The effect of altitude on soil organic carbon content in semi-arid mediterranean climate

Abstract

One of the most effective means in the combating climate change and desertification is soil organic carbon (SOC) management. However, land use puts a high pressure to fragile SOC pools particularly in semi-arid environments where SOC decomposition rate is high due to low soil moisture. Therefore, at higher elevations of Mediterranean Basin with cooler temperature SOC is higher than the coastal plains due to the better soil moisture contents. Agricultural pressure on highlands has increased in recent years because of the relatively low water requirement of crops. The purpose of this study is to analyze and determine the SOC dynamics in relation to the variations of soil physical and chemical characteristics from different elevations, ranging from 64 meters to 756 meters at semi-arid Mediterranean climate. SOC revealed decreases versus altitude increases that varied from 24.7 to 38.7 t ha-1 with a correlation coefficient of 0.527. The main driver of decreasing SOC by elevation is most probably displacing of fine particles from surface horizons by accelerated erosion at sloping and cultivated lands of higher altitudes. As a result, it is necessary to focus both on the plant pattern along with land management techniques for enhancing soil organic matter in agricultural production for enhancing SOC at higher elevations.