毛竹林的立竹度对秆形的影响

<正> 毛竹林中,单位面积上的立竹株数称立竹度,用每亩竹林中的立竹株数表示。立竹度是竹林结构的重要因子,反映单株竹子所占的林地空间。它不仅影响竹林的生态条件(光、温、水、肥、气等)的变化,而且对竹子的秆形也有深刻的影响。为了研究毛竹林的立竹度对秆形的影响,1980年9月间,我们在宜兴林场20块不同立竹度的标准地中,共砍伐毛竹1060株,选取标准竹826株,按竹林立竹度把标准竹分成七个组,对各组分别进行统计分析。按幂函数式作相关配合,计算出胸径D(cm)与高度H(m)、枝下高H_(c1)(m)、秆重W(Kg),枝叶重W_(b1)(Kg)和枝下节数(Nb1)的关系,参数a、b列于表1中。

THE INFLUENCE OF BAMBOO NUMBER PER MU ON CULM FORM IN PHYLLOSTACTHYS PUBESCENS STANDS

This paper deals with mathematical models of culm forms of Phyllostachys pubes-cens. Based on 826 culms collected from 20 sample plots in Yixing, Jingsu in 1980, four basic mathematical models have been worked out through statistical procedures. They are: ’1, The relationship between the bamboo number per mu (N) and the length (H) of culms:H = 0.8459 N0.1745 D0.782, The relationship between the bamboo number per mu (N) and the clear length (Hcl) of culms:Hcl=0.0398 N0.4668D3, The relationship between the bamboo number per mu (N) and the total fresh weight of branches and leaves (Ww):Wbl = 2.5998 N-0.4030 D1.254, The relationship between the bamboo number per mu (N) and the knot number (Nw) of clear culms:Nbl= 1.7228 N0.2661 D0.55, The bamboo number per mu have no influence on the fresh weight of individual culms in Phyllostachys pubescer.s stands.