沙棘根系模糊聚类及生长分布规律的探讨

本文对黄土残塬沟壑区人工沙棘林单株根系进行了系统研究。结果表明:1.主根龄是影响沙棘单株根系间模糊聚类的决定性因素,幼龄期单株根系间极易聚合,随着主根龄增加,同龄单株根系间差异逐渐加大而较难聚合。2.用灰色Verhoulst模型对单株沙棘根量、根长的变化过程进行描述和预测,当主根龄达到17龄左右时,根系基本停止生长。3.沙棘根量、根长在土体中的垂直分布规律呈双曲函数关系,各实测值与计算值拟合非常贴切。4.沙棘根系密集层随主根龄的增加而加深,最终稳定在0-50cm左右,粗壮根系多集中在该层。文中还建立了沙棘根量与叶量的线性回归方程。

A STUDY ON FUZZY CLUSTERS AND GROWTH DOSTRIBUTION LAWS OF SEABUCKTHORN ROOTS

The roots of individual seabuckthorn plant grown in loess remaining plat- eau and gully region plantation have been studied systematically in this paper. The results show. (1) The age of the main root is the critical factor for the fuzzy cluster among individual plants. The roots at juvanile ages are clustered easily, and it is more difficult to cluster with the increase in the age of main root because of the differences in the roots of the same age individual plants. (2) Changes in root biomass and length of individual seabuckthorn plant have been described and forecasted by the grey Verhaulst model. The roots stop grow- ing when the main roots are about at the age of 17. (3) The vertical distr- ibution laws of root biomass and length in soil are in binary curve function, the goodness of fit between real data and calculated values is perfect. (4) The dense layers of seabackthorn roots increase in deepth with the main root ages and become stable at about 0-50cm finally. The large diameter roots are mostly in this layer. The linear regression equation between root biomass and leaf bi- omass of seabuckthorn has been established in this paper.