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林业科学 ›› 2006, Vol. 42 ›› Issue (12): 6-12.doi: 10.11707/j.1001-7488.20061202

• 论文及研究报告 • 上一篇    下一篇

林带小钻杨树冠的分维结构

陈军 李春平 关文彬 张楠楠 汪西林   

  1. 北京林业大学水土保持学院水土保持与荒漠化防治教育部重点实验室,北京100083
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2006-12-25 发布日期:2006-12-25

Fractal Characteristics of Tree Crown of Populus×xiaozhuanica in Shelterbelts

Chen Jun,Li Chunping,Guan Wenbin,Zhang Nannan,Wang Xilin   

  1. Key Laboratory of Soil and Water Conservation and Desertification Combating, Beijing Forestry University Beijing 100083
  • Received:1900-01-01 Revised:1900-01-01 Online:2006-12-25 Published:2006-12-25

摘要:

以分形理论为基础,论述不同年龄小钻杨分枝和树冠结构分维特征。小钻杨侧枝在各方位上均匀分布,侧枝倾角在各角度级上正态分布。通过计盒维数法计算出林带小钻杨分枝的分形维度值为1.510~1.733。对小钻杨各器官生物量、胸径和树高用W=a(D21.3H)b模型进行回归,结果表明它们之间相关性极显著。利用双数量法计算得到的树冠分数维度值为2.065~2.765;在应用双数量法中,用枝生物量代替叶生物量,计算得小钻杨无叶期树冠分数维度值为2.003~2.464。探讨了不同树冠体积和叶生物量下的树冠分数维度值的变化,在小的叶生物量等级时,分数维度值随着叶生物量的增加而明显增加,达到一定叶生物量后,叶生物量的增加对其影响逐渐减弱。不同树冠体积均有1个基本的叶生物量值以维持其表面积,也有1个最佳值,树冠分数维度不再有明显变化。

关键词: 小钻杨, 树冠, 分维数, 树体结构, 最佳结构

Abstract:

Based on destructive measurements, box-counting dimensions of branching patterns and fractal dimension of the crown of Populus×xiaozhuanica were estimated. Branching orientation were uniform distribution and branching angle were normal distribution. Fractal dimensions of Populus×xiaozhuanica branching patterns were between 1.510~1.733. The highest correlation coefficients were found between biomass of organs and diameter-at-breast-height (DHB) and height using models W=a(D21.3H)b. The two-surface method allows one to calculate fractal dimension from the regression of foliage area (mass) on the area (or volume) of the crown. Fractal dimensions of tree crown calculated by foliage mass and crown volume were 2.065~2.765. In defoliation period fractal dimensions of tree crown were 2.003~2.464, which were calculated by biomass of branch and crown volume. This paper investigated the relationship between the fractal dimension of crown and foliage mass and crown volume. The results show that when the foliage mass is small, fractal dimensions of tree crown increase significantly with the increase of foliage mass, this influence becomes weak until foliage mass increasing to a certain value. There is a certain foliage mass for each different volume to maintain its surface area, there also exists an optimum value, after which the fractal dimension will not change with the increase of foliage mass.

Key words: Populus×, xiaozhuanica, tree crown, fractal dimension, tree architecture, optimum structure