摘要
以民勤荒漠绿洲4～16年生的二白杨为研究对象,对不同径阶的标准木进行全株破坏性取样,运用分形理论和方法,研究叶片、树冠、单株树木干枝总体积的分形特征。结果表明:(1)二白杨叶形多样,叶片分维数随叶形和立地条件而变化。与箭杆杨叶片形状近似的叶片,分维数均值为1.915 0。与小叶杨叶片形状近似的叶片,分维数均值为1.820 8。施肥植株的叶片分维数均值为1.906 0,未施肥的为1.861 4。叶片分维数,映射出其父本小叶杨和母本箭杆杨的遗传性状,以及树木生长地立地条件的优劣;(2)二白杨树冠空间曲面分维数在2.014～2.605之间,平均值为2.310。树冠体积分维数在2.015～2.533之间,平均值为2. 274。当树冠叶面积饱和值K2<1.0时,树冠空间曲面分维数与树冠叶面积饱和值K2呈正相关。当K2=1.0时,树冠空间曲面分形维数达到最大值2.44;(3)二白杨干枝总体积分维数在2.376～2.597之间,平均值为2.487,但干枝总体积与树冠叶面积饱和值K2的相关不紧密。
Populous gansuensis is an endemic plant in Minqin desert oasis.In this research,4~16 years old individual standard wood of different DBH ranks were destructively sampled as the material.Based on the methodology of fractal theory,the direct measurements of tree crowns,trunk,branches and leaves were used to infer the fractal characteristics of leave,crown,and the total volume of stems and branches at the individual level.The results showed:(1)the leaf shape of Populous gansuensis is variable.The leaf fractal dimension changes with the leaf shape and site condition.The mean value of the fractal dimension for Populous gansuensis is 1.915 0 and 1.820 8 for leaves which have similar shape to Populus nigra and Populus simonii respectively.The mean value of the fractal dimensions also differ among fertilization levels,which is 1.906 0 for fertilized individuals and 1.861 4 for non-fertilized individuals.The fractal characteristics reflect both the site condition and the genetic traits of male parent(Populus simonii)and female parent(Populus nigra);(2)the fractal dimension of the crown space surface(D(S-L))is between 2.014~2.605,with mean value of 2.310.The fractal dimension of the crown volume(D(V-L))is between 2.015~2.533,with mean value of 2.274.When the crown leaf area saturation value is K2<1.0,the fractal dimension of crown space surface is positively correlated with the saturation value of canopy leaf area.The maximum D(S-L)appear at 2.44 when K2=1.0;(3)the fractal dimension of the total volume of stem and branch is 2.376~2.597,and the average value is 2.487.The correlation between the fractal dimension D(Vsb-Ba)and the saturation value(K2)of the crown leaf area is not significant.
作者
马良清
林海晏
黄小辉
冯大兰
MA Liang-qing;LIN Hai-yan;HUANG Xiao-hui;FENG Da-lan(Chongqing Academy of Forestry, Chongqing 400036, China)
出处
《甘肃林业科技》
2018年第3期34-39,53,共7页
Journal of Gansu Forestry Science and Technology
关键词
二白杨
叶面积
树冠
干枝总体积
分形
Populous gansuensis
leaf area
crown
total volume of stem and branch
fractal
