不同落羽杉种源木材密度的变异

Variation of Wood Density of 16 Taxodium distichum (L.)Rich Provenances

对16个不同落羽杉种源的木材密度进行了研究，结果表明：（1）不同种源间木材基本密度、气干密度和全干密度均存在显著差异，其中5号、4号和3号种源木材的3种密度均较高，而10号种源的最小；（2）16个种源落羽杉的木材气干密度、全干密度、基本密度总变异系数分别为7．96％、8．92％、8．92％，变异幅度分别为0．3232～0．5104g／cm^3、0．2933～0．4629g／cm^3、0．2685～0．4004g／cm^3；（3）落羽杉由基干到顶部不同树高处的木材基本密度存在显著差异，12号种源的木材基本密度随树木高度的增加而逐渐增大，13和30号种源则在2．5m处较高；（4）落羽杉不同部位木材密度径向变异模式并不一致，从髓心向北，均呈现出中间高两边低的趋势，而从髓心往南，变化趋势不一致。

The wood density of 16 Taxodium distichum provenances was studied. The results were as follows： （1） The air-dry density,complete-dry density and basic density of 16 provenance had a significant difference, and the air-dry density, complete-dry density and basic density of No. 5, No. 4 and No. 3 provenances were all highest,and those of No. 10 provenance were lowest; （2） The total variation coefficients of the air-dry density, complete-dry density and basic density of 16 provenances were 7. 96%, 8. 92% and 8. 92% respectively, and variation ranges were 0. 323 2 - 0. 510 4 g/cm^3, 0. 293 3-0. 462 9 g/cm^3 and 0. 268 5-0. 400 4 g/cm^3 respectively; （3） Wood basic densities from base to top of the stem had a significant variation,and wood basic density increased with increasing of tree height ; （4） The radial variation of wood basic density in different positions of stem had a different changing trend, and the wood basic density had a changing trend of low-high-low from marrow to north,and the changing trend from marrow to south was different in different conditions of stem.