A Volume table is a chart to aid in the estimation of standing timber volume. These tables are based on volume equations and use correlations between certain aspects of a tree to estimate the volume to a degree of certainty. The diameter at breast height (DBH) and the merchantable height are used to determine the total volume. Difficulties occur when estimating the form class of the tree in question. The Mesavage and Girard form classes used to classify the trees to decide which volume table should be used. These volume tables are also based on different log rules such a Scribner, Doyle, and International ¼” scale. In order to be effective, the proper form class must be selected as well as accurate DBH and height measurements.

Standard Volume Table, International 1/4in Rule, Form Class 80
Volume by 16-ft logs (bd-ft)
DBH (in) 1 2 3 4
10 39 63 80
12 59 98 127 146
14 83 141 186 216
16 112 190 256 305
18 144 248 336 402
20 181 314 427 512
22 221 387 528 638
24 266 469 644 773
26 315 558 767 931
28 367 654 904 1096
30 424 758 1050 1272
32 485 870 1213 1480
34 550 989 1383 1691
36 620 1121 1571 1922
38 693 1256 1772 2167
40 770 1403 1977 2432

History

In 1804, Heinrich Cotta suggested the idea of a volume table.[1] However, it was not carried out until 1846 when the Bavarian Government conducted an extensive study which was used to find the volume of entire stands rather than single trees. From this, variations grew based on variables including growth rate, species, and site index.

Fundamentals

One of the most common ways to calculate volume of a standing tree or of a log is by using the Doyle log rule. This formula uses the small end diameter of a log (D) (in inches) along with the log length (L) (in feet) to estimate the volume of a log. The Doyle log rule on average under estimates the volume of a log. See formula below:

Doyle: Bd.Ft =

Combining the Doyle log rule along with the Mesavage-Girard Form-Class, and Girard Upper-Log Taper Tables gives a quality estimation of log volume on and off stem. Using these Girard's tables one can estimate not only the first log of the tree but also the logs following the butt log.

References

  1. ↑ Clark, J.F. 1902. Volume Tables and the bases on which they may be built. Forestry Quarterly. 1:6-11

Avery and Burkhart (2002). "Forest Measurements" Fifth addition. USDA (2001). "Tables for Estimating Board-Foot Volume of Timber"

Further reading

  • Avery, Thomas; Burkhart, Harold (2002). Forest Measurements (5th ed.). New York: McGraw Hill.
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