竹阔混交林中阔叶树对毛竹生长的影响及竞争关系

Effect of everygreen brood-leaved trees on Phyllostachys pubescens growth and their competition in the mixed forest

竹阔混交林是一种优良的竹类农用林业模式。以人为干扰较少的竹阔混交林为研究对象,对竹阔混交林中毛竹Phyllostachys pubescens空间分布以及阔叶树对毛竹生长影响及竞争进行了定量分析研究。结果表明:①阔叶树对周围不同环形带内毛竹立竹数以及新竹分布有较大的影响。阔叶树周围单位面积内毛竹立竹数随距离增加而快速增加,由1.5 m内平均0.27株.m-2增至5.7 m内平均0.42株.m-2。从立竹数而言,阔叶树对周围毛竹的影响范围最大可达6.0 m。②随距阔叶树基干距离的增加,新竹平均胸径迅速增加。阔叶树对毛竹胸径影响的最大范围可达到7.0 m,且7.0 m内新竹平均胸径为10.4 cm的情况比较稳定。③在竹阔混交林中,毛竹种内和种间竞争强度均有随径级增大而增加的趋势。混交林林分总竞争强度较大,毛竹种内竞争也强,但阔叶树对周围毛竹的竞争强度都非常小,约占20.3%。

A quantitative analysis of the growth of moso bamboo （ Phyllastachys pubescens ） in the mixed forest of moso bamboo and evergreen broad-leaved trees and their competition were studied. The results were as follows： （1） the broad-leaved trees had great influence on the spatial distribution of bamboo and DBH of new culms in the different annular zones around the trees. The number of culms increased from average 0.27 culms·m^- 2 in 1.5 m annular zone to average 0.42 culmso·m^-2 in 5,7 m annular ：zone, according to the distance from the broad-leaved trees. As for the effect on bamboo, the maximum effective scope was about 6.0 m. （2） The average DBH of new bamboo increased with the increasing distance from the tree. The maximum effective scope of broad-leaved trees was about 7.0 m and the mean DBH of bamboos within the scope was 10.4 era. （3） The intraspecific competition of moso bamboo and interspecific competition between moso bamboo and evergreen broad-leaved trees were increasing along with DBH. The interspecific competition intensity of evergreen broad-leaved trees was about 20.3 %. [ Ch, 6 tab. 11 ref. ]