Owing to plastic growth,the relations among average DBH,average dry weight of individual plants and density of population varied among spruce populations in various types of forest.

• 由于可塑性生长的影响，不同林型中沙地云杉种群的平均胸径、单株平均干重与种群密度关系之间的变化幅度也不相同，但都表现出幂函数的变化特征。