长江滩地立木腐朽杨树与正常杨树生长与材性的比较研究

COMPARATIVE RESEARCH ON GROWTH AND WOOD PROPERTIES BETWEEN ROTTEN POPLAR TREE AND NORMAL ONE ON FLOOD BEACHES ALONG YANGTZER RIVER

本文对长江滩地意杨的生长和木材材性进行了初步研究 ,着重讨论长江滩地立木腐朽杨树与正常杨树在树高、胸径生长的差异 ,通过回归分析 ,给出了杨树胸径生长与年龄的回归方程。分析研究腐朽木和正常木在年轮宽度、含水率、木材密度、干缩率等方面的差异。通过扫描电镜观测腐朽木和正常木细胞壁层的差异和菌丝在木材细胞的分布状况。研究结果表明 :地势低是导致杨树立木腐朽的直接原因 ;腐朽对杨树的胸径生长和高生长及木材材性有显著影响 ;腐朽材内部生材含水率远低于正常材内部生材含水率 ,这是由于腐朽杨树内部导管比量明显比正常材低导致其输导水分功能减弱所致 ;而腐朽材的密度和干缩率均高于正常材 ;腐朽木中出现了具有应拉木特征的区域 ,菌丝入侵立木杨树主要通过夹皮裂隙 。

To look for impact of trunk rot on growth and wood properties of poplar tree on beaches along Yangtzer River, the growth of poplar tree was investigated and some wood properties were determined. The value of green moisture content of internal part of rotted poplar tree is smaller than that of normal one. The values of basic density and ratio of drying shrinkage of rotted poplar tree are higher than that of normal one. The tension wood was detected in rotted poplar wood by scan electronic microscope. Fungi and bacteria attack the poplar trees through check of bark pocket . The mycelium spreads from vessels and ray cells to fiber cells in poplar wood.