Developing fully compatible taper and volume equations for all stem components of Eucalyptus globoidea Blakely trees in New Zealand

Background: Individual-tree taper and volume equations are essential for forest management. They provide estimates of that incorporated into plot-level also growth yield models to estimate volumes per hectare in crops. Moreover, allow managers dimensions logs can be cut from stems their forests when they have measured diameters at breast height heights trees inventories. Compatible the property same individual tree estimated either equation or by integrating equation. Durable eucalypt species such as Eucalyptus globoidea Blakely, however, especially valuable heartwood so require shapes zones within trees. Simple overall wood would therefore inadequate. Methods: 74 were destructively sampled 8 different trial plots throughout New Zealand. Tree ages 7 29 years old, DBHs 11 67.6 cm 7.2 35.4 m. All felled lengths outside bark measured. To measure sapwood, discs irregular intervals along stems. Heartwood sapwood components identified applying methyl orange dye quantified using image analysis. In this study we extended compatibility sums separate stems, bark, heartwood, equal estimates. addition, made inside compatible with respective equations. Parameters five whole stem, wood, simultaneously estimated. stem equations, thereby creating a fully system. Results: Root mean squared error (RMSE) 0.1248298 m3 0.05496807 0.1539625 0.1108201 0.1439786 including bark. RMSE was 2.572765 2.348552 2.474088 Conclusions: A system multiple fitted through simultaneous fitting parameters minimal bias precision levels ± 0.055-0.154 2.35 2.57 Leave-one-out cross-validation yielded very similar those encountered entire dataset.