Country: Cameroon
Administrative region: Littoral (Region)
Central co-ordinates: 3.81223 N, 10.12943 E
Area: 0.1km²
Qualifying IPA Criteria
A(i)Site contains one or more globally threatened species
IPA assessment rationale
The site qualifies as a an IPA under criterion A(i), A(iii) and A(iv) due to the presence of two globally threatened (CR) which are narrowly endemic to the site.
Site description
The waterfalls on the Sanaga at Edea are the surviving part of a formerly more impressive feature which has been exploited since the 1950s with a dam for a major hydro-electric power station...
Botanical significance
Three Critically Endangered narrowly endemic rheophytes of the Podostemaceae family, Zehnderia microgyna, Dicraeanthus zehnderi and Winklerella dichotoma survive at the site next to the dam (Ghogue, 2010a, 2010b).
[Ghogue's IUCN assessment seems to suggest that Ledermanniella thalloidea also occurs here but the only record is of a tributary of the Sanaga, 10 km north of Edea.
Leiothylax quangensis: "In Cameroon the plant is known from one site (Edea waterfall, two small populations; confirmation is needed that these populations still exist after the construction of the Edea dam) and the distribution in Angola and the DRC is not known".
Habitat and geology
Conservation issues
The three endemic species are reported to survive next to the dam in a reduced population, acutely vulnerable to extension or other disurbtance related to the operation of the dam. The altered seasonal flows of the river, due to this tam but also those existing (the Lom-Pangar dam) and under construction (the Nachtigal hydro project) are also likely to impact the regeneration of these species which tend to require seasonal variation in water levels to flower and fruit.
Site assessor(s)
Bruce Murphy, 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 |
|---|---|---|---|---|---|---|---|
| Winklerella dichotoma Engl. | A(i), A(iii), A(iv) |  |
|
|
|
 |
|
| Dicraeanthus zehnderi H.Hess | A(i) | |
|
|
|
|
|
| Zehnderia microgyna C.Cusset | A(i), A(iii), A(iv) | |
|
|
|
|
|
| Leiothylax quangensis (Engl.) Warm | A(i) | |
|
|
|
|
Winklerella dichotoma Engl.
Qualifying sub-criterion:
A(i), A(iii), A(iv)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Dicraeanthus zehnderi H.Hess
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Zehnderia microgyna C.Cusset
Qualifying sub-criterion:
A(i), A(iii), A(iv)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Leiothylax quangensis (Engl.) Warm
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
General site habitats
| General site habitat | Percent coverage | Importance |
|---|---|---|
| Wetlands (inland) - Permanent Rivers, Streams, Creeks [includes waterfalls] | 100 | Major |
Wetlands (inland) - Permanent Rivers, Streams, Creeks [includes waterfalls]
Percent coverage:
100
Importance:
Major
Threats
| Threat | Severity | Timing |
|---|---|---|
| Natural system modifications - Dams & water management/use - Large dams | High | Ongoing - stable |
| Energy production & mining - Renewable energy | High | Ongoing - stable |
Natural system modifications - Dams & water management/use - Large dams
Severity:
High
Timing:
Ongoing - stable
Energy production & mining - Renewable energy
Severity:
High
Timing:
Ongoing - stable
Bibliography
Winklerella dichotoma. The IUCN Red List of Threatened Species 2010: e.T185552A8434624.
Dicraeanthus zehnderi. The IUCN Red List of Threatened Species 2010: e.T185600A8444300
Recommended citation
Bruce Murphy (2024) Tropical Important Plant Areas Explorer: Edea Falls (Cameroon). https://tipas.kew.org/site/edea-falls/ (Accessed on 15/09/2024)