FTIR-ATR-based prediction and modelling of lignin and energy contents reveals independent intra-specific variation of these traits in bioenergy poplars

Table 1 Performance indicators of Fourier transform infrared spectroscopy with attenuated total reflection-based partial least squares regression model for prediction of acetyl bromide lignin content within lignin ranges from 23.4% to 32.1% for calibration and from 23.6% to 29.9% for independent validation, with various preprocessing methods as well as manual and automatic restriction of the wavenumber range

^a Descriptor explanations are as follows: R² = coefficient of determination (a measure of the degree of fit of the regression); RMSEC = root mean square error of the calibration samples; RMSECV = root mean square error of the cross validation samples; RMSEP = root mean square error of the prediction samples; VN = vector normalization.
^b Wavenumber range for the mid-infrared region is 2000 - 700 cm^-1.
^c The wavenumber ranges resulting from automatic restriction are 1802 - 1690 cm^-1, 1362 - 1250 cm^-1, and 1140 - 1028 cm^-1.
^d The wavenumbers resulting from manual restriction are 1650 - 1380 cm^-1.

ISSN: 1746-4811