Tororo Rock

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

Tororo Rock qualifies as an IPA under criterion A(i) as it contains a major portion of the global population of Aloe tororoana, a species currently assessed on the IUCN Red List as Vulnerable.

Tororo Rock is a prominent volcanic peak situated within Tororo District of Eastern Region, Uganda, within 10 km of the Kenya border. It falls within the Tororo municipality, rising precipitously ca. 280 m above the surrounding town to a maximum height of 1,428 m. The slopes of the mountain support intact bushland, and extensive areas of exposed rock with a lithophytic flora on the steeper slopes.

Tororo Rock is of global botanical importance for holding the largest and most secure population of the Ugandan endemic aloe, Aloe tororoana. Here, A. tororoana grows plentifully on steep and often inaccessible slopes and cliffs in areas without dense vegetation (Carter et al. 2011; Andima et al. 2014; Cole & Forrest 2017). It is currently assessed on the IUCN Red List as Vulnerable under criterion D2 (IUCN SSC East African Plants Red List Authority 2013), but given ongoing threats to some of its subpopulations, this assessment should be upgraded to Endangered under criterion B. Away from Tororo Rock, it is known only from the Osukuru (Sukulu) Hills to the southwest of Tororo, which are subject to ongoing and planned industrial activity through the Osukuru Industrial Complex, including phosphorite and iron ore deposits. A record of this species from the Toror Hills in the Northern Region of Uganda (based on H.C. Dawkins #636, MO), mentioned in the Red List assessment, is believed to be in error as this site is a long way out of the range for this species.

Tororo Rock is a volcanic plug comprising carbonatite (high-carbonate alkaline igneous rock) of Middle Eocene age (ca. 40 Ma), as an intrusion within Pre-Cambrian syenites (Williams 1952; HiTech AlkCarb 2022). Other, lower lying carbonatite outcrops occur immediately to the south of the rock, but these are not included in the IPA because they have been extensively denuded of vegetation. Tororo Rock is surrounded by urban development, but as the slopes steepen, natural bushland vegetation remains intact. On the steeper slopes there are areas of bare rock with pockets of shallow soil that support a succulent flora including Aloe tororoana and Euphorbia magnicapsula, both plentiful here.

Tororo experiences a humid climate, with average annual rainfall of over 2,000 mm. The main wet season peaks in April and May, with a shorter wet season in November-December; minimum rainfall months are February and July.

Tororo Rock is included in Uganda’s Key Biodiversity Areas network based on the population of Aloe tororoana (Plumptre et al. 2017). However, this site is not formally protected at present and it faces a number of threats, in part driven by its proximity to Tororo town. Encroachment for settlement and agriculture, cattle grazing, uncontrolled burning and harvesting of firewood and poles continue to degrade the vegetation, particularly on the lower slopes (P. Nyadoi, pers. comm. 2022). Past extraction of the carbonatite rock for local construction and roadbuilding has occurred but community protests led to this being halted (IUCN SSC East African Plants Red List Authority 2013). However, the lower-lying extrusions of carbonatite immediately to the south of Tororo Rock, outside of the IPA boundary, are mined for cement. The erection of a series of telecommunication masts at the summit of the rock with associated power lines resulted in localised clearance of vegetation (IUCN SSC East African Plants Red List Authority 2013). Tourist footfall at the site is significant, with ladders having been erected to allow easy access to the summit, but the tourist route is clearly defined and most of the populations of the Aloe are on inaccessible parts of the cliff. Rock climbing by mountaineers may, however, cause some erosion of the species’ fragile habitats. There are also some concerns over unsustainable harvesting of the Aloe for its medicinal uses (see Key Ecosystem Services below).

Between 2014 and 2018, Uganda Wildlife Society implemented a conservation initiative at this site which included replanting of some indigenous species and collaborating with Tororo District council and local communities to promote the protection of the fragile habitats and to develop an ordinance for the site. However, the funded project ended before completion of the ordinance, and some recommendations were not implemented, including the formal demarcation of the site boundary (P. Nyadoi, pers. comm. 2022).

Tororo Rock is an important site for tourism in eastern Uganda, and the 1–2-hour hike to the summit for the panoramic view over the Uganda-Kenya border region is a popular attraction, alongside rock-climbing. The presence of ancestral caves and rock paintings are of cultural importance to the Jopadhola people, and add to the tourist appeal (Uganda Tourism Center 2022). This tourism provides a source of income for local businesses and tourist guides (Mukade 2018). Signage to indicate the presence of the aloe species and other interesting flora may promote ecotourism here in the future.

Aloe tororoana itself provides some provisioning services. It is used in traditional medicine for a number of ailments including stomach pains, fever and coughs as well as for poultry diseases (Cole & Forrest 2017), and preliminary phytochemical analyses have demonstrated the presence of compounds of potential use in antimicrobial drugs (Andima et al. 2014). However, any further use of this species would have to be managed sustainably given the small and fragile global population. At present, the harvesting of this species is considered to be unsustainable (P. Nyadoi, pers. comm. 2022).

A number of tree species are also harvested on the rock for a range of uses; these include several Acacia, Albizia and Ficus spp. and Shirakiopsis ellipticus. This harvesting is resulting in local declines in these species (P. Nyadoi, pers. comm. 2022).

Iain Darbyshire, Royal Botanic Gardens, Kew