野化培训大熊猫采食和人为砍伐对拐棍竹无性系种群结构的影响

Effects of wilderness-training Ailuropoda melanoleuca’s feeding and artificial harvesting on population structure of Fargesia robusta clone

2003—2007年,采用样方法和定位观察法测量了卧龙自然保护区拐棍竹无性系种群密度、地径和高度,研究野化培训大熊猫采食和人为砍伐对拐棍竹无性系种群更新的影响;并用Weibull概率密度分布函数的尺度和形状参数比较分析了不同处理方式(大熊猫采食、人为砍伐和对照)对拐棍竹无性系种群结构(年龄、径级和高度级)的影响.结果表明:在相同种群数量和环境条件的基础上,大熊猫采食和人为砍伐有利于拐棍竹的无性系更新,经过3年多的自然恢复,竹子的种群密度趋于一致,并达到较稳定的状态.大熊猫采食样方的拐棍竹径级和高度级分布曲线、尺度参数和形状参数与对照样方无明显差异;而人为砍伐样方的分布曲线大多呈倒"J"型,且尺度参数和形状参数均明显小于大熊猫采食和对照样方,当年生竹笋和多年生竹的生长质量远不及大熊猫采食影响下的竹子种群,难以达到大熊猫取食的选择标准.

From 2003 to 2007,the methods of plot sampling and positioning observation were adopted to investigate the population density,basal diameter,and plant height of Umbrella bamboo （Fargesia robusta） clone in the Wolong Natural Reserve of China.In the meantime,the effects of wilderness-training Ailuropoda melanoleuca’s feeding and artificial harvesting on the population regeneration of the clone were studied,and the responses of the population structure （age-,size-,and height-class distribution） to different management modes （A.melanoleuca’s feeding,artificial harvesting,control） were approached with the scale-and shape-parameters of Weibull distribution function.The results showed that under the same F.robusta clone population density and the same environmental conditions （P0.05）,A.melanoleuca’s feeding and artificial harvesting promoted the clone regeneration.After 3 years natural restoration,the population density of the clone tended to be equal to the control,and came to a steady state （P0.05）.The curves of size-and height-class distribution as well as the scale-and shape-parameters had no significant differences between A.melanoleuca’s feeding plot and control plot.The curves of size-and height-class distribution in artificial harvesting plot were in converse ＂J＂ shape,and the values of the scale-and shape-parameters were significantly lower than those in the other two plots （P0.05）.The young and adult bamboos in artificial harvesting plot were far poor in shoot quality,and A.melanoleuca rejected to feed with them.