Itwara Central Forest Reserve

UGATIPA8
Itwara Central Forest Reserve

Country: Uganda

Administrative region: Western (Region)

Central co-ordinates: 0.79857 N, 30.47115 E

Area: 86.8km²

Qualifying IPA Criteria

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

IPA assessment rationale

xxxxx

Site description

Itwara Central Forest Reserve is located within the Albertine Rift area, on the rift escarpment around 25 km south of Lake Albert, across the districts of Kabarole and Kyenjojo in Western Uganda. The site is known to be important for a number of threatened plant species. Fieldwork was undertaken at this site in 2023 as part of the Uganda TIPAs project and some of the below information is derived from observations and collections made.

Botanical significance

Eight plant species that are threatened with extinction are known from Itwara CFR. The Endangered species, Tiliacora latifolia, is of particular importance as a Ugandan endemic known from only five sites nationally. Two other Endangered species are known from this site, Eggelingia ligulifolia and Vepris eggelingii, both of which are thought to be threatened at this site by disturbance caused by tree felling (Amani et al. 2022; Fischer et al. 2019). This could have a significant impact on E. linguifolia as an epiphytic orchid. This species is only known at this site from one collection made in 1943 and therefore more research is required to better understand the population of E. linguifolia at Itwara.

In addition to these Endangered species, five Vulnerable species are known from this IPA. One of these, Turraeanthus africana, differs from the other four in that it is widespread across central and western Africa. But as a valuable timber species it has been overexploited and populations have been depleted in parts of its range (Barstow 2020). The Ugandan Albertine Rift represents the easternmost edge of this species’ range and as such Itwara is an important site for conserving this species both nationally and globally. Other Vulnerable species of note include Rhipidoglossum bilobatum, a second threatened epiphytic orchid species, and Brachystephanus glaberrimus, an understorey herb or shrub, both of which are cross-border Albertine Rift endemics. The latter species was last collected at Itwara in 1950, but many Brachystephanus species display periodic, monocarpic mass-flowering, with life cycles of several years to a decade, and so can be easily overlooked or under-collected if botanical expeditions do not coincide with flowering events. Good habitat for this species remains and so it is likely still extant at this site but under collected due to this reproduction strategy.

Rytigynia bagshawei var. lebrunii was collected during fieldwork by the Uganda TIPAs project in 2024. This species was previously only known from the Central Africa floral region (D.R. Congo, Rwanda and Burundi), although this species was subsequently collected at Kalinzu during the same fieldwork. Further surveying will likely reveal additional interesting species from this site.

Habitat and geology

Itwara CFR is dominated by moist evergreen forest, categorised as Parinari Forest by Langdale-Brown et al. (1964). Dominant species include Olea welwitschii and Parinari excelsa (Howard 1991). In the areas to the south of the site that were surveyed during 2023 fieldwork, common forest taxa included Trema orientalis, Abilizia, Celtis and Tabernaemontana, possibly associated with past disturbance and regeneration.
The site has a gently undulating topology and is underlaid by sedimentary geology.

Conservation issues

Itwara is surrounded by tea plantations and it is suspected that the scarcity of land in turn increases pressure on Itwara (CUPTD Workshop, pers. comm. 2023). Threats at this site include charcoal processing, pit sawing and agricultural encroachment (Mugume et al. 2015). In addition, the invasive species Senna spectabilis and Broussonetia papyrifera have been observed at this site (CUPTD Workshop, pers. comm. 2023).
Large areas of the north-west of the site have been given over to forestry plantation (Google Earth 2023). Satellite imagery and the Langdale-Brown et al. (1964) classification suggest this area was previously a savannah – forest mosaic. The Management Plan 2008-2018 for this site states that such areas should be targeted for industrial forestry (Ministry of Water and Environment 2008). While the known species of conservation importance at this site are all forest species, without ecological impact surveys prior to the establishment of these forests, it is not clear whether any species of conservation importance were lost through this habitat transformation. In addition, there may be ongoing impacts on ecosystem function and services caused by the establishment of forest here, particularly related to watershed regulation. However, the provision of productive forests in this area likely mitigates against disturbance elsewhere in the reserve, helping to conserve the important species residing there. The management plan also called for restoration of degraded areas of forest and the demarcation of forest stands of high conservation value. This was based mostly on landscape features, such as proximity to rivers and slope inclines, and could be further informed by the distribution of threatened and endemic species within this site.
Alongside this work, Wildlife Conservation Society Uganda partnered with NFA for forest restoration work at the site to help protect forests and the Lake Albert Water Management Zone (WCS 2021).

Ecosystem services

The forest is used by local people as a source of timber, charcoal and medicines (Davenport et al. 1996; Mujuni 2018). Wild coffee species, Coffea canephora and C. eugenioides, are known from this site (Davis et al. 2023).
Itwara falls within the Lake Albert watershed, with the Wamisu and Sogahi rivers running through this site and draining northwards (Howard 1991; Ministry of Water and Environment 2008).
Several primate species including grey-cheeked mangabey (VU) and chimpanzee (EN) are known from this reserve – the forests provide important habitats for their conservation (Mugume et al. 2015; Rich et al. 2020). Although this site is not a major tourist destination compared to neighbouring protected areas, there may be good tourist potential due the diversity of plants, mammals and birds and its proximity to Fort Portal (Ministry of Water and Environment 2008).

Site assessor(s)

Sophie Richards, Royal Botanic Gardens, Kew

IPA criterion A species

Species Qualifying sub-criterion ≥ 1% of global population ≥ 5% of national population 1 of 5 best sites nationally Entire global population Socio-economically important Abundance at site
Grewia ugandensis Sprague A(i) False True True False False Unknown
Turraeanthus africana (Welw. ex C.DC.) Pellegr. A(i) False False True False False Unknown
Tiliacora latifolia Troupin A(i) True True True False False Unknown
Eggelingia ligulifolia Summerh. A(i) False True True False False Unknown
Rhipidoglossum bilobatum (Summerh.) Szlach. & Olszewski A(i) False False True False False Unknown
Vepris eggelingii (Kokwaro) Mziray A(i) True False True False False Unknown
Zanthoxylum mildbraedii (Engl.) P.G.Waterman A(i) True False False False False Unknown
Brachystephanus glaberrimus Champl. A(i) True True True False False Unknown

Grewia ugandensis Sprague

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
False
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:
Unknown

Turraeanthus africana (Welw. ex C.DC.) Pellegr.

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
False
≥ 5% of national population:
False
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:
Unknown

Tiliacora latifolia Troupin

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:
Unknown

Eggelingia ligulifolia Summerh.

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
False
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:
Unknown

Rhipidoglossum bilobatum (Summerh.) Szlach. & Olszewski

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
False
≥ 5% of national population:
False
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:
Unknown

Vepris eggelingii (Kokwaro) Mziray

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
False
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:
Unknown

Zanthoxylum mildbraedii (Engl.) P.G.Waterman

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
False
1 of 5 best sites nationally:
False
Entire global population:
False
Socio-economically important:
False
Abundance at site:
Unknown

Brachystephanus glaberrimus Champl.

Qualifying sub-criterion:
A(i)
≥ 1% of global population:
True
≥ 5% of national population:
True
1 of 5 best sites nationally:
True
Entire global population:
False
Socio-economically important:
False
Abundance at site:
Unknown

General site habitats

General site habitat Percent coverage Importance
Forest - Subtropical/Tropical Moist Lowland Forest No value Major
Artificial - Terrestrial - Arable Land No value Minor
Artificial - Terrestrial - Plantations No value Minor

Forest - Subtropical/Tropical Moist Lowland Forest

Percent coverage:
No value
Importance:
Major

Artificial - Terrestrial - Arable Land

Percent coverage:
No value
Importance:
Minor

Artificial - Terrestrial - Plantations

Percent coverage:
No value
Importance:
Minor

Land use types

Land use type Percent coverage Importance
Nature conservation No value Major
Forestry No value Major
Agriculture (arable) No value Minor

Nature conservation

Percent coverage:
No value
Importance:
Major

Forestry

Percent coverage:
No value
Importance:
Major

Agriculture (arable)

Percent coverage:
No value
Importance:
Minor

Protected areas

Protected area name Protected area type Relationship with IPA Areal overlap
Itwara Central Forest Reserve Forest Reserve (conservation) protected/conservation area matches IPA 87

Itwara Central Forest Reserve

Protected area type:
Forest Reserve (conservation)
Relationship with IPA:
protected/conservation area matches IPA
Areal overlap:
87

Conservation designation

Designation name Protected area Relationship with IPA Areal overlap
Itwara Forest Reserve Key Biodiversity Area protected/conservation area matches IPA 87

Itwara Forest Reserve

Protected area:
Key Biodiversity Area
Relationship with IPA:
protected/conservation area matches IPA
Areal overlap:
87

Management type

Management type Description Year started Year finished
Site management plan in place No value No value

Site management plan in place

Year started:
No value
Year finished:
No value

Bibliography

Howard, P. C., 1991

Nature Conservation in Uganda’s Tropical Forest Reserves

Langdale-Brown, I., Osmaston, H. A., & Wilson, J. G., 1964

The Vegetation of Uganda and its Bearing on Land-Use

Google Earth, 2023

Google Earth Pro 2023

Amani, C., Kalema, J., Nshutiyayesu, S., & Ntore, S., 2022

Vepris eggelingii. The IUCN Red List of Threatened Species 2022: e.T154349549A154388286

Available online

Barstow, M., 2020

Turraeanthus africana. The IUCN Red List of Threatened Species 2020: e.T33064A69047658

Available online

Davenport, T., Howard, P., & Matthews, R., 1996

Itwara Forest Reserve Biodiversity Report

Davis, A.P., Kiwuka, C., Faruk, A., Mulumba, J., Kalema, J., Islam, T., Sheikh Mujibur Rahman, B., Pandey, A., Guyot, R.A., & Kumar Huded, A.C., 2023

A review of the indigenous coffee resources of Uganda and their potential for coffee sector sustainability and development

Frontiers in Plant Science Available online

Fischer, E., Beentje, H. J., Kabuye, C., Kalema, J., Kayombo, C., Luke, W. R. Q., Nshutiyayesu, S., & Ntore, S., 2019

Eggelingia ligulifolia. The IUCN Red List of Threatened Species 2019: e.T16565868A16565871

Available online

Ministry of Water and Environment, 2008

Forest Management Plan for Itwara Group of Central Forest Reserves

Available online

Mugume, S., Chapman, C. A., Isabirye-Basuta, G., & Otali, E., 2015

Can we rely on forest reserves for primate conservation?

African Journal of Ecology, Vol 53, page(s) 465-472 Available online

Mujuni, D., 2018

The effect of illegal charcoal burning on the conservation status of priority medicinal tree species in Itwara Central Forest Reserve

Available online

Rich, A. M., Wasserman, M. D., Hunt, K. D., & Kaestle, F. A., 2020

Chimpanzee (Pan troglodytes schweinfurthii) population spans multiple protected areas in the Albertine Rift

Folia Primatologica, Vol 91, page(s) 595-609 Available online

WCS, 2021

Community Based Monitor (CBM) Opportunity/ies at Wildlife Conservation Society

Available online

Recommended citation

Sophie Richards (2024) Tropical Important Plant Areas Explorer: Itwara Central Forest Reserve (Uganda). https://tipas.kew.org/site/itwara-central-forest-reserve/ (Accessed on 21/05/2024)