摘要
树木在生长过程中容易受到许多外界因素的干扰,如地形、风吹、雪压、相临木竞争等,使得树木偏离原有的生长状态,发生树干倾斜、弯曲、树冠偏冠等现象(Alméras et al.,2005;John et al.,2003;Yamashita et al.,2007)。在这些因素的干扰下,树木为了更好地获得生存空间必须形成一个抵御机制。
The well distributed and planted poplar clone 107 was selected as studying materials in this study. Surface longitudinal growth strain of eccentric growth standing tree and inner residual longitudinal growth strain of eccentric growth fallen tree were determined. Both variation patterns of the surface strain and the inner strain were deduced. According to two variation patterns above,mechanism of some factors which affect growth strain was discussed. The result indicated that varied scope of the surface strain was -2 243 -348 με. Generally,the maximum of surface strain located at the lowest part of leaned trunk or convex part of bended trunk,and it was increasing along decreasing distance from testing position to lowest part or convex part. Multiple factors variance analysis shown the surface strain varied significantly among different trees and different position at periphery,however,different height of same tree could not significant affect the surface strain. Varied scope of the inner strain was -1 763 -2 279 με. General radial variation trend of inner longitudinal growth strain of fallen tree was similar to parabola with upward opening,and peak located at pith. Outer part of trunk shown compressive strain (tensile stress),while tensile strain (compressive stress) was illustrated at inner part of trunk. In addition,value of the inner strain at tension wood zone was smaller than corresponding value at opposite wood zone according scatter map. It meant that tensile stress of tension wood zone was greater than the opposite zone.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2010年第4期171-177,共7页
Scientia Silvae Sinicae
基金
瑞典国际自然科学基金项目(D/4155-1)
安徽农业大学"人工林生物形成和高效利用"创新团队项目
安徽省高校木材科学与技术重点实验室联合资助