Effect of thinning on growth of Brant's oak (Quercus brantii Lindl.) sprout- clumps in Kermanshah

The vegetative potential of stump is divided among various sprouts in coppice stands. The main objectives of this research were to 1) identify the growth respond of Brant`s oak (Quercus brantii Lindl.) sprout clumps to thinning and 2) to choose the best intensity of thinning. This study was done based on completely randomized design with four treatments and three replications in Kermanshah province (Darbadam forests).We assessed the effect of different thinning intensities on growth of oaks in Darbadam region, Kermanshah, during a 5-year period. Four treatments including heavy (decreasing 30 percent of basal area), medium (decreasing 20 percent of basal area) and light (decreasing 10 percent of basal area) thinning, each with 3 replications was used. One treatment was considered as control with no intervention. Prior to thinning quantitative characteristics of sample trees were measured. In the last year of research, the measurements were repeated to calculate the growth values. Based on results, heavy thinning had considerably positive impact on growth of sprout-clumps crown area and basal area of sprouts. However, no significant difference was observed between treatments regarding to height of sprout-clumps and diameter of sprouts. We concluded that the heavy thinning with removing 30% of basal area was the most influential on sprout clumps growth that is applicable in thinning projects in Zagros oak coppice stands.