Investigating the Effectiveness of DSH and DBH in Allometric Relationships of Coppice Shoot Iranian oak (Quercus brantii Lindl)

This research was carried out with the aim of achieving a suitable height for diameter measurement in coppice Iranian oak trees in the middle Zagros vegetation area. For this purpose, three categories in terms of destruction level of stands including: destroyed, medium and less destroyed were selected in Qala Gol area of Khorram Abad and then in each category a square sample plot  of one-hectare was laid out and D.B.H, D.S.H, large and small crown diameter, crown height and tree height were measured. The results of Pearson's correlation coefficient showed that there was a significant correlation between two target diameters with All variables. Regression models showed that the highest R squares is related to the relationship between the DBH and the area of the crown in the less degraded sample (0.74) and the lowest level is related to the relationship between the DSH with tree height in the degraded sample (0.45), Also, the lowest amount of RMSE% (11.5%) and MAE% (10.6%) related to the relationship between DBH and crown area in the less degraded sample, and the highest related to the relationship between DSH and tree height In the degraded sample, it was 15.6% and 14.5%. In total, the results of this research showed that the DBH due to the relatively strong relationship between the investigated variables of the trees is a more suitable height for measuring the diameter in coppice Iranian oak forest.