TABLE A1.

Correlations between daily accumulated sapflux (three age categories) and PPFD in five phenological stages.

Age	Phenological stages
	Incubation	Culm-elongation	Branch-development	Leafing	Established
A1	0.51*	0.45*	0.74**	0.93**	0.87**
A2	0.47*	0.74**	0.86**	0.96**	0.86**
A3	0.25	0.54**	0.65**	0.94**	0.81**

The numbers are R² of linear fit; * indicates significant correlation and ** very significant.