Table 1 Mean values of photosynthetic, anatomical, and morphological traits of the 4–22 fully-expanded mature leaves in the 4-year-old trees.

A_max (μmol m⁻² s⁻¹)

9.4 (0.3)

14.8 (0.6)^***

g_s (mol m⁻² s⁻¹)

0.0796 (0.0063)

0.0966 (0.0034)^n.s.

g_m (mol m⁻² s⁻¹)

0.0325 (0.0022)

0.0598 (0.0075)^***

A₁₅₀₀/E₁₅₀₀ (μmol CO₂ mmol H₂O⁻¹)

3.01 (0.13)

3.96 (0.12)^***

V_cmax (μmol m⁻² s⁻¹)

36.6 (0.7)

45.5 (1.5)^***

J (μmol electrons m⁻² s⁻¹)

71.1 (2.2)

89.5 (3)^***

S_c (m² m⁻²)

9.1 (0.7)

14.7 (0.3)^***

Mesophyll cell wall thickness (μm)

0.183 (0.014)

0.208 (0.005)^n.s.

Mesophyll cell number (mm⁻¹ section)

336 (14)

457 (11)^***

Mesophyll palisade cell width (μm)

9.7 (0.4)

7.8 (0.2)^***

Mesophyll palisade cell length (μm)

64.3 (1.8)

63.6 (1.7)^n.s.

Mesophyll spongy cell width (μm)

8.9 (0.3)

9.4 (0.3)^n.s.

Mesophyll spongy cell length (μm)

19.9 (1.4)

26.5 (0.5)^***

Epidermal cell width (μm)

22.6 (1.6)

18.2 (0.5)^*

Epidermal cell thickness (μm)

18.5 (0.5)

15.9 (0.2)^***

Chloroplasts (10³ mm⁻¹ section)

1.46 (0.08)

2.24 (0.06)^***

Chloroplast width (μm)

5.23 (0.15)

4.02 (0.11)^***

Chloroplast thickness (μm)

1.26 (0.06)

1.09 (0.02)^**

Leaf area (cm²)

31.5 (2.3)

14.9 (0.3)^***

Leaf mass per area (g m⁻²)

73.6 (3.5)

90.5 (3.8)^**

Mesophyll thickness (μm)

256 (7)

247 (4)^n.s.

Chlorophyll content (SPAD)

34.4 (0.8)

41.0 (0.6)^***

Stomatal length (μm)

11.9 (0.3)

12.3 (0.3)^n.s.

Stomatal width (μm)

6.26 (0.19)

6.17 (0.15)^n.s.

Stomatal density (mm⁻²)

521 (44)

495 (39)^n.s.