volume, height and wood production modeling using the changes in a nine years rotation (case study: gorazbon district in kheyroud forest, north of iran)

the oriental beech constitute one third of northern forests area and stocking volume in the north ofiran. these stands obseve in pure and mixed. in order to properly management which guaranteesustained yield, it is crucial to collect basic information including stocking (volume and stem number),tree growth, diameter distribution pattern, diameter-height relationship, diameter-volume relationshipand models estimating wood production. this study carried out in the gorazbon district in kheirudforest with an area around 934.24 ha.volume increment and stem number were measured directlyusing permanent sample plots. a steady state variable of dbh used for estimation of tree height andvolume. wood production was estimated by wood production models. results showed that, with afraction of 31% of all individuals, beech allocated 57% of standing volume in the gorazbon district.the total stem number of beech trees were 70777 and 71567 in the years 2003 and 2012 respectively.mean stem number of beech was 9203 and 9308 tree per ha in the years 2003 and 2012 respectively.standing volume of the species was increased from 192 sylv per ha in 2003 to 197 sylv per ha in 2012.total stem number increment and total volume increment were 116203 stem and 115301sylv,respectively. analysis showed the prodan model as a best fit to dbh-height.