An application of mixed-effects model to evaluate the role of age and size on radial variation in wood specific gravity in teak (Tectona grandis)

Journal of Wood Science

Official Journal of the Japan Wood Research Society

Table 6 Summary results for fitting different covariance structures to WSG data

	Par	− 2L_ML	− 2Inλ_N	df	P
Simple	1	− 912.6
Compound symmetry	2	− 1084.3	171.66	1	< 0.0001
Autoregressive (1)	2	− 1389	476.39	1	< 0.0001
Autoregressive (1) with random tree effect	3	− 1394.3	481.70	2	< 0.0001
Toeplitz (banded)	10	− 1428.7	516.04	9	< 0.0001
Antedependence (1)	19	− 1424.1	511.51	18	< 0.0001
Unstructured	55	− 1538.3	625.69	54	< 0.0001

Par number of parameters, − 2L_ML minus twice the maximum log-likelihood value of ML, − 2Inλ_N likelihood ratio statistic testing vs model Simple, df degree of freedom, P P value corresponding to the likelihood ratio test