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为了给优良的观赏和夏秋笋用竹种四季竹的丰产林分密度建立提供理论依据,开展了四季竹纯林4种林分密度(17500～27500株·hm-2,D1;37500～42500株·hm-2,D2;55000～62500株·hm-2,D3;72500～82500株·hm-2,D4)的分株构件因子调查,并对立竹主要形态特征因子进行了主成分分析。结果表明:随着林分密度的增大,四季竹立竹胸径和相同胸径下的节间长分别呈“∧”和“∨”形变化,极值分别出现在D3和D2密度。相同胸径下的立竹冠幅和枝盘数均呈“∨”形变化,并且最小值都出现在D2密度;立竹枝长和残枝率均呈倒“N”形变化,枝长最大值和残枝率的最小值均出现在D3密度。林分叶面积指数呈“∧”形变化,最大值出现在D3密度;立竹单叶面积与林分密度呈显著正相关。相同胸径下的立竹全高、胸高壁厚、枝下高和枝夹角、单叶质量、比叶面积在不同林分密度间无显著差异。经主成分分析,立竹表型形态与秆形构件关系最为密切,其次为枝条构件,最后是叶片构件。经通径分析,各林分密度立竹表型综合得分大小顺序为:D3>D4>D2>D1。在试验林立竹胸径条件下,D3是四季竹无性系生理整合成本和效益的密度阀值,是分株形态良好建成的适宜林分密度。
In order to provide a theoretical basis for the establishment of excellent ornamental and summer and autumn bamboo shoots with high yield stand density of bamboo species, the four species density (17500 ~ 27500 plants · hm-2, D1; 37500 ~ 42500 plants) Hm-2, D2; 55000-62500 plants · hm-2, D3; 72500-82500 plants · hm-2, D4) were investigated. Principal component analysis (PCA) The results showed that with the increase of stand density, the DBH diameter and the internode length under the same DBH were changed to “∧” and “∨”, respectively, and the extreme values appeared at the density of D3 and D2 . The crown diameter and branch number of standing bamboo under the same DBH showed “∨ ” shape change, and the minimum values appeared at D2 density. The minimum values for both the value and the rate of stubs appear at the D3 density. The leaf area index of forest stands in the shape of “∧ ”, and the maximum value appears in the density of D3. There is a significant positive correlation between stand leaf area and stand density. Under the same diameter at breast height, the height of thymus wall, the height of thymus wall, the angle between branch height and branch, leaf mass and specific leaf area were not significantly different among different stand density. According to the principal component analysis, the morphological characteristics of Phyllostachys pubescens are most closely related to the stalk components, followed by the branches and finally the leaf components. According to the path analysis, the order of the comprehensive scores of stand phenotypes was: D3> D4> D2> D1. Under the conditions of bamboo diameter at test, D3 is the density threshold of the cost and benefit of physiological integration of the four-year-old bamboo clones, and is an appropriate stand density for the morphological establishment of ramet.