PROGRAM HTVOL: The Determination of Tree Crown Volume by Layers

A FORTRAN IV computer program calculates, from a few field measurements, the volume of tree crowns. This volume is in layers of a specified thickness of trees or large shrubs. Each tree is assigned one of 15 solid forms, formed by using one of five side shapes (a circle, an ellipse, a neiloid, a triangle, or a parabolalike shape), and one of three bottom shapes (a circle, an ellipse, or a triangle). A test of the accuracy of this technique shows that it produces estimates within acceptable limits of error if the shape is carefully selected. The program sorts these volume data by layer within species for each sample plot. Any number of plots can be run at one pass through the computer, and up to 100 species can be designated.