Determination of forest stands growth through Swiss control (Study area: Gorazbon district)

In close to nature silviculture system knowing the amount of forest stocking is critical issue to management, optimal and sustainable utilization of forest and its production. This research was done in compartments of 305, 306, and 309 with total area of 88 ha. Volume increment calculated using direct method by full calipering inventory. Current stocking volumes (2014) were acquired 431.6, 457.6, 455.7 m3ha-1 for 305, 306 and 309, respectively. The volume growth results showed that the gross annual volume increments were 3.3, 4.6, and 3.8 m3ha-1 for 305, 306 and 309, respectively. Furthermore, the percentage of the annual volume growth rate compared to beginning of period (2004) for small, intermediate and large diameter trees were 2.54, 2.03 and 0.96 in compartment 305 respectively. Moreover, the percentage of the annual volume growth rate compared to beginning of period (2004) for small, intermediate and large diameter trees were 2.58, 3.1 and 1.55 in compartment 306, respectively. The percentage of the annual volume growth rate compared to beginning of period (2004) for small, intermediate and large diameter trees were 7.08, 3 and 1 in compartment 309 respectively. The maximum amount of volume growth was occurred in 35 and 40 cm diameter classes while the growth rate was gradually reduced diameter classes greater than 75 cm.