Optimization of Proden's Six Tree Sampling Method

follows: basal area (m2/ha) and density (number per hectare).We used data related to six tree sampling method practiced in Pattom section in kheyroud kenar forest. We analyzed three hypotheses:
A. Plot radius equals to the distance between the center plot and nth tree plus half of the nth tree diameter.
B. Plot radius equals to the distance between center plot and nth tree plus the nth tree diameter.
C. Plot radius equals to the distance between center plot and nth tree plus the nth tree diameter and half of the distance between nth tree and (n+1)th tree.
We used these hypotheses and calculated basal area and density for each plot. Then we calculated density and basal area for all forest with weighted mean, arithmetic mean and corrected mean with bias correcting factor. We used Wilcoxon and t tests to compare the result of n-tree sampling method with true values. As a result, weighted mean and second hypothesis are suitable for estimating basal area. However for density, corrected mean and third hypothesizes are better. When the number of trees in a sample plot increases the precision of sampling method increases too. The results of n-tree sampling method are not significantly different from each other.