Sampling study of applicability of point-center quarter

Point-center Quarter method is one of the distance sampling methods for estimating the plant density and canopy cover. For plant density measurements, two formulas, one by Pollard (1982) and the other one by the author (2006) have been developed. In this study, applicability of these formulas with regard to accuracy to estimate the density and canopy cover of Zagross Oak (Quercus persica) forestes in research and educational Forest of Higher Education Center of Qasr-e Shirin (Kermanshah province) were examined. Firstly, 50 hectars of these forest area was selected and the inventory of the population was carried out. Then, 50 systematic random sampling points for Point-center Quarter method in this area were measured and recorded. The resultes show that none of the formulas could provide an acceptable estimate based on 10% accepted accuracy; eventhough, the our formula has more accuracy level for density and crown coverage for this kind of forests and it could provide an acceptable estimate for management works baced on 25% acceptable accuracy.