Table 3. Factors and their interactions which are retained in the reduced model [1] for response variable ‘plant biomass of Douglas-fir’.

Source of Variation	Df	Mean Sq	p-values
Temperature	1	0.001304	0.6872
Mycorrhization	1	0.215359	<0.0001*
Block	1	0.012354	0.2166
Temperature : Mycorrhization	1	0.10695	0.0004*
Temperature : Block	1	0.019461	0.1217
Residuals	114	0.008003

^* = significant at α = 0.05.