Table 2.

Summary of analysis of variance (ANOVA, presented as F-values) for the effects of month, CO₂, year, and their interactions on the photosynthetic rate at 25 °C under growth CO₂ concentration (P_growth25), leaf nitrogen content (N_area), stomatal conductance at 25°C (g_s), intercellular CO₂ concentration at 25 °C (C_i), the maximum rate of electron transport at 25 °C (J_max25), the maximum rate of RuBP carboxylation at 25 °C (V_cmax25), the J_max to V_cmax ratio at 25 °C (J/V), activation energy of J_max (E_aj), activation energy of V_cmax (E_av), and optimum temperature of photosynthesis predicted by the model (T_opt)

Source of variation	d.f.	Pgrowth25	Narea	gs	Ci	Jmax25	Vcmax25	J/V	Eaj	Eav	Topt
Year	1	10·11	0·23	19·92*	39·51*	22·58*	14·45	7·06	0·22	2·03	13·44
Main plot error	2	11·74	2·75	6·56	1·48	2·67	7·10	0·59	1·08	3·08	1·44
CO2	1	462·73**	4·88	25·45*	1215·25***	3·19	26·71*	3·72	11·16	4·01	78·87*
CO2 × Year	1	17·19	0·41	12·83	5·44	0·19	7·61	1·88	0·46	5·11	4·16
Subplot error	2	0·10	2·28	0·18	1·72	0·83	0·49	1·25	0·97	0·73	0·80
Month	3	216·26***	175·72***	4·09*	19·87***	229·24***	307·07***	22·33***	0·83	6·41**	3·74*
Month × CO2	3	3·50*	6·72**	0·54	1·61	1·93	2·89	0·23	0·65	0·28	1·34
Month × Year	3	11·01***	18·63***	4·64*	3·21	6·56**	7·91**	2·22	1·79	5·10*	5·66*
CO2 × Month × Year	3	1·03	0·26	0·68	0·59	0·86	1·88	0·41	7·71**	10·33**	5·27*
Sub-subplot error	12

P_growth25, N_area, g_s and C_i are measured values. J_max25, V_cmax25, J/V, E_aj, E_av and T_opt are calculated values. Significance levels: ^***, P < 0·001; ^**, P < 0·01; ^*, P < 0·05.