. EFFECT OF ECOLOGICAL FACTORS AND HEAVY METALS ON THE DISTRIBUTION OF SOIL ISOPODA (ARTHROPODA, CRUSTACEA) IN ASSIUT, EGYPT

Abstract

Terrestrial isopods are members of crustaceans which play an important role in soil formation. The present study is an atteinpt to through the light on this group in Assiut and explain the effect of ecological factors and heavy metals on their abundance and distribution. Four different sites have been chosen for study. Monthly samples were taken from studied sites for a period of 17 months; from January 1999 till May 2000. Isopods were separated, classified and counted. Air and soil temperatures were recorded during sampling. Also, pH, water content and organic matter content of soil were determined. Besides, the concentration offour heavy metals (Cd, Cu, Pb & Zn) in soil and litter were recorded during 12 months; from March 1999 till February 2000, as limiting factors for isopods.