Effect of thinning on growth of coppice Brant's oak (Quercus brantii Lindl.) trees (Case study: Chegeni forest of Khorramabad)

As the first phase of a 16-year project, this research was carried out in a section of coppice Brant`s oak (Quercus brantii Lindl.) trees in Chegeni, Khorramabad, Lorestan province. We assessed the effect of different thinning treatments on growth of Brant`s oaks during a 4-year period. Three treatments with 3 replications were used including heavy (decreasing 30 percent of basal area), medium (decreasing 20 percent of basal area) and light (decreasing 10 percent of basal area) thinnings. One treatment was considered as control with no intervention. Quantitative characteristics of sample trees were measured prior to thinning. The measurements were repeated during 4 years to calculate the growth values. Based on results, heavy thinning had considerably positive impact on growth of diameter, height and basal area of sprouts as well as on growth of sprout-clumps crown area. It is concluded that thinning operations can improve the unsustainable structural characteristics of young coppice stands within Zagros forests.