Semuliki

A(i)Site contains one or more globally threatened species, B(iii)Site contains an exceptional number of socially, economically or culturally valuable species, C(iii)Site contains nationally threatened or restricted habitat or vegetation types, AND/OR habitats that have severely declined in extent nationally

Semuliki National Park qualifies as an IPA under sub-criterion A(i), with three globally Endangered species and four Vulnerable species meeting IPA thresholds.
This site also triggers IPA criterion B(iii) for exceptional botanical richness in useful species, with 9% of the national checklist, and C(iii) as one of the five best areas of medium altitude, semi-deciduous forest nationally.

Semuliki National Park, formerly Bwamba forest, is within Bundibugyo District of Western Uganda. Covering an area of 220 km2 (UNEP-WCMC 2022), the site falls within the Albertine Rift region and is the lowest altitude forest in Uganda. Bordered in the west by the Semuliki River, this IPA forms a section of the border between D.R. Congo and Uganda, while in the east the site is bordered by the Fort Portal-Bundibugyo Road. Overlooking Semuliki National Park in the southeast is the northern spur of the Ruwenzori Mountains. This site was visited in February 2023 as part of the Uganda TIPAs project and some of the information below is based on observations made during this fieldwork.

Semuliki National Park is unique nationally as the lowest-altitude forest in Uganda, with altitudes as low as 652 m. The IPA is an important area of medium altitude semi-deciduous forest, encompassing 6.8% of the national area of this habitat and being one of the five best sites nationally for this habtiat.
Seven threatened species are known from this IPA including three Endangered species: Chlorophytum hirsutum, an Albertine Rift endemic, Oxyanthus ugandensis, which is known from only three localities globally including Semuliki NP, and Justicia francoiseana, which is highly disjunct known also from a small number of localities in Mozambique and Zimbabwe. The latter species was collected for the first time within Semuliki during fieldwork in 2023 and only a small number of individuals were seen.
Five Vulnerable species have also been recorded at this site. One of these, Cnestis mildbraedii, is of particular note as the IUCN Red List assessment states that this species is “only effectively protected at Semuliki National Park” (Amani et al. 2022), while for another, Leptonychia semlikiensis, Semuliki NP encompasses the entire national population of this species (Rotton et al. 2023). This species was found to be locally abundant in the Sempaya area of the national park during fieldwork by the Uganda TIPAs project in 2023. Although not threatened with extinction, Semuliki NP is similarly important for Euphorbia bwambensis as the entire national population is restricted to this site. Only two other localities, Okapi Wildlife Reserve in D.R. Congo and Kasye Forest in Tanzania, are known globally for this species (Luke et al. 2019).
One of the five Vulnerable species, Afzelia bipindensis, is a timber species that is nationally highly localised to Semuliki as a lowland forest species, and is threatened by overexploitation (Brenan 1967; African Regional Workshop 1998; World Conservation Monitoring Centre 2017). A. bipindensis is one of 103 useful plant species known from this IPA. Semuliki therefore triggers criterion B(iii), for exceptional botanical richness in useful species, as it contains 9% of the national checklist, well above the 3% trigger threshold. Semuliki is one of the top 15 most species-rich sites, ranking 12th within the IPA network. The site holds a significant proportion of species under the “materials” use category nationally (65 spp., 21%), including Bridelia scleroneura and Albizia coriaria.
Botanical survey of this extensive site is far from exhaustive, 2023 Uganda TIPAs fieldwork for instance found two species which had not previously been recorded from Uganda, Bertiera aethiopica and Campylospermum lunzuense. Further fieldwork may well find new records, including range-restricted and threatened plant species.

Much of the site is dominated by Cynometra alexandri forest, along with other tree species like Elaeis guineensis and Ficus spp. commonly co-occurring in areas of mixed forest. The shrub layer is variable with species of Celtis, Alchornea, Capparis and Vepris frequent. In wetter areas, trees of Macaranga and Cola are more frequent, and in waterlogged swamp forest, Elaeis and Tabernaemontana dominate with frequent Pandanus and Mitragyna. Open areas of waterlogged marsh are dominated by sedges of Elaeocharis, while shrubs of Pluchea are common.
Within the marshes near Sempaya are hot springs in sedimentary rock associated with the Rift Valley bounding faults at the foot of the Ruwenzori Mountains, with maximum temperatures close to 95°C (Schumann et al. 2015). Much of the landscape is flat, with some gentle undulations in places. The substrate consists largely of poorly drained alluvial clay soils of low fertility.

The site was first designated as a Central Forest Reserve in 1932 and upgraded to a National Park in 1993, coming under the management of the Ugandan Wildlife Authority (Howard 1991; UNEP-WCMC & IUCN 2022). The site is largely secure and well-staffed with Uganda Wildlife Authority (UWA) rangers. However, some threats to the site remain. While collection of deadwood from the multiple resource use zone by communities adjacent to the park and limited felling of exotic tree species is permitted within the national park under the exotic eradication program for ecosystem management, with access regulated by UWA, we observed also evidence of small-scale, mechanized felling of native tree species.

Coffee and Cacao were previously planted by the local communities within the forest reserve before it was upgraded to National Park status. While this practice has since ended, with these species instead growing now on neighbouring community land, Theobroma cacao is propagated by monkey species at the site and is frequent, particularly in the eastern areas of the National Park.

Exotic and invasive species at this site include Cedrela odorata, Senna siamea and Toona cilliata (CUPTD workshop, pers. comm 2023) including Terminalia species (Balyesiima Godfrey, pers.com 2024) Excessive flooding in parts of the national park has led to tree die-back around the Kirimia and Tokwe Rivers and, anecdotally, it has been suggested that weather extremes caused by climate change and poor land use practices may be responsible.

Semuliki is a hotspot for ecotourism, with bird and butterfly diversity being a particular draw for enthusiasts, while charismatic mammals such as primates are also known from this site (UWA 2023). The hot springs in the southeast of Semuliki are also a significant tourist attraction.
Semuliki NP has cultural importance to the Bamaga clan, with communities believing that female and male ancestors reside within the “Female” and “Male” Hot Springs, respectively. The springs are, as a result, used for cultural ceremonies where local people might ask their ancestors for assistance, for example, good health, fertility, bumper crop harvest, luck or financial prosperity.
Local communities are permitted by UWA to collect water, fish, craft materials (Rattan cane, phoenix leaves, Marantochloa etc), firewood and herbs for medicinal purposes a few times a month, though collection by debarking trees has been banned due to commercialization and evident drying of the affected species. The site qualifies as one of the richest in Uganda for useful plant species (see Botanical Importance). The oil palm, Elaeis guineensis, is frequent within the forests, although local communities tend to obtain palm nuts from trees outside the national park.

Sophie Richards, Royal Botanic Gardens, Kew

Iain Darbyshire, Royal Botanic Gardens, Kew

Florence O'Sullivan, Royal Botanic Gardens, Kew

Samuel Ojelel, Makerere University Herbarium

James Kalema, Makerere University Herbarium

Haley Gladitsch, Royal Botanic Gardens, Kew

Date of first assessment: 23rd Dec 2024

Balyesiima Godfrey, Semuliki National Park