Bonga forest (6284)
Ethiopia, Africa

Site overview

KBA status: confirmed

Year of last assessment: 2011

National site name: Bonga forest

Central coordinates: Latitude: 7.2100, Longitude: 36.2900

System: freshwater, terrestrial

Elevation (m): 1000 to 3400

Area of KBA (km²): 1648.71541

KBA classification: Global/Regional TBD

Legacy site: Yes

Site details

Site description: Bonga forest is in Keficho-Shekicho Zone, south-west Ethiopia. The zonal capital, Bonga, is c.100 km south-west of Jimma. Bonga forest cloaks the highland area to the east of the Dincha river. The area comprises ridges and valleys through which the Guma, Sheko, Bittno and Ihina rivers and several small streams drain into the Dincha. Habitats include rivers and streams with riverine forest, upland montane forest and an Erica arborea zone above 3,000 m. The main forested area is broadleaf (Afro-montane) forest, which lies between 1,500 and 2,500 m and has many large tree species forming a canopy 10–>30 m high. The tallest trees are Aningeria adolfi-friderici. Other canopy species include Ocotea kenyensis, Olea capensis, Sapium ellipticum, Macaranga capensis, several species of Albizia, Euphorbia ampliphylla, Polyscias fulva, Schefflera abyssinica and several different Ficus spp. There is a rich understorey that includes the tree-fern Cyathea manniana found in moist ravines and near waterfalls, Dracaena steudneri and Coffea arabica. The higher parts of the forest support smaller trees such as Hagenia abyssinica and Prunus africana. Bonga forest has long been exploited for its large timber species and this is continuing. Some areas have been left to regenerate naturally, but over 2,000 ha have been planted with exotic and native species such as Eucalyptus, Hagenia abyssinica, Cordia africana, Cuppressus, Grevillea and Pinus patula. Local people make extensive use of the forest and many non-timber forest products are collected, particularly coffee and honey.

Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance because it meets one or more previously established criteria and thresholds for identifying sites of biodiversity importance (including Important Bird and Biodiversity Areas, Alliance for Zero Extinction sites, and Key Biodiversity Areas) KBA identified in the process of compiling the CEPF Ecosystem Profile of the East Afromontane Hotspot. Species taxonomy and threat category was based on IUCN Red List 2010-4. The site holds a significant population of the following plant species which, although not yet Red-List-assessed at the global level, are thought likely to be categorised as globally threatened once assessed (thus meeting the KBA Vulnerability criterion), based on existing regional or national Red List assessments (species also considered as site-endemic are tagged with Irr1 [KBA Irreplaceability 1 criterion]): Dorstenia soerensenii, Justicia bizunesiae, Rinorea friisii, Scadoxus nutans, Sesbania melanocaulis, Vepris dainellii. The forest coffee, Coffea arabica, of Bonga is genetically important, as it was from this area, near Wushwush, that the first plants with natural resistance to coffee berry disease were identified. Tree-ferns Cyathea manniana are known from only a few locations in Ethiopia; they require well-shaded and moist conditions to grow and would disappear if the forest were destroyed.

Additional biodiversity: See Box and Table 3 for key species. The forest avifauna in south-west Ethiopia is less diverse than in the country’s bushland habitats. During surveys in December 1995, 100 species were recorded at this site. Afrotropical Highlands biome species include Lybius undatus and good numbers of Poeoptera stuhlmanni. Other interesting forest species present are Apaloderma narina and Coracina caesia. Cisticola troglodytes has also been recorded from the area. Non-bird biodiversity: Although there are no endemic tree species in these forests, undergrowth and epiphyte diversity is high and includes endemics such as cardamom Aframomum corrorima.

Delineation rationale: 2013-07-10 (BL Secretariat): following CEPF East Afromontane ecosystem profiling process, the reported IBA area of 161423 ha has been changed to 160000 ha (as measured in GIS from latest boundary polygon, rounded to nearest 10%).

Habitats

Land use: agriculture | forestry | water management

IUCN Habitat	Coverage %	Habitat detail
Artificial - Terrestrial	37
Forest	61
Wetlands(Inland)	2

Threats

Summary of threats to biodiversity at KBA: High-altitude forest is severely threatened in Ethiopia. Although Bonga forest is designated a National Forest Priority Area, little has been done to enforce the existing legislation. The current forest extent is unknown, but it has decreased since the 1970s. The forest is next to two major roads, making the removal of timber relatively easy. The more accessible parts of the forest are highly disturbed and now comprise thick undercover that could certainly be a hindrance to the larger mammals reported to occur. The fact that any forest remains is almost certainly due to the broken terrain within the Dincha watershed. Major threats include the introduction of exotic tree plantations, clearance for agriculture, and some grazing. The effect of grazing is currently not serious, but could become so, severely affecting the potential for forest regeneration. The forest coffee, Coffea arabica, of Bonga is genetically important, as it was from this area, near Wushwush, that the first plants with natural resistance to coffee berry disease were identified. Tree-ferns Cyathea manniana are known from only a few locations in Ethiopia; they require well-shaded and moist conditions to grow and would disappear if the forest were destroyed.

Threat level 1	Threat level 2	Threat level 3	Timing
Biological resource use	Logging & wood harvesting	Unintentional effects: large scale (species being assessed is not the target) [harvest]	Ongoing
Agriculture & aquaculture	Wood & pulp plantations	Agro-industry plantations	Ongoing
Agriculture & aquaculture	Livestock farming & ranching	Small-holder grazing, ranching or farming	Ongoing
Agriculture & aquaculture	Annual & perennial non-timber crops	Small-holder farming	Ongoing

Additional information