以树冠投影面积导算林分最大密度的研究

STUDIES ON COUNTING GREATEST DENSITY OF STAND USING PROJECTED AREAS OF TREE-CROWN

一、问题的提出及其意义定量间伐方法有数种,其一认为:“假设林分中平均木以上的立木,在其生长发育中不受其相邻立木的挤压,因而能获得正常的生长条件,能正确地反映生长规律”,因此,在任一林分内首先要调查林分的平均胸径;凡大于或等于平均胸径的立木(有明显偏冠、损伤者除外)都选作调查对象。“并用每个径阶的冠幅面积除单位面积(公顷),而得各径阶单位面积上的株数,称为林分理论最大密度(以下简称理论密度)。”

Because the tree-crown of mean wood assortment in China are obviously greater, the numbers of trees in a stand are counted by projected areas of tree-crown of dominant trees, the trees above mean trees and double indexes, mean trees, all trees of a stand (N=10000/(π/4)(CWD)~2, CWD--diameter of tree-crown). Except special kinds of trees, the numbers of trees are different greatly with greatest density of stand. Form the above, the conclusions can be drawn: It is lack of fully theoretical bases that the numbers of trees counted by projected areas of tree-crown are as greatest density of a stand.