Table 1.

Summary of steady‐state values for photosynthetic induction by a sunfleck in leaves from the bottom or top of the canopy, in three provenances of Fagus sylvatica trees grown in Helsinki.

Provenance	Canopy depth	State	Net CO2 assimilation, A n (μmol m−2 s−1)	Stomatal conductance, g s (mol m−2 s−1)	Intrinsic water use efficiency, A n/g s (μmol mol−1)
Blaviksliarna Sweden (SE)	Bottom	SS0	1.01 ± 0.14 a	0.013 ± 0.002 ab	93.33 ± 25.03 e
		SS1	4.76 ± 0.47 b	0.059 ± 0.009 abc	89.49 ± 15.89 e
		SS2	1.11 ± 0.15 a	0.013 ± 0.002 ab	97.72 ± 17.33 e
	Top	SS0	0.49 ± 0.18 a	0.05 ± 0.018 abc	24.35 ± 10.52 abc
		SS1	14.37 ± 1.37 c	0.183 ± 0.029 de	86.52 ± 14.7 de
		SS2	0.57 ± 0.15 a	0.047 ± 0.015 abc	19.44 ± 7.14 a
Eichelberg Germany (DE)	Bottom	SS0	0.71 ± 0.16 a	0.014 ± 0.002 ab	58.57 ± 14.77 abcde
		SS1	5.51 ± 0.56 b	0.078 ± 0.013 c	79.06 ± 12.02 bcde
		SS2	0.73 ± 0.11 a	0.014 ± 0.002 ab	62.86 ± 16.28 abcde
	Top	SS0	0.29 ± 0.15 a	0.027 ± 0.009 ab	22.34 ± 9.68 ab
		SS1	12.53 ± 1.63 c	0.144 ± 0.028 d	99.23 ± 15.05 e
		SS2	0.34 ± 0.12 a	0.027 ± 0.006 ab	31.05 ± 19.1 abcd
Montejo de la Sierra Spain (ES)	Bottom	SS0	0.77 ± 0.18 a	0.012 ± 0.003 a	89.97 ± 34.29 e
		SS1	6.43 ± 0.66 b	0.091 ± 0.014 c	78.9 ± 10.94 cde
		SS2	0.79 ± 0.18 a	0.018 ± 0.004 ab	50.15 ± 9.39 abcde
	Top	SS0	0.31 ± 0.19 a	0.055 ± 0.009 abc	6.26 ± 4.03 a
		SS1	16.41 ± 1.25 d	0.229 ± 0.031 e	80.79 ± 15.94 cde
		SS2	0.31 ± 0.11 a	0.061 ± 0.013 bc	6.42 ± 2.61 a

SS0, low light before the sunfleck (20 μmol m⁻² s⁻¹); SS1, high light during the sunfleck (1200 μmol m⁻² s⁻¹); SS2, low light after the sunfleck. Values are means ± standard error. Letters represent statistically significant differences between groups tested by post hoc pairwise comparisons (P < 0.05).