Determining growth increment and density of trees in forest, using permanent sample plots (Case study: Gorazbon district of Kheyroud Forest)

One of the main and important knowledge for forest management and its optimal and sustainable utilization is to determine its trees volume and number and its production potential. Actually, future forest management is based on its inventory and information. Thus for a precise planning its required to have information about forest standing stock volume and increment, distribution of diameter classes curve and spices structure. Determination of annual allowable cutting is required for wood utilization planning and management, based on stands volume increment data. The research was conducted in Gorzbon district (934.24 ha) at Kheyroud Educational- Experimental Forest (Caspian region of Iran), using 258 permanent sample plots and applying the directed method of inventory to measure volume increment and trees number two times with nine year interval. Results showed that average trees number and stocking volume per hectare were 298.15 and 335.8 sylve in 2003 and 290.14 and 367.7 sylve in 2012, respectively. Although 31% of the forest tree number belonged to Fagus orientalis, but 57% of the standing stock volume belonged to this species. Volume increment was 4 sylve/ha/year and average trees number growth was 5.8 ha/year. Overall, the beech species had the greatest volume increment. In fact, such huge research area and data analysis was carried out for the first time in Khyroud forest and the results showed that applying permanent sample plots method provides essential and precise information and data for measuring forest increment