北京地区银杏木材密度及其变异研究

该文对北京地区 1 7年生银杏 (GinkgobilobaL .)木材年轮宽度、木材密度及变异特点进行了研究 .结果表明 ,年轮宽度近髓心部位较窄 ,进入正常生长年轮较宽 .木材年轮密度、最大密度和最小密度近髓心部位略大一些 ,随着年龄的增加 ,略有下降趋势 ,之后呈平缓的生长状态 .年轮宽度、年轮密度、最大密度和最小密度均值分别为0 72 0cm ,0 5 49g/cm3 ,0 6 46 g/cm3 和 0 4 77g/cm3 .年与年之间的年轮密度有一定联系 ,年轮相距越近 ,正相关系数越大 ,年轮相距越远 ,相关程度变小 ,往往呈负相关形式增大 .年轮宽度与年轮密度、最大密度、最小密度都呈较显著的负相关关系 .最小密度与年轮密度都呈较显著的正相关 ,变异幅度与年轮宽度呈较显著的正相关关系 .银杏作为人工用材林树种 ,有很好的发展前景

Wood density and variation of ginkgo from Beijing area

The wood properties of 17 year old ginkgo (Ginkgo biloba L.), from Beijing area, were studied in this paper. The results show that the ring is wider near pith than that near bark; after about 13 years old, the width began to slightly decrease. The wood density near pith is higher than that near bark. The ring width is 0.72 cm, ring density is 0.543 g/cm 3, maximum density is 0.646 g/cm 3, minimum density is 0.477 g/cm 3.The correlations of age age with wood density show that there are close relationships between growing speed and wood density from one to other. The nearer the two rings, the bigger the correlation coefficients. The correlation coefficients are from positive to negative, constantly increase with negative correlation. This means that densities of nearby rings of correlation are bigger; if the distant is far from one ring to the other, the correlation coefficient is smaller. The ring widths have significant positive correlation with ring density. There are significant positive correlations between ring density and maximum density and minimum density, variation range has significant positive correlation with ring width.