Land types and vegetation in the Luuq district of south-western Somalia

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ABSTRACTA land use survey involving land typing and vegetation classification was conducted within the Luuq District Refugee Area (200,000 ha) in south-western Somalia. Average rainfall and annual temperature of the area are 310 mm and 30.5° C. The area is composed of limestone and basalt uplands, gypsiferous and alluvial interplains, and ancient and recent alluvial terraces of the Juba River.Land types were identified by aerial photo survey and ground observation and mapped on a 1:100,000 scale LandSat Satellite (colour) Image. Soil types were classified according to the method used by the US Department of Agriculture, Soil Conservation Service. Vegetation was sampled according to the Braun-Blanquet approach in 52 releves located within previously mapped land types, and analysed using the traditional phytosociological methods and the DECORANA and TWINSPAN computer programs. The results of these methods are compatible with one another. Most community types identify distinct land types: basalt and limestone uplands, gypsum and alluvial interplains, and depressions and gentle rises of the Juba River terrace.Commiphora and Acacia species dominate the open thorny bushland. They are mostly medium-sized shrubs and trees, 1 to 4 m in height. There is little herbaceous ground cover except in depressions and drainageways. Total shrub and tree cover averages 34%. Due to the large influx of refugees, there has been excessive cutting for fuelwood and construction material and notable bushland converted to cropland. Degradation of the vegetation and soils is prominent and is most evident on the upper and lower terraces of the Juba River.