<正>通过对受酸雨危害和未受危害的南方型杨树的对比研究 ,发现酸雨对杨树木材构造有明显的影响。受害材的边材宽度和年轮宽度均小于健康材 ,边材率无显著差异。导管是对酸雨敏感的一种组织 ,受害材导管的弦向直径小于健康材。受害材的纤维长度和纤维双壁厚与健康材相似 ,但纤维宽度明显低于健康材 ,由此而造成纤维长宽比的显著差异。通过扫描电镜观察分析 ,发现受害材的木材构造发生多种变异 ,观察到假年轮和窄年轮、变异的导管、浸填体含量的增加、木纤维细胞壁变薄和木材内裂等构造缺陷

Wood structure of poplar ( Populus×euramericana ) selected from healthy and acid rain damaged froests was analyzed to evaluate the effects of acid rain on wood properties. Ring width and sapwood width of diseased poplar decreased significantly than that of healthy poplar, but sapwood portion was same. Vessel is known to be sensitive to acid rain, its tangential diameter of diseased poplar decreased than that of healthy poplar. The significant difference of fiber width between diseased and healthy poplar led to the significant difference of ratio of fiber length to fiber width. The variation of microstructure of diseased poplar wood, i.e. false annual ring, double annual ring, variation of vessel section, rise of tylosis in vessel, parenchyma fiber and split, were observed by image analysis system and scan electron microscope.