Influence of the temperature on soil's exchangeable cations and cation exchange capacity, Derna district, Libya: A field and Laboratory study

This study conducted in Aljabal alakhdar (Green Mountain), Derna, Libya. It is the only wet region in Libya. Like other Mediterranean forests, it is exposed to the risk of fires. To assist in this, two different geographical units from the region (coastal and mountain), which been burned at different times; to identify whether these soils are regaining their pre-burn status over time. The studied properties were: the soil clay content, the soil organic matter (O M), the soil exchangeable cations and soil cation exchange capacity (CEC). It is obvious from the results that there is a relatively low clay content, compared to the contents of silt and sand, in both study sites and their burned and unburned areas. Soils of both study sites characterized by low organic matter content. The results indicated that, the basic exchangeable cations ranking was: Ca++ > Mg++ > Na+ > K+, in both study sites, for burned and unburned areas and at all depths. The rank order of these four cations did not change with depth in the four study areas except that sometimes-exchangeable potassium was more abundant than exchangeable sodium. The exchangeable calcium and magnesium account for about 80% of the CEC results so, the patterns of behaviour of the soil CEC are similar to the patterns of behaviour of these two elements.