樟子松人工幼中龄林不同生长级林木叶面积分布

Needle Area Distribution of Trees in Different Growth Classes from Young and Middle-Aged Plantations of Pinus sylvestris var. mongolica

根据东北东部山地3个地点7块样地的调查结果,分析了樟子松人工幼中龄林中不同生长级林木的叶面积分布状况。结果表明:①不同生长级林木之间叶面积有明显差异,以上层木叶面积最大,中层木次之,下层木最小,其中上层木与中层木之间的叶面积差异相对较小;②叶面积主要集中在树冠的中、上部,下部比例很小;③构成叶面积主要部分的都是1 a和2 a针叶,3 a针叶的叶面积量较少;④密度过大就会使各生长级林木的叶面积大大降低,尤其是低生长级林木的叶面积降低幅度极大。这些结果为制定合理间伐和修枝措施提供了科学依据。

A study was conducted to analyze the needle area distribution of trees in different growth classes from young and middle-aged plantations of Pinus sylvestris var.mongolica by means of the data from 7 sample plots at 3 sites in eastern mountain region of Northeast China.Results showed that there was an evident difference in needle area among trees in different growth classes,that is,the needle area of trees in the upper storey was the biggest,followed by middle story and lower story,but there was little difference in needle area of trees between the upper story and the middle story.The upper and middle layers of the tree crown accounted for a large proportion of needle area,while the lower layer occupied a small proportion.Needle area was mainly from 1,2-year-old needles,just a little from 3-year-old needles.Needle area of trees in different growth classes decreased sharply when stand density was too high,especially for those trees in lower growth classes.