Table I. Mixed model analyses of altitudinal clines in plant height and local adaptation using total seed number as a fitness proxy in 11 Arabidopsis accessions collected from altitudes from 820 to 2,700 m in the Swiss Alps.

Accessions were transplanted into experimental sites at 640, 2,000, and 2,170 m a.s.l. Effects were tested using likelihood ratio tests between nested models with the fixed effects site, altitude of origin (alt.), and the interaction of these factors.

Model (Fixed Effects)a	Degrees of Freedom	Model Comparison	Plant Height		Total Seed No.b
			Deviance	P	Deviance	P
1: alt. + site + alt. * site	8		2,943		533.4
2: alt. + site	6	2 vs. 1	2,946	0.2330	546.0	0.0018
3: Site	5	3 vs. 2	2,951	0.0301	−c
4: Altitude	4	4 vs. 2	3,015	<9.4*10−16	−c	−c

^aAll models included accession as a random effect.

^bLog transformed.

^cNo further model reduction because of significant interaction term.