is characterized by high pterophyte diversity and high abundance of Afromontane endemics or near endemics. Forest below 1,800 m asl has a greater diversity of tree species and pytogeographical elements, and is further divided in a moister type (Mankira forest fragment) and a drier type (Kayakela forest fragment).