Alternative Taper Curve Estimation Methods for Eucalyptus cloeziana (F. Muell.)

Abstract

Three types of taper estimation methods for Eucalyptus cloeziana were applied and compared by using Zambian and Zimbabwean plantation data. The methods are: (1) Schumacher's taper equation, (2) diameter prediction method and (3) polynomial taper curve. The Schumacher's taper equation method uses volume equations to derive taper functions, while the diameter prediction method uses underbark diameters at different relative heights of the stem to describe the tree form. The polynomial taper curve method uses a high degree polynomial equation based on relative diameters and heights along the tree stem to describe the taper. Linear and non-linear regression techniques were used to estimate parameters for these methods. Method 3 was the most reliable, followed by Method 2, while the Schumacher's taper equation method was found to be the least reliable. The polynomial taper curve method also provided the best estimates for a regional model developed from the combined Zambian and Zimbabwean data. It is recommende...