Table 3.

ANCOVA results for the five species on the dependence of competitive ability index (CA) on the predictor variable species composition of the neighborhood (six or three constellations in the moist or dry treatments, respectively) and the most influential parameter characterizing neighbor plant size (leaf area LA, basal area BA, or biomass) as covariate.

Species	Moist treatment					Dry treatment
	Predictor	df	SS	F	p	Predictor	df	SS	F	p
F. excelsior	LA	1	3.18	17.76	<0.001	LA	1	0.45	2.84	0.116
	SpecComp	5	0.39	2.18	0.081	SpecComp	2	0.10	0.30	0.743
	Error	32	0.18			Error	13	2.08
A. pseudopl	LA	1	0.65	2.70	0.111	LA	1	0.30	3.57	0.085
	SpecComp	5	0.66	0.55	0.736	SpecComp	2	0.30	1.78	0.214
	Error	32	7.68			Error	11	0.92
C. betulus	LA	1	1.86	8.14	0.007	LA	1	0.22	0.56	0.469
	SpecComp	5	0.62	0.54	0.744	SpecComp	2	1.43	1.87	0.201
	Error	34	7.76			Error	11	4.20
T. cordata	Biomass	1	0.19	0.84	0.366	LA	1	0.92	6.02	0.032
	SpecComp	5	3.70	3.34	0.018	SpecComp	2	0.00	0.00	0.999
	Bm × SpecComp	5	3.11	2.81	0.036	Error	11	1.69
	Error	27	5.79
F. sylvatica	BA	1	0.17	2.16	0.151	LA	1	0.08	1.09	0.315
	SpecComp	5	0.39	0.97	0.448	SpecComp	2	0.32	2.04	0.170
	Error	33	2.63			Error	13	1.01

Bold F and p-values highlight significant effects on CA scores (p < 0.10).