Some physioloical and biochemical changes in young oak stands after forest fire

Most of forests and some type of plant communities are fire dependent in different parts of the world. Whereas, wildfires are an increasing concern in fire sensitive regions of the World. In this study; seasonal changes in the amount of prolin, total soluble sugar, stomatal conductivities and water potentials were investigated on leaves of two different oak species (Quercus cerris and Quercus pupescens) exposed to different fire intensities. Three different fire intensities were identified; low, high and control. Proline, total soluble sugar, stomatal conductivity and water potentials were measured every month during the first vegetation period after the fire. According to study results, significant differences were found in the amount of seasonal proline in both between tree species and fire intensity. The proline amount and total soluble sugar amounts were the highest in control groups and the lowest in high intensity fires. Quercus pupescens generally had a higher amount of proline and total soluble sugar than Quercus cerris. Seasonally, the lowest values of proline, total soluble sugar and mid-day plant water potentials were generally measured in mid-summer (August-September). These values were high in pre-summer and post-summer months. When water potentials related to fire intensity were examined, the lowest water potential was measured in the control plots in all months. The highest water potential was measured in trees burned by high intensity fire. Stomatal conductivity was found the lowest at oak trees in control groups that were never exposed to fire.