Distribution and nature of Red Mediterranean soils in Lebanon along an altitudinal sequence

Abstract

Red Mediterranean soils in Lebanon occur at various altitudes. Information on these soils is rather limited. This study characterizes six profiles from locations ranging in elevation between 25 m to 2000 m and relates their properties to pedogenetic processes responsible for their formation Samples were collected from each horizon and studied using chemical and micromorphological techniques, and X-ray fluorescence spectroscopy. The pedons are predominantly Ca and Mg saturated and show features specific of Alfisols. Decreasing amounts of montmorillonite and gradual dominance of well crystalline kaolinite were linked with increasing elevation and precipitation (xeric and udic moisture regimes). The high proportion of kaolinite in calcareous pedons at lower elevation may be due to inheritance from different paleopedoclimatic conditions. Neoformation may explain the high amounts of kaolinite in pedons from the higher rainfall zone. Distribution of these soils on extreme landscape positions makes terracing necessary. This can introduce a significanct anthropic factor to the soil formation.