Effect of soil structure on soil fauna in a desert wadi in Southern Egypt

This study investigates the soil fauna in a part of the rainless desert of southern Egypt. Three sites were examined: two downstream of Wadi Allaqi, both of which have been inundated by the water of Lake Nasser for several years. The third site is in Wadi Quleib, a principal tributary of Wadi Allaqi which was not inundated. Soil fauna were collected by pitfall traps during April-November 1989. Data were treated by multivariate analysis techniques, including correspondence analysis and ascending hierarchic classification. Most species were Arthropoda, particularly Coleoptera (7 species). Wadi Quleib was richer than Wadi Allaqi both in number of species and density. In Wadi Allaqi, the first site was richer than the second, both in species and density. These differences are partially related to differences in soft texture between Wadi Quleib and Wadi Allaqi, and to the presence of dense groves of Tamarix nilotica in the first site of Wadi Allaqi.