Fig. 2

Distribution (95% confidence intervals) of calibration and validation statistics from 200 simulations of models predicting WBD from 0°, 45°, 90° angles and the mixed angle of multiple tree species using full length NIR spectra. Each model permutation included 80% of the data for internal calibration and the remaining 20% for validation. The blue vertical line represents the highest R² and lowest RMSE (g/cm³) value, The black vertical line in each box represents median value, the red colour box represents the 90° angles model