Hagihara A, Hozumi K
Silviculture Laboratory, Department of Forestry, School of Agriculture. Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464, Japan.
Tree Physiol. 1986 Jun;1(1):9-20. doi: 10.1093/treephys/1.1.9.
A Weibull function was used to model the vertical distribution of leaf area of individual trees in a 25-year-old Chamaecyparis obtusa (Siebold & Zucc.) Endl. plantation. The parameter representing the shape of the leaf distribution was independent of tree size. A scale parameter tended to decrease with tree size suggesting a critical minimum height for retention of foliage by trees. On the basis of leaf distribution, the photosynthetic production of individual trees was estimated from the canopy photosynthetic production, which was determined from a model of canopy photosynthesis. The data indicated that the photosynthesis of a tree was proportional to the corresponding tree weight to the power of 1.84. Furthermore, the photosynthetic production varied as the 3/2nd power of total leaf area of the tree. Thus, it was concluded that the photosynthetic production per unit of leaf area, that is, the mean photosynthetic activity of a tree, is proportional to the stem girth at clear length, or the square root of the leaf area of the tree.
采用威布尔函数对树龄25年的日本扁柏人工林中单株树木叶面积的垂直分布进行建模。表示叶片分布形状的参数与树的大小无关。一个尺度参数倾向于随树的大小而减小，这表明树木保留树叶存在一个临界最小高度。基于叶片分布，根据冠层光合作用模型确定的冠层光合产量估算单株树木的光合产量。数据表明，树木的光合作用与相应树重的1.84次方成正比。此外，光合产量随树木总叶面积的3/2次方变化。因此，得出结论：单位叶面积的光合产量，即树木的平均光合活性，与净干围或树木叶面积的平方根成正比。
