The effect of fire on vegetation structure in Zagros forests (Case Study: Sarvabad, Kurdistan province)

Climate change and increasing in mean annual temperature and on the other hand, the human activities increased the fire rate in forests and pastures. It seems that the fire affects the vegetation and changes the forest stand structures. In this study, the changes in woody species composition, structure, viability and regeneration of forest biomass in the forests of Sarvabad, Kurdistan province were investigated. In this study, two burned and unburned stands (control), each of them four hectares with similar environmental conditions and plant community were selected, reticulated in 40 plots and were investigated using 100% inventory method. Fire treatments and control data comparisons were performed using independent t-test. The results showed that 10 years after fire occurrence, the share of oak trees has been decreased, while the proportion of Amygdalus and Crataegus has been increased. No significant difference was observed for Pistacia. Furthermore, pistachio and almond were the more resistant species against fire, compared with Quercus brantii. The coppice number in burned area was more than control one, although the difference was not significant. The average collar diameter of Q. brantii in control area was significantly less than those in burned one, however the total height in control region was more than burned region. Also the significant variations were observed in terms of seedling age and height in control and burned plots, however the number of observed regenerations in plot showed no significant differences.