Ecology and Development Series No. 10, 2003 - ZEF

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Current state of knowledgeThe studies of Friis (1992) are the latest in the series of developments towards acomprehensive classification and mapping of the forest vegetation of Ethiopia. Accordingto these, seven vegetation types occur in Ethiopia, namely: Dry peripheral semi-deciduousGuino-Congolian forest, transitional rain forest, Afromontane rain forest, undifferentiatedAfromontane forest of the Ethiopian Highlands, dry single-dominant Afromontane forest ofthe Ethiopian highlands, dry single-dominant Afromontane forest of the escarpments andriverine forest. Four forest vegetation types among these occur in SW Ethiopia. Moredetailed descriptions of these forests, namely: (A) dry peripheral semi-deciduous Guineo-Congolian forest, (B) transitional rain forest, (C) Afromontane rain forest, and (D) riverineforest, are given below.2.1.1 Dry peripheral semi-deciduous Guineo-Congolian forestThe dry peripheral semi-deciduous Guineo-Congolian forests are restricted to the Barolowlands, in Gambella State (formerly western part of the Illubabor administrative region).Chaffey (1979) was the first to make an inventory of such a forest. In the 1980s and later,several botanists and ecologists studied the forest. It occurs in a rather flat area with analtitudinal range of 450-600 m. The mean temperature is high, with a mean annualmaximum of 35-38 0 C and a mean annual minimum of 18-20 0 C. The mean annual rainfall isbetween 1300 mm and 1800 mm, and the wettest period is between May and September.The forest occurs mainly on rocky or sandy and well-drained soils, and is semideciduous,with a 15-20 m tall continuous canopy of Baphia abyssinica (which is endemicto southwestern Ethiopia and adjacent areas of the Sudan), mixed with less common speciessuch as Celtis toka, Diospyros abyssinica, Lecaniodiscus fraxinifolius, Malacanthaalnifolia, Trichilia prieureana, Zanha golungensis, and Zanthozylum leprieurii. Somespecies which emerge high above the main canopy are: Alstonia boonei, Antiaris toxicaria,Celtis gomphophylla, and Milicia excelsa. Small trees such as Acalypha neptunica,Erythroxylum fischeri, Tapura fischeri, Ziziphus pubescens, and Xylopia parviflora form acontinuous stratum below the canopy. The shrub layer is composed of Alchornea laxiflora,Argomuellera macrophylla, Mimulopsis solmisii, Oncoba spinosa, Oxyanthus speciosus,Rinorea ilicifolia, and Whitfieldia elongata.11
Current state of knowledgeLianas are not common. However, the lower strata of the forest are often denselypopulated with woody climbers. There is no record of any epiphytic species. The ground ismostly covered with thick litter, and there are apparently very few species of forest floorherbs except Streptogyna crinita.2.1.2 Transitional rain forestThe transitional rain forest is found on the escarpments of the southwestern highlands inWelling, Illubabor and Kufa, between the dry peripheral semi-deciduous Guineo-Congolianforest and the Afromontane rain forest. These forests occur at altitudes between 500 and1500 m, partly in river valleys, and partly in areas with a high water table. The annualtemperature ranges from 20-25 0 C. The mean annual rainfall is about 2000 mm, with rainfalling all year round, the highest amounts falling in September. More detailed informationabout such forests is found in some Italian sources (Friis 1992) and Chaffey (1979). Thetransitional rain forests are similar in physiognomy and composition to the humid broadleavedAfromontane rain forest of southwestern Ethiopia described below, with additionalspecies from the lowland forest described above. However, a few species of forest trees orshrubs known in neither of these two forests appear to be restricted to the transitional forest.A list of these species includes: Aningeria altissima, Anthocleista schweinfurthii,Campylospermum bukobense, Celtis philippensis, Celtis zenkeri, Croton sylvaticus,Dracaena fragrans, Elaeodendron buchananii, Eugenia bukobensis, Ficus exasperata,Garcinia huillensis, Manilkara butugi, Morus mesozygia, Phoenix reclinata, Strychnosmitis, Trichilia dregeana, Trilepisium madagascariense and Vepris dainellii. Friis (1992)noted that this forest type may contain Guineo-Congolian forest species, which are not yetrecorded in Ethiopia. This forest type, therefore, deserves further studies.2.1.3 Afromontane rain forestThese forests occur in the SW highlands and on the Bale Mountains in the SE highlands ofEthiopia. They characteristically contain a mixture of Podocarpus and broad-leavedangiosperm species in the canopy, but Podocarpus becomes gradually more infrequenttowards the southwest of Kafa and Illubabor, while Aningeria adolfi-friederici becomes12
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Page 4 and 5: Wäldern weist im Wesentlichen zwei
Page 6 and 7: 4.4 Discussion ....................
Page 8 and 9: General introduction1 GENERAL INTRO
Page 10 and 11: General introductionoutbreaks and e
Page 12 and 13: General introductionunfavorable cha
Page 14 and 15: General introductionand their patte
Page 16 and 17: Current state of knowledge2 STATE O
Page 20 and 21: Current state of knowledgemore prom
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Floristic analysis of the undisturb
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Impacts of human use on the forest
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Conservation of the wild Coffea ara
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Conclusions and recommendations7 CO
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Conclusions and recommendations3. R
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ReferencesBatisse M. 1986 Developin
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ReferencesDavis A.P. and Rokotonaso
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ReferencesESRI. 1996. ArcView GIS:
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ReferencesIUCN 1992. Protected Area
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ReferencesMesfin Ameha and Bayetta
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ReferencesSmith R.F. 1985. A histor
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ReferencesVan Jaarsveld A.S., Freit
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Appendices9 APPENDICESAppendix 1 Li
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AppendicesD. repandum (Vahl) DC, [H
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AppendicesSapotaceaeAningeria altis
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AppendicesAppendix 3 Families of va
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AppendicesAppendix 5. ANOVA tables:
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AppendicesAppendix 7 Height class d
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AppendicesGFUNDFOR OLSFOR SF-NEW SF
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AppendicesAppendix 10. List of loca
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AppendicesNumber Family name Scient
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ACKNOWLEDGEMENTSI am very grateful
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Ecology and Development Series No. 10, 2003 - ZEF

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