Sawana - Oum Lellé (6642)
Mauritania, Africa
Site overview
KBA status: confirmed
Year of last assessment: 2001
National site name: Sawana - Oum Lellé
Central coordinates: Latitude: 16.3333, Longitude: -9.2833
System: freshwater, terrestrial
Elevation (m): 160 to 160
Area of KBA (km2): 9.65067
KBA classification: Regional
Legacy site: Yes
Site details
Site description: Gâat Sawana (more than 800 ha) and Tâmourt Oum Lellé (more than 400 ha) are located 67 km south-east of the regional capital, Ayoûn. Gâat Sawana is a clay depression on an open plain where seasonal rains accumulate. It is an important area for traditional flood-recession agriculture. When flooded, it presents a large open expanse of water with abundant aquatic vegetation. Rainwater is fed in from two wadis and water reaches a depth of up to 1 m. Water is retained in the depression for five to eight months. The sandy zone around the depression supports grasses such as Cenchrus biflorus, Panicum and Aristida spp. and trees and bushes including Leptadenia pyrotechnica, Balanites aegyptiaca and Acacia raddiana. The vegetation of the floodable zone inlcudes Helioptropium sp.,Indigofera sp., Eragrostis tremula, Sesbania leptocarpa and Cyperus esculentus, while the aquatic zone on clay soils supports Cyperus sp., Nymphaea sp., Sporobolus helvolus, Oryza barthii and Ipomoea aquatica with Acacia nilotica and Ziziphus mauritiana. Oum Lellé lies 11 km north of Sawana in another clay-lined depression. The tâmourt is deeper than the gâat, holds water for longer and is characterized by a woodland of Acacia nilotica in the centre of the depression and by the absence of aquatic vegetation. The surrounding area is a zone of rich pastoral land dominated by grasses such as Cenchrus biflorus, Panicum and Aristida spp. while trees and shrubs include Acacia raddiana, A. ehrenbergiana, Balanites aegyptiaca and Leptadenia pyrotechnica.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that was identified using previously established criteria and thresholds for the identification of Important Bird and Biodiversity Areas (IBAs) and for which available data indicate that it does not meet global KBA criteria and thresholds set out in the Global Standard.
Additional biodiversity: See Box for key species. In January 2000, 85 Aythya nyroca and 17,000 Anas querquedula were recorded at this site. Non-bird biodiversity: The tortoise Geochelone sulcata (VU) occurs.
Habitats
Land use: agriculture | water management
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Artificial - Terrestrial | 7 | |
| Grassland | 92 |
Threats
Summary of threats to biodiversity at KBA: The twin sites have been proposed as a Ramsar Site. Sawana is the second most productive agricultural zone in Hodh El Gharbi. The agriculture practised is flood-recession cultivation of, predominantly, sorghum. Oum Lellé is a daily watering hole for at least 12,000 animals and is one of the most important sources of surface water in the region. A traditional agreement divides activities between the two wetlands; Oum Lellé is reserved for animal herding and Sawana for agriculture. Due to this traditional management the wetlands are currently in good ‘health’, but appropriate management plans would help reduce threats posed by the expansion of agriculture and the subsequent clearing of land and habitat loss.