Effect of Three Successive Years of Fire on Some Physicochemical Properties of a Forest Soil around Zarivar Lake in Marivan

The present study was conducted to investigate the effects of three successive years of fire burning on some physicochemical properties of surface (0-5 cm) and subsurface soil (5-10 cm) in Tappeh Darvish forest located in the surroundings of Zarivar Lake, Marivan. A control with similar conditions, but not affected by fire was selected in the vicinity of the fire burned area. Three composite soil samples were taken from the mentioned depths in the burned site and from control site. The samples were analyzed for texture, EC, pH, T.O.C, T.N, Nava. (NO3- and NH4), Pava., Kava., Ca ava., Mg ava., Cation Exchangeable Capacity (CEC) and Total Neutralizing Value (TNV) contents using standard methods. The results showed that, in general, changes in the soil properties following fire were greatest at the subsurface soil and more modest at the subsurface soils. Soil TNV and EC content changed notably, following fire, with higher values in burned soils. Nitrogen, potassium, phosphorus, calcium and magnesium became more available following fire, while CEC levels were found to be unchanged in the burned soil in comparison with the unburned soil. Soil pH, total C and N content slightly increased in the burned soil. Furthermore, the soil texture became lighter following fire with a lower content of clay in the burned soils. In total, it was concluded that fire significantly affects soil physicochemical properties and reduces the quality of soil as in forestlands.