Litter ash chemical properties of wildfire in forest floor of Brant`s oak (Quercus brantii Lindl.) in Darehvaran area, Marivan

Wildfire leads to accumulation of ash in the surface soil, which it can have effect on the biochemical cycle of elements in the ecosystem. The goal of this study was to investigate some ash chemical properties of wildfire in litter of the Brant`s oak (Quercus brantii Lindl.) and vegetation of forest floor and determination gradiant from beneath of tree crown to the outside of the tree crown. Ash samples were collected immediately after forest wildfire in the summer 2016 in the Darehvaran area in Marivan. One transect was installed on a couner line with 300 m long on burnt slope. Ten Brant`s oak trees were selected at 30 meters intervals. Three samples of ash were collected in each tree. The 3 positions of ash samples including: at a distance of 1.5 meters from the base trunk, tree crown border and five-meters far from tree crown. Chemical properties of ash samples were measured in laboratory. The results showed that the content of C, N and P of ash increased significantly with movement from tree trunk to outside. The content of Ca and Mg of ash decreased signifcanly by moving from tree trunks toward the spaces between them, but the amount of K increased signifcantly. The EC and the pH of the ash decreased from the trunk side to the outside of the tree crown. In general, it seems that intensity of the wildfire decreased by moving from the tree trunk to the space between the trees because of the difference in the amount of litter accumulated.