笋材两用毛竹林林分结构数量关系研究

THE STRUCTURE OF A CULM AND SHOOT PRODUCING STAND OF PHYLLOSTACHYS PUBESCENS

作为在闽中尤溪县 6年试验研究结果的一部分 ,采用 PCA方法分析笋材两用毛竹林 (Phyllostachyspubescens)林分结构因素。结果表明 ,新成竹数量、竹林密度、年龄结构和新竹平均胸围 (GBH)是影响笋材两用毛竹林林分结构的主导因素。对各类林分进行系统聚类分析 ,笋材两用毛竹林可分为 3类 ,大致相当于竹林密度 2 5 0 0株· hm- 2 以下、2 80 0～ 40 0 0株· hm- 2 和 40 0 0株· hm- 2 以上 3种情形。用正态分布拟合新成竹胸围 (GBH )分布效果较好。新成竹胸围与竹林密度相关不显著。

This paper presents results from pa rt of an experiment investigating the structure of a culm and shoot producing st and of Phyllostachys pubescens which was performed over 6 years in Youxi Cou nty, Fujian Province. Principal component analysis (PCA) indicated that the majo r factors affecting stand structure were the quantity of new bamboo stems in the stand, its density, age structure, and the girth of new bamboo stems at breast height (GBH). Cluster analysis showed that the bamboo stand could be divided int o three different structure types: low (under 2500 stem·hm -2 ), middle (28 00-4000 stem·hm -2 ) and high (above 4000 stem·hm -2 ) density. The GBH of new bamboo stems fits a normal distribution which was not related to variation in the density of the stand.