Table 4. Parameter estimates, standard errors (SE), and random effects of the frost hardiness development model (Eq. 3).
Parameters	Fixed part			Random part
				Parameters	Estimates	Correlations
	Estimate	SE	p-values			Ambient T+1 °C	Ambient T+4 °C	Ambient T+4 °C + CO2
Ambient T+1 °C; β0	8.2463184a	0.4665176	< 0.001	variance (ai(1))	0.722192	1	0.15	–0.02
Ambient T+4 °C; β0+ β1	9.3113819b	0.4869418	< 0.001	variance (ai(2))	1.297782		1	0.38
Ambient T+4 °C + CO2; β0+ β2	10.006337b	0.5008949	< 0.001	variance (ai(3))	1.266242			1
Day; β3	–0.1186385	0.0366558	–	variance (djt)	0.010722
Day2; β4	–0.0067618	0.0008185	< 0.001	–	–
–	–	–		Box; variance (bt)	1.673232
Different letters following estimated values indicate differences among climate treatments (p < 0.05). Ambient T+1 °C – 1 °C above ambient and ambient CO2, Ambient T+4 °C – 4 °C above ambient and ambient CO2, Ambient T+4 °C + CO2 – 4 °C above ambient and elevated CO2.