Effect of fire on soil chemical and physical properties in the Solan rangelands, Hamadan Province, Iran

Fire affects all components of the ecosystem and reduces its quality. In this study, to investigate the effect of fire on soil properties, burned and control soil samples were taken from the surface depth (0-30 cm) during three years 2018-2020 from the Solan region of Hamadan; then, organic carbon, phosphorus, and potassium, salinity, pH, lime, sand, clay, and silt were measured. The results showed that the fire increased the percentage of sand (12.75%) and decreased silt and clay percentage (12.09 and 0.66%, respectively). Available soil phosphorus increased (90.32%) in the burned treatment. Lime and soil pH levels were very close in both control and burned treatments. The amount of organic matter (30%), available potassium (8.45%), and soil salinity (more than 16%) decreased in burn treatment. During the three years after the fire occurrence, the percentage of sand increased, and the lime percentage and soil salinity decreased; however, the other characteristics did not show a definite trend of changes. According to the results, it is necessary to prevent intentional and unintentional fires with proper management of natural ecosystems. In case of such incidents, these areas should be rehabilitated and their production capacity strengthened by increasing organic matter and soil organisms.