Crown architecture of short-rotation, intensively cultured Populus. III. A model of first-order branch architecture

A model was developed to describe the first-order branch architecture of Populus clones grown under short-rotation, intensive culture. Four basic model components describe branch location along the tree bole, orientation of the branch in the plane in which it arises, taper of the branch, and the relation between leaf surface area supported by the branch and branch size. Branch arrangement along the tree bole was found to be symmetric for portions of the bole containing branches. Branch orientation was well described by assuming curvature to be constant, and branch taper was successfully modeled using a simple power function. Branch surface area was determined to be the most appropriate predictor of leaf surface area supported by the branch. Combining the four model components in a computer program allows an analysis of the dynamics of Populus crowns not previously possible.