Efficiency evaluation of the plotless method methods for estimating the spatial structure of Persian oak (Quercus macranthera) stands in Arasbaran forests

This study was conducted to investigate the non-framed sampling methods for estimating the structure and spatial distribution pattern in Persian oak (Quercus macranthera) stands. Field sampling with distance method as a non-framed sampling methods was done in nine plots, each with one hectare, and totally by 81 points using systematic random network. Density, basal area, canopy of trees and spatial distribution pattern were calculated. According to the results, the Hopkins spatial pattern distribution indices were calculated. The results of Clump distribution, Eberhart and Johnson-Zimmer indices showed uniform distribution pattern for the species. In addition, structural indices showed that the value of the indices of distance to neighbor was 4.45, height difference was 0.28, diameter difference was 0.17, and the species interspecific index was 0.73 which indicate high composition of Q. macranthera with other accompanying species in the studied area. Also, the average value of the uniform angle index was 0.52. Density, basal area, canopy of trees resulted by sampling method had significant differenc with real amount that resulted from 100% inventory.