Table 4 Chemical and anatomical characteristics of stem tissues of P. trichocarpa grown without (LN) or with nitrogen fertilization (HN) for 1.5 months

EZ

Lignin (%)

17.61 ± 1.50

21.28 ± 0.78

0.037

Soluble phenolics (μg mg⁻¹)

5.96 ± 0.52

7.89 ± 0.54

0.022

Lumen per vessel (μm²)

189.0 ± 13.0

478.1 ± 32.9

<0.001

Cell wall thickness of vessels (μm)

1.80 ± 0.15

2.20 ± 0.13

0.021

FW/DW

5.10 ± 0.18

5.51 ± 0.06

0.035

Developing Xylem

Lignin (%)

11.43 ± 1.02

8.45 ± 1.33

0.063

Soluble phenolics (μg mg⁻¹)

0.86 ± 0.13

0.55 ± 0.08

0.045

Lumen per vessel (μm²)

221.0 ± 32.5

600.6 ± 51.2

0.008

Cell wall thickness of vessels (μm)

1.89 ± 0.12

1.74 ± 0.14

0.212

FW/DW

3.15 ± 0.42

5.17 ± 0.24

0.003

Wood

Lignin (%)

24.55 ± 1.67

21.89 ± 1.39

0.134

FW/DW

2.23 ± 0.09

2.45 ± 0.12

0.100

Vessel lumen area (μm²)

940.7 ± 53.0

1459.6 ± 81.1

<0.001

Fiber double wall thickness (μm)

4.36 ± 1.32

3.44 ± 1.38

<0.001