An improved tree height measurement technique tested on mature southern pines.

摘要

Virtually all techniques for tree height determination follow one of two principles: the similar triangles or the tangent method. Most people apply the latter approach, which uses the tangents of the angles to the top and bottom and a true horizontal distance to the subject tree. However, few adjust this method for ground slope, tree lean, crown shape, and crown configuration, making errors commonplace. Given documented discrepancies exceeding 30% with the current methods, a reevaluation of height measurement is in order. The sine method is an alternative method that measures a real point in the crown. Hence, it is not subject to the same assumptions as the similar triangle and tangent approaches. In addition, the sine method is insensitive to the distance from tree or observer position and can not overestimate tree height. The advantages of the sine approach are shown in three mature pines (an 89-cm Pinus taeda, a 91-cm dbh and a 49-cm dbh Pinus echinata) from Arkansas.