Fundamentals
Volume equation
A formula estimating stem volume from measurable tree dimensions, usually diameter and height.
Volume equations summarise taper for a species or region. They let a field team estimate volume from DBH and height without felling trees.
Local equations outperform imported ones, because form varies with genetics, site and silviculture. Where only foreign equations exist, the resulting bias should be acknowledged and, where possible, tested against a small destructive sample.
Frequently asked questions
Why not just use a cylinder formula?
Because stems taper, so a cylinder overestimates volume substantially.
Do equations cover branches?
Usually not. Expansion factors handle the non-merchantable portion.