Table 3.

Summary statistics of a literature survey of studies predicting lignin contents from different plant tissues using spectroscopic methods.

	Species38	Lignin [mg]36	Val/Cal35	RPD28	${\mathbf{R}}_{\mathbf{P}}^{\mathbf{2}}$ 33	RMSEP [%]19	SEP [%]21
Min	1	100	0.12	0.5	0.05	0.19	0.28
Q25	1	275	0.29	1.61	0.61	0.68	0.65
Q75	1	500	0.50	3.56	0.90	1.88	2.27
Max	32	2500	3.55	9.5	0.99	3.48	5.00
Med	1	300	0.38	2.45	0.83	1.03	0.87
This study	61	10	0.68	2.67	0.86	2.82	2.78

Given are minimum, maximum and interquartile ranges of the number of species examined per study (Species), sample volume used for chemical lignin extraction (Lignin) and proportion of samples used for model validation and calibration (Val/Cal). Additional abbreviations as in Table 1. Superscript numbers indicate the number of individual datasets that entered the analysis. See Table S1 for details on individual studies.