The determination of suitable sample plot area to the pure beech natural stand structures study in sefid ab forest park. (Case study)

ABSTRACT: Forest structure is the representation of the age or diametric or canopy types distribution in a forest stand. Respecting to stand situation and forest composition the needed space for sample plot in order to the study of forest structure changes. 4 one – hectare diamond –shaped sample plots each of which is composed of four inter current sample plots with the spaces of 0/25 , 0/5 , 0/75 and 1 hectare , were specified in the under studies area to study forest structure . Then the number distribution curve in of each of the metric classes was drawn by means diametric was drawn by means of the needed data collecting in order to study forest structure also two characteristics of number in hectare and volume in hectare of each of the metric classes related to each of the 0/25, 0/5, 0/75 and 1hectare sample plots were calculated and the suitable space for structure study was determined by means of square. K statistical method. The studies showed that there is a meaningful difference between 0/25 and 1hectare sample plots in two potential level %5 and %1 about number in hectare characteristics but about volume in hectare characteristics, there is a meaningful difference between 0/25 and 1hectare sample plots in two %1 and %5 potential level and also 0/5 1hectare sample plot and 1hectare sample plot have a meaningful difference in %5 potential level.