Table 4.

Best-fitting mixed-effects models for RGR of tree height of (a) European beech (Fagus sylvatica), (b) Sessile oak (Quercus petraea) and (c) Douglas fir (Pseudotsuga menziesii).

Fixed effects	d.f.	L-ratio	P-value
(a) Fagus sylvatica
Initial tree height (H)	1	56.3	<0.001
Treatment (T)	3	2.3	0.517
Species composition (C)	3	10.5	0.014
H × T	3	15.3	0.002
H × C	3	20.9	<0.001
(b) Quercus petraea
Initial tree height (H)	1	4.2	0.040
Treatment (T)	3	6.7	0.082
Species composition (C)	2	1.2	0.543
H × C	2	10.0	0.007
(c) Pseudotsuga menziesii
Initial tree height (H)	1	15.6	<0.001
Treatment (T)	3	8.4	0.039
Species composition (C)	2	9.2	0.002

P-values were derived from likelihood-ratio tests based on maximum likelihood (ML) estimations.