Construction of forest hydrological tree form model for Japanese cedar and cypress trees

Nobuhiro EBISU, Keiji TAKASE and Natsuko OTAKE

A simple and effective tree form model is needed for water cycle and rainfall interception studies in forest hydrological research. The purpose of this study is to develop a two�]dimensional tree model for Japanese cedar and cypress trees. The model includes a functional relationship between branch lengths and tree height for a single tree. We show that the relationship between them can be modeled by a quadratic curve using the tree form factor with Japanese cedar and cypress trees. The relationship between stand density and the tree form parameter could be expressed by a power equation. In addition, the relationships among leaf area, storage capacity, and branch length could be represented by power equations. Using this model, the storage capacity of the canopy and leaf area index were estimated under different conditions of crown height for Japanese cypress and cedar. The effects of forest management on transpiration and branch storage are suggested by the results.