Abstract
The purpose of this study was to determine the full density curves of branches on standing trees. Sixty sample trees of Quercus acuta in a single stand were selectively cut in the Tokyo University Forest in Chiba, and then diameters and lengths of those branches with more than 2cm diameter that were at a length between 3.3m and 9.3m above ground were measured at one meter intervals along their stems and branches. To derive the full density curve of branches, the number of branches at a specific length and the maximum average volumes of branches above that length were selected to be independent and dependent variables, respectively in reference to the pipe model theory. The linear relationships between these variables were investigated on a log-log scale. The result showed that the regression estimates were significant for lengths from 4.3m to 8.3m, and that the full density curves for these significant lengths were considered to have a common slope parameter of -0.9801. This implied that the -3/2 power law of self-thinning is effective for branches on standing trees that are similar to the standing trees in forest stands. Further research was required, however, to investigate whether this slope is applicable not only to Quercus acuta but also to other species.
