Evaluation of Soil Properties Under The Canopy of Wild Pistachio (Pistacia atlantica Desf.) and Wild Almond (Prunus orientalis (Mill.) Koehne) (Case Study: Tang Khoshk, Semirom)

Stability of forest ecosystems, especially in arid and semi-arid areas with non-dense cover, depends on the soil quality maintenance. Therefore, knowledge of the soil properties of these areas can play an effective role in their management. The purpose of this study was to investigate some physical, chemical and biological properties of the soil under wild pistachio (Pistacia atlantica Desf.) and wild almond (Prunus orientalis (Mill.) Koehne) canopy in Tang Khoshk forest reserve of Semirom. Surface soil samples (0 to 15 cm) were randomly collected from the sites under the canopy of P. atlantica and P. orientalis species and outside the canopy (control sample). Some chemical properties including electrical conductivity, pH, total nitrogen, organic carbon, available phosphorus, potassium, iron, zinc, copper and manganese, soluble calcium and magnesium and calcium carbonate equivalent, physical properties including bulk density, soil texture and gravimetric water content, and biological properties of basal respiration, induced respiration, microbial biomass carbon and nitrification potential of soils were measured. The electrical conductivity, organic carbon and potassium in the soil under the canopy of P. atlantica and P. orientalis species were significantly higher than those in the control soil. The reverse trend was observed for the available phosphorus, iron and copper. The mean total nitrogen in the soil under the canopy was at least 1.46 times higher than that of the control soil. Soil bulk density decreased significantly at the presence of canopy compared to the control soil. The basal and induced respirations of the soil under the canopy were significantly higher than in the canopy outside, while the microbial biomass carbon and nitrification potential were significantly greater in the control soil compared to the sites under the canopy. According to the results of current research, the type of plant and its canopy can have different effects on soil properties.