Wood Physical and Chemical Properties of Natural and Planted Taxus wallichina var. mairei Forest in Wuyi County of Zhejiang Province

Determinations were implemented on density, shrinkage, swelling, bending strength, modulus of elasticity, hardness and chemical composition of natural (200-year) and planted (10-year) Taxus wallichiana var. mairei wood from Wuyi county of Zhejiang province. The results showed that under wood moisture content of 12%, the air-dried densities of natural forest and plantation wood were 0.656 g/cm3 and 0.654 g/cm3, and the oven-dried densities were 0.599 g/cm3 and 0.586 g/cm3, without significant difference (P＞0.05). The wood shrinkage of natural and planted forest was 4.805% and 4.837%. The wood dimensional stability of natural forest was slightly better than that of planted forest, but the difference was not significant (P＞0.05). The swelling of wood from natural and planted forest was 3.945% and 3.279%. The bending strength of natural and planted forest was 97.36 MPa and 63.41 MPa, the modulus of elasticity was 9 292.02 MPa and 4 489.57 MPa, with significant difference. The reason was perhaps related to the tree age. The wood end surface, radial and tangential hardness of natural forest was 3 044 N, 2 516 N and 2 806 N, and was significant higher that of plantation, except radial hardness, perhaps it caused by age. The contents of lignin, holocellulose and pentose in natural forest wood were 27.02%, 75.33% and 8.88%, because that the lignification degree of natural forest wood is higher than that of plantation. The contents of cold and hot water extractives and ash were 4.84%, 8.36% and 0.29%, higher than that in plantation wood because of the organic extracts and inorganic minerals.