A. Figueiredo et al., Testing accuracy of log volume calculation procedures against water displacement techniques (xylometer), CAN J FORES, 30(6), 2000, pp. 990-997
Citations number
20
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE
The accuracy of three traditional formulas to calculate log volumes (Smalia
n, Huber, and Newton) and three recent methods (cubic splines, centroid sam
pling, and overlapping bolts) were compared and tested against volumes dete
rmined by the water-displacement technique (xylometer). Fifty-two felled tr
ees were measured in a Pinus elliottii Engelm. plantation. The accuracy of
these six procedures was analyzed considering total and merchantable outsid
e bark volumes with 1-, 2-, 4-, and 6-m log lengths. The results showed tha
t Huber's formula was superior for all volumes and log lengths considered.
Centroid and Newton had a similar performance to Huber but with some higher
errors. As expected, Smalian was the procedure with the worst performance.
When log lengths of 1 and 2 m were employed, all procedures used to calcul
ate total volume presented errors lower than 4.77%. However, the errors inc
reased when the merchantable volume involves a large top diameter (veneer v
olumes, for example) or for calculating volumes from trees with large diame
ters. The results of this and other research have shown that Huber's formul
a has been accurate for several species, ages, geographic regions, etc. Thu
s, Huber's formula could be used in the majority of circumstances with log
lengths greater than 2 m, reducing drastically the costs and sampling effor
t.