DEVELOPING DOUBLE-ENTRY TREE VOLUME TABLE FOR ASH IN TURKEY
The objective of this study is to construct double-entry tree volume table for ash (Fraxinus angustifolia subsp. oxycarpa) in Turkey. Total 391 sample trees were selected from ash stands in Turkey for this objective. By using Smalian’s formula, the volume of each section in a sample tree stem was calculated. Regression Analysis was used and total twenty-six equations were examined according to six performance criteria (Average Residuals or Bias, Average Absolute Residual, Standard Deviation of the Residual or Precision, Percent Variation Explained, Percent Total Error and Percent Absolute Mean Error). Coefficient of determination, standard error, total error and absolute mean error of the best fitted volume equation were found 0.987, 0.312 m3, -0.02 % and 10.13 % respectively. The equation was also tested with another independent data set and concluded that the equation could be used for other ash stands in Turkey with 0.05 significant level.