摘要
本文比较观察了三种不同木材类型的正常与矮化树木的木材结构:针叶材的太白红杉(Larix chinensis Beissn.)、散孔材的辽东桤木(Alnus sibirica Fisch.)和环孔材的蒙古栎(Quercus mongolica Fisch.)。这些植物在个体发育过程中,各年的年轮宽度及管状分子长度、宽度等变化,存在各自的规律性。这些规律并不因生长环境的差异而变更。不过,逆境下生长的矮化植株的年轮宽度和管状分子的大小明显地比正常的要窄小,同时在木材结构的其它数量性状上,也有较大变化;然而,其各自的种属定性特征仍保持稳定。这些似乎可说明:生态环境的变化对木材结构的数量性状有较大影响,但是对木材种属的定性特征则无明显作用。
Wood structure of three species i.e.Larix chinensis Beissn.,Alnus sibirica Fisch.and Quercus mongolica Fisch.of normal.and dwarf trees were comparatively studied.The age va- riation of width of annual rings and size of tracheary elements in these trees follows their own regularities respectively during the course of ontogenesis.In normal,as trees grow,the width of annual rings increases gradually,reaches maximum,then declines in subsequence;while the size of tracheary elements exhibits a crescendo increment,and remains constant after reaching maximum.These trends were not affected by the change of enviromental conditions in which the trees grow.However,the width of annual rings and size of tracheary elements of dwarf trees which grow in adverse circumstances are respectively narrower and smaller than those of normal troes.Further,in dwarf tree of L.chinensis(coniferous wood);the diameter of bordered pits on tracheids of early wood decreases,ray height is lower and ray frequence is higher.In dwarf tree of A.sibirica(diffuse porous wood),vessel frequence increases and the number of bars per perforation decreases.The quatitative features of wood structure of dwarf trees,as compared with those of normal trees,showed more variations;whereas,their own qualitative features of wood structure remain constant.These findings might indicate that modifications of wood structure responsing directly to change of enviromental,conditions are usually only qualitative.
关键词
正常树木
矮化树木
木材结构
Normal tree
Dwarf tree
Wood
Annual ring
Tracheary element
