Table 1.

F values of experimental site, region of plant origin and herbivory treatment effects on plant performance traits and damage in June and August (mixed models)

Factor	df	Shoot biomass	Shoot length		No. shoots		No. flower stalks		Damage
			June	August	June	August	June	August	June	August
Site	2	342.64***	120.22***	41.55***	269.45***	263.01***	72.59***	57.86***	186.17***	7.89**
Plant origin	2	46.31***	9.86**	62.48***	0.66	4.54*	6.12*	6.48*	2.02	1.95
Herbivory	1	57.89***	44.20***	56.21***	17.39**	17.71***	19.36**	48.04***	100.04***	427.70***
Site × origin	4	0.31	0.89	1.34	0.51	0.44	2.95*	1.44	1.28	1.08
Origin × herbivory	2	0.37	3.18	0.82	0.31	0.45	0.29	0.29	0.62	1.86
Site × herbivory	2	4.01*	6.90**	4.06*	2.65	1.92	17.35***	10.57***	62.84***	10.66***
Origin × site × herbiv.	4	1.59	0.64	1.48	0.78	0.27	0.16	1.72	0.10	2.27
X-coordinate	1	5.89*	0.29	21.26***	0.2	3.69	5.59*	1.32	2.88	3.37*
Y-coordinate	1	25.24***	16.42***	16.94***	0.45	0.02	2.94	0.57	0.98	0.25

Bold values indicate signficant role by 3 factors site, origin and herbivory

Models included plant population as a random factor nested in origin and its interaction with site and treatment (not shown). x and y coordinates of plant position in the experimental plots were added as covariates. N = 649

*** P < 0.0001, ** P < 0.005, * P < 0.05