Ajai

A(i)Site contains one or more globally threatened species

Ajai qualifies as an IPA under criterion A(i) triggered by the presence of the globally threatened tree species of Ochna leucophloeos subsp. ugandensis (Endangered) and Xylopia nilotica (Vulnerable).

Ajai Important Plant Area (IPA) matches the Ajai Wildlife Reserve (WR). Named after Chief Ajai, the site was declared a Game Sanctuary in 1937, a White Rhino sanctuary in 1962 (Byaruhanga et al. 2001) and later as a Game Reserve under the Game Department in 1965 (UWA 2021, UNEP-MCMC 2025). It was designated a Wildlife Reserve in 2002 and is managed by Uganda Wildlife Authority (UWA). The Northern White Rhino (Ceratotherium simum subsp. simum) is now locally and nationally extinct in the wild, but efforts are being made to re-introduce the species in Ajai WR.

Ajai IPA is located in Madi Okollo District (West Nile region), within the U1 floristic region of Uganda. To the West it is bordered by the seasonal rivers Linya and Ala and the South-East by River Acharo, while to the East it touches the Albert Nile. The IPA is 431 km northwest of the capital city Kampala. It covers an area of 166 km2 (UWA 2021) and its altitudinal range is 620 to 880 m ASL (Google Earth 2025).

Ajai IPA is a small but important site. It is one of the four known localities for occurrence of the globally
Endangered tree, Ochna leucophloeos subsp. ugandensis (Rotton et al. 2024), in Uganda. This subspecies is rare and endemic to Uganda, known from four herbarium collections, only protected in Ajai and Toro-Semliki Wildlife Reserves, both of which are IPAs. Ajai and Toro-Semliki WRs are hence the most important sites in Uganda for conservation of this taxon.

The site also contains the Vulnerable small tree Xylopia nilotica (Cosiaux et al. 2019). This is a very rare species, known only from three other countries, i.e. Ethiopia, South Sudan and Sudan (Friis and Weber 2024). In Uganda, it is known from only four collections, with only two, Ajai and Murchison Falls National Park, another IPA, where it is protected (IUCN and UNEP-WCMC 2018). The globally threatened (Vulnerable) tree Vitellaria paradoxa (Syn Butyrospermun paradoxum) also occurs in this IPA.

In a botanical study conducted by Kalema (2005), Ajai registered a total of 423 species of plants from 260 genera and 83 families. Albizia species are listed in Uganda as Reserved Tree Species under Schedule 8 of the Forestry and Tree Planting Act 2003. Those occurring in Ajai IPA are A. coriaria, A. malacophylla var. ugandensis and A. zygia.

Within the site, Langdale-Brown et al. (1964) recognized six different vegetation types: Swamp; communities on sites of impeded drainage; Dry Combretum savanna; Moist Combretum savanna; Dry thicket; Grass savanna and Post-cultivation communities. Kalema (2005) described the vegetation as mostly wooded grassland with Combretum, Terminalia and Acacia spp. The ridge to the Southwest particularly supports the dry savanna of Loudetia simplex wooded with Combretum collinum, Hexalobus monopetalus var. monopetalus, Strychnos innocua and Terminalia macroptera. There are areas of moist Acacia polyacantha-Panicum maximum savanna that grade into moist woodland. The woodlands adjoin Phoenix swamp forests along the major rivers. In some instances, these grade into permanent swamps of Echinochloa, Leersia and eventually Phragmites-Cyperus papyrus community, especially along the Nile. The drier parts support Acacia, Combretum, Hyperthelia and Hyparrhenia. The small shallow valleys support Chloris gayana, Brachiaria, Panicum and sometimes Echinochloa.

Lying within the Sudanian Regional Centre of Endemism, the climate of this IPA is characterized by a unimodal rainfall distribution with one long wet season that occurs between April and October and a dry spell from November through March (Uganda Government 1967). The geology of Ajai is composed of Cainozoic rocks with Rift Valley sediments (Uganda Government 1967). The soils are predominantly Ferralitic, dominant colour red, on loose sandy sediments. These are usually deep with little differentiation into clear horizons, and with a fine granular structure (Government of Uganda 1967). There are also Vertisols with black cracking clays (Black cotton soils), mostly in depressions and low-lying sites with poor internal drainage. The terrain is predominantly undulating with shallow depressions of seasonally flooded grassland areas. The highest point is a ridge in the southwestern part of the IPA, and this is bouldery with gravelly soils.

Ajai is also a Key Biodiversity Area (KBA) and an Important Bird Area (IBA) including two globally Near Threatened bird species, the Shoebill (Balaeniceps rex) and Papyrus Gonolek (Laniarius mufumbiri). Despite these important designations, the IPA suffered heavy encroachment by the local communities who had opened up a number of areas for cultivation, causing heavy degradation (Kalema and Beentje 2012). Others had settled inside the reserve (Kalema 2005). The reserve is bordered by communities that depend entirely on agricultural activities, including farming and bush burning. Fishing villages expanded into the reserve, and this encouraged encroachment by local people (Key Biodiversity Areas Partnership 2025). Tree felling for charcoal burning also goes on in the IPA. There is also illegal grazing and uncontrolled bush burning in the reserve, reducing habitat quality.

There is hope that during the 2021-2031 General Management Plan, the extinct White Rhino, for which the reserve was known, will be re-introduced and the population of large mammals will continue to rise (UWA 2021). This will inevitably lead to a reduction of the threats facing the habitat, thereby enhancing the conservation of the trigger species (see 'Botanical significance')

Ajai IPA is important for provisioning, regulatory and supporting services in the area, and has important resources for community livelihood and socio-economic activities. The surrounding communities have had historical access and use rights, including for animal grazing, and fishing, as well as the collection of firewood, poles for construction, thatching grass and medicinal plants. They attach strong cultural values to the site, including Ajai Island, which was the palace of the renowned Chief Ajai (UWA 2021). These services support community livelihoods.

The IPA serves as a key water shed for rivers including the Nile and its tributaries. It supports the constant flow of water to the surrounding communities, filtering it and regulating water yield. The vegetation cover supports the hydrological cycle and controls floods, reducing surface erosion and protecting against sedimentation.

The diverse vegetation types provide a wide range of habitats, that support faunal diversity including the wetland habitat-specific Sitatunga, and some primates such as the Black and White Colobus Monkey. The IPA is therefore a wildlife habitat supporting a variety of vertebrate and invertebrate fauna. Ajai qualified as an IBA on account of two criteria: the presence of Globally Threatened species viz: the Shoebill and the Papyrus Gonolek, both of which are Near Threatened; and the Sudan–Guinea savanna biome species (Byaruhanga et al. 2001). It has been evaluated and found to be a suitable habitat for the now locally extinct Northern White Rhino, with advanced plans to have the species reintroduced (UWA 2021). The re-introduction is expected also to bolster conservation and tourism in the reserve.

The site also has high aesthetic values such as attractive scenery of the Nile bank and extensive grasslands and wetlands that can be viewed from high elevation points, especially in the western part of the IPA. The site also provides opportunities for education, research and recreation.

Assessed by:

James Kalema, Makerere University Herbarium

Iain Darbyshire, Royal Botanic Gardens, Kew

Samuel Ojelel, Makerere University Herbarium

Haley Gladitsch, Royal Botanic Gardens, Kew

Date of first assessment: 6th Feb 2025

Reviewed by:

Edgar Buhanga, Uganda Wildlife Authority