Mabira Forest Reserve is the largest block of moist semi-deciduous forest remaining in the central region of Uganda. The reserve occupies gently undulating country, characterized by numerous flat-topped hills and wide, shallow valleys. Some of these valleys have papyrus (Cyperus papyrus) swamps. The topography is such that the land drains to the north, even though the reserve’s southern boundary lies only 13 km from the shores of Lake Victoria. Forest in the reserve covers c.29,000 ha and is considered to be secondary, in which the distinct vegetation-types are sub-climax communities, heavily influenced by humans over prolonged periods of time. The reserve is isolated from other protected areas by settled agricultural land. Commercial use began when some parts were harvested for timber in the early 1900s, and until 1988, agricultural encroachment for intensive coffee/banana plantations was badly damaging large parts of the reserve. The closeness of Mabira to Kampala, and the presence of various ecotourism facilities, make this IBA a popular site for visitors.
See Box and Table 3 for key species. The list for Mabira Forest Reserve contains almost 300 species. Many species of the Guinea–Congo Forests biome are not well-represented in other protected areas in Uganda, for instance Francolinus nahani, Caprimulgus nigriscapularis, Phyllanthus atripennis, Macrosphenus concolor and Trochocercus nitens. Mabira Forest was heavily encroached in the 1970s and 1980s, which may have had adverse effects on the forest birds, particularly on the habitat specialists. Three species of the Lake Victoria Basin biome are known, but further surveys in the valley papyrus swamps could reveal more. The site also holds one species of the Sudan–Guinea Savanna biome and four of the Afrotropical Highlands biome.
Non-bird biodiversity: Two hundred and two tree species have been recorded, including one (Diphasia angolensis) not known from elsewhere in Uganda. Five tree species from this reserve are of international conservation concern: Milicia excelsa (LR/nt), Cordia millenii, Irvingia gabonensis (LR/nt), Entandrophragma angolense(VU) and Lovoa swynnertonii (EN). The present status of the larger mammals is not known; Loxodonta africana (EN) was last recorded in the mid-1950s.
Pressure/threats to key biodiversity
About 21% and 26% of the reserve have been designated as Strict Nature Reserve and Buffer Zone, respectively, and forest in these areas is currently recovering, helped by extensive plantings of native tree species. The forest is surrounded by a densely populated area and there are several villages within its boundaries, all of which existed before its designation as a Forest Reserve. Mabira has been mechanically harvested for timber since 1906, but the management has often been poor. The forest was one of the main sources of charcoal to the nearby towns of Jinja and Kampala, and produced an estimated 1,500 tons (60,000 bags) per year in the 1960s. In the 1980s, the forest was heavily encroached by settlers and subsistence farmers, encouraged by politicians. In 1988, the Forest Department enumerated a total of 3,506 families who lived or cultivated in the reserve. As a result, over 25% of the reserve was heavily degraded or cleared. However, the encroachers were evicted in 1988. Despite this, illegal activities such as pit-sawing, charcoal-burning, collection of poles (for building) and of medicinal plants have continued, although on a reduced scale. Mabira represents the best opportunity to maintain a complete forest community characteristic of this important biogeograghical region. Also, by virtue of its location between two main urban centres, the reserve is likely to assume increasing importance as a recreational area; it is already popular for picnics, walks and trail-biking.
BirdLife International (2019) Important Bird Areas factsheet: Mabira Forest Reserve. Downloaded from
http://www.birdlife.org on 22/05/2019.