Property | Core wood | Outer wood | t value (p value) |
---|
Mean | SD | Mean | SD |
---|
WFL (mm) | 0.89 | 0.07 | 1.17 | 0.07 | − 0.281 (< 0.001) |
VEL (mm) | 0.54 | 0.01 | 0.69 | 0.01 | − 0.146 (< 0.001) |
BD (g/cm3) | 0.50 | 0.03 | 0.59 | 0.03 | − 0.089 (< 0.001) |
AD (g/cm3) | 0.59 | 0.00 | 0.67 | 0.00 | − 0.085 (< 0.001) |
DMOE (GPa) | 8.52 | 1.08 | 13.02 | 1.09 | − 4.499 (< 0.001) |
MOE (GPa) | 5.65 | 1.35 | 9.70 | 2.51 | − 4.049 (< 0.001) |
MOR (MPa) | 60.0 | 6.5 | 102.8 | 6.8 | − 42.731 (< 0.001) |
U (kJ/m2) | 40.5 | 3.5 | 113.9 | 5.2 | − 73.349 (< 0.001) |
CS (MPa) | 35.8 | 0.7 | 49.0 | 0.7 | − 13.260 (< 0.001) |
SS (MPa) | 6.8 | 1.1 | 11.4 | 1.0 | − 4.550 (< 0.001) |
- Number of trees = 10. WFL, wood fiber length; VEL, vessel element length; BD, basic density; AD, air-dry density after drying at around 22 °C and 65% relative humidity for 2 weeks (11.3 ± 0.5% of moisture content); DMOE, dynamic Young’s modulus; MOE, modulus of elasticity; MOR, modulus of rupture; U, absorbed energy in impact bending; CS, compressive strength parallel to grain; SS, shearing strength of small clear specimens. Wood properties were estimated from the first to 70th annual ring in each tree using the best developed model for the radial pattern (Model II, Tables 2 and 5). The means and standard deviations (SDs) of the core wood and outer wood were calculated from the first ring to boundary age (listed in Table 6) and from the boundary age to 70th annual ring, respectively. Significant differences between the core and outer wood were detected using a paired t test